@font-face {
  font-family: "Inter";
  src: url("./assets/Inter/Inter-VariableFont_opsz,wght.ttf") format("truetype");
  font-weight: 100 900;
  font-style: normal;
  font-display: swap;
}

@font-face {
  font-family: "Inter";
  src: url("./assets/Inter/Inter-Italic-VariableFont_opsz,wght.ttf") format("truetype");
  font-weight: 100 900;
  font-style: italic;
  font-display: swap;
}

@font-face {
  font-family: "Manrope";
  src: url("./assets/Manrope/Manrope-VariableFont_wght.ttf") format("truetype");
  font-weight: 200 800;
  font-style: normal;
  font-display: swap;
}

:root {
  color-scheme: light;
  --app-height: 100vh;
  --font-body: "Inter", sans-serif;
  --font-display: "Manrope", "Inter", sans-serif;
  --bg-top: #f6f7f8;
  --bg-mid: #edf1f3;
  --bg-bottom: #e3eaed;
  --panel: rgba(242, 246, 247, 0.92);
  --panel-strong: rgba(255, 255, 255, 0.98);
  --panel-border: rgba(190, 202, 207, 0.9);
  --panel-shadow: rgba(17, 28, 35, 0.1);
  --panel-shadow-strong: rgba(17, 28, 35, 0.16);
  --text: #172127;
  --text-muted: #52606a;
  --text-soft: #7b8790;
  --accent: #1d6f78;
  --accent-strong: #155e67;
  --accent-soft: rgba(29, 111, 120, 0.11);
  --success: #257a5f;
  --warning: #b77a2a;
  --danger: #c05243;
  --bg-orb-a: radial-gradient(circle, rgba(127, 175, 155, 0.14) 0%, rgba(127, 175, 155, 0.04) 46%, rgba(127, 175, 155, 0) 76%);
  --bg-orb-b: radial-gradient(circle, rgba(201, 135, 61, 0.11) 0%, rgba(201, 135, 61, 0.03) 46%, rgba(201, 135, 61, 0) 76%);
  --bg-grid-line: rgba(37, 111, 96, 0.06);
  --bg-grid-mask: linear-gradient(180deg, rgba(0, 0, 0, 0.24), rgba(0, 0, 0, 0.08));
  --chip-border: rgba(190, 202, 207, 0.96);
  --chip-bg: rgba(249, 251, 251, 0.96);
  --badge-border: rgba(190, 202, 207, 0.98);
  --badge-bg: rgba(255, 255, 255, 0.98);
  --badge-shadow: rgba(17, 28, 35, 0.1);
  --card-border: rgba(190, 202, 207, 0.88);
  --card-bg: rgba(255, 255, 255, 0.94);
  --header-bg: linear-gradient(180deg, rgba(249, 251, 251, 0.98), rgba(241, 245, 246, 0.94));
  --header-border: rgba(190, 202, 207, 0.9);
  --section-divider: rgba(190, 202, 207, 0.78);
  --section-divider-soft: rgba(190, 202, 207, 0.56);
  --title-underline: rgba(190, 202, 207, 0.72);
  --title-placeholder: rgba(119, 131, 132, 0.76);
  --input-border: rgba(190, 202, 207, 0.96);
  --input-bg: rgba(249, 251, 251, 0.96);
  --focus-border: rgba(29, 111, 120, 0.58);
  --focus-ring: rgba(29, 111, 120, 0.15);
  --title-focus-border: rgba(29, 111, 120, 0.64);
  --title-focus-shadow: rgba(29, 111, 120, 0.18);
  --overflow-trigger-border: rgba(190, 202, 207, 0.92);
  --overflow-trigger-bg: rgba(255, 255, 255, 0.92);
  --overflow-trigger-hover-border: rgba(29, 111, 120, 0.3);
  --overflow-trigger-hover-bg: rgba(255, 255, 255, 0.98);
  --overflow-trigger-shadow: rgba(17, 28, 35, 0.1);
  --overflow-menu-border: rgba(190, 202, 207, 0.94);
  --overflow-menu-bg: rgba(255, 255, 255, 0.98);
  --overflow-menu-shadow: rgba(17, 28, 35, 0.16);
  --overflow-divider: rgba(190, 202, 207, 0.76);
  --overflow-section-label: var(--text-soft);
  --overflow-item-hover-bg: rgba(29, 111, 120, 0.08);
  --overflow-item-selected-bg: rgba(29, 111, 120, 0.12);
  --overflow-item-selected-color: var(--accent-strong);
  --overflow-check-fill: var(--accent);
  --overflow-check-ring: rgba(37, 111, 96, 0.18);
  --notation-underline-soft: rgba(29, 111, 120, 0.22);
  --notation-underline-strong: rgba(29, 111, 120, 0.42);
  --variation-border: rgba(29, 111, 120, 0.22);
  --notation-text-size: 1.35rem;
  --space-2xs: 0.25rem;
  --space-xs: 0.5rem;
  --space-sm: 0.75rem;
  --space-md: 1rem;
  --space-lg: 1.5rem;
  --space-xl: 2rem;
  --nav-button-border: rgba(190, 202, 207, 0.94);
  --nav-button-bg: rgba(255, 255, 255, 0.9);
  --nav-button-hover-border: rgba(29, 111, 120, 0.32);
  --nav-button-hover-bg: rgba(29, 111, 120, 0.08);
  --tab-active-border: rgba(29, 111, 120, 0.48);
  --control-border: rgba(190, 202, 207, 0.94);
  --control-bg: rgba(255, 255, 255, 0.96);
  --control-hover-shadow: rgba(17, 28, 35, 0.1);
  --button-primary-border: rgba(29, 111, 120, 0.32);
  --button-primary-bg: #1d6f78;
  --button-primary-text: #ffffff;
  --button-tonal-border: rgba(29, 111, 120, 0.24);
  --button-tonal-bg: rgba(255, 255, 255, 0.98);
  --button-danger-border: rgba(192, 82, 67, 0.24);
  --button-danger-bg: rgba(192, 82, 67, 0.1);
  --button-danger-text: #9f4236;
  --segment-group-border: rgba(190, 202, 207, 0.92);
  --segment-group-bg: rgba(242, 246, 247, 0.92);
  --segment-selected-border: rgba(29, 111, 120, 0.36);
  --segment-selected-bg: rgba(29, 111, 120, 0.12);
  --piece-tool-border: rgba(190, 202, 207, 0.96);
  --piece-tool-bg: rgba(255, 255, 255, 0.94);
  --piece-tool-armed-border: rgba(29, 111, 120, 0.5);
  --piece-tool-armed-bg: rgba(29, 111, 120, 0.12);
  --checkbox-border: rgba(190, 202, 207, 0.94);
  --checkbox-bg: rgba(255, 255, 255, 0.92);
  --details-border: rgba(190, 202, 207, 0.94);
  --banner-border: rgba(190, 202, 207, 0.72);
  --banner-bg: rgba(255, 255, 255, 0.76);
  --banner-success-border: rgba(37, 122, 95, 0.3);
  --banner-success-bg: rgba(37, 122, 95, 0.1);
  --banner-success-text: #236c57;
  --banner-warning-border: rgba(183, 122, 42, 0.28);
  --banner-warning-bg: rgba(183, 122, 42, 0.12);
  --banner-warning-text: #7b5723;
  --banner-danger-border: rgba(192, 82, 67, 0.28);
  --banner-danger-bg: rgba(192, 82, 67, 0.12);
  --banner-danger-text: #9f4236;
  --status-border: rgba(190, 202, 207, 0.82);
  --pv-line-border: rgba(29, 111, 120, 0.24);
  --move-index-border: rgba(190, 202, 207, 0.92);
  --move-index-bg: rgba(249, 251, 251, 0.94);
  --move-current-border: rgba(29, 111, 120, 0.4);
  --move-current-bg: rgba(29, 111, 120, 0.12);
  --move-empty-bg: rgba(255, 255, 255, 0.64);
  --workspace-tools-border: rgba(190, 202, 207, 0.72);
  --board-light: #eee3cb;
  --board-dark: #71925a;
  --board-frame-top: #ffffff;
  --board-frame-bottom: #f8f7f0;
  --board-frame-border: #c7d3cc;
  --board-shadow-primary: rgba(47, 36, 13, 0.12);
  --board-shadow-secondary: rgba(37, 111, 96, 0.1);
  --board-frame-shell-border: rgba(199, 211, 204, 0.96);
  --board-frame-shell-bg: #fffffc;
  --board-frame-shell-shadow-primary: rgba(47, 36, 13, 0.14);
  --board-frame-shell-shadow-secondary: rgba(37, 111, 96, 0.08);
  --board-grid-gloss: rgba(255, 255, 255, 0.6);
  --board-hover-outline: rgba(255, 255, 255, 0.5);
  --piece-shadow: rgba(7, 17, 15, 0.28);
  --coord-light-color: rgba(24, 38, 41, 0.72);
  --coord-dark-color: rgba(244, 247, 244, 0.78);
  --eval-track-border: rgba(199, 211, 204, 0.94);
  --eval-track-bg: linear-gradient(180deg, #182629 0%, #06100e 100%);
  --eval-track-gloss: rgba(255, 255, 255, 0.58);
  --eval-bar-fill: linear-gradient(180deg, rgba(255, 255, 255, 0.98), rgba(244, 245, 241, 0.96));
  --eval-divider: rgba(37, 111, 96, 0.2);
  --eval-rail-track-width: 0.8rem;
  --eval-rail-gap: 0rem;
  --eval-rail-shadow: rgba(47, 36, 13, 0.2);
  --board-size: 42rem;
  --captured-cell-min: 1.3rem;
  --captured-cell-divisor: 12;
  --captured-cell-max: 1.85rem;
  --captured-row-extra-height: 0.7rem;
  --captured-count-extra-width: 1.2rem;
  --captured-row-gap: clamp(0.24rem, calc(var(--board-size, 42rem) / 140), 0.4rem);
  --captured-cell-size: clamp(var(--captured-cell-min), calc(var(--board-size, 42rem) / var(--captured-cell-divisor)), var(--captured-cell-max));
  --captured-row-height: calc(var(--captured-cell-size) + var(--captured-row-extra-height) + 2px);
  --captured-row-border: rgba(199, 211, 204, 0.94);
  --captured-row-bg: linear-gradient(180deg, rgba(255, 255, 252, 0.98), rgba(248, 247, 240, 0.96));
  --captured-row-shadow: rgba(47, 36, 13, 0.12);
  --captured-dark-piece-slot-border: rgba(78, 96, 90, 0.38);
  --captured-dark-piece-slot-bg: rgba(255, 255, 252, 0.98);
  --captured-light-piece-slot-border: rgba(23, 39, 43, 0.42);
  --captured-light-piece-slot-bg: rgba(24, 38, 41, 0.96);
  --captured-count-bg: rgba(228, 196, 107, 0.96);
  --captured-count-color: #07100f;
  --captured-count-border: rgba(83, 40, 14, 0.32);
  --selection: rgba(201, 169, 74, 0.92);
  --last-move-arrow: rgba(47, 111, 105, 0.88);
  --last-move-arrow-outline: rgba(255, 255, 252, 0.78);
  --legal-target: #e09a2c;
  --legal-target-rim: rgba(78, 45, 8, 0.52);
  --legal-target-halo: rgba(255, 255, 252, 0.9);
  --legal-target-shadow: rgba(78, 45, 8, 0.28);
  --legal-capture: #d35f35;
  --legal-capture-rim: rgba(83, 40, 14, 0.38);
  --turn-marker-size: clamp(0.9rem, calc(var(--board-size, 42rem) / 34), 1.3rem);
  --turn-marker-gap: clamp(0.5rem, calc(var(--board-size, 42rem) / 52), 0.82rem);
  --turn-marker-offset: clamp(0.42rem, calc(var(--board-size, 42rem) / 40), 0.88rem);
  --turn-marker-white: linear-gradient(135deg, #ffffff 0%, #f7f8f4 52%, #dfe8e1 100%);
  --turn-marker-white-border: rgba(45, 61, 56, 0.72);
  --turn-marker-white-ring: rgba(24, 38, 41, 0.42);
  --turn-marker-black: linear-gradient(135deg, #263034 0%, #111a1d 56%, #030807 100%);
  --turn-marker-black-border: rgba(7, 16, 18, 0.88);
  --turn-marker-black-ring: rgba(255, 255, 252, 0.9);
  --turn-marker-shadow: rgba(47, 36, 13, 0.24);
  --setup-crosshair-cursor: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='24' height='24' viewBox='0 0 24 24'%3E%3Cpath d='M12 3v18M3 12h18' stroke='%2307100f' stroke-width='4.2' stroke-linecap='round'/%3E%3Cpath d='M12 3v18M3 12h18' stroke='%23f7faf5' stroke-width='2.2' stroke-linecap='round'/%3E%3C/svg%3E") 12 12, crosshair;
  --drag-hover: rgba(228, 196, 107, 0.42);
  --annotation-accent-rgb: 37, 111, 96;
  --annotation-paint: rgba(var(--annotation-accent-rgb), 0.78);
  --annotation-ring: rgba(var(--annotation-accent-rgb), 0.96);
  --annotation-star: rgba(var(--annotation-accent-rgb), 0.96);
  --annotation-arrow: rgba(var(--annotation-accent-rgb), 0.96);
  --modal-scrim: rgba(12, 20, 22, 0.46);
  --modal-border: rgba(190, 202, 207, 0.88);
  --modal-bg: rgba(255, 255, 255, 0.98);
  --modal-shadow: rgba(12, 20, 22, 0.28);
  --radius-panel: 12px;
  --radius-card: 8px;
  --radius-pill: 999px;
  --ease: 180ms ease;
}

