:root{--lightningcss-light: ;--lightningcss-dark:initial;color-scheme:dark;--canvas:#242321;--canvas-raised:#292825;--surface-1:#302e2b;--surface-2:#393631;--surface-3:#423e38;--line:#4c4740;--text:#f5f1e8;--text-muted:#b7b0a5;--text-faint:#a49c8f;--accent:#d8ad61;--success:#88a866;--action-green:#739c3e;--action-green-hover:#81aa49;--action-green-edge:#476425;--error:#ce6b5e;--font-score:ui-monospace, "Cascadia Mono", "SF Mono", Consolas, monospace;--font-ui:Inter, ui-sans-serif, system-ui, -apple-system, "Segoe UI", sans-serif;--text-xs:12px;--text-sm:13px;--text-md:15px;--text-xl:24px;--text-lg:18px;--text-2xl:32px;--s-1:4px;--s-2:8px;--s-3:12px;--s-4:16px;--s-5:24px;--s-6:32px;--s-7:48px;--lamp:radial-gradient(60% 55% at 50% 45%, #d8ad611a, transparent 70%);--panel-bg:#2b2926;--radius-sm:8px;--radius-md:12px;--radius-lg:16px;--panel-line:#423e38;--turn-white:#f5f1e8;--turn-black:#1b1a18;--brass:var(--accent);--brass-strong:#e7c27f;--brass-ink:#241c0e;--good:var(--success);--bad:var(--error);--brand-muted:#c1c3ad;--board-edge:#42493b;--danger-text:#f09283;--success-text:#b9cc9e;--shadow-color:#000;--sheet-backdrop:#121210b8;--shadow-soft:color-mix(in srgb, var(--shadow-color) 20%, transparent);--shadow-deep:color-mix(in srgb, var(--shadow-color) 44%, transparent);--button-highlight:color-mix(in srgb, var(--text) 6%, transparent);--ease:cubic-bezier(.2, .7, .1, 1);--dur-1:.14s;--dur-2:.24s;--dur-3:.42s}@media (width<=767px){.app-shell:not(.home-shell):not(.stats-shell):has(.stacked-layout){--safe-top:env(safe-area-inset-top,0px);--safe-height:calc(var(--safe-top) + var(--safe-bottom));padding-top:var(--safe-top)}.workbench.stacked-layout{--reference-board-offset:calc(742px / 3 - 62px);--board-size:min(calc(100vw - 2px), calc(100dvh - var(--safe-height) - var(--reference-board-offset) - 77px));--prompt-height:calc(var(--reference-board-offset) - 52px - 44px);grid-template-rows:var(--prompt-height) 44px var(--board-size) minmax(0, 1fr) auto;margin-inline:calc(-1 * var(--s-4))}.workbench.stacked-layout .board-column{display:contents}.workbench.stacked-layout .turn-prompt{grid-area:1/1;align-self:start;width:calc(100% - 32px)}.workbench.stacked-layout .board-footer{grid-area:2/1;justify-self:center;width:calc(100% - 32px)}.workbench.stacked-layout .compact-facts{align-self:start;margin-top:2px}.workbench.stacked-layout .board-heading{z-index:1;grid-area:2/1;place-self:end start;width:calc(100% - 80px);margin:0 0 4px 16px}.workbench.stacked-layout>.board-column>.move-feedback,.workbench.stacked-layout>.board-column>.position-loading{width:var(--board-size);grid-area:3/1;justify-self:center}.workbench.stacked-layout .mobile-summary{grid-area:4/1;width:calc(100% - 32px)}.workbench.stacked-layout .panel-actions{grid-area:5/1;margin-inline:0}}*{box-sizing:border-box}body{background:var(--canvas);color:var(--text);margin:0;font-family:Inter,ui-sans-serif,system-ui,-apple-system,BlinkMacSystemFont,Segoe UI,sans-serif;font-size:15px}button,input,select{font:inherit}button,a,input,select{outline-offset:2px}button:focus-visible,a:focus-visible,input:focus-visible,select:focus-visible,[tabindex]:focus-visible{outline:2px solid var(--brass-strong)}button{border:1px solid var(--panel-line);border-radius:var(--radius-md);min-height:44px;padding:var(--s-3) var(--s-4);color:var(--text);cursor:pointer;background:0 0;font-weight:600}button:hover{background:var(--surface-3)}:where(.sheet) button{background:var(--surface-2)}button:disabled{opacity:.45;cursor:default}a{color:var(--accent)}.app-shell{--safe-height:calc(env(safe-area-inset-top,0px) + env(safe-area-inset-bottom,0px));max-width:1240px;height:100dvh;padding:env(safe-area-inset-top,0px) max(12px, 2vw, env(safe-area-inset-right,0px)) env(safe-area-inset-bottom,0px) max(12px, 2vw, env(safe-area-inset-left,0px));grid-template-rows:52px minmax(0,1fr) 22px;gap:4px;margin:auto;display:grid}.topbar{justify-content:space-between;align-items:center;gap:12px;display:flex}.brand{color:var(--text);letter-spacing:-1px;flex-shrink:0;align-items:center;gap:8px;font-size:23px;text-decoration:none;display:inline-flex}.brand img{width:32px;height:32px;display:block}.brand-name{font-weight:650}.brand-name>span{color:var(--brass);font-weight:650}.topbar nav{align-items:center;gap:6px;display:flex}.topbar