:root{--lightningcss-light: ;--lightningcss-dark:initial;color-scheme:dark;--bg:#0c0f14;--bg-soft:#12171f;--surface:#171d27;--surface-2:#1e2633;--line:#f3e6c71a;--gold:#d4af37;--gold-2:#f0d78c;--cream:#f3e6c7;--text:#efe7d6;--muted:#9a917e;--good:#7dcea0;--warn:#e7b56a;--bad:#e07a6a;--board-light:#f0d9b5;--board-dark:#b58863;--hi-from:#f6e58d9e;--hi-to:#f6e58d6b;--hi-sel:#d4af3780;--hi-legal:#2ecc7147;--hi-check:#e74c3c7a;--safe-top:env(safe-area-inset-top,0px);--safe-bottom:env(safe-area-inset-bottom,0px);--nav-h:calc(64px + env(safe-area-inset-bottom,0px));background:var(--bg);color:var(--text);font-family:Outfit,system-ui,sans-serif;line-height:1.45}*{box-sizing:border-box}html,body,#root{min-height:100%}body{background:radial-gradient(1200px 600px at 50% -10%, #d4af3714, transparent 50%), var(--bg);-webkit-tap-highlight-color:transparent;margin:0}button,input{font:inherit}a{color:inherit;text-decoration:none}h1,h2,h3,.display{letter-spacing:-.03em;font-family:Outfit,system-ui,sans-serif;font-weight:600}.app-shell{min-height:100dvh;padding:calc(18px + var(--safe-top)) 16px calc(var(--nav-h) + 16px);max-width:720px;margin:0 auto}.topbar{justify-content:space-between;align-items:baseline;gap:12px;margin-bottom:18px;display:flex}.brand{color:var(--gold-2);font-family:Outfit,system-ui,sans-serif;font-size:1.35rem;font-weight:600}.brand span{color:var(--muted);margin-left:8px;font-family:Outfit,sans-serif;font-size:.78rem}.bottom-nav{height:var(--nav-h);padding:8px 10px var(--safe-bottom);-webkit-backdrop-filter:blur(16px);backdrop-filter:blur(16px);border-top:1px solid var(--line);z-index:20;background:#0c0f14eb;justify-content:space-around;display:flex;position:fixed;bottom:0;left:0;right:0}.nav-link{color:var(--muted);flex-direction:column;flex:1;align-items:center;gap:3px;padding:6px 0;font-size:.7rem;font-weight:500;display:flex}.nav-link svg{width:22px;height:22px}.nav-link.active{color:var(--gold-2)}.card{background:var(--surface);border:1px solid var(--line);border-radius:18px;padding:16px}.card+.card,.stack>*+*{margin-top:12px}.grid-2{grid-template-columns:1fr 1fr;gap:10px;display:grid}.muted{color:var(--muted)}.tiny{font-size:.78rem}.gold{color:var(--gold-2)}.btn{appearance:none;border:1px solid var(--line);background:var(--surface-2);color:var(--text);cursor:pointer;border-radius:12px;padding:11px 14px;font-weight:500}.btn.primary{color:#1a1406;background:linear-gradient(#e3c56a,#b8922a);border-color:#0000}.btn.ghost{background:0 0}.btn.wide{width:100%}.btn:disabled{opacity:.5}.chip{background:var(--surface-2);color:var(--muted);border:1px solid var(--line);border-radius:999px;align-items:center;padding:4px 9px;font-size:.72rem;display:inline-flex}.chip.gold{color:#1a1406;background:var(--gold);border-color:#0000}.hero h1{margin:8px 0 6px;font-size:2rem}.hero p{color:var(--muted);margin:0 0 16px}.stat{background:var(--surface-2);border-radius:14px;padding:12px}.stat b{font-family:Outfit,system-ui,sans-serif;font-size:1.3rem;display:block}.board-wrap{width:min(100%,560px);margin:0 auto;position:relative}.board{aspect-ratio:1;touch-action:none;-webkit-user-select:none;user-select:none;border-radius:10px;grid-template-rows:repeat(8,1fr);grid-template-columns:repeat(8,1fr);width:100%;display:grid;overflow:hidden;box-shadow:0 18px 40px #00000059}.sq{cursor:pointer;border:0;justify-content:center;align-items:center;padding:0;display:flex;position:relative}.sq.light{background:var(--board-light)}.sq.dark{background:var(--board-dark)}.sq.from{background:var(--hi-from)}.sq.to{background:var(--hi-to)}.sq.sel{box-shadow:inset 0 0 0 3px var(--hi-sel)}.sq.check{background:var(--hi-check)}.sq.mark{box-shadow:inset 0 0 0 3px #5dade2cc}.coord{opacity:.55;pointer-events:none;font-size:9px;font-weight:600;position:absolute}.coord.file{bottom:2px;right:3px}.coord.rank{top:2px;left:3px}.piece{pointer-events:none;filter:drop-shadow(0 