@supports (height: 100dvh) {
  :root {
    --app-height: 100dvh;
  }
}

:root[data-theme="dark"] {
  color-scheme: dark;
  --bg-top: #071012;
  --bg-mid: #0b1517;
  --bg-bottom: #101d20;
  --panel: rgba(17, 29, 32, 0.94);
  --panel-strong: rgba(28, 43, 48, 0.98);
  --panel-border: rgba(52, 74, 78, 0.92);
  --panel-shadow: rgba(0, 0, 0, 0.32);
  --panel-shadow-strong: rgba(0, 0, 0, 0.46);
  --text: #f7faf5;
  --text-muted: #b9c6c3;
  --text-soft: #899695;
  --accent: #8ad8b7;
  --accent-strong: #b0e8cf;
  --accent-soft: rgba(138, 216, 183, 0.16);
  --success: #8ad8b7;
  --warning: #d6a15d;
  --danger: #ff927d;
  --bg-orb-a: radial-gradient(circle, rgba(138, 216, 183, 0.14) 0%, rgba(138, 216, 183, 0.04) 44%, rgba(138, 216, 183, 0) 76%);
  --bg-orb-b: radial-gradient(circle, rgba(228, 196, 107, 0.1) 0%, rgba(228, 196, 107, 0.03) 44%, rgba(228, 196, 107, 0) 76%);
  --bg-grid-line: rgba(185, 198, 195, 0.055);
  --bg-grid-mask: linear-gradient(180deg, rgba(0, 0, 0, 0.62), rgba(0, 0, 0, 0.2));
  --chip-border: rgba(52, 74, 78, 0.94);
  --chip-bg: rgba(28, 43, 48, 0.88);
  --badge-border: rgba(52, 74, 78, 0.94);
  --badge-bg: rgba(28, 43, 48, 0.98);
  --badge-shadow: rgba(5, 10, 18, 0.45);
  --card-border: rgba(52, 74, 78, 0.94);
  --card-bg: rgba(27, 42, 46, 0.92);
  --header-bg: linear-gradient(180deg, rgba(17, 29, 32, 0.99), rgba(7, 16, 18, 0.94));
  --header-border: rgba(52, 74, 78, 0.92);
  --section-divider: rgba(52, 74, 78, 0.9);
  --section-divider-soft: rgba(52, 74, 78, 0.72);
  --title-underline: rgba(52, 74, 78, 0.72);
  --title-placeholder: rgba(137, 150, 149, 0.76);
  --input-border: rgba(52, 74, 78, 0.94);
  --input-bg: rgba(16, 29, 32, 0.96);
  --focus-border: rgba(138, 216, 183, 0.74);
  --focus-ring: rgba(138, 216, 183, 0.2);
  --title-focus-border: rgba(138, 216, 183, 0.82);
  --title-focus-shadow: rgba(138, 216, 183, 0.28);
  --overflow-trigger-border: rgba(52, 74, 78, 0.94);
  --overflow-trigger-bg: rgba(27, 42, 46, 0.88);
  --overflow-trigger-hover-border: rgba(138, 216, 183, 0.38);
  --overflow-trigger-hover-bg: rgba(28, 43, 48, 0.98);
  --overflow-trigger-shadow: rgba(0, 0, 0, 0.32);
  --overflow-menu-border: rgba(52, 74, 78, 0.94);
  --overflow-menu-bg: rgba(28, 43, 48, 0.98);
  --overflow-menu-shadow: rgba(5, 10, 18, 0.54);
  --overflow-divider: rgba(52, 74, 78, 0.9);
  --overflow-section-label: var(--text-muted);
  --overflow-item-hover-bg: rgba(138, 216, 183, 0.14);
  --overflow-item-selected-bg: rgba(138, 216, 183, 0.18);
  --overflow-item-selected-color: #a0e1c4;
  --overflow-check-fill: #8ad8b7;
  --overflow-check-ring: rgba(138, 216, 183, 0.24);
  --notation-underline-soft: rgba(138, 216, 183, 0.24);
  --notation-underline-strong: rgba(138, 216, 183, 0.46);
  --variation-border: rgba(138, 216, 183, 0.26);
  --nav-button-border: rgba(52, 74, 78, 0.9);
  --nav-button-bg: rgba(27, 42, 46, 0.86);
  --nav-button-hover-border: rgba(138, 216, 183, 0.34);
  --nav-button-hover-bg: rgba(138, 216, 183, 0.14);
  --tab-active-border: rgba(138, 216, 183, 0.52);
  --control-border: rgba(52, 74, 78, 0.94);
  --control-bg: rgba(28, 43, 48, 0.96);
  --control-hover-shadow: rgba(0, 0, 0, 0.32);
  --button-primary-border: rgba(138, 216, 183, 0.4);
  --button-primary-bg: #8ad8b7;
  --button-primary-text: #06100e;
  --button-tonal-border: rgba(52, 74, 78, 0.98);
  --button-tonal-bg: rgba(28, 43, 48, 0.98);
  --button-danger-border: rgba(255, 146, 125, 0.38);
  --button-danger-bg: rgba(255, 146, 125, 0.16);
  --button-danger-text: #ff927d;
  --segment-group-border: rgba(52, 74, 78, 0.92);
  --segment-group-bg: rgba(16, 29, 32, 0.96);
  --segment-selected-border: rgba(138, 216, 183, 0.44);
  --segment-selected-bg: rgba(138, 216, 183, 0.18);
  --piece-tool-border: rgba(52, 74, 78, 0.94);
  --piece-tool-bg: rgba(27, 42, 46, 0.94);
  --piece-tool-armed-border: rgba(138, 216, 183, 0.56);
  --piece-tool-armed-bg: rgba(138, 216, 183, 0.2);
  --checkbox-border: rgba(52, 74, 78, 0.94);
  --checkbox-bg: rgba(27, 42, 46, 0.92);
  --details-border: rgba(52, 74, 78, 0.94);
  --banner-border: rgba(52, 74, 78, 0.74);
  --banner-bg: rgba(16, 29, 32, 0.8);
  --banner-success-border: rgba(138, 216, 183, 0.34);
  --banner-success-bg: rgba(30, 52, 48, 0.82);
  --banner-success-text: #b0e8cf;
  --banner-warning-border: rgba(214, 161, 93, 0.38);
  --banner-warning-bg: rgba(58, 48, 24, 0.92);
  --banner-warning-text: #e4c46b;
  --banner-danger-border: rgba(255, 146, 125, 0.38);
  --banner-danger-bg: rgba(74, 38, 33, 0.92);
  --banner-danger-text: #ff927d;
  --status-border: rgba(52, 74, 78, 0.9);
  --pv-line-border: rgba(138, 216, 183, 0.34);
  --move-index-border: rgba(52, 74, 78, 0.94);
  --move-index-bg: rgba(16, 29, 32, 0.92);
  --move-current-border: rgba(138, 216, 183, 0.44);
  --move-current-bg: rgba(31, 58, 49, 0.92);
  --move-empty-bg: rgba(28, 43, 48, 0.76);
  --workspace-tools-border: rgba(52, 74, 78, 0.74);
  --board-light: #f1e3c6;
  --board-dark: #6f8f72;
  --board-frame-top: #1c2b30;
  --board-frame-bottom: #101d20;
  --board-frame-border: #344a4e;
  --board-shadow-primary: rgba(0, 0, 0, 0.48);
  --board-shadow-secondary: rgba(138, 216, 183, 0.18);
  --board-frame-shell-border: rgba(52, 74, 78, 0.94);
  --board-frame-shell-bg: #17262a;
  --board-frame-shell-shadow-primary: rgba(0, 0, 0, 0.42);
  --board-frame-shell-shadow-secondary: rgba(0, 0, 0, 0.24);
  --board-grid-gloss: rgba(255, 255, 255, 0.12);
  --board-hover-outline: rgba(255, 255, 255, 0.16);
  --piece-shadow: rgba(0, 0, 0, 0.4);
  --coord-light-color: rgba(15, 20, 25, 0.72);
  --coord-dark-color: rgba(247, 250, 245, 0.78);
  --eval-track-border: rgba(52, 74, 78, 0.94);
  --eval-track-bg: linear-gradient(180deg, #06100e 0%, #030807 100%);
  --eval-track-gloss: rgba(255, 255, 255, 0.16);
  --eval-bar-fill: linear-gradient(180deg, rgba(247, 250, 245, 0.98), rgba(185, 198, 195, 0.9));
  --eval-divider: rgba(138, 216, 183, 0.24);
  --eval-rail-track-width: 0.8rem;
  --eval-rail-gap: 0rem;
  --eval-rail-shadow: rgba(0, 0, 0, 0.34);
  --captured-row-border: rgba(52, 74, 78, 0.96);
  --captured-row-bg: linear-gradient(180deg, rgba(28, 43, 48, 0.98), rgba(16, 29, 32, 0.96));
  --captured-row-shadow: rgba(0, 0, 0, 0.3);
  --captured-dark-piece-slot-border: rgba(190, 214, 206, 0.3);
  --captured-dark-piece-slot-bg: rgba(245, 248, 243, 0.98);
  --captured-light-piece-slot-border: rgba(214, 235, 227, 0.44);
  --captured-light-piece-slot-bg: rgba(12, 19, 22, 0.98);
  --captured-count-bg: rgba(228, 196, 107, 0.96);
  --captured-count-color: #06100e;
  --captured-count-border: rgba(247, 250, 245, 0.34);
  --selection: rgba(228, 196, 107, 0.9);
  --last-move-arrow: rgba(126, 213, 177, 0.9);
  --last-move-arrow-outline: rgba(7, 16, 14, 0.72);
  --legal-target: #f0b247;
  --legal-target-rim: rgba(247, 250, 245, 0.7);
  --legal-target-halo: rgba(6, 16, 14, 0.62);
  --legal-target-shadow: rgba(0, 0, 0, 0.34);
  --legal-capture: #ff927d;
  --legal-capture-rim: rgba(6, 16, 14, 0.56);
  --turn-marker-white: linear-gradient(135deg, #ffffff 0%, #f2f5ef 52%, #b9c6c3 100%);
  --turn-marker-white-border: rgba(247, 250, 245, 0.78);
  --turn-marker-white-ring: rgba(7, 16, 18, 0.94);
  --turn-marker-black: linear-gradient(135deg, #1c2b30 0%, #071012 62%, #020506 100%);
  --turn-marker-black-border: rgba(199, 232, 220, 0.68);
  --turn-marker-black-ring: rgba(247, 250, 245, 0.88);
  --turn-marker-shadow: rgba(0, 0, 0, 0.44);
  --drag-hover: rgba(138, 216, 183, 0.28);
  --annotation-accent-rgb: 138, 216, 183;
  --annotation-paint: rgba(var(--annotation-accent-rgb), 0.72);
  --annotation-ring: rgba(var(--annotation-accent-rgb), 0.96);
  --annotation-star: rgba(var(--annotation-accent-rgb), 0.96);
  --annotation-arrow: rgba(var(--annotation-accent-rgb), 0.96);
  --modal-scrim: rgba(4, 9, 10, 0.72);
  --modal-border: rgba(52, 74, 78, 0.92);
  --modal-bg: rgba(28, 43, 48, 0.98);
  --modal-shadow: rgba(0, 0, 0, 0.54);
}

* {
  box-sizing: border-box;
}

[hidden] {
  display: none !important;
}

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

html,
body {
  margin: 0;
  height: 100%;
  min-height: 100%;
  overflow: hidden;
}

body {
  min-height: var(--app-height);
  font-family: var(--font-body);
  color: var(--text);
  background: linear-gradient(180deg, var(--bg-top) 0%, var(--bg-mid) 52%, var(--bg-bottom) 100%);
}

body.loading .page-shell {
  visibility: hidden;
}

.loading-overlay {
  position: fixed;
  inset: 0;
  z-index: 9999;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--card-bg, #fff);
  color: var(--text, #000);
  font-family: var(--font-display, sans-serif);
  font-size: 1.15rem;
  font-weight: 700;
}

button,
input,
textarea,
select {
  font: inherit;
}

button {
  cursor: pointer;
}

code {
  font-family: "Consolas", "Cascadia Code", monospace;
}

.page-shell {
  position: relative;
  height: var(--app-height);
  padding: 0.75rem;
  overflow: hidden;
}

.backdrop-orb {
  position: absolute;
  border-radius: 50%;
  filter: blur(0);
  pointer-events: none;
}

.orb-a {
  width: 34rem;
  height: 34rem;
  top: -10rem;
  left: -8rem;
  background: var(--bg-orb-a);
}

.orb-b {
  width: 28rem;
  height: 28rem;
  right: -6rem;
  bottom: -6rem;
  background: var(--bg-orb-b);
}

.backdrop-grid {
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(var(--bg-grid-line) 1px, transparent 1px),
    linear-gradient(90deg, var(--bg-grid-line) 1px, transparent 1px);
  background-size: 48px 48px;
  mask-image: var(--bg-grid-mask);
  pointer-events: none;
}

.workspace {
  --workspace-gap: clamp(0.55rem, 1.1vw, 0.9rem);
  position: relative;
  z-index: 1;
  display: grid;
  grid-template-columns: minmax(22rem, calc(var(--board-size, 42rem) + 1rem + 2px)) minmax(19rem, 29rem);
  justify-content: center;
  row-gap: var(--workspace-gap);
  column-gap: calc(var(--workspace-gap) * 2);
  min-height: calc(var(--app-height) - 1.5rem);
  max-width: calc(72rem + var(--workspace-gap));
  margin: 0 auto;
  padding: 0;
  align-items: start;
}

.board-pane,
.control-pane {
  min-width: 0;
  min-height: 0;
}

.board-pane {
  position: relative;
}

.board-stage-card {
  position: sticky;
  top: 0.75rem;
  display: grid;
  gap: 0.5rem;
  padding: 0;
  background: transparent;
  border: 0;
  box-shadow: none;
  height: calc(var(--app-height) - 1.5rem);
  min-width: 0;
  min-height: 0;
}

.recording-hidden {
  display: none !important;
}

.board-stage-head {
  display: flex;
  justify-content: space-between;
  gap: 1rem;
  align-items: flex-start;
}

.eyebrow {
  margin: 0 0 var(--space-2xs);
  font-size: 0.8rem;
  font-weight: 700;
  letter-spacing: 0;
  text-transform: uppercase;
  color: var(--text-muted);
}

.board-stage-title,
.hero-title {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 700;
  letter-spacing: 0;
}

.board-stage-title {
  font-size: var(--notation-text-size);
}

.head-pills,
.hero-stats,
.meta-strip {
  display: flex;
  flex-wrap: wrap;
  gap: 0.55rem;
}

.head-pills {
  justify-content: flex-end;
}

.pill,
.meta-token {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.35rem;
  min-height: 2rem;
  padding: 0.35rem 0.8rem;
  border-radius: var(--radius-pill);
  border: 1px solid var(--chip-border);
  background: var(--chip-bg);
  color: var(--text-muted);
  font-size: 0.82rem;
  font-weight: 700;
}

.pill-primary {
  border-color: var(--button-primary-border);
  background: var(--accent-soft);
  color: var(--accent-strong);
}

.eval-bar-wrap.is-hidden {
  display: none !important;
}

.board-block {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 0;
  align-items: stretch;
  width: 100%;
  min-height: 0;
  height: 100%;
  overflow: hidden;
}

.board-column {
  --board-frame-padding: 0.5rem;
  --captured-row-gap: clamp(0.24rem, calc(var(--board-size, 42rem) / 140), 0.4rem);
  --captured-cell-size: clamp(var(--captured-cell-min), calc(var(--board-size, 42rem) / var(--captured-cell-divisor)), var(--captured-cell-max));
  --captured-row-height: calc(var(--captured-cell-size) + var(--captured-row-extra-height) + 2px);
  --board-available-height: calc(
    var(--app-height)
    - var(--space-lg)
    - (var(--captured-row-height) * 2)
    - (var(--captured-row-gap) * 2)
    - (var(--board-frame-padding) * 2)
  );
  --board-frame-shell-height: calc(var(--board-size) + (var(--board-frame-padding) * 2) + 2px);
  --board-system-height: calc(
    (var(--captured-row-height) * 2)
    + (var(--captured-row-gap) * 2)
    + var(--board-frame-shell-height)
  );
  --board-system-offset: max(0px, calc((100% - var(--board-system-height)) / 2));
  position: relative;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: flex-start;
  gap: var(--captured-row-gap);
  width: 100%;
  min-width: 0;
  min-height: 0;
}

.captured-row {
  width: min(100%, calc(var(--board-size) + (var(--board-frame-padding) * 2) + 2px));
  height: var(--captured-row-height);
  min-height: var(--captured-row-height);
  margin: 0 auto;
  padding: 0.24rem var(--board-frame-padding);
  border: 1px solid var(--captured-row-border);
  background: var(--captured-row-bg);
  box-shadow: 0 8px 18px var(--captured-row-shadow);
  pointer-events: none;
  overflow: hidden;
}

.captured-row.is-empty .captured-piece-shell.is-empty-slot {
  opacity: 0.3;
}
.captured-piece-shell.is-empty-slot {
  opacity: 0.4;
  border-style: dashed;
}
.captured-piece-placeholder {
  width: 96%;
  height: 96%;
  display: block;
}

.captured-pieces {
  height: 100%;
  min-height: 0;
  display: flex;
  flex-wrap: nowrap;
  justify-content: flex-end;
  align-items: center;
  gap: 0.18rem;
  overflow: visible;
}

.captured-piece-shell {
  position: relative;
  display: inline-flex;
  flex: 0 0 auto;
  align-items: center;
  justify-content: center;
  width: var(--captured-cell-size);
  height: var(--captured-cell-size);
  border: 1px solid transparent;
  border-radius: 0.22rem;
  box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.08);
}

.captured-piece-shell.has-count {
  width: auto;
  min-width: calc(var(--captured-cell-size) + var(--captured-count-extra-width));
  padding: 0 0.12rem 0 0.04rem;
  justify-content: flex-start;
  gap: 0.08rem;
}

.captured-piece-shell.is-dark-piece {
  border-color: var(--captured-dark-piece-slot-border);
  background: var(--captured-dark-piece-slot-bg);
}

.captured-piece-shell.is-light-piece {
  border-color: var(--captured-light-piece-slot-border);
  background: var(--captured-light-piece-slot-bg);
}

.captured-piece {
  width: 96%;
  height: 96%;
  object-fit: contain;
  filter: drop-shadow(0 1px 2px var(--piece-shadow));
}