button{font-size:13px}.text-button{color:var(--text-muted);border-color:#0000;align-items:center;gap:8px;display:inline-flex}.icon-button{justify-content:center;align-items:center;width:44px;padding:4px;display:inline-flex}.workbench{--board-size:min(760px, calc(100dvh - 304px - var(--safe-height)), calc(96vw - 24px));grid-template-columns:minmax(0, var(--board-size));grid-template-rows:auto auto;place-content:center;gap:8px;min-height:0;display:grid}.board-column{min-width:0;width:var(--board-size);align-self:center}.board-heading,.board-footer{color:var(--text-muted);justify-content:space-between;align-items:center;gap:8px;font-size:12px;display:flex}.board-heading{height:36px}.board-footer{height:24px;color:var(--text-faint)}.last-move{font-family:var(--font-score);white-space:nowrap;align-items:baseline;gap:7px;min-width:0;display:flex}.last-move strong{color:var(--text);font-size:14px}.move-number{color:var(--text-faint)}.move-route{color:var(--text-muted);font-size:11px}.line-progress{color:var(--text-faint);margin-top:3px;font-size:10px;display:block}.mode-button,.board-flip{color:var(--text-muted);white-space:nowrap;border:0;align-items:center;gap:6px;padding:0 2px;font-size:12px;font-weight:450;display:inline-flex}.mode-button{margin-left:auto}.board-flip{min-height:24px}.mode-button:hover,.board-flip:hover{color:var(--text);background:0 0}.board-wrap{aspect-ratio:1;border:2px solid var(--board-edge);width:100%;box-shadow:0 8px 28px var(--shadow-soft);touch-action:none;border-radius:8px;position:relative}.square-access{touch-action:none;width:100%;height:100%;position:relative}.square-access:focus-visible{outline-offset:-3px;z-index:5}.board-wrap [data-square]>span>span{color:var(--turn-black)}.chess-piece{pointer-events:none;-webkit-user-select:none;user-select:none;-webkit-user-drag:none;width:100%;height:100%;display:block}.context-panel{grid-template-rows:minmax(104px,auto) 56px;min-height:0;display:grid}.panel-copy{align-content:center;min-height:0;padding:2px 8px}.turn-prompt h1{font-size:var(--text-xl);letter-spacing:-.3px;align-items:center;gap:8px;margin:0 0 3px;font-weight:600;line-height:1.2;display:flex}.turn-prompt p{font-size:var(--text-md);color:var(--text-muted);margin:0;line-height:1.35}.panel-copy>a{font-size:12px}.turn-prompt{min-height:var(--prompt-height,112px);height:var(--prompt-height,112px);border-left:3px solid #0000;align-content:start;overflow-y:auto}.turn-prompt--good{border-left-color:var(--good)}.turn-prompt--mistake{border-left-color:var(--bad)}.turn-disc,.turn-tick{flex:0 0 20px;width:20px;height:20px}.turn-disc{border:1px solid var(--panel-line);background:var(--turn-white);border-radius:50%}.turn-disc--b{background:var(--turn-black)}.turn-tick{color:var(--good)}.turn-tick path{stroke-dasharray:1;stroke-dashoffset:0;animation:solved-tick var(--dur-3) var(--ease) both}.streak-value{display:inline-block}.move-feedback{width:100%;position:relative}.move-feedback-grid{pointer-events:none;position:absolute;inset:2px}.stacked-layout .move-feedback-grid{inset:0}.correct-move-ring{width:12.5%;height:12.5%;box-shadow:inset 0 0 0 4px var(--good);animation:correct-move-pulse var(--dur-2) var(--ease) both;position:absolute}@keyframes correct-move-pulse{0%{opacity:1;transform:scale(1)}50%{opacity:1;transform:scale(1.04)}to{opacity:0;transform:scale(1)}}@keyframes solved-tick{0%{stroke-dashoffset:1px}to{stroke-dashoffset:0}}[data-reduced=true] .turn-tick path,[data-reduced=true] .correct-move-ring{animation:none}.turn-prompt .turn-feedback{font-size:var(--text-sm)}.panel-actions{background:0 0;border-radius:8px;grid-template-columns:repeat(3,minmax(0,1fr)) minmax(100px,1.5fr);gap:8px;display:grid}.primary-slot{min-width:0;display:flex}.primary-slot>button{width:100%}.panel-actions button{background:var(--surface-2);min-width:0;min-height:56px;color:var(--text);box-shadow:inset 0 -4px 0 var(--canvas), inset 0 1px 0 var(--button-highlight);white-space:nowrap;border:0;border-radius:8px;flex-direction:column;justify-content:center;align-items:center;gap:4px;padding:5px 2px;font-size:11px;font-weight:700;display:flex}.panel-actions button:first-child,.panel-actions button:last-child{border-radius:8px}.panel-actions .design-icon{width:21px;height:21px}.panel-actions .advance-button.primary{color:var(--brass-ink);background:var(--brass);box-shadow:inset 