.captured-piece-shell.has-count .captured-piece {
  flex: 0 0 var(--captured-cell-size);
  width: var(--captured-cell-size);
  height: 96%;
}

.captured-piece-count {
  position: static;
  flex: 0 0 auto;
  min-width: 1.2rem;
  height: 0.95rem;
  padding: 0 0.18rem;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border: 1px solid var(--captured-count-border);
  border-radius: 999px;
  background: var(--captured-count-bg);
  color: var(--captured-count-color);
  font-size: 0.75rem;
  font-weight: 800;
  line-height: 1;
  box-shadow: 0 2px 4px rgba(7, 17, 15, 0.22);
  pointer-events: none;
}

.board-frame {
  width: min(100%, calc(var(--board-size) + (var(--board-frame-padding) * 2) + 2px));
  height: calc(var(--board-size) + (var(--board-frame-padding) * 2) + 2px);
  margin: 0 auto;
  padding: var(--board-frame-padding);
  border-radius: 0;
  border: 1px solid var(--board-frame-shell-border);
  background: var(--board-frame-shell-bg);
  box-shadow:
    0 20px 34px var(--board-frame-shell-shadow-primary),
    0 4px 10px var(--board-frame-shell-shadow-secondary);
}

.board-surface {
  position: relative;
  width: 100%;
  height: 100%;
  aspect-ratio: 1 / 1;
}

.board-grid {
  position: relative;
  z-index: 1;
  display: grid;
  grid-template-columns: repeat(8, minmax(0, 1fr));
  grid-template-rows: repeat(8, minmax(0, 1fr));
  width: 100%;
  height: 100%;
  border-radius: 0;
  overflow: hidden;
  user-select: none;
  box-shadow: inset 0 1px 1px var(--board-grid-gloss);
}

.board-annotation-overlay {
  position: absolute;
  inset: 0;
  z-index: 4;
  width: 100%;
  height: 100%;
  pointer-events: none;
  overflow: visible;
}

.last-move-overlay {
  position: absolute;
  inset: 0;
  z-index: 2;
  width: 100%;
  height: 100%;
  pointer-events: none;
  overflow: visible;
}

.board-square {
  position: relative;
  display: flex;
  align-items: center;
  justify-content: center;
  aspect-ratio: 1 / 1;
  min-width: 0;
  min-height: 0;
}

.board-square.is-setup {
  cursor: var(--setup-crosshair-cursor);
}

.board-square.is-playable {
  cursor: pointer;
}

.board-square.light {
  background: var(--board-light);
}

.board-square.dark {
  background: var(--board-dark);
}

.board-square.drag-hover {
  box-shadow: inset 0 0 0 4px var(--selection);
}

.board-square.selected {
  box-shadow: inset 0 0 0 3px var(--selection);
}

.board-square.legal-target::after,
.board-square.legal-capture::after {
  content: "";
  position: absolute;
  z-index: 2;
  border-radius: 999px;
  pointer-events: none;
}

.board-square.legal-target::after {
  width: 24%;
  height: 24%;
  background: radial-gradient(circle at 38% 32%, rgba(255, 255, 255, 0.45) 0 18%, var(--legal-target) 19% 100%);
  box-shadow:
    0 0 0 2px var(--legal-target-halo),
    0 0 0 4px var(--legal-target-rim),
    0 8px 16px var(--legal-target-shadow);
}

.board-square.legal-capture::after {
  inset: 10%;
  border: 3px solid var(--legal-capture);
  box-shadow:
    inset 0 0 0 2px var(--legal-target-halo),
    0 0 0 2px var(--legal-capture-rim),
    0 8px 18px var(--legal-target-shadow);
}

.board-square.is-setup:hover {
  box-shadow: none;
}

.board-annotation {
  position: absolute;
  display: block;
  pointer-events: none;
  z-index: 1;
}

.board-annotation-paint {
  inset: 0;
  background: var(--annotation-paint);
}

.board-annotation-paint.is-orange {
  background: rgba(226, 126, 49, 0.78);
}

.board-annotation-paint.is-blue {
  background: rgba(51, 122, 220, 0.72);
}

.board-annotation-circle {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  box-sizing: border-box;
  border: 4px solid var(--annotation-ring);
  border-radius: 50%;
}

.board-annotation-circle.is-orange {
  border-color: rgba(226, 126, 49, 0.96);
}

.board-annotation-circle.is-blue {
  border-color: rgba(51, 122, 220, 0.96);
}

.board-annotation-star {
  inset: 7%;
  width: 86%;
  height: 86%;
  background: var(--annotation-star);
  clip-path: polygon(
    50% 0%,
    61% 35%,
    98% 35%,
    68% 57%,
    79% 91%,
    50% 70%,
    21% 91%,
    32% 57%,
    2% 35%,
    39% 35%
  );
}

.board-annotation-star.is-orange {
  background: rgba(226, 126, 49, 0.96);
}

.board-annotation-star.is-blue {
  background: rgba(51, 122, 220, 0.96);
}

.board-annotation-arrow {
  fill: none;
  stroke: var(--annotation-arrow);
  stroke-width: 12;
  stroke-linecap: round;
  stroke-linejoin: round;
}

.board-annotation-arrow.is-preview {
  opacity: 0.72;
}

.board-annotation-arrow.is-orange {
  stroke: rgba(226, 126, 49, 0.96);
}

.board-annotation-arrow.is-blue {
  stroke: rgba(51, 122, 220, 0.96);
}

.board-annotation-arrow-head {
  fill: var(--annotation-arrow);
}

.board-annotation-arrow-head.is-preview {
  opacity: 0.72;
}

.board-annotation-arrow-head.is-orange {
  fill: rgba(226, 126, 49, 0.96);
}

.board-annotation-arrow-head.is-blue {
  fill: rgba(51, 122, 220, 0.96);
}

.last-move-arrow-outline,
.last-move-arrow {
  fill: none;
  stroke-linecap: round;
  stroke-linejoin: round;
}

.last-move-arrow-outline {
  stroke: var(--last-move-arrow-outline);
  stroke-width: 18;
  opacity: 0.78;
}

.last-move-arrow {
  stroke: var(--last-move-arrow);
  stroke-width: 8;
  opacity: 0.92;
}

.last-move-arrow-head-outline {
  fill: var(--last-move-arrow-outline);
  stroke: var(--last-move-arrow-outline);
  stroke-width: 10;
  stroke-linejoin: round;
  opacity: 0.78;
}

.last-move-arrow-head {
  fill: var(--last-move-arrow);
  opacity: 0.92;
}

.board-piece-shell {
  position: relative;
  z-index: 3;
  width: 100%;
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: center;
}

.board-piece-shell.is-draggable {
  cursor: grab;
  touch-action: none;
}

.board-piece-shell.is-draggable:active {
  cursor: grabbing;
}

.board-piece-shell.is-pointer-dragging {
  opacity: 0.32;
}

.board-piece {
  width: 96%;
  height: 96%;
  object-fit: contain;
  pointer-events: none;
  filter: drop-shadow(0 1px 1px var(--piece-shadow));
}

.board-square.is-setup .board-piece {
  filter: none;
}

.setup-drag-preview {
  position: fixed;
  top: -1000px;
  left: -1000px;
  z-index: -1;
  display: flex;
  align-items: center;
  justify-content: center;
  border: 0;
  background: transparent;
  box-shadow: none;
  pointer-events: none;
}

.setup-drag-preview img {
  width: 100%;
  height: 100%;
  object-fit: contain;
  filter: none;
}

.board-pointer-drag-preview {
  position: fixed;
  z-index: 1500;
  display: flex;
  align-items: center;
  justify-content: center;
  transform: translate(-50%, -50%);
  pointer-events: none;
  filter: drop-shadow(0 8px 12px rgba(7, 17, 15, 0.3));
}

.board-pointer-drag-preview img {
  width: 100%;
  height: 100%;
  object-fit: contain;
}

.coord-rank,
.coord-file {
  position: absolute;
  z-index: 2;
  font-size: 0.9rem;
  font-weight: 800;
  line-height: 1;
  opacity: 0.9;
  pointer-events: none;
  text-shadow:
    0 1px 1px rgba(0, 0, 0, 0.18),
    0 0 2px rgba(255, 255, 255, 0.3);
}

.coord-rank {
  top: clamp(0.22rem, calc(var(--board-size, 42rem) / 160), 0.34rem);
  left: clamp(0.22rem, calc(var(--board-size, 42rem) / 150), 0.36rem);
}

.coord-file {
  right: clamp(0.22rem, calc(var(--board-size, 42rem) / 150), 0.36rem);
  bottom: clamp(0.18rem, calc(var(--board-size, 42rem) / 170), 0.32rem);
}

.coord-light {
  color: var(--coord-light-color);
}

.coord-dark {
  color: var(--coord-dark-color);
}

.eval-bar-wrap {
  position: absolute;
  top: calc(var(--board-frame-padding) + 1px);
  height: var(--board-size);
  left: calc(50% - (var(--board-size) / 2) - var(--eval-rail-track-width) - var(--eval-rail-gap));
  z-index: 2;
  display: flex;
  align-items: stretch;
  width: var(--eval-rail-track-width);
  pointer-events: none;
}

/* Shift eval bar down when top captured row is visible */
.board-column:has(> .captured-row:first-child:not(.is-empty)) .eval-bar-wrap {
  top: calc(var(--captured-row-height) + var(--captured-row-gap) + var(--board-frame-padding) + 1px);
}


.eval-bar-track {
  position: relative;
  width: 100%;
  height: 100%;
  border-radius: var(--radius-pill);
  overflow: hidden;
  border: 1px solid var(--eval-track-border);
  background: var(--eval-track-bg);
  box-shadow:
    inset 0 1px 1px var(--eval-track-gloss),
    0 8px 18px var(--eval-rail-shadow);
}

.eval-bar-white {
  position: absolute;
  height: 50%;
  background: var(--eval-bar-fill);
  transition: height var(--ease);
}

.eval-bar-wrap[data-orientation='white'] .eval-bar-white {
  inset: auto 0 0;
}

.eval-bar-wrap[data-orientation='black'] .eval-bar-white {
  inset: 0 0 auto;
}

.eval-bar-divider {
  position: absolute;
  left: 0;
  right: 0;
  top: calc(50% - 1px);
  height: 2px;
  background: var(--eval-divider);
}

.turn-side-marker {
  position: absolute;
  top: var(--turn-marker-offset);
  left: calc((var(--turn-marker-size) + var(--turn-marker-gap)) * -1);
  width: var(--turn-marker-size);
  height: var(--turn-marker-size);
  border-radius: 3px;
  border: 1px solid var(--turn-marker-white-border);
  background: var(--turn-marker-white);
  box-shadow:
    0 0 0 2px var(--turn-marker-white-ring),
    0 8px 18px var(--turn-marker-shadow);
  pointer-events: none;
}

.turn-side-marker::after {
  content: "";
  position: absolute;
  inset: 25%;
  border-radius: 1px;
  background: rgba(255, 255, 255, 0.55);
  opacity: 0.7;
}

.turn-side-marker[data-side='b'] {
  border-color: var(--turn-marker-black-border);
  background: var(--turn-marker-black);
  box-shadow:
    0 0 0 2px var(--turn-marker-black-ring),
    0 8px 18px var(--turn-marker-shadow);
}

.turn-side-marker[data-side='b']::after {
  background: rgba(255, 255, 255, 0.18);
  opacity: 0.45;
}

.eval-bar-wrap[data-orientation='white'][data-turn-side='w'] .turn-side-marker,
.eval-bar-wrap[data-orientation='black'][data-turn-side='b'] .turn-side-marker {
  top: auto;
  bottom: var(--turn-marker-offset);
}

.board-stage-foot {
  display: grid;
  gap: 0.9rem;
}

.fen-stack {
  display: grid;
  gap: 0.7rem;
}

.fen-card {
  padding: 0.45rem 0.58rem;
  border-radius: var(--radius-card);
  border: 1px solid var(--card-border);
  background: var(--card-bg);
}

.fen-label {
  margin-bottom: 0.36rem;
  font-size: 0.74rem;
  font-weight: 700;
  letter-spacing: 0;
  text-transform: uppercase;
  color: var(--text-soft);
}

.fen-code {
  display: block;
  white-space: pre-wrap;
  word-break: break-word;
  line-height: 1.25;
  color: var(--text);
  font-size: 0.72rem;
}

.control-pane {
  min-width: 0;
  position: sticky;
  top: 0.75rem;
  display: grid;
  grid-template-rows: minmax(0, 1fr);
  gap: 0;
  align-self: start;
  margin-left: 0;
  height: calc(var(--app-height) - 1.5rem);
  max-height: calc(var(--app-height) - 1.5rem);
}

.control-pane-scroll,
.lesson-overflow-menu,
.custom-select-menu {
  scrollbar-width: thin;
  scrollbar-color: var(--text-soft) transparent;
}

.control-pane-scroll::-webkit-scrollbar,
.lesson-overflow-menu::-webkit-scrollbar,
.custom-select-menu::-webkit-scrollbar {
  width: 8px;
  height: 8px;
}

.control-pane-scroll::-webkit-scrollbar-thumb,
.lesson-overflow-menu::-webkit-scrollbar-thumb,
.custom-select-menu::-webkit-scrollbar-thumb {
  border-radius: 4px;
  background: var(--text-soft);
}

.control-pane-scroll::-webkit-scrollbar-track,
.lesson-overflow-menu::-webkit-scrollbar-track,
.custom-select-menu::-webkit-scrollbar-track {
  background: transparent;
}

.control-pane-scroll {
  scrollbar-gutter: stable;
}

.control-pane-scroll {
  display: grid;
  gap: var(--space-sm);
  align-content: start;
  min-height: 0;
  overflow-y: auto;
  overflow-x: hidden;
  padding: 0 0 0.3rem;
  padding-inline-end: max(0.35rem, 8px);
  border: 0;
  background: transparent;
  box-shadow: none;
}

.lesson-header,
.lesson-notation,
.lesson-tools,
.lesson-section {
  display: grid;
  gap: var(--space-sm);
  align-content: start;
  align-items: start;
}

.lesson-header {
  position: relative;
  z-index: 1;
  gap: var(--space-xs);
  padding: var(--space-2xs) 0 var(--space-xs);
  border-bottom: 0;
  background: var(--header-bg);
}

html[data-active-tab="play"] .lesson-title-input,
html[data-active-tab="puzzle"] .lesson-title-input {
  display: none;
}

.lesson-section + .lesson-section {
  padding-top: var(--space-md);
  border-top: 1px solid var(--section-divider);
}

.lesson-notation {
  padding-top: 0;
  border-top: 0;
}

.lesson-tools {
  padding-top: var(--space-md);
  border-top: 1px solid var(--section-divider-soft);
}

.lesson-header-main {
  display: grid;
  gap: var(--space-2xs);
}

.title-input.lesson-title-input {
  min-height: 3.05rem;
  padding: 0.64rem 0.82rem;
  font-family: var(--font-display);
  font-size: 1.5rem;
  font-weight: 700;
  letter-spacing: 0;
  line-height: 1.2;
}

.lesson-title-input::placeholder {
  color: var(--title-placeholder);
}

.lesson-meta-strip {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: var(--space-sm) var(--space-md);
}

.lesson-meta-item {
  display: grid;
  gap: 0.18rem;
}

.lesson-meta-label {
  font-size: 0.8rem;
  font-weight: 700;
  letter-spacing: 0;
  text-transform: uppercase;
  color: var(--text-soft);
}

.lesson-meta-value {
  font-size: 1.05rem;
  font-weight: 700;
}

.lesson-section-header {
  display: flex;
  justify-content: space-between;
  gap: 0.8rem;
  align-items: flex-start;
}

.lesson-section-eyebrow {
  margin-bottom: var(--space-2xs);
}

.lesson-section-title {
  margin: 0;
  font-family: var(--font-display);
  font-size: 1.2rem;
  font-weight: 700;
  letter-spacing: 0;
}

.lesson-subtitle {
  margin: 0;
  font-size: 1rem;
  font-weight: 700;
  letter-spacing: 0;
}

.lesson-subsection {
  display: grid;
  gap: 0.25rem;
}

.section-divider {
  height: 1px;
  background: var(--section-divider);
}

.lesson-section-compact {
  gap: 0.7rem;
}

.field-label {
  display: inline-block;
  margin-bottom: var(--space-xs);
  font-size: 0.9rem;
  font-weight: 700;
  color: var(--text-muted);
}

.title-input,
.field-input,
.field-select,
.field-textarea {
  width: 100%;
  border: 1px solid var(--input-border);
  background: var(--input-bg);
  color: var(--text);
  transition: border-color var(--ease), box-shadow var(--ease), background-color var(--ease);
}

.title-input {
  min-height: 3.35rem;
  padding: 0.78rem 0.95rem;
  border-radius: var(--radius-card);
  font-size: 1.06rem;
  font-weight: 700;
}

.lesson-title-input:focus {
  outline: none;
  border-bottom-color: var(--title-focus-border);
  box-shadow: inset 0 -2px 0 var(--title-focus-shadow);
}

.title-input:not(.lesson-title-input):focus,
.field-input:focus,
.field-select:focus,
.field-textarea:focus {
  outline: none;
  border-color: var(--focus-border);
  box-shadow: 0 0 0 4px var(--focus-ring);
}

.hero-helper {
  margin: 0.1rem 0 0;
  color: var(--text-soft);
  line-height: 1.45;
}

.hero-banner {
  margin-top: 0.2rem;
}

.lesson-command-row {
  display: grid;
  grid-template-columns: minmax(6rem, 1fr) auto auto auto;
  gap: var(--space-xs);
  align-items: center;
  min-width: 0;
}

.lesson-command-row > * {
  min-width: 0;
}

.lesson-picker-overflow {
  width: 100%;
  display: flex;
}

.lesson-picker-trigger {
  width: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.5rem;
  text-align: left;
  cursor: pointer;
  background-color: var(--input-bg);
  border: 1px solid var(--input-border);
  color: var(--text);
}

.lesson-picker-trigger:hover {
  border-color: var(--overflow-trigger-hover-border);
  background-color: var(--overflow-trigger-hover-bg);
}

.lesson-picker-value {
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  flex: 1;
}

.lesson-picker-arrow {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  color: var(--text-soft);
  transition: transform var(--ease);
  flex-shrink: 0;
}

.lesson-picker-overflow.is-open .lesson-picker-arrow {
  transform: rotate(180deg);
}

.lesson-picker-overflow .lesson-picker-menu {
  left: 0;
  right: auto;
  min-width: 100%;
  width: max-content;
  max-width: 22rem;
  max-height: calc(100vh - 200px);
}

.lesson-picker-item {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  padding: 0.54rem 0.74rem;
  min-height: 3.2rem;
}

.lesson-picker-item-content {
  display: flex;
  flex-direction: column;
  gap: 0.18rem;
  min-width: 0;
  flex: 1;
}

.lesson-picker-item-title {
  font-size: 0.85rem;
  font-weight: 700;
  color: var(--text);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.lesson-picker-item-meta {
  font-size: 0.72rem;
  font-weight: 500;
  color: var(--text-soft);
}

.lesson-picker-item-check {
  color: var(--accent-strong);
  display: inline-flex;
  align-items: center;
  flex-shrink: 0;
}

.lesson-picker-item.is-selected {
  background-color: var(--overflow-item-selected-bg);
  color: var(--overflow-item-selected-color);
}

.lesson-picker-item.is-selected .lesson-picker-item-title {
  color: var(--overflow-item-selected-color);
}

.lesson-picker-add-item {
  min-height: 2.5rem;
  color: var(--accent-strong);
}

.lesson-picker {
  min-height: 2.35rem;
  padding: 0.42rem 0.64rem;
  font-size: 0.88rem;
  font-weight: 700;
}

.lesson-actions-button {
  min-height: 2.35rem;
  padding: 0.4rem 0.7rem;
  white-space: nowrap;
}

.header-analyze-button {
  min-width: 6rem;
  min-height: 2.35rem;
  padding: 0.4rem var(--space-sm);
  white-space: nowrap;
  font-size: 0.95rem;
}

.lesson-overflow {
  position: relative;
  display: inline-flex;
}

.lesson-overflow-trigger {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 2.35rem;
  height: 2.35rem;
  padding: 0;
  border: 1px solid var(--overflow-trigger-border);
  border-radius: var(--radius-card);
  background: var(--overflow-trigger-bg);
  color: var(--text-soft);
  transition: border-color var(--ease), color var(--ease), background-color var(--ease), box-shadow var(--ease);
}

.lesson-overflow-trigger:hover,
.lesson-overflow.is-open .lesson-overflow-trigger {
  border-color: var(--overflow-trigger-hover-border);
  background: var(--overflow-trigger-hover-bg);
  color: var(--text);
  box-shadow: 0 10px 20px var(--overflow-trigger-shadow);
}

.lesson-overflow-trigger:focus-visible {
  outline: none;
  border-color: var(--focus-border);
  box-shadow: 0 0 0 4px var(--focus-ring);
}

.lesson-overflow-dots {
  display: inline-flex;
  gap: 0.16rem;
  pointer-events: none;
}

.lesson-overflow-dot {
  width: 0.22rem;
  height: 0.22rem;
  border-radius: 999px;
  background: currentColor;
}

.lesson-overflow-menu {
  position: absolute;
  top: calc(100% + 0.4rem);
  right: 0;
  z-index: 8;
  display: grid;
  gap: 0.1rem;
  min-width: 10rem;
  padding: 0.28rem;
  padding-inline-end: max(0.28rem, 8px);
  border: 1px solid var(--overflow-menu-border);
  border-radius: var(--radius-panel);
  background: var(--overflow-menu-bg);
  box-shadow: 0 16px 30px var(--overflow-menu-shadow);
  overflow-x: hidden;
  overflow-y: auto;
  overscroll-behavior: contain;
}

.lesson-book-actions-menu {
  left: 0;
  right: auto;
  min-width: 8.5rem;
}

.lesson-settings-overflow .lesson-overflow-menu {
  min-width: 13.5rem;
}

.lesson-overflow-menu[data-placement='down'] {
  top: calc(100% + 0.4rem);
  bottom: auto;
}

.lesson-overflow-menu[data-placement='up'] {
  top: auto;
  bottom: calc(100% + 0.4rem);
}

.lesson-overflow-item {
  width: 100%;
  min-height: 2.5rem;
  padding: 0.48rem var(--space-sm);
  border: 0;
  border-radius: var(--radius-card);
  background: transparent;
  color: var(--text);
  text-align: left;
  font-size: 0.88rem;
  font-weight: 700;
  transition: background-color var(--ease), color var(--ease);
}

.lesson-overflow-item:hover,
.lesson-overflow-item:focus-visible {
  outline: none;
  background: var(--overflow-item-hover-bg);
  color: var(--accent-strong);
}

.lesson-overflow-item-danger {
  color: var(--button-danger-text);
}

.lesson-overflow-item:disabled {
  cursor: not-allowed;
  opacity: 0.56;
}

.lesson-overflow-item:disabled:hover,
.lesson-overflow-item:disabled:focus-visible {
  background: transparent;
  color: inherit;
}

.lesson-overflow-divider {
  height: 1px;
  margin: 0.18rem 0 0.08rem;
  background: var(--overflow-divider);
}

.lesson-overflow-section-label {
  margin: 0.08rem 0 0.04rem;
  padding: 0.18rem 0.55rem 0;
  color: var(--overflow-section-label);
  font-size: 0.66rem;
  font-weight: 700;
  letter-spacing: 0;
  text-transform: uppercase;
}

.lesson-overflow-item-toggle {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.75rem;
  cursor: pointer;
}

.theme-toggle-switch {
  position: relative;
  display: inline-flex;
  align-items: center;
  width: 2.3rem;
  height: 1.3rem;
  flex-shrink: 0;
  border: 1px solid transparent;
  border-radius: 999px;
  background-color: var(--overflow-trigger-border);
  transition: background-color var(--ease), border-color var(--ease), box-shadow var(--ease);
}

.lesson-overflow-item-toggle:hover .theme-toggle-switch,
.lesson-overflow-item-toggle:focus-visible .theme-toggle-switch {
  border-color: var(--focus-border);
  box-shadow: 0 0 0 2px var(--focus-ring);
}

.lesson-overflow-item-toggle[aria-checked="true"] .theme-toggle-switch {
  background-color: var(--overflow-check-fill);
}

.theme-toggle-thumb {
  position: absolute;
  top: 0.1rem;
  left: 0.1rem;
  width: 1.05rem;
  height: 1.05rem;
  border-radius: 50%;
  background-color: #fff;
  box-shadow: 0 2px 4px rgba(0, 0, 0, 0.2);
  transition: transform var(--ease);
}

.lesson-overflow-item-toggle[aria-checked="true"] .theme-toggle-thumb {
  transform: translateX(1rem);
}

.menu-submenu {
  overflow: hidden;
  margin-bottom: 0.18rem;
  border-radius: var(--radius-card);
  transition: background-color var(--ease);
}

.menu-submenu[open] {
  background-color: var(--overflow-item-hover-bg);
}

.menu-submenu-title {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.5rem;
  width: 100%;
  padding: 0.55rem 0.68rem;
  color: var(--text-soft);
  cursor: pointer;
  font-size: 0.72rem;
  font-weight: 800;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  list-style: none;
  user-select: none;
  transition: color var(--ease), background-color var(--ease);
}

.menu-submenu-title::-webkit-details-marker {
  display: none;
}

.menu-submenu-title:hover {
  color: var(--accent-strong);
  background-color: var(--overflow-item-hover-bg);
}

.menu-submenu-arrow {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 1rem;
  height: 1rem;
  color: currentColor;
  opacity: 0.7;
  transition: transform 0.2s ease;
}

.menu-submenu-arrow svg {
  width: 0.85rem;
  height: 0.85rem;
  fill: none;
  stroke: currentColor;
  stroke-width: 2.5;
  stroke-linecap: round;
  stroke-linejoin: round;
}

.menu-submenu[open] .menu-submenu-arrow {
  transform: rotate(180deg);
}

.menu-submenu-content {
  display: flex;
  flex-direction: column;
  gap: 0.05rem;
  margin: 0 0 0.22rem 0.62rem;
  padding: 0.1rem 0.24rem 0.28rem 0.5rem;
  border-left: 1px solid var(--overflow-divider);
}

.menu-submenu-content .lesson-overflow-item {
  min-height: 2.2rem;
  padding: 0.38rem 0.58rem;
  font-size: 0.8rem;
  font-weight: 650;
}

.lesson-overflow-item-radio {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.7rem;
}

.lesson-overflow-item-radio.is-selected,
.lesson-overflow-item-radio[aria-checked="true"] {
  background: var(--overflow-item-selected-bg);
  color: var(--overflow-item-selected-color);
}

.lesson-overflow-check {
  width: 0.7rem;
  height: 0.7rem;
  border-radius: 999px;
  border: 1px solid var(--overflow-check-ring);
  background: transparent;
  box-shadow: inset 0 0 0 0 var(--overflow-check-fill);
  transition: background-color var(--ease), box-shadow var(--ease), border-color var(--ease);
}

.lesson-overflow-item-radio.is-selected .lesson-overflow-check,
.lesson-overflow-item-radio[aria-checked="true"] .lesson-overflow-check {
  border-color: var(--overflow-check-fill);
  background: var(--overflow-check-fill);
  box-shadow: 0 0 0 3px var(--overflow-check-ring);
}

.lesson-file-status {
  min-height: 0;
  margin: 0;
  color: var(--text-soft);
  font-size: 0.88rem;
  line-height: 1.4;
}

.lesson-file-status:empty {
  display: none;
}

.notation-panel {
  min-height: 6.2rem;
}

.notation-content-stack {
  display: grid;
  gap: var(--space-md);
}

.notation-text {
  color: var(--text);
  font-family: var(--font-display);
  font-size: var(--notation-text-size);
  line-height: 2;
  word-break: break-word;
}

.notation-move-number {
  margin-right: 0;
  color: var(--text-soft);
  font-weight: 600;
}

.notation-move {
  display: inline;
  padding: 0 0 0.02rem;
  margin: 0 0.5rem 0 0;
  border: 0;
  border-radius: 0;
  background: transparent;
  color: var(--text);
  font: inherit;
  font-weight: 600;
  line-height: inherit;
  box-shadow: inset 0 -1px 0 transparent;
  transition: color var(--ease), box-shadow var(--ease);
}

.notation-move:hover {
  color: var(--accent-strong);
  box-shadow: inset 0 -1px 0 var(--notation-underline-soft);
}

.notation-move.is-current {
  color: var(--accent-strong);
  box-shadow: inset 0 -2px 0 var(--notation-underline-strong);
}

.notation-tree,
.notation-variation-list {
  display: grid;
  gap: 0.5rem;
}

.notation-segment {
  display: grid;
  gap: 0.4rem;
}

.notation-line {
  line-height: 1.55;
}

.notation-root-comment {
  margin: 0;
}

.notation-inline-comment {
  color: var(--text-soft);
  font-style: italic;
}

.notation-variation-list {
  padding-left: 0.95rem;
}

.notation-variation {
  display: grid;
  gap: 0.4rem;
  padding-left: 0.95rem;
  border-left: 1px solid var(--variation-border);
}

.notation-variation .notation-text {
  font-size: 1.18rem;
}

.notation-empty {
  margin: 0;
  color: var(--text-muted);
  line-height: 1.6;
}

.notation-note {
  display: grid;
  gap: 0.8rem;
  padding-top: 0.95rem;
  border-top: 1px solid var(--section-divider-soft);
}

/* PGN comment collapsible toggle */
.pgn-comment-toggle {
  display: flex;
  align-items: center;
  gap: var(--space-xs);
  background: none;
  border: none;
  padding: 0;
  margin: 0;
  color: var(--text-muted);
  font-family: var(--font-display);
  font-size: 1.05rem;
  font-weight: 700;
  cursor: pointer;
  width: fit-content;
  text-align: left;
  transition: color var(--ease);
}

.pgn-comment-toggle:hover {
  color: var(--text);
}

.pgn-comment-arrow {
  display: inline-block;
  width: 1em;
  font-size: 0.8rem;
  transition: transform 0.2s ease;
}

.pgn-comment-content {
  margin-top: 0.5rem;
}

.notation-pv {
  display: grid;
  gap: 0.8rem;
  padding-top: 0.95rem;
  border-top: 1px solid var(--section-divider-soft);
}

.notation-pv-head {
  display: flex;
  justify-content: space-between;
  gap: 0.8rem;
  align-items: flex-start;
}

.notation-pv-head > div {
  min-width: 0;
}

.notation-pv-title {
  margin: 0;
  font-family: var(--font-display);
  font-size: 1.05rem;
  font-weight: 700;
}

.notation-note-head {
  display: flex;
  justify-content: space-between;
  gap: 0.8rem;
  align-items: flex-start;
}

.notation-note-head > div {
  min-width: 0;
}

.notation-note-title {
  margin: 0;
  font-family: var(--font-display);
  font-size: 1.05rem;
  font-weight: 700;
}

.notation-note-input {
  min-height: 7rem;
}

.notation-toolbar {
  display: inline-grid;
  grid-auto-flow: column;
  grid-auto-columns: minmax(0, 1fr);
  gap: 0.34rem;
  align-items: center;
  justify-self: start;
  width: fit-content;
  max-width: 100%;
  margin-top: 0.08rem;
  padding: 0.28rem;
  border: 1px solid var(--card-border);
  border-radius: var(--radius-panel);
  background: var(--card-bg);
  box-shadow: 0 12px 26px var(--panel-shadow);
  backdrop-filter: blur(14px);
}