0 -4px 0 var(--shadow-soft), inset 0 1px 0 var(--brass-strong)}.panel-actions .advance-button.primary:hover{background:var(--brass-strong)}.panel-actions button:focus-visible{outline:2px solid var(--brass-strong);outline-offset:2px}.primary{background:var(--brass);color:var(--brass-ink);box-shadow:inset 0 -4px 0 var(--shadow-soft), inset 0 1px 0 var(--brass-strong);border-color:#0000;justify-content:space-between;align-items:center;min-height:48px;padding-bottom:14px;font-weight:750;display:flex}.primary:hover{background:var(--brass-strong)}.advance-button{border-color:var(--panel-line);transition:none}.site-footer{min-width:0;color:var(--text-faint);justify-content:space-between;align-items:center;gap:12px;font-size:10px;display:flex}.site-footer>span{text-overflow:ellipsis;white-space:nowrap;min-width:0;overflow:hidden}.site-footer button{min-height:22px;color:var(--text-muted);border:0;flex-shrink:0;padding:0 2px;font-size:10px}.notice{z-index:40;top:max(60px, env(safe-area-inset-top));border:1px solid var(--line);background:var(--surface-1);width:min(520px,100vw - 24px);box-shadow:0 8px 30px var(--shadow-deep);border-radius:8px;justify-content:space-between;align-items:center;gap:12px;padding:8px 12px;font-size:13px;display:flex;position:fixed;left:50%;transform:translate(-50%)}.notice button{border:0;min-width:44px;padding:4px}.design-icon{vertical-align:middle;flex:none;width:20px;height:20px}.mode-button .design-icon,.board-flip .design-icon,.utility-row .design-icon{width:16px;height:16px}.utility-row{flex-wrap:wrap;gap:8px;display:flex}.utility-row button{flex:1;justify-content:center;align-items:center;gap:6px;padding:8px;font-size:13px;display:inline-flex}.review-actions{gap:10px;display:grid}.review-actions>p{margin:0 0 6px}.continuation-button{background:color-mix(in srgb, var(--brass) 12%, var(--panel-bg));border-color:var(--brass);color:var(--text);justify-content:space-between;align-items:center;display:flex}.continuation-button:hover{background:color-mix(in srgb, var(--brass) 20%, var(--panel-bg))}.theme-tags{flex-wrap:wrap;gap:6px;margin:14px 0;display:flex}.theme-tags>span{border:1px solid var(--panel-line);color:var(--text-muted);border-radius:3px;padding:4px 7px;font-size:10px}.promotion-backdrop{background:color-mix(in srgb, var(--shadow-color) 60%, transparent);z-index:20;place-items:center;display:grid;position:absolute;inset:0}.promotion{background:var(--surface-1);border-radius:8px;max-width:calc(100% - 12px);margin:6px;padding:12px}.promotion h2{margin:0 0 10px;font-size:16px}.promotion>div{grid-template-columns:repeat(4,minmax(0,1fr));gap:4px;margin-bottom:8px;display:grid}.promotion>div button{flex-direction:column;align-items:center;gap:2px;min-width:0;padding:4px;font-size:10px;display:flex}.promotion>div img{max-width:100%;height:auto}.sheet{color:var(--text);background:0 0;border:0;width:min(500px,100vw - 24px);max-height:calc(100dvh - 32px);padding:0;overflow:visible}.sheet::backdrop{background:var(--sheet-backdrop);-webkit-backdrop-filter:blur(4px);backdrop-filter:blur(4px)}.sheet-content{background:var(--panel-bg);border:1px solid var(--panel-line);border-radius:var(--radius-lg);padding:var(--s-5);overscroll-behavior:contain;max-height:calc(100dvh - 32px);box-shadow:0 24px 70px var(--shadow-deep);overflow:auto}.sheet-header{justify-content:space-between;align-items:center;gap:16px;margin-bottom:20px;display:flex}.sheet-header h2{letter-spacing:-.4px;margin:0;font-size:21px;font-weight:550}.sheet-header button{border:0;justify-content:center;align-items:center;min-width:44px;padding:0;display:inline-flex}.settings-grid{gap:18px;display:grid}.settings-grid label{color:var(--text-muted);flex-direction:column;gap:10px;font-size:13px;display:flex}.settings-grid .toggle{flex-direction:row;justify-content:space-between;align-items:center;min-height:44px}.settings-grid input:not([type=checkbox]),.settings-grid select{background:var(--canvas);border:1px solid var(--line);border-radius:var(--radius-sm);width:100%;min-height:44px;color:var(--text);padding:8px}.settings-grid input[type=range]{accent-color:var(--accent);padding:0}.settings-grid input[type=checkbox]{width:20px;height:20px;accent-color:var(--accent)}.muted,.shortcut-guide{color:var(--text-muted);font-size:13px;line-height:1.7}.shortcut-guide{font-size:11px}.danger{color:var(--danger-text);border-color:var(--bad)}.history-list{gap:8px;margin:20px 