.notation-nav-button {
  position: relative;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 2rem;
  height: 2rem;
  padding: 0;
  border: 1px solid var(--nav-button-border);
  border-radius: var(--radius-pill);
  background: linear-gradient(180deg, var(--nav-button-bg), var(--control-bg));
  color: var(--text-muted);
  box-shadow:
    0 10px 18px var(--panel-shadow),
    inset 0 1px 0 rgba(255, 255, 255, 0.36);
  transition:
    transform var(--ease),
    box-shadow var(--ease),
    color var(--ease),
    background-color var(--ease),
    border-color var(--ease);
}

.notation-nav-icon {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 1.15rem;
  height: 1.15rem;
}

.notation-nav-icon svg {
  width: 100%;
  height: 100%;
  fill: none;
  stroke: currentColor;
  stroke-width: 1.8;
  stroke-linecap: round;
  stroke-linejoin: round;
}

.notation-nav-button:hover,
.notation-nav-button:focus-visible {
  outline: none;
  border-color: var(--nav-button-hover-border);
  background: var(--nav-button-hover-bg);
  color: var(--accent-strong);
  transform: translateY(-1px);
  box-shadow:
    0 14px 24px var(--control-hover-shadow),
    inset 0 1px 0 rgba(255, 255, 255, 0.4);
}

.notation-nav-button:active {
  transform: translateY(0);
  box-shadow:
    0 8px 16px var(--panel-shadow),
    inset 0 1px 0 rgba(255, 255, 255, 0.28);
}

.notation-nav-button:disabled {
  cursor: not-allowed;
  opacity: 0.46;
  transform: none;
  box-shadow: none;
}

.tab-nav {
  display: flex;
  flex-wrap: wrap;
  gap: 0.9rem;
  border-bottom: 1px solid var(--section-divider-soft);
  margin-bottom: 0.4rem;
}

.tab-chip {
  padding: 0 0 var(--space-xs);
  border: 0;
  border-bottom: 2px solid transparent;
  border-radius: 0;
  background: transparent;
  color: var(--text-muted);
  font-size: 0.95rem;
  font-weight: 700;
  transition: border-color var(--ease), color var(--ease);
  margin-bottom: -1px;
}

.tab-chip:hover {
  color: var(--text);
}

.tab-chip.is-active {
  border-color: var(--tab-active-border);
  color: var(--accent-strong);
}

.tab-panel {
  display: grid;
  gap: var(--space-sm);
  padding-top: var(--space-sm);
  border-top: 1px solid var(--section-divider);
}

.section-copy,
.muted-copy {
  margin: var(--space-2xs) 0 0;
  color: var(--text-muted);
  font-size: 0.875rem;
  line-height: 1.45;
}

.setup-turn-indicator {
  margin: 0.5rem 0 0;
  display: inline-flex;
  align-items: center;
  gap: 0.42rem;
  color: var(--text);
  font-size: 0.82rem;
  font-weight: 700;
}

.setup-turn-swatch {
  width: 0.82rem;
  height: 0.82rem;
  border-radius: 999px;
  border: 1px solid var(--turn-marker-white-border);
  background: var(--turn-marker-white);
  box-shadow: 0 0 0 2px var(--turn-marker-white-ring);
}

.setup-turn-swatch.is-black {
  border-color: var(--turn-marker-black-border);
  background: var(--turn-marker-black);
  box-shadow: 0 0 0 2px var(--turn-marker-black-ring);
}

.setup-active-summary {
  display: inline-flex;
  align-items: center;
  gap: 0.48rem;
  min-height: 2.45rem;
  padding: 0.52rem 0.68rem;
  border-radius: var(--radius-card);
  border: 1px solid var(--segment-selected-border);
  background: var(--accent-soft);
  color: var(--accent-strong);
  font-size: 0.88rem;
}

.setup-active-summary,
.setup-board-divider {
  display: none;
}

#fenInput {
  min-height: 2.6rem;
  height: 2.6rem;
  padding: 0.52rem 0.6rem;
  font-size: 0.88rem;
  line-height: 1.25;
}

.panel-grid {
  display: grid;
  gap: 1rem;
}

.action-row {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-sm);
}

.action-row-compact {
  gap: var(--space-xs);
}

.action-button,
.segmented-button,
.promotion-choice,
.move-button,
.icon-button {
  border: 1px solid var(--control-border);
  background: var(--control-bg);
  color: var(--text);
  transition: transform var(--ease), box-shadow var(--ease), border-color var(--ease), background-color var(--ease), color var(--ease);
}

.action-button {
  min-height: 2.55rem;
  padding: var(--space-xs) 0.86rem;
  border-radius: var(--radius-card);
  font-size: 0.95rem;
  font-weight: 600;
}

.lesson-actions-button,
.header-analyze-button {
  min-height: 2.35rem;
  padding: 0.4rem 0.7rem;
}

.action-button:hover,
.promotion-choice:hover,
.move-button:hover,
.icon-button:hover {
  transform: translateY(-1px);
  box-shadow: 0 12px 18px var(--control-hover-shadow);
}

.action-button.action-button-static:hover {
  transform: none;
}

.action-button.primary {
  border-color: var(--button-primary-border);
  background: var(--button-primary-bg);
  color: var(--button-primary-text);
}

.action-button.tonal {
  border-color: var(--button-tonal-border);
  background: var(--button-tonal-bg);
  color: var(--accent-strong);
}

.action-button.is-active {
  border-color: var(--tab-active-border);
  background: var(--accent-soft);
  color: var(--accent-strong);
}

.action-button.danger {
  border-color: var(--button-danger-border);
  background: var(--button-danger-bg);
  color: var(--button-danger-text);
}

.action-button:disabled,
.segmented-button:disabled,
.promotion-choice:disabled,
.move-button:disabled,
.icon-button:disabled {
  cursor: not-allowed;
  opacity: 0.56;
  transform: none;
  box-shadow: none;
}

.segment-group {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  align-items: stretch;
  gap: 0.35rem;
  padding: 0.22rem;
  border-radius: var(--radius-card);
  border: 1px solid var(--segment-group-border);
  background: var(--segment-group-bg);
}

.segmented-button {
  appearance: none;
  margin: 0;
  position: relative;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 0.18rem;
  min-height: 3rem;
  padding: 0 0.75rem;
  border-radius: calc(var(--radius-card) - 2px);
  line-height: 1;
  font-weight: 700;
  white-space: nowrap;
  text-align: center;
}

.segmented-button:hover,
.segmented-button:focus-visible {
  outline: none;
  transform: none;
  border-color: var(--segment-selected-border);
  background: var(--segment-selected-bg);
  color: var(--accent-strong);
  box-shadow: 0 12px 18px var(--control-hover-shadow);
}

.segmented-button.is-selected {
  border-color: var(--button-primary-border);
  background: var(--button-primary-bg);
  color: var(--button-primary-text);
  box-shadow:
    inset 0 0 0 1px var(--segment-selected-border),
    0 10px 18px var(--control-hover-shadow);
}

.segmented-button-main {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.38rem;
}

.segmented-button-status {
  font-size: 0.62rem;
  line-height: 1;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  opacity: 0.88;
}

.side-segment-swatch {
  flex: 0 0 auto;
  width: 0.78rem;
  height: 0.78rem;
  border-radius: 999px;
  border: 1px solid var(--turn-marker-white-border);
  background: var(--turn-marker-white);
  box-shadow: 0 0 0 2px var(--turn-marker-white-ring);
}

.side-segment-swatch.is-black {
  border-color: var(--turn-marker-black-border);
  background: var(--turn-marker-black);
  box-shadow: 0 0 0 2px var(--turn-marker-black-ring);
}

.piece-palette {
  display: grid;
  grid-template-columns: repeat(7, minmax(0, 1fr));
  gap: 0.65rem;
}

.piece-tool {
  display: grid;
  justify-items: center;
  gap: 0.45rem;
}

.piece-tool-button {
  width: 100%;
  aspect-ratio: 1;
  padding: 0;
  border-radius: var(--radius-card);
  border: 1px solid var(--piece-tool-border);
  background: var(--piece-tool-bg);
}

.piece-tool-button.is-armed {
  border-color: var(--piece-tool-armed-border);
  background: var(--piece-tool-armed-bg);
}

.piece-tool-icon {
  width: 78%;
  height: 78%;
  object-fit: contain;
  pointer-events: none;
}

.piece-tool-icon.eraser-icon {
  width: 58%;
  height: 58%;
  color: var(--text-soft);
  transition: color var(--ease);
}

.piece-tool-label {
  font-size: 0.8rem;
  font-weight: 700;
  color: var(--text-soft);
}

.stack-grid {
  display: grid;
  gap: var(--space-sm);
}

.analysis-target-depth-row {
  display: grid;
  gap: var(--space-xs);
}

.analysis-target-depth-control {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.8rem;
}

.analysis-target-depth-input {
  width: min(100%, 7rem);
}

.range-control-wrap {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  width: 100%;
}

.range-control-wrap input[type="range"] {
  flex: 1;
  accent-color: var(--accent);
}

.field-value {
  min-width: 3.7rem;
  color: var(--text);
  font-weight: 700;
  text-align: right;
}

.field-row {
  display: grid;
  gap: 0.4rem;
}

.field-input,
.field-select {
  min-height: 3rem;
  padding: 0.64rem 0.8rem;
  border-radius: var(--radius-card);
}

.field-textarea {
  min-height: 6rem;
  padding: 0.78rem 0.85rem;
  border-radius: var(--radius-card);
  resize: vertical;
  line-height: 1.42;
}

.two-col,
.castling-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 0.85rem;
}

.castling-column {
  display: grid;
  gap: 0.55rem;
}

.checkbox-chip {
  display: flex;
  align-items: center;
  gap: 0.65rem;
  min-height: 3rem;
  padding: 0.62rem 0.78rem;
  border-radius: var(--radius-card);
  border: 1px solid var(--checkbox-border);
  background: var(--checkbox-bg);
  color: var(--text);
}

.checkbox-chip input {
  margin: 0;
}

.details-toggle {
  width: 100%;
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 0.75rem;
  min-height: 3rem;
  padding: 0.65rem 0;
  border-radius: 0;
  border: 1px solid var(--details-border);
  border-width: 0 0 1px;
  background: transparent;
  color: var(--text);
  font-weight: 700;
}

.details-toggle-copy {
  font-size: 0.9rem;
  color: var(--text-soft);
  font-weight: 600;
}

.details-toggle-main {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.36rem 0.56rem;
  text-align: left;
}

.details-toggle-status {
  display: inline-flex;
  align-items: center;
  min-height: 1.42rem;
  padding: 0.18rem 0.52rem;
  border-radius: var(--radius-pill);
  background: var(--accent-soft);
  color: var(--accent-strong);
  font-size: 0.76rem;
  font-weight: 700;
}

.details-body {
  margin-top: 0.3rem;
}

.banner {
  display: flex;
  gap: 0.7rem;
  align-items: flex-start;
  padding: 0.72rem 0.85rem;
  border-radius: var(--radius-card);
  border: 1px solid var(--banner-border);
  background: var(--banner-bg);
  line-height: 1.45;
}

.banner.success {
  border-color: var(--banner-success-border);
  background: var(--banner-success-bg);
  color: var(--banner-success-text);
}

.banner.warning {
  border-color: var(--banner-warning-border);
  background: var(--banner-warning-bg);
  color: var(--banner-warning-text);
}

.banner.danger {
  border-color: var(--banner-danger-border);
  background: var(--banner-danger-bg);
  color: var(--banner-danger-text);
}

.status-grid {
  display: grid;
  gap: 0;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  border-top: 1px solid var(--status-border);
  border-bottom: 1px solid var(--status-border);
}

.status-tile {
  padding: 0.8rem 0.2rem 0.8rem 0;
  border: 0;
  background: transparent;
  display: grid;
  gap: 0.25rem;
}

.status-tile + .status-tile {
  margin-left: 1rem;
  padding-left: 1rem;
  border-left: 1px solid var(--status-border);
}

.status-tile-label {
  font-size: 0.74rem;
  font-weight: 700;
  letter-spacing: 0;
  text-transform: uppercase;
  color: var(--text-soft);
}

.status-tile-value {
  font-size: 1rem;
  font-weight: 700;
  color: var(--text);
}

.pv-line-list {
  display: grid;
  gap: var(--space-sm);
}

.pv-line-list.is-stale {
  opacity: 0.55;
  transition: opacity 0.15s ease;
}

.pv-line {
  display: grid;
  gap: 0.24rem;
  margin: 0;
  padding: 0.18rem 0 0.18rem 0.9rem;
  border-left: 2px solid var(--pv-line-border);
  background: transparent;
  color: var(--text);
}

.pv-line-head {
  display: flex;
  flex-wrap: wrap;
  gap: 0.45rem;
  align-items: baseline;
}

.pv-line-index {
  font-size: 0.8rem;
  font-weight: 700;
  letter-spacing: 0;
  text-transform: uppercase;
  color: var(--accent-strong);
}

.pv-line-depth {
  font-size: 0.78rem;
  font-weight: 700;
  letter-spacing: 0;
  text-transform: uppercase;
  color: var(--text-soft);
}

.pv-line-score {
  font-size: 0.9rem;
  font-weight: 700;
  color: var(--text-soft);
}

.pv-line-text {
  color: var(--text);
  font-size: 1.15rem;
  font-weight: 500;
  line-height: 1.55;
  word-break: break-word;
}

.pv-line.is-empty .pv-line-text {
  min-height: 1.55em;
  min-height: 1lh;
  color: var(--text-muted);
}

.move-table {
  display: grid;
  gap: 0.5rem;
}

.move-row {
  display: grid;
  grid-template-columns: 3.5rem minmax(0, 1fr) minmax(0, 1fr);
  gap: 0.55rem;
  align-items: stretch;
}

.move-index {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border-radius: var(--radius-pill);
  border: 1px solid var(--move-index-border);
  background: var(--move-index-bg);
  font-size: 0.88rem;
  font-weight: 600;
  color: var(--text-soft);
}

.move-button {
  min-height: 3rem;
  padding: 0.7rem 0.8rem;
  border-radius: var(--radius-card);
  text-align: left;
  font-weight: 600;
}

.move-button.is-current {
  border-color: var(--move-current-border);
  background: var(--move-current-bg);
  color: var(--accent-strong);
}

.move-button.is-empty {
  cursor: default;
  color: var(--text-soft);
  background: var(--move-empty-bg);
}

.empty-card {
  padding: 1.05rem 1.1rem;
}

.app-footer {
  padding: 1rem 0 0.2rem;
  border-top: 1px solid var(--section-divider);
  color: var(--text-soft);
  line-height: 1.55;
}

.workspace-tools {
  margin-top: var(--space-2xs);
  padding-top: var(--space-md);
  border-top: 1px solid var(--workspace-tools-border);
}

.workspace-tools .lesson-tools {
  padding-top: 0;
  border-top: 0;
}

.line-navigation-meta {
  display: none;
}

.play-section-heading {
  width: 100%;
}

.play-section-title {
  font-size: 1.12rem;
}

.play-start-action-row {
  margin-top: 0.45rem;
}

.play-start-action-row .action-button {
  width: 100%;
  min-height: 2.25rem;
  padding: 0.42rem 0.74rem;
}

.play-clocks-container {
  display: flex;
  justify-content: space-between;
  gap: 0.45rem;
}

.play-clock {
  flex: 1;
  display: grid;
  justify-items: center;
  gap: 0.12rem;
  padding: 0.46rem;
  border: 1px solid var(--control-border);
  border-radius: var(--radius-card);
  background: var(--control-bg);
  box-shadow: 0 3px 8px var(--panel-shadow);
  transition: background-color var(--ease), border-color var(--ease), box-shadow var(--ease);
}

.play-clock.is-active {
  border-color: var(--accent);
  background: var(--accent-soft);
  box-shadow: 0 5px 12px rgba(29, 111, 120, 0.15);
}

.play-clock-label {
  color: var(--text-soft);
  font-size: 0.66rem;
  font-weight: 800;
  text-transform: uppercase;
}

.play-clock-time {
  min-width: 5.4ch;
  color: var(--text);
  font-family: "Consolas", "Cascadia Code", monospace;
  font-size: 1.45rem;
  font-weight: 800;
  font-variant-numeric: tabular-nums;
  letter-spacing: 0.015em;
}

.play-clock.is-low .play-clock-time {
  color: var(--danger);
}

.play-options-grid > .field-row {
  min-width: 0;
}

.play-action-row {
  display: flex;
  gap: 0.5rem;
  margin-top: 0;
}

.play-action-row .action-button {
  flex: 1;
}

.play-action-row .action-button:only-child {
  width: 100%;
}

.game-result-actions {
  justify-content: center;
  margin-top: 1.5rem;
}

.promotion-modal {
  position: fixed;
  inset: 0;
  z-index: 20;
  display: grid;
  place-items: center;
  padding: 1rem;
  background: var(--modal-scrim);
  backdrop-filter: blur(8px);
}

.promotion-dialog {
  width: min(28rem, 100%);
  padding: 1rem;
  border-radius: var(--radius-panel);
  border: 1px solid var(--modal-border);
  background: var(--modal-bg);
  box-shadow: 0 24px 44px var(--modal-shadow);
}

.promotion-head {
  display: flex;
  justify-content: space-between;
  gap: 0.75rem;
  align-items: center;
}

.promotion-head h3 {
  margin: 0;
  font-size: 1.1rem;
}

.promotion-subtitle {
  margin: 0.5rem 0 0.95rem;
  color: var(--text-muted);
}

.promotion-choices {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 0.75rem;
}

.promotion-choice {
  display: grid;
  justify-items: center;
  gap: 0.5rem;
  min-height: 7rem;
  padding: 0.75rem 0.55rem;
  border-radius: var(--radius-card);
}

.promotion-choice img {
  width: 70%;
  height: auto;
}

.icon-button {
  width: 3rem;
  height: 3rem;
  padding: 0;
  border-radius: 999px;
  font-size: 1.35rem;
  line-height: 1;
}

.is-hidden {
  visibility: hidden;
  opacity: 0;
  pointer-events: none;
}

.focus-mode-controls {
  position: fixed;
  top: clamp(0.8rem, 2vw, 1.4rem);
  right: clamp(0.8rem, 2vw, 1.4rem);
  z-index: 18;
  display: flex;
  gap: 0.35rem;
  padding: 0.28rem;
  border: 1px solid var(--card-border);
  border-radius: var(--radius-pill);
  background: var(--modal-bg);
  box-shadow: 0 18px 34px var(--panel-shadow-strong);
  backdrop-filter: blur(14px);
}

.focus-mode-button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 2.65rem;
  height: 2.65rem;
  padding: 0;
  border-radius: var(--radius-pill);
  border: 1px solid var(--button-tonal-border);
  background: var(--button-tonal-bg);
  color: var(--accent-strong);
  transition: transform var(--ease), border-color var(--ease), background-color var(--ease), color var(--ease), box-shadow var(--ease);
}

.focus-mode-button svg {
  width: 1.15rem;
  height: 1.15rem;
  fill: none;
  stroke: currentColor;
  stroke-width: 2.2;
  stroke-linecap: round;
  stroke-linejoin: round;
}

.focus-mode-button:hover,
.focus-mode-button:focus-visible {
  outline: none;
  transform: translateY(-1px);
  border-color: var(--focus-border);
  box-shadow: 0 0 0 4px var(--focus-ring), 0 12px 18px var(--control-hover-shadow);
}

.focus-mode-button.primary {
  border-color: var(--button-primary-border);
  background: var(--button-primary-bg);
  color: var(--button-primary-text);
}

.focus-mode-button.danger {
  border-color: var(--button-danger-border);
  background: var(--button-danger-bg);
  color: var(--button-danger-text);
}

.focus-mode-button:disabled {
  cursor: not-allowed;
  opacity: 0.52;
  transform: none;
  box-shadow: none;
}

/* Focus mode brand watermark — lower-right corner, focus mode only */
.focus-mode-brand {
  display: none;
  position: fixed;
  bottom: clamp(1rem, 2.5vw, 1.8rem);
  right: clamp(1rem, 2.5vw, 1.8rem);
  z-index: 17;
  align-items: center;
  gap: 0.65rem;
  pointer-events: none;
  user-select: none;
  opacity: 0;
  transition: opacity 0.3s ease;
}

.page-shell.is-focus-mode ~ .focus-mode-brand,
.is-focus-mode .focus-mode-brand {
  display: flex;
  opacity: 1;
}

.focus-mode-brand-img {
  width: clamp(4.8rem, 8vw, 6.4rem);
  height: clamp(4.8rem, 8vw, 6.4rem);
  border-radius: 50%;
  object-fit: contain;
}

.page-shell.is-focus-mode {
  --focus-padding: clamp(0.75rem, 2vmin, 1.5rem);
  display: flex;
  align-items: center;
  justify-content: center;
  height: var(--app-height);
  min-height: var(--app-height);
  overflow: hidden;
  padding: var(--focus-padding);
}

@supports (height: 100dvh) {
  .page-shell.is-focus-mode {
    height: 100dvh;
    min-height: 100dvh;
  }
}

.page-shell.is-focus-mode .workspace {
  display: grid;
  grid-template-columns: 1fr;
  justify-content: normal;
  place-items: center;
  width: 100%;
  height: 100%;
  min-height: 0;
  max-width: none;
  margin: 0;
}

.page-shell.is-focus-mode .control-pane {
  display: none;
}

.page-shell.is-focus-mode .board-pane,
.page-shell.is-focus-mode .board-stage-card,
.page-shell.is-focus-mode .board-block {
  width: 100%;
  height: 100%;
  min-height: 0;
  display: grid;
  place-items: center;
}

.page-shell.is-focus-mode .board-stage-card {
  position: static;
  top: auto;
  height: 100%;
  max-height: 100%;
  overflow: visible;
}

.page-shell.is-focus-mode .board-column {
  --board-frame-padding: clamp(0.35rem, 0.7vw, 0.65rem);
  --eval-rail-track-width: clamp(0.78rem, 1.1vw, 1rem);
  --eval-rail-gap: clamp(0.55rem, 1vw, 0.8rem);
  --focus-side-offset: calc(
    var(--eval-rail-track-width)
    + var(--eval-rail-gap)
    + var(--turn-marker-size)
    + var(--turn-marker-gap)
  );
  --focus-board-shell-width: calc(var(--board-size) + (var(--board-frame-padding) * 2) + 2px);
  width: calc(
    var(--focus-board-shell-width)
    + var(--focus-side-offset)
  );
  max-width: 100%;
  max-height: 100%;
  align-self: center;
  justify-self: center;
}

.page-shell.is-focus-mode .board-frame {
  margin: 0 0 0 var(--focus-side-offset);
}

.page-shell.is-focus-mode .eval-bar-wrap {
  left: calc(var(--turn-marker-size) + var(--turn-marker-gap));
}

.page-shell.is-focus-mode .captured-row {
  margin: 0 0 0 var(--focus-side-offset);
  padding-right: 4.5rem;
}

.page-shell.is-focus-mode .captured-piece {
  width: 106%;
  height: 106%;
}

.page-shell.is-focus-mode .captured-piece-shell.has-count .captured-piece {
  width: calc(var(--captured-cell-size) * 1.06);
  height: 106%;
}

/* Mobile-only engine lines slot: hidden on desktop/tablet, shown below board on mobile */
.mobile-engine-lines-slot {
  display: none;
}

/* ---------- Embed mode (app loaded inside a lesson page iframe) ---------- */
body.is-embed {
  background:
    radial-gradient(circle at 18% 12%, rgba(138, 216, 183, 0.16), transparent 34%),
    radial-gradient(circle at 82% 88%, rgba(228, 196, 107, 0.12), transparent 38%),
    linear-gradient(145deg, rgba(14, 29, 31, 0.92), rgba(5, 14, 15, 0.98));
}
body.is-embed .page-shell,
html[data-embed="1"] .page-shell {
  padding: clamp(0.55rem, 1.2vw, 1rem);
}
body.is-embed .board-stage-card,
html[data-embed="1"] .board-stage-card {
  border: 1px solid rgba(138, 216, 183, 0.18);
  background:
    linear-gradient(145deg, rgba(27, 42, 46, 0.72), rgba(7, 16, 18, 0.82)),
    radial-gradient(circle at 22% 18%, rgba(138, 216, 183, 0.12), transparent 34%);
  box-shadow:
    inset 0 0 0 1px rgba(255, 255, 255, 0.025),
    0 18px 60px rgba(0, 0, 0, 0.34);
}
body.is-embed .board-block,
html[data-embed="1"] .board-block {
  padding: clamp(0.45rem, 1vw, 0.85rem);
}
body.is-embed .board-frame,
html[data-embed="1"] .board-frame {
  border-color: rgba(190, 202, 207, 0.48);
  background:
    linear-gradient(145deg, rgba(255, 247, 223, 0.18), rgba(138, 216, 183, 0.13)),
    rgba(7, 16, 18, 0.78);
  box-shadow:
    0 20px 46px rgba(0, 0, 0, 0.36),
    0 0 0 1px rgba(255, 255, 255, 0.04);
}
body.is-embed .focus-mode-button[data-action="exit-focus-mode"] {
  display: none;
}
body.is-embed .focus-mode-brand,
body.is-embed ~ .focus-mode-brand,
.is-embed .focus-mode-brand {
  display: none !important;
}
body.is-embed .focus-mode-controls {
  top: 0.4rem;
  right: 0.4rem;
}

/* Embed mode: no in-iframe PV/tablebase rendering — it goes to the parent page popup */
body.is-embed .mobile-engine-lines-slot,
body.is-embed .notation-pv {
  display: none !important;
}

/* Embed mode: hide loading overlay immediately — the app initializes synchronously
   in embed mode (no draft hydration), so the overlay only flashes the wrong state.
   Both [data-embed] (set pre-render on <html>) and body.is-embed (set by app.js) are covered. */
html[data-embed="1"] .loading-overlay,
body.is-embed .loading-overlay {
  display: none !important;
}

/* Embed lesson iframe: make captured pieces readable */
body.is-embed .board-column,
html[data-embed="1"] .board-column {
  --captured-cell-min: 1.55rem;
  --captured-cell-divisor: 10;
  --captured-cell-max: 2.15rem;
  --captured-row-extra-height: 0.75rem;
  --captured-count-extra-width: 1.45rem;
}

body.is-embed .captured-piece,
html[data-embed="1"] .captured-piece {
  width: 120%;
  height: 120%;
}

body.is-embed .captured-piece-count,
html[data-embed="1"] .captured-piece-count {
  font-size: 0.78rem;
  min-width: 1.25rem;
  height: 1.25rem;
}

/* Board-only teacher popup mode: keep the app to board + optional setup tools. */
html[data-board-only="1"],
html[data-board-only="1"] body {
  overflow: hidden;
}

body.is-board-only .board-stage-head,
body.is-board-only .board-stage-foot,
body.is-board-only .lesson-header,
body.is-board-only .tab-nav,
body.is-board-only .lesson-notation,
body.is-board-only .mobile-engine-lines-slot,
body.is-board-only .puzzle-instruction-container,
body.is-board-only .focus-mode-controls,
body.is-board-only .eval-bar-wrap,
html[data-board-only="1"] .board-stage-head,
html[data-board-only="1"] .board-stage-foot,
html[data-board-only="1"] .lesson-header,
html[data-board-only="1"] .tab-nav,
html[data-board-only="1"] .lesson-notation,
html[data-board-only="1"] .mobile-engine-lines-slot,
html[data-board-only="1"] .puzzle-instruction-container,
html[data-board-only="1"] .focus-mode-controls,
html[data-board-only="1"] .eval-bar-wrap {
  display: none !important;
}

.page-shell.is-board-only.is-focus-mode {
  --focus-padding: clamp(0.35rem, 1.1vw, 0.8rem);
  --captured-cell-min: 0.8rem;
  --captured-cell-divisor: 20;
  --captured-cell-max: 1.12rem;
  --captured-row-extra-height: 0.22rem;
  --captured-row-gap: clamp(0.12rem, calc(var(--board-size, 42rem) / 260), 0.22rem);
  --captured-row-height: calc(var(--captured-cell-size) + var(--captured-row-extra-height) + 2px);
  padding: var(--focus-padding);
}

.page-shell.is-board-only.is-focus-mode .workspace {
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(0.45rem, 1vw, 0.8rem);
}

.page-shell.is-board-only.is-focus-mode .board-column {
  --captured-cell-min: 0.8rem;
  --captured-cell-divisor: 20;
  --captured-cell-max: 1.12rem;
  --captured-row-extra-height: 0.22rem;
  --captured-row-gap: clamp(0.12rem, calc(var(--board-size, 42rem) / 260), 0.22rem);
  --captured-cell-size: clamp(var(--captured-cell-min), calc(var(--board-size, 42rem) / var(--captured-cell-divisor)), var(--captured-cell-max));
  --captured-row-height: calc(var(--captured-cell-size) + var(--captured-row-extra-height) + 2px);
  --focus-board-shell-width: calc(var(--board-size) + (var(--board-frame-padding) * 2) + 2px);
  width: min(100%, calc(var(--board-size) + (var(--board-frame-padding) * 2) + 2px));
  max-height: calc(
    var(--focus-board-shell-width)
    + (var(--captured-row-height) * 2)
    + (var(--captured-row-gap) * 2)
  );
}

.page-shell.is-board-only.is-focus-mode .board-frame,
.page-shell.is-board-only.is-focus-mode .captured-row {
  margin-left: 0;
  padding-right: var(--board-frame-padding);
}

.page-shell.is-board-only.is-focus-mode .captured-row {
  box-shadow: none;
}

.page-shell.is-board-only.is-focus-mode .captured-piece,
.page-shell.is-board-only.is-focus-mode .captured-piece-placeholder {
  width: calc(var(--captured-cell-size) * 0.82);
  height: calc(var(--captured-cell-size) * 0.82);
}

.page-shell.is-board-only.is-focus-mode .captured-piece-count {
  min-width: 0.95rem;
  height: 0.95rem;
  font-size: 0.62rem;
}

.page-shell.is-board-only.is-focus-mode.is-board-only-setup-open .workspace {
  grid-template-columns: minmax(0, 1fr) minmax(17rem, 22rem);
  align-items: stretch;
}

.page-shell.is-board-only.is-board-only-setup-open .control-pane {
  display: block;
  height: 100%;
  max-height: 100%;
  overflow: hidden;
}

.page-shell.is-board-only.is-board-only-setup-open .control-pane-scroll {
  max-height: 100%;
  min-height: 0;
  padding: 0;
  overflow: auto;
  scrollbar-gutter: stable;
}

.page-shell.is-board-only.is-board-only-setup-open .workspace-tools {
  display: block;
  border-top: 0;
  padding: 0;
}

.page-shell.is-board-only.is-board-only-setup-open .workspace-tools[hidden] {
  display: none !important;
}

.page-shell.is-board-only .setup-board-section,
.page-shell.is-board-only .setup-palette-panel,
.page-shell.is-board-only .lesson-section {
  border-radius: 8px;
}

@media (max-width: 760px) {
  .page-shell.is-board-only.is-focus-mode {
    overflow: auto;
    align-items: stretch;
    justify-content: stretch;
  }

  .page-shell.is-board-only.is-focus-mode.is-board-only-setup-open {
    height: auto;
    min-height: var(--app-height);
  }

  .page-shell.is-board-only.is-focus-mode.is-board-only-setup-open .workspace {
    grid-template-columns: 1fr;
    grid-template-rows: auto auto;
    place-items: stretch;
  }

  .page-shell.is-board-only.is-board-only-setup-open .control-pane {
    height: auto;
    max-height: 42vh;
  }
}

@media (max-width: 1100px) {
  html,
  body {
    overflow: auto;
  }

  .page-shell {
    height: auto;
    min-height: var(--app-height);
    overflow: visible;
  }

  .workspace {
    grid-template-columns: 1fr;
    justify-content: normal;
    min-height: 0;
  }

  .board-stage-card {
    position: static;
    height: calc(var(--app-height) - 1.8rem);
  }

  .control-pane {
    margin-left: 0;
    position: static;
    height: auto;
    max-height: none;
  }