0;display:grid}.history-list button{text-align:left;justify-content:space-between;align-items:center;gap:20px;padding:14px;display:flex}.history-list button>span:first-child{flex-direction:column;gap:6px;display:flex}.history-list small{color:var(--text-muted);font-size:10px}.history-list button>span:last-child{font-size:11px}.success-text{color:var(--success-text)}.confidence{flex-wrap:wrap;gap:6px;display:flex}.confidence button{font-size:12px}.license-copy{font-size:14px;line-height:1.7}.design-credit{border-bottom:1px solid var(--line);align-items:center;gap:10px;margin-bottom:20px;padding:0 0 18px;font-size:13px;text-decoration:none;display:flex}.empty-practice{text-align:center;color:var(--text-muted);padding:20px 12px 28px}.empty-practice img{opacity:.8;margin:0 auto 16px;display:block}.sr-only{clip:rect(0, 0, 0, 0);white-space:nowrap;width:1px;height:1px;position:absolute;overflow:hidden}@media (width<=899px) and (orientation:portrait),(width<=519px){.app-shell{padding-left:env(safe-area-inset-left,0px);padding-right:env(safe-area-inset-right,0px)}.topbar,.site-footer{padding-inline:10px}.workbench{--board-size:min(760px, calc(100vw - env(safe-area-inset-left,0px) - env(safe-area-inset-right,0px)), calc(100dvh - 304px - var(--safe-height)));grid-template-rows:minmax(104px,auto) auto 56px}.context-panel{display:contents}.turn-prompt{grid-row:1;margin-inline:8px}.board-column{grid-row:2}.panel-actions{grid-row:3}.board-heading,.board-footer{padding-inline:8px}.board-wrap{border:0;border-radius:0}.sheet{width:100%;max-height:90dvh;margin:auto auto 0}.sheet-content{max-height:90dvh;padding-bottom:calc(24px + env(safe-area-inset-bottom));border-radius:16px 16px 0 0}}@media (width<=599px){.brand{gap:6px;font-size:21px}.brand img{width:28px;height:28px}.topbar nav{gap:2px}.topbar .text-button{justify-content:center;width:40px;padding:0}.practice-label{display:none}}@media (orientation:landscape) and (height<=540px) and (width>=520px){.app-shell{padding-bottom:max(4px, env(safe-area-inset-bottom));grid-template-rows:40px minmax(0,1fr);gap:4px}.site-footer,.board-footer{display:none}.workbench{--board-size:min(760px, calc(100dvh - 132px - var(--safe-height)), calc(96vw - 252px));grid-template-columns:var(--board-size) 236px;grid-template-rows:auto 56px;gap:0 16px}.board-heading{height:28px}.board-heading .mode-button{min-height:28px;font-size:10px}.board-heading .move-route{display:none}.board-heading .last-move{gap:4px}.context-panel{display:contents}.panel-copy{grid-area:1/2;align-self:center;padding:8px}.panel-actions{grid-area:2/1/auto/-1}}@media (prefers-reduced-motion:reduce){*,:before,:after{scroll-behavior:auto!important;transition:none!important;animation:none!important}}.position-loading{aspect-ratio:1;border:1px solid var(--line);border-radius:8px;grid-template-rows:repeat(8,1fr);grid-template-columns:repeat(8,1fr);width:100%;animation:1.6s ease-in-out infinite board-loading-pulse;display:grid;overflow:hidden}.skeleton-light{background:var(--surface-1)}.skeleton-dark{background:var(--surface-2)}.position-loading[data-reduced=true]{animation:none}@keyframes board-loading-pulse{0%,to{opacity:1}50%{opacity:.5}}.recent-practice{margin-bottom:var(--s-5);padding-bottom:var(--s-4);border-bottom:1px solid var(--panel-line)}.recent-practice-heading{justify-content:space-between;align-items:center;gap:var(--s-2);display:flex}.recent-practice-heading h2{font-size:var(--text-md);margin:0}.recent-practice-heading button{align-items:center;gap:var(--s-2);font-size:var(--text-sm);padding:var(--s-2);flex-shrink:0;display:inline-flex}.recent-practice .session-strip{border:0}.practice-modes{grid-template-columns:1fr 1fr;gap:10px;display:grid}.practice-modes button{text-align:left;white-space:normal;flex-direction:column;gap:8px;padding:14px;display:flex}.practice-modes button span{color:var(--text-muted);font-size:12px;font-weight:400;line-height:1.4}.practice-modes button[aria-pressed=true]{border-color:var(--accent);background:color-mix(in srgb, var(--brass) 12%, transparent)}.resume-button{align-items:center;gap:18px;margin:0 0 20px;display:flex}.panel-actions button{flex-direction:row;gap:8px;font-size:12px}.panel-actions .retry-action{background:var(--surface-3);color:var(--text);box-shadow:inset 0 -4px 0 var(--canvas-raised), inset 0 1px 0 var(--button-highlight)}.panel-actions button:hover:not(:disabled){background:var(--surface-3)}.panel-actions .advance-button.primary:hover:not(:disabled){background:var(--brass-strong)}.panel-actions button:active:not(:disabled),.primary:active:not(:disabled){box-shadow:inset 0 -1px 0 var(--shadow-soft), inset 0 2px 3px var(--shadow-soft)}.panel-actions button:disabled{opacity:.4;box-shadow:none}.panel-actions .advance-button{font-size:14px;font-weight:750}@media (width<=700px){.home-menu{grid-template-columns:1fr;gap:24px;padding:24px 0}.practice-builder{padding:18px}.panel-actions button{flex-direction:column;gap:4px}}.choice-field{border:0;min-width:0;margin:0;padding:0}.choice-field legend{color:var(--text-muted);margin-bottom:10px;padding:0;font-size:13px}.icon-choices{grid-template-columns:repeat(3,minmax(0,1fr));gap:8px;display:grid}.icon-choices button{flex-direction:column;justify-content:center;align-items:center;gap:6px;min-height:84px;padding:10px 6px;font-size:12px;display:flex}.icon-choices button[aria-pressed=true]{border-color:var(--brass);background:color-mix(in srgb, var(--brass) 12%, transparent);color:var(--text);box-shadow:inset 0 0 0 1px var(--brass)}.difficulty-choices button{border-width:2px}.difficulty-choices button[aria-pressed=true]{border-color:var(--brass);background:color-mix(in srgb, var(--brass) 12%, transparent);color:var(--text);box-shadow:none}.icon-choices small{color:var(--text-muted);font-size:10px;font-weight:400}.practice-icon{flex-shrink:0;width:27px;height:27px}.theme-choices{scrollbar-gutter:stable;grid-template-columns:repeat(4,minmax(0,1fr));max-height:none;padding:3px;overflow-y:auto}.advanced-settings summary{cursor:pointer;min-height:44px;padding:12px 0}.advanced-settings label{gap:8px;display:grid}@media (width<=420px){.theme-choices{grid-template-columns:repeat(3,minmax(0,1fr))}.practice-modes button{padding:10px}}.practice-modes{grid-template-columns:repeat(2,minmax(0,1fr))}.theme-step-heading{flex-wrap:wrap;align-items:center;gap:12px;display:flex}.puzzle-facts,.session-strip{margin:0}.puzzle-facts{gap:var(--s-2) var(--s-4);grid-template-columns:minmax(0,1fr) minmax(0,1fr);display:grid}.puzzle-facts dt,.session-strip dt,.scoresheet h2{font:400 var(--text-xs)/1.3 var(--font-score);letter-spacing:.08em;text-transform:uppercase;color:var(--text-muted)}.puzzle-facts dd{margin:var(--s-1) 0 0;font-size:var(--text-md)}.puzzle-identity{min-height:44px;position:relative}.puzzle-identity dd{align-items:center;padding-right:38px;display:flex}.puzzle-identity dd>span{text-overflow:ellipsis;white-space:nowrap;min-width:0;color:var(--text-muted);font:var(--text-xs)/1.5 var(--font-score);overflow:hidden}.puzzle-identity button{border:0;width:44px;height:44px;padding:0;position:absolute;top:0;right:-6px}.puzzle-themes{grid-column:1/-1}.puzzle-themes dd{gap:var(--s-1);flex-wrap:wrap;max-height:60px;display:flex;overflow-y:auto}.puzzle-themes dd span{border:1px solid var(--panel-line);border-radius:var(--radius-sm);font-size:var(--text-xs);color:var(--text-muted);overflow-wrap:anywhere;padding:2px 6px}.scoresheet{gap:var(--s-1);flex-direction:column;flex:1;min-height:0;display:flex}.scoresheet h2{margin:0}.score-scroll{overscroll-behavior:contain;scrollbar-gutter:stable;flex:1;min-height:0;overflow-y:auto}.scoresheet table{border-collapse:collapse;width:100%;font:var(--text-md)/1.5 var(--font-score)}.scoresheet th{color:var(--text-faint);text-align:left;width:20%;font-weight:400}.scoresheet td{border-left:3px solid #0000;width:40%;padding:3px 8px}.scoresheet td[aria-current]{border-left-color:var(--brass);background:color-mix(in srgb, var(--brass) 10%, transparent)}.score-route{color:var(--text-muted);font-size:var(--text-sm);white-space:nowrap;display:block}.session-strip{gap:var(--s-2);border-top:1px solid var(--panel-line);padding-top:var(--s-2);grid-template-columns:repeat(3,minmax(0,1fr));display:grid}.session-strip dd{font:600 var(--text-lg)/1.3 var(--font-score);margin:var(--s-1) 0 0}.notebook-content{display:contents}@media (width>=1024px) and (orientation:landscape),(orientation:landscape) and (height<=540px) and (width>=520px){.app-shell:not(.home-shell){grid-template-rows:44px minmax(0,1fr) 16px;gap:0;overflow:clip}.workbench{--board-size:min(720px, calc(100dvh - 140px), calc(100vw - 360px - 96px));grid-template-columns:var(--board-size) 360px;column-gap:var(--s-6);padding-top:var(--s-5);grid-template-rows:auto;place-content:start center;align-items:start}.board-column{isolation:isolate;align-self:start;position:relative}.board-column:before{content:"";z-index:-1;pointer-events:none;background:var(--lamp);position:absolute;inset:-15%}.board-heading{height:44px;position:absolute;top:-44px;right:0}.board-footer{justify-content:flex-end;height:44px;display:flex}.board-flip{min-height:44px}.context-panel{gap:var(--s-5);height:var(--board-size);background:var(--panel-bg);border:1px solid var(--panel-line);border-radius:var(--radius-lg);min-width:0;padding:var(--s-5);flex-direction:column;display:flex}.context-panel>:not(.scoresheet){flex-shrink:0}.turn-prompt{padding:0 0 0 var(--s-2);margin:0}.panel-actions{grid-template-columns:repeat(2,minmax(0,1fr));grid-auto-rows:48px;height:104px;margin-top:auto}.panel-actions button{border-radius:var(--radius-md);height:48px;min-height:48px;font-size:var(--text-xs);flex-direction:column;gap:2px;padding:3px;transition:none}.panel-actions .hint-action{grid-area:1/1}.panel-actions .replay-action{grid-area:1/2}.panel-actions .review-action{grid-area:2/1}.panel-actions .primary-slot{grid-area:2/2}.context-panel :focus-visible,.board-column button:focus-visible{outline:2px solid var(--brass-strong);outline-offset:2px}}@media (width>=1024px) and (orientation:landscape) and (height<=800px){.context-panel{padding:var(--s-3);gap:var(--s-2)}.puzzle-facts{gap:var(--s-1) var(--s-4)}.puzzle-themes dd{max-height:48px}.session-strip{padding-top:var(--s-1)}}@media (width>=1024px) and (orientation:landscape) and (height<=640px){.context-panel{padding:var(--s-2);gap:var(--s-1)}}.practice-notebook{gap:var(--s-4);margin-bottom:var(--s-5);display:grid}.practice-notebook .score-scroll{max-height:180px}.app-shell:not(.home-shell){--safe-bottom:env(safe-area-inset-bottom,0px)}.app-shell:not(.home-shell) :focus-visible{outline:2px solid var(--brass-strong);outline-offset:2px}.app-shell:not(.home-shell) .brand{min-height:44px}@media (width<=1023px),(orientation:portrait){.app-shell:not(.home-shell){--safe-height:calc(env(safe-area-inset-top,0px) + var(--safe-bottom));padding:env(safe-area-inset-top,0px) var(--s-4) 0;grid-template-rows:52px minmax(0,1fr);gap:0}.app-shell:not(.home-shell) .topbar{padding:0}.app-shell:not(.home-shell) .topbar .text-button{min-width:44px}.app-shell:not(.home-shell) .site-footer{display:none}.stacked-layout{--prompt-height:112px;--board-size:min(760px, calc(100vw - 32px), calc(100dvh - var(--prompt-height) - 189px - var(--safe-height)));grid-template-columns:minmax(0,1fr);grid-template-rows:var(--prompt-height) auto minmax(0, 1fr) auto;align-content:stretch;align-items:start;gap:0;padding:0}.stacked-layout .context-panel{display:contents}.stacked-layout .turn-prompt{width:var(--board-size);padding:var(--s-2) 0 var(--s-1) var(--s-2);grid-row:1;justify-self:center;margin:0}.stacked-layout .turn-prompt h1{font-size:var(--text-lg);margin:0}.stacked-layout .turn-feedback{margin-top:var(--s-1)}.stacked-layout .board-column{grid-row:2;place-self:start center}.stacked-layout .board-heading{height:16px;margin:0;padding:0}.stacked-layout .last-move,.stacked-layout .last-move strong{font-size:var(--text-xs);line-height:16px}.stacked-layout .board-wrap{border:0;border-radius:0}.stacked-layout .board-footer{gap:var(--s-1);height:44px;padding:0}.mobile-facts{align-items:center;gap:var(--s-1);min-width:0;min-height:44px;font-size:var(--text-sm);color:var(--text-muted);border:0;padding:0;font-weight:400;display:flex}.mobile-facts>span{white-space:nowrap;text-overflow:ellipsis;overflow:hidden}.mobile-facts .design-icon{flex-shrink:0;width:16px}.stacked-layout .board-flip{flex:0 0 44px;justify-content:center;height:44px}.stacked-layout .board-flip span{display:none}.stacked-layout .panel-actions{gap:var(--s-2);margin-inline:calc(-1 * var(--s-4));padding:var(--s-3) var(--s-4) calc(var(--s-3) + var(--safe-bottom));background:var(--canvas);border-top:1px solid var(--panel-line);z-index:1;height:calc(77px + var(--safe-bottom));border-radius:0;grid-row:4;grid-template-columns:repeat(4,minmax(0,1fr));align-self:end;position:sticky;bottom:0}.stacked-layout .panel-actions button{height:52px;min-height:52px;font-size:var(--text-xs);flex-direction:column;transition:none}}@media (width>=600px) and (orientation:portrait){.stacked-layout{--prompt-height:96px}}@media (orientation:landscape) and (height<=540px) and (width>=520px){.app-shell:not(.home-shell){--safe-height:calc(env(safe-area-inset-top,0px) + var(--safe-bottom));padding:env(safe-area-inset-top,0px) max(var(--s-4), env(safe-area-inset-right,0px)) var(--safe-bottom) max(var(--s-4), env(safe-area-inset-left,0px));grid-template-rows:44px minmax(0,1fr);gap:0}.app-shell:not(.home-shell) .topbar{padding:0}.app-shell:not(.home-shell) .site-footer{display:none}.notebook-layout{--board-size:min(440px, calc(100dvh - 96px - var(--safe-height)), calc(100vw - 312px));grid-template-columns:var(--board-size) minmax(248px, 440px);column-gap:var(--s-4);padding-top:var(--s-2)}.notebook-layout .board-column{grid-row:1}.notebook-layout .board-heading{height:44px;padding:0;inset:auto auto 0 0}.notebook-layout .mode-button{min-height:44px;font-size:var(--text-xs)}.notebook-layout .board-footer{padding:0}.notebook-layout .board-flip span{display:none}.notebook-layout .board-flip{justify-content:center;width:44px}.notebook-layout .context-panel{height:calc(100dvh - 52px - var(--safe-height));padding:var(--s-2);gap:var(--s-1)}.notebook-layout .notebook-content{overscroll-behavior:contain;gap:var(--s-1);flex-direction:column;flex:1 1 0;min-height:0;display:flex;overflow-y:auto}.notebook-content>*{flex-shrink:0}.notebook-layout .turn-prompt{padding:0 0 0 var(--s-2);align-self:stretch}.notebook-layout .turn-prompt h1{font-size:var(--text-lg)}.notebook-layout .puzzle-facts{gap:var(--s-1) var(--s-2);grid-template-columns:60px minmax(0,1fr) minmax(84px,1fr)}.notebook-layout .puzzle-identity{order:3}.notebook-layout .puzzle-themes{grid-column:auto}.notebook-layout .puzzle-themes dd{max-height:28px}.notebook-layout .scoresheet{flex:1 0 68px}.notebook-layout .score-scroll{max-height:100px}.notebook-layout .session-strip{padding-top:var(--s-1)}.notebook-layout .session-strip>div{align-items:baseline;gap:0 var(--s-1);flex-wrap:wrap;display:flex}.notebook-layout .session-strip dd{font-size:var(--text-md);margin-top:0}.notebook-layout .panel-actions{gap:var(--s-1);flex-shrink:0;grid-area:auto;grid-auto-rows:44px;width:100%;height:92px}.notebook-layout .panel-actions button{height:44px;min-height:44px}}.topbar .icon-button{border-radius:var(--radius-md);border:1px solid var(--panel-line);width:40px;height:40px;min-height:40px}.topbar .brand img{border-radius:7px;width:32px;height:32px}@media (width<=359px){.topbar .brand{letter-spacing:-.6px;font-size:17px}.topbar{gap:6px}}.home-shell{height:100dvh;min-height:0;padding-inline:max(16px, env(safe-area-inset-left)) max(16px, env(safe-area-inset-right));grid-template-rows:52px minmax(0,1fr);gap:0}.home-shell .topbar{padding:0}.home-shell .site-footer{display:none}.home-menu{place-self:center;width:min(100%,560px);height:min(100%,664px);min-height:0;padding:12px 0;display:flex}.practice-builder{flex-direction:column;width:100%;min-width:0;min-height:0;padding:0;display:flex}.practice-title{flex-shrink:0;justify-content:space-between;align-items:center;height:44px;display:flex}.practice-title h1,.theme-step-heading h1{font-size:var(--text-lg);margin:0}.practice-title .resume-button{font-size:var(--text-sm);border:0;gap:4px;margin:0;padding:4px}.practice-setup{flex-direction:column;flex:1;gap:12px;min-height:0;display:flex}.practice-modes{border:1px solid var(--panel-line);border-radius:var(--radius-md);grid-template-columns:1fr 1fr;gap:0;display:grid}.practice-modes button{height:44px;min-height:44px;font-size:var(--text-sm);border-color:#0000;justify-content:center;align-items:center;padding:4px}.practice-modes button[aria-pressed=true]{color:var(--brass);border-color:var(--brass)}.mode-description{color:var(--text-muted);font-size:var(--text-sm);margin:0;line-height:18px}.difficulty-field{flex-direction:column;flex:1;min-height:172px;max-height:264px;display:flex}.difficulty-field legend{margin-bottom:8px}.difficulty-choices{flex:1;grid-template-rows:repeat(2,minmax(72px,120px));grid-template-columns:repeat(3,minmax(0,1fr))}.difficulty-choices