  .control-pane-scroll {
    max-height: none;
    min-height: 0;
    padding-inline-end: 0;
    scrollbar-gutter: auto;
  }
}

@media (max-width: 760px) {
  :root {
    --notation-text-size: 1.14rem;
  }

  .page-shell {
    padding: 0.55rem;
  }

  .workspace {
    gap: 0.65rem;
  }

  .board-stage-card {
    height: auto;
  }

  .board-block {
    height: auto;
  }

  .board-column {
    --captured-cell-min: 1.1rem;
    --captured-cell-divisor: 14;
    --captured-cell-max: 1.5rem;
    --captured-row-extra-height: 0.55rem;
    --captured-count-extra-width: 1rem;
    --captured-cell-size: clamp(var(--captured-cell-min), calc(var(--board-size, 42rem) / var(--captured-cell-divisor)), var(--captured-cell-max));
    --captured-row-height: calc(var(--captured-cell-size) + var(--captured-row-extra-height) + 2px);
  }

  .board-stage-head,
  .lesson-section-header,
  .notation-note-head,
  .notation-pv-head {
    flex-direction: column;
  }

  .two-col,
  .castling-grid,
  .status-grid {
    grid-template-columns: 1fr;
  }

  .promotion-choices {
    grid-template-columns: repeat(4, minmax(0, 1fr)) !important;
    gap: 0.35rem;
    justify-content: center;
    width: 100%;
  }

  .promotion-choice {
    min-height: 0 !important;
    max-width: 56px;
    height: 56px;
    padding: 0.25rem;
    aspect-ratio: 1;
    justify-self: center;
    align-items: center;
    box-sizing: border-box;
  }

  .promotion-choice span {
    display: none !important;
  }

  .promotion-choice img {
    width: 90% !important;
    height: 90% !important;
    object-fit: contain;
  }

  .control-pane-scroll {
    padding: 0;
  }

  .title-input.lesson-title-input {
    min-height: 2.65rem;
    padding: 0.46rem 0.66rem;
  }

  .notation-toolbar {
    width: 100%;
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

  .notation-nav-button {
    width: 100%;
    height: 2.35rem;
  }

  .lesson-meta-strip {
    grid-template-columns: 1fr;
  }

  html[data-active-tab="setup"] .lesson-notation {
    display: none;
  }

  html[data-active-tab="setup"] .board-stage-foot {
    display: none;
  }

  .piece-palette {
    grid-template-columns: repeat(7, minmax(0, 1fr));
    gap: 0.35rem;
  }

  .piece-tool {
    gap: 0;
  }

  .piece-tool-button {
    width: clamp(2.05rem, 10vw, 2.5rem);
    justify-self: center;
    border-radius: var(--radius-card);
  }

  .piece-tool-label {
    display: none;
  }

  .board-block {
    grid-template-columns: 1fr;
  }

  .captured-row {
    width: min(100%, calc(var(--board-size) + (var(--board-frame-padding) * 2) + 2px));
  }

  .status-tile + .status-tile {
    margin-left: 0;
    padding-left: 0;
    border-left: 0;
    border-top: 1px solid var(--status-border);
    padding-top: 0.8rem;
  }
}

@media (max-width: 760px) and (orientation: portrait) {
  .workspace {
    grid-template-columns: minmax(0, 1fr);
  }

  .control-pane,
  .control-pane-scroll {
    display: contents;
  }

  .lesson-header {
    order: 0;
    position: sticky;
    top: 0;
    z-index: 30;
    gap: 0.22rem;
    padding: 0.12rem 0 0.16rem;
    border-bottom: 1px solid var(--section-divider-soft);
  }

  .board-pane {
    order: 1;
    position: relative;
    z-index: 1;
    margin-inline: -0.55rem;
    width: auto;
  }

  .board-column {
    --board-frame-padding: 0;
    --eval-rail-track-width: 0.8rem;
    --turn-marker-size: 0.38rem;
    --turn-marker-gap: 0.12rem;
    --turn-marker-offset: 0.2rem;
    --captured-cell-min: 0.5rem;
    --captured-cell-divisor: 24;
    --captured-cell-max: 0.65rem;
    --captured-row-extra-height: 0.2rem;
    --captured-count-extra-width: 0.5rem;
    max-width: none;
    width: 100%;
  }

  .board-frame {
    border: none;
    padding: 0;
    background: transparent;
    box-shadow: none;
    width: var(--board-size);
    height: var(--board-size);
  }

  .captured-row {
    border: none;
    box-shadow: none;
    background: transparent;
    width: var(--board-size);
    padding: 0.1rem 0;
    margin: 0 auto;
  }

  /* Mobile engine lines slot: show between board (order:1) and workspace tools (order:3) */
  .mobile-engine-lines-slot {
    display: block;
    order: 2;
    /* Compact spacing between board and engine lines */
    padding-top: 0;
    padding-bottom: 0;
  }

  /* Hide the engine lines inside the notation panel on mobile —
     they are shown in .mobile-engine-lines-slot instead */
  #notationPanel .notation-pv {
    display: none;
  }

  .control-pane-scroll > :not(.lesson-header) {
    order: 4;
  }

  .control-pane-scroll > .workspace-tools {
    order: 3;
    padding-top: 0;
  }

  .lesson-notation,
  .lesson-position-builder-panel {
    order: 4;
  }

  .lesson-tools,
  .tab-panel,
  .setup-board-section,
  .setup-palette-panel {
    gap: 0.48rem;
  }

  .tab-panel {
    padding-top: 0.42rem;
  }

  html[data-active-tab="setup"] .tab-nav {
    display: flex;
  }

  html[data-active-tab="setup"] #setupPanel {
    padding-top: 0;
  }

  .setup-board-section .lesson-section-header {
    display: none;
  }

  .setup-palette-panel {
    order: 0;
  }

  .setup-piece-palette {
    order: 0;
  }

  .setup-active-summary {
    order: 1;
    min-height: 2.15rem;
    padding: 0.42rem 0.58rem;
  }

  .setup-palette-color {
    order: 2;
  }

  .setup-board-actions {
    order: 1;
  }

  .setup-board-divider {
    display: none;
  }

  .lesson-command-row {
    grid-template-columns: minmax(0, 1fr) auto auto auto;
    gap: 0.18rem;
  }

  .lesson-picker {
    min-height: 1.75rem;
    padding-inline: 0.3rem;
    font-size: 0.72rem;
  }

  .lesson-actions-button,
  .header-analyze-button {
    min-width: auto;
    min-height: 1.75rem;
    padding: 0.2rem 0.3rem;
    font-size: 0.68rem;
  }

  .coord-rank,
  .coord-file {
    font-size: 0.4rem;
    font-weight: 700;
  }

  .coord-rank {
    top: clamp(0.08rem, 0.3vw, 0.12rem);
    left: clamp(0.08rem, 0.3vw, 0.12rem);
  }

  .coord-file {
    right: clamp(0.08rem, 0.3vw, 0.12rem);
    bottom: clamp(0.05rem, 0.2vw, 0.08rem);
  }

  .eval-bar-wrap {
    top: 0;
  }

  .board-column:has(> .captured-row:first-child:not(.is-empty)) .eval-bar-wrap {
    top: calc(var(--captured-row-height) + var(--captured-row-gap));
  }

  /* Slim evaluation bar on mobile — reduced border-radius, no shadow. */
  .eval-bar-track {
    border-radius: 3px;
    box-shadow: none;
  }

  /* Side-to-move marker hidden on portrait — the page title already states
     "White to move" / "Black to move", so the floating square is redundant. */
  .turn-side-marker {
    display: none !important;
  }

  /* Bottom toolbar (FEN, meta-strip) hidden on portrait — duplicates
     controls already available above the board. */
  .board-stage-foot {
    display: none !important;
  }

  .header-analyze-button {
    position: relative;
    width: 2rem;
    min-width: 2rem;
    padding: 0;
    font-size: 0;
  }

  .header-analyze-button::before,
  .header-analyze-button::after {
    content: "";
    position: absolute;
    top: 50%;
    left: 50%;
    display: block;
    pointer-events: none;
  }

  .header-analyze-button::before {
    width: 0.76rem;
    height: 0.76rem;
    border: 0.13rem solid currentColor;
    border-radius: 50%;
    transform: translate(-58%, -58%);
  }

  .header-analyze-button::after {
    width: 0.46rem;
    height: 0.13rem;
    border-radius: 999px;
    background: currentColor;
    transform: translate(-5%, -5%) rotate(45deg);
  }

  .header-analyze-button.is-analyzing::before {
    width: 0.82rem;
    height: 0.82rem;
    border: 0;
    border-radius: 0.18rem;
    background: currentColor;
    transform: translate(-50%, -50%);
  }

  .header-analyze-button.is-analyzing::after {
    display: none;
  }

  .lesson-overflow-trigger {
    width: 1.75rem;
    height: 1.75rem;
  }

  .lesson-overflow-menu {
    z-index: 40;
    max-width: calc(100vw - 1.1rem);
  }

  .lesson-overflow-item {
    min-height: 1.75rem;
    padding: 0.28rem 0.44rem;
    font-size: 0.7rem;
  }

  .play-section-title {
    font-size: 1rem;
  }

  .play-start-action-row {
    margin-top: 0.36rem;
  }

  .play-start-action-row .action-button {
    min-height: 2.12rem;
    padding: 0.36rem 0.62rem;
  }

  .play-clocks-container {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 0.35rem;
  }

  .play-clock {
    min-width: 0;
    gap: 0.08rem;
    padding: 0.34rem 0.28rem;
  }

  .play-clock-label {
    font-size: 0.58rem;
  }

  .play-clock-time {
    min-width: 5.4ch;
    font-size: 1.18rem;
  }

  /* Slim scrollbar — thin, low-contrast, supports scrolling without competing
     with the board. */
  .control-pane-scroll::-webkit-scrollbar,
  .lesson-overflow-menu::-webkit-scrollbar,
  .custom-select-menu::-webkit-scrollbar {
    width: 4px;
    height: 4px;
  }
  .control-pane-scroll::-webkit-scrollbar-thumb,
  .lesson-overflow-menu::-webkit-scrollbar-thumb,
  .custom-select-menu::-webkit-scrollbar-thumb {
    background: rgba(128, 128, 128, 0.25);
    border-radius: 4px;
  }

  /* Tighter vertical rhythm — compress spacing between sections. */
  .board-stage-card {
    gap: 0.25rem;
  }
  .board-block {
    gap: 0;
  }
}

/* ---- Mobile-width tweaks (any orientation) ----
   Mirrors the portrait block above so these also apply in landscape /
   inside the lessons iframe, which may not report orientation: portrait. */
@media (max-width: 760px) {
  /* Higher-specificity selector so it also wins inside the landscape
     media block (which sets min-width: 5.4rem on this button). */
  .lesson-command-row .header-analyze-button {
    position: relative;
    width: 1rem;
    min-width: 1rem;
    min-height: 1rem;
    padding: 0;
    font-size: 0;
  }
  .lesson-command-row .header-analyze-button::before,
  .lesson-command-row .header-analyze-button::after {
    content: "";
    position: absolute;
    top: 50%;
    left: 50%;
    display: block;
    pointer-events: none;
  }
  .lesson-command-row .header-analyze-button::before {
    width: 0.36rem;
    height: 0.36rem;
    border: 0.06rem solid currentColor;
    border-radius: 50%;
    transform: translate(-58%, -58%);
  }
  .lesson-command-row .header-analyze-button::after {
    width: 0.21rem;
    height: 0.06rem;
    border-radius: 999px;
    background: currentColor;
    transform: translate(-5%, -5%) rotate(45deg);
  }
  .lesson-command-row .header-analyze-button.is-analyzing::before {
    width: 0.37rem;
    height: 0.37rem;
    border: 0;
    border-radius: 0.08rem;
    background: currentColor;
    transform: translate(-50%, -50%);
  }
  .lesson-command-row .header-analyze-button.is-analyzing::after {
    display: none;
  }

  .coord-rank,
  .coord-file {
    font-size: 0.4rem;
    font-weight: 700;
  }
  .coord-rank {
    top: clamp(0.08rem, 0.3vw, 0.12rem);
    left: clamp(0.08rem, 0.3vw, 0.12rem);
  }
  .coord-file {
    right: clamp(0.08rem, 0.3vw, 0.12rem);
    bottom: clamp(0.05rem, 0.2vw, 0.08rem);
  }

  /* Side-to-move marker: keep it a VISIBLE SQUARE (not a tiny dot), and show
     it on the side to move — beside the top captured row when the top side is
     to move, or beside the bottom captured row when the bottom side is to move
     (mirrors the eval bar's own top/bottom turn logic). */
  .eval-bar-wrap .turn-side-marker {
    --turn-marker-size: 0.46rem;
    --turn-marker-gap: 0.12rem;
    top: calc(-1 * (var(--captured-row-gap) + (var(--captured-row-height) / 2) - (var(--turn-marker-size) / 2)));
    bottom: auto;
    left: calc(var(--eval-rail-track-width) + var(--eval-rail-gap));
  }
  .eval-bar-wrap[data-orientation='white'][data-turn-side='w'] .turn-side-marker,
  .eval-bar-wrap[data-orientation='black'][data-turn-side='b'] .turn-side-marker {
    top: auto;
    bottom: calc(-1 * (var(--captured-row-gap) + (var(--captured-row-height) / 2) - (var(--turn-marker-size) / 2)));
  }

  /* Maximize chess board: 1 vw padding each side → board gets ~98 % width. */
  .page-shell {
    padding: 0 1vw;
  }
  .board-pane {
    margin-inline: 0;
    width: 100%;
  }
  .board-column {
    width: 100%;
    max-width: none;
  }
  .board-block {
    grid-template-columns: 1fr;
  }
  .board-stage-card {
    height: auto;
  }
}

@media (max-width: 1100px) and (min-width: 640px) and (orientation: landscape) {
  :root {
    --notation-text-size: 1.14rem;
  }

  html,
  body {
    overflow: hidden;
  }

  .page-shell {
    height: var(--app-height);
    min-height: 0;
    padding: 0.65rem;
    overflow: hidden;
  }

  .workspace {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    justify-content: normal;
    gap: clamp(0.55rem, 1.4vw, 0.8rem);
    min-height: calc(var(--app-height) - 1.3rem);
    max-width: none;
  }

  .board-stage-card,
  .control-pane {
    position: sticky;
    top: 0.65rem;
  }

  .board-stage-card {
    gap: 0.35rem;
    height: calc(var(--app-height) - 1.3rem);
  }

  .board-column {
    --board-frame-padding: 0.35rem;
    --board-available-height: calc(
      var(--app-height)
      - 1.3rem
      - (var(--captured-row-height) * 2)
      - (var(--captured-row-gap) * 2)
      - (var(--board-frame-padding) * 2)
    );
  }

  .control-pane {
    margin-left: 0;
    height: calc(var(--app-height) - 1.3rem);
    max-height: calc(var(--app-height) - 1.3rem);
  }

  .control-pane-scroll {
    gap: 0.75rem;
    min-height: 0;
    padding: 0 0 0.15rem;
    padding-inline-end: max(0.35rem, 8px);
    overflow-y: auto;
    scrollbar-gutter: stable;
  }

  .lesson-header,
  .lesson-notation,
  .lesson-tools,
  .lesson-section,
  .tab-panel {
    gap: var(--space-xs);
  }

  .lesson-header {
    padding: 0.1rem 0 0.2rem;
  }

  .title-input.lesson-title-input {
    min-height: 2.8rem;
    padding: 0.56rem 0.74rem;
  }

  .lesson-command-row {
    gap: 0.35rem;
  }

  .lesson-picker,
  .lesson-actions-button,
  .header-analyze-button,
  .lesson-overflow-trigger {
    min-height: 2.25rem;
  }

  .header-analyze-button {
    min-width: 5.4rem;
  }

  .notation-panel {
    min-height: 5.2rem;
  }

  .notation-toolbar {
    margin-top: 0;
  }

  .lesson-tools,
  .workspace-tools {
    padding-top: var(--space-sm);
  }

  .piece-palette {
    grid-template-columns: repeat(7, minmax(0, 1fr));
    gap: 0.35rem;
  }