button{gap:3px;min-height:72px;padding:6px 2px}.rating-range{grid-template-columns:1fr 1fr;gap:12px;display:grid}.rating-range label{gap:4px}.rating-note{font-size:var(--text-xs);color:var(--text-muted);margin:0;line-height:16px}.practice-start{flex-shrink:0;margin-top:auto;padding-top:8px}.practice-start .primary{width:100%;height:52px}.theme-step-heading{flex-shrink:0;justify-content:space-between;gap:8px;display:flex}.theme-step-heading button{font-size:var(--text-sm);color:var(--text-muted);border:0;padding:0}.theme-step-heading h1{font-size:var(--text-md)}.theme-scroll{overscroll-behavior:contain;gap:12px;min-height:0;padding:2px;display:grid;overflow-y:auto}.theme-scroll legend{letter-spacing:.06em;text-transform:uppercase;margin-bottom:6px;font-size:11px}.theme-choices{grid-template-columns:repeat(3,minmax(0,1fr));gap:4px;padding:0;display:grid;overflow:visible}.theme-choices button{text-align:left;align-items:center;gap:4px;min-width:0;height:44px;min-height:44px;padding:0 5px;font-size:13px;font-weight:450;display:flex}.theme-choices .practice-icon{width:18px;height:18px}.theme-choices span{white-space:nowrap;letter-spacing:-.25px;font-size:13px}.theme-choices button[aria-pressed=true]{border-color:var(--brass);color:var(--brass);background:color-mix(in srgb, var(--brass) 12%, transparent)}.stats-shell.app-shell{height:auto;min-height:100dvh;padding-inline:max(16px, env(safe-area-inset-left)) max(16px, env(safe-area-inset-right));flex-direction:column;display:flex;overflow:visible}.stats-shell .topbar{flex-shrink:0;height:52px;padding:0}.stats-shell .site-footer{display:none}.stats-page{width:min(100%,1000px);margin:12px auto 32px}.stats-heading{align-items:center;gap:16px;margin-bottom:24px;display:flex}.stats-heading h1{font-size:var(--text-xl);margin:0}.stats-columns{grid-template-columns:minmax(0,1fr) minmax(0,1.5fr);gap:32px;display:grid}.stats-page h2{font-size:var(--text-lg)}.stats-summary,.stats-history{min-width:0}.stats-summary .scoresheet{max-height:280px;margin-top:24px}.stats-page .recent-practice{margin-bottom:24px}.stats-history .history-list{margin-top:12px}.stats-history button{overflow-wrap:anywhere}.compact-facts{flex:1;align-items:center;gap:8px;min-width:0;display:flex}.compact-facts dt{clip-path:inset(50%);width:1px;height:1px;position:absolute;overflow:hidden}.compact-facts dd{font-size:var(--text-xs);margin:0}.compact-facts>div{min-width:0}.compact-facts .puzzle-identity{order:3;max-width:96px;min-height:0}.compact-facts .puzzle-identity dd{padding:0}.compact-facts .puzzle-identity button{display:none}.compact-facts .puzzle-themes{flex:1}.compact-facts .puzzle-themes dd{scrollbar-width:none;flex-wrap:nowrap;max-height:32px;display:flex;overflow-x:auto}.compact-facts .puzzle-themes dd span{white-space:nowrap}.mobile-summary{min-height:0;width:var(--board-size);justify-self:center;container-type:size}.mobile-summary .session-strip{display:none}@container (height>=64px){.mobile-summary .session-strip{margin-top:8px;display:grid}}@media (width<=1023px),(orientation:portrait){.stacked-layout{grid-template-rows:auto minmax(0, 1fr) var(--prompt-height) auto}.stacked-layout .board-column{grid-row:1}.stacked-layout .mobile-summary{grid-row:2;align-self:stretch}.stacked-layout .turn-prompt{background:var(--canvas);grid-row:3;align-self:end;width:100%}.stacked-layout .panel-actions{grid-row:4}.home-menu{height:100%}.stats-columns{grid-template-columns:minmax(0,1fr);gap:16px}}@media (height<=700px){.home-menu{padding-block:4px}.practice-setup{gap:8px}.custom-setup{gap:4px}.theme-scroll{gap:8px}}@media (orientation:landscape) and (height<=540px) and (width>=520px){.home-menu{width:min(100%,900px)}.practice-title{height:32px}.practice-setup:not(.theme-setup){grid-template-rows:44px 24px minmax(0,1fr) auto;grid-template-columns:1fr 1.5fr;gap:4px 16px;display:grid}.practice-modes{grid-area:1/1}.mode-description{grid-area:2/1}.difficulty-field{grid-area:1/2/5}.rating-range{grid-area:3/1}.rating-note{grid-area:3/1;align-self:start;font-size:10px}.custom-setup .rating-note{display:none}.practice-start{grid-area:4/1;padding:0}.theme-setup{grid-template-rows:1fr auto;grid-template-columns:1fr 2fr;display:grid}.theme-step-heading{flex-direction:column;grid-column:1;align-self:start;align-items:start}.theme-scroll{grid-area:1/2/3}}