  .piece-tool {
    gap: 0;
  }

  .piece-tool-button {
    width: clamp(2.05rem, 10vw, 2.5rem);
    justify-self: center;
    border-radius: var(--radius-card);
  }

  .piece-tool-label {
    display: none;
  }
}

:root[data-theme="dark"] .piece-tool-button.is-black-piece {
  background: rgba(255, 255, 255, 0.85);
  border-color: rgba(255, 255, 255, 0.15);
}

:root[data-theme="dark"] .piece-tool-button.is-black-piece.is-armed {
  background: rgba(255, 255, 255, 0.95);
  border-color: var(--piece-tool-armed-border);
  box-shadow: 0 0 8px var(--piece-tool-armed-border);
}

/* Custom Select Dropdowns */
.custom-select-wrapper {
  position: relative;
  width: 100%;
  display: flex;
  flex-direction: column;
}

.custom-select-trigger {
  width: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.5rem;
  text-align: left;
  cursor: pointer;
  background-color: var(--input-bg);
  border: 1px solid var(--input-border);
  color: var(--text);
  min-height: 3rem;
  padding: 0.64rem 0.8rem;
  border-radius: var(--radius-card);
  transition: border-color var(--ease), box-shadow var(--ease), background-color var(--ease);
}

.custom-select-trigger:hover:not(:disabled) {
  border-color: var(--overflow-trigger-hover-border);
  background-color: var(--overflow-trigger-hover-bg);
}

.custom-select-trigger:focus-visible,
.custom-select-wrapper.is-open .custom-select-trigger {
  outline: none;
  border-color: var(--focus-border);
  box-shadow: 0 0 0 4px var(--focus-ring);
}

.custom-select-trigger:disabled {
  cursor: not-allowed;
  opacity: 0.56;
}

.custom-select-value {
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  flex: 1;
}

.custom-select-arrow {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  color: var(--text-soft);
  transition: transform var(--ease);
  flex-shrink: 0;
}

.custom-select-wrapper.is-open .custom-select-arrow {
  transform: rotate(180deg);
}

.custom-select-menu {
  position: absolute;
  left: 0;
  right: 0;
  z-index: 100;
  display: grid;
  gap: 0.1rem;
  min-width: 100%;
  padding: 0.28rem;
  padding-inline-end: max(0.28rem, 8px);
  border: 1px solid var(--overflow-menu-border);
  border-radius: var(--radius-panel);
  background: var(--overflow-menu-bg);
  box-shadow: 0 16px 30px var(--overflow-menu-shadow);
  max-height: 12.8rem;
  overflow-y: auto;
  overflow-x: hidden;
  overscroll-behavior: contain;
}

.custom-select-menu[data-placement='down'] {
  top: calc(100% + 0.4rem);
  bottom: auto;
}

.custom-select-menu[data-placement='up'] {
  top: auto;
  bottom: calc(100% + 0.4rem);
}

.custom-select-item {
  width: 100%;
  min-height: 2.5rem;
  padding: 0.48rem 0.74rem;
  border: 0;
  border-radius: var(--radius-card);
  background: transparent;
  color: var(--text);
  text-align: left;
  font-size: 0.82rem;
  font-weight: 700;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.75rem;
  transition: background-color var(--ease), color var(--ease);
  cursor: pointer;
}

.custom-select-item:hover,
.custom-select-item:focus-visible {
  outline: none;
  background: var(--overflow-item-hover-bg);
  color: var(--accent-strong);
}

.custom-select-item.is-selected {
  background-color: var(--overflow-item-selected-bg);
  color: var(--overflow-item-selected-color);
}

.custom-select-item.is-selected .custom-select-item-title {
  color: var(--overflow-item-selected-color);
}

.custom-select-item-title {
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  flex: 1;
}

.custom-select-item-check {
  color: var(--accent-strong);
  display: inline-flex;
  align-items: center;
  flex-shrink: 0;
}


/* --- Endgame Puzzles (premium feature) ----------------------------------- */

.tab-chip-premium-star {
  margin-left: 0.3rem;
  font-size: 0.72em;
  color: #d4a017;
  vertical-align: 0.12em;
}

.puzzle-plan-pill {
  margin-left: 0.5rem;
  vertical-align: middle;
  white-space: nowrap;
}

.puzzle-stats-row {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 0.55rem;
}

.puzzle-stat {
  display: grid;
  justify-items: center;
  gap: 0.1rem;
  padding: 0.5rem 0.4rem;
  border-radius: var(--radius-card);
  border: 1px solid var(--card-border);
  background: var(--input-bg);
}

.puzzle-stat-value {
  font-size: 1.15rem;
  font-weight: 700;
  color: var(--accent-strong);
  line-height: 1.1;
}

.puzzle-stat-label {
  font-size: 0.72rem;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--text-muted);
}

.puzzle-objective-banner {
  display: grid;
  gap: 0.3rem;
  padding: 0.8rem 0.9rem;
  border-radius: var(--radius-card);
  border: 1px solid var(--accent);
  background: var(--accent-soft);
  line-height: 1.4;
}

.puzzle-objective-kicker {
  font-size: 0.72rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--accent-strong);
}

.puzzle-objective-meta {
  font-size: 0.8rem;
  color: var(--text-muted);
}

.puzzle-generating-banner {
  align-items: center;
}

.puzzle-spinner {
  flex-shrink: 0;
  width: 1.1rem;
  height: 1.1rem;
  border-radius: 50%;
  border: 2px solid var(--accent-soft);
  border-top-color: var(--accent);
  animation: puzzle-spinner-rotate 0.8s linear infinite;
}

@keyframes puzzle-spinner-rotate {
  to {
    transform: rotate(360deg);
  }
}

.puzzle-section-label {
  font-size: 0.72rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--text-muted);
  margin: 0 0 0.35rem 0;
}

.puzzle-lock-card {
  display: grid;
  justify-items: center;
  gap: 0.5rem;
  padding: 1.2rem 1rem;
  text-align: center;
  border-radius: var(--radius-card);
  border: 1px dashed var(--card-border);
  background: var(--input-bg);
}

.puzzle-lock-icon {
  font-size: 1.6rem;
  line-height: 1;
}

.premium-dialog {
  max-width: 26rem;
}

.premium-benefits {
  margin: 0.2rem 0 0.8rem;
  padding-left: 1.2rem;
  display: grid;
  gap: 0.3rem;
  font-size: 0.86rem;
  line-height: 1.45;
}

.premium-key-row {
  margin-bottom: 0.4rem;
}

.premium-key-input {
  width: 100%;
  padding: 0.55rem 0.7rem;
  border-radius: var(--radius-card);
  border: 1px solid var(--input-border);
  background: var(--input-bg);
  color: inherit;
  font-family: inherit;
  font-size: 0.92rem;
  letter-spacing: 0.06em;
  text-transform: uppercase;
}

.premium-key-input:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 1px;
}

.premium-modal-status {
  min-height: 1.2em;
  margin: 0 0 0.4rem;
  font-size: 0.84rem;
}

.premium-modal-status.is-error {
  color: var(--banner-danger-text);
}

.premium-modal-status.is-success {
  color: var(--banner-success-text);
}

@media (max-width: 760px) {
  .puzzle-stats-row {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

.puzzle-instruction-container {
  width: 100%;
  box-sizing: border-box;
}

.pgn-game-picker-dialog {
  max-width: 600px;
  width: 90%;
  max-height: 80vh;
  display: flex;
  flex-direction: column;
}

#pgnGamePickerList {
  overflow-y: auto;
  flex: 1;
  margin-bottom: 1rem;
  padding-right: 0.25rem;
}

.pgn-game-item {
  border: 1px solid var(--card-border);
  background: var(--card-bg);
  border-radius: var(--radius-card);
  padding: 1rem;
  margin-bottom: 0.75rem;
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
  transition: border-color 0.2s, box-shadow 0.2s, transform 0.2s;
}

.pgn-game-item:hover {
  border-color: var(--focus-border);
  box-shadow: 0 4px 12px var(--control-hover-shadow);
}

.pgn-game-item-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  border-bottom: 1px solid var(--section-divider-soft);
  padding-bottom: 0.35rem;
}

.pgn-game-number {
  font-weight: 700;
  font-size: 0.9rem;
  color: var(--accent-strong);
}

.pgn-game-date {
  font-size: 0.8rem;
  color: var(--text-soft);
  font-weight: 500;
}

.pgn-game-players {
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  align-items: center;
  gap: 0.5rem;
  margin: 0.25rem 0;
}

.pgn-game-player {
  font-weight: 600;
  font-size: 0.95rem;
  color: var(--text);
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.pgn-game-player.black {
  text-align: right;
}

.pgn-game-result {
  font-size: 0.8rem;
  padding: 0.15rem 0.45rem;
  background: var(--accent-soft);
  color: var(--accent-strong);
  border-radius: 4px;
  font-weight: 700;
  min-width: 2.5rem;
  text-align: center;
}

.pgn-game-details {
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 0.8rem;
  color: var(--text-muted);
}

.pgn-game-event {
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
  max-width: 70%;
}

.pgn-game-round {
  text-align: right;
}

.load-game-btn {
  width: 100%;
  margin-top: 0.25rem;
}

/* Opening Book Display */
.opening-info-display {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 0.82rem;
  color: var(--text-soft);
  min-width: 0;
  max-width: 100%;
  margin-top: 0.25rem;
}

.opening-eco-text {
  font-weight: 700;
  color: var(--accent-strong);
  background: var(--accent-soft);
  padding: 0.1rem 0.35rem;
  border-radius: 4px;
  flex-shrink: 0;
  font-size: 0.75rem;
}

.opening-name-text {
  min-width: 0;
  flex: 1;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

/* Right Sidebar and Multi-PGN Layout Fixes */
.control-pane,
.lesson-header,
.lesson-command-row,
.imported-pgn-container,
.notation-panel {
  min-width: 0;
  max-width: 100%;
}

.lesson-command-row button,
.lesson-actions-button,
.actions-button,
.header-analyze-button,
.analyze-button,
.lesson-overflow-trigger,
.settings-button {
  flex-shrink: 0;
}

.imported-pgn-container {
  margin-top: 0.5rem;
  padding: 0.5rem;
  border: 1px solid var(--section-divider-soft);
  border-radius: var(--radius-card);
  background: var(--header-bg);
  flex-direction: column;
  gap: 0.25rem;
  min-width: 0;
  max-width: 100%;
}

.imported-pgn-filename {
  font-size: 0.85rem;
  color: var(--text);
  min-width: 0;
  max-width: 100%;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.imported-pgn-meta {
  font-size: 0.85rem;
  color: var(--text);
  display: flex;
  flex-direction: column;
  gap: 0.25rem;
  min-width: 0;
  max-width: 100%;
  overflow: hidden;
}

.imported-pgn-title {
  min-width: 0;
  max-width: 100%;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

/* Game Picker Modal Layout Fixes */
.pgn-game-item {
  min-width: 0;
  max-width: 100%;
  box-sizing: border-box;
}

.pgn-game-item-content {
  min-width: 0;
  flex: 1;
}

.pgn-game-title-row {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 0.5rem;
  min-width: 0;
}

.pgn-game-title-text {
  font-weight: 600;
  font-size: 0.95rem;
  color: var(--text);
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
  min-width: 0;
  flex: 1;
}

.pgn-game-meta-row {
  display: flex;
  justify-content: space-between;
  font-size: 0.8rem;
  color: var(--text-soft);
  gap: 0.5rem;
  margin-top: 0.25rem;
  min-width: 0;
}

.pgn-game-event-text {
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
  min-width: 0;
  flex: 1;
}

.pgn-game-round-date {
  flex-shrink: 0;
  white-space: nowrap;
}

.pgn-game-item-actions {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-top: 0.5rem;
  gap: 0.5rem;
  flex-shrink: 0;
}

.last-move-arrow-outline,
.last-move-arrow-head-outline {
  display: none !important;
}

/* ═══════════════════════════════════════════════════════════
   Lesson Position Builder
   ═══════════════════════════════════════════════════════════ */

.lesson-position-builder-panel {
  display: grid;
  gap: 0.9rem;
}

.lesson-position-builder-panel[hidden] {
  display: none;
}

.lesson-builder-inner {
  display: grid;
  gap: 0.9rem;
}

.lesson-builder-header {
  display: grid;
  gap: 0.65rem;
}

.lesson-builder-file-actions {
  flex-wrap: wrap;
}

.lesson-builder-layout {
  display: grid;
  grid-template-columns: 1fr;
  gap: 0.9rem;
}

@media (min-width: 640px) {
  .lesson-builder-layout {
    grid-template-columns: 1fr 1fr;
  }
}

.lesson-builder-list-panel {
  min-width: 0;
}

.lesson-builder-position-list {
  display: grid;
  gap: 0.45rem;
  max-height: 24rem;
  overflow-y: auto;
  padding-inline-end: max(0.25rem, 8px);
}

.lesson-builder-position-item {
  display: grid;
  grid-template-columns: 2.4rem minmax(0, 1fr) auto;
  align-items: center;
  gap: 0.55rem;
  width: 100%;
  min-height: 3rem;
  padding: 0.48rem 0.6rem;
  border-radius: var(--radius-card);
  border: 1px solid var(--control-border);
  background: var(--control-bg);
  color: var(--text);
  text-align: left;
  cursor: pointer;
  transition: border-color var(--ease), background-color var(--ease), box-shadow var(--ease);
}

.lesson-builder-position-item:hover,
.lesson-builder-position-item:focus-visible {
  outline: none;
  border-color: var(--focus-border);
  box-shadow: 0 0 0 3px var(--focus-ring);
}

.lesson-builder-position-item.is-selected {
  border-color: var(--tab-active-border);
  background: var(--accent-soft);
}

.lesson-builder-position-item.has-error {
  border-color: var(--banner-danger-border);
  background: var(--banner-danger-bg);
}

.lesson-builder-position-number {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 2rem;
  height: 2rem;
  border-radius: 1rem;
  border: 1px solid var(--move-index-border);
  background: var(--move-index-bg);
  color: var(--text-muted);
  font-size: 0.78rem;
  font-weight: 700;
}

.lesson-builder-position-title {
  min-width: 0;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
  font-weight: 700;
}

.lesson-builder-position-meta {
  display: flex;
  align-items: center;
  gap: 0.35rem;
  color: var(--text-muted);
  font-size: 0.78rem;
  font-weight: 600;
  white-space: nowrap;
}

.lesson-builder-default-badge {
  display: inline-flex;
  align-items: center;
  padding: 0.15rem 0.45rem;
  border-radius: var(--radius-pill);
  background: var(--accent-soft);
  color: var(--accent-strong);
  font-size: 0.72rem;
  font-weight: 700;
  border: 1px solid var(--accent-border);
}

.lesson-builder-error-indicator {
  display: inline-flex;
  align-items: center;
  padding: 0.15rem 0.45rem;
  border-radius: var(--radius-pill);
  background: var(--banner-danger-bg);
  color: var(--banner-danger-text);
  font-size: 0.72rem;
  font-weight: 700;
}

.lesson-builder-editor {
  display: grid;
  gap: 0.85rem;
  min-width: 0;
}

.lesson-builder-field {
  display: grid;
  gap: 0.3rem;
}

.lesson-builder-fen-input {
  min-height: 2.6rem;
  height: 2.6rem;
  padding: 0.52rem 0.6rem;
  font-family: ui-monospace, SFMono-Regular, Consolas, "Liberation Mono", monospace;
  font-size: 0.82rem;
  line-height: 1.25;
}

.lesson-builder-note-input {
  min-height: 5rem;
}

.lesson-builder-actions {
  flex-wrap: wrap;
  padding-top: 0.2rem;
}

.lesson-builder-validation-summary {
  margin-top: 0.25rem;
}

/* Guided review mobile `order` fix — reused for builder panel */
@media (max-width: 639px) {
  .lesson-position-builder-panel {
    order: 4;
  }
  .lesson-builder-position-list {
    max-height: 16rem;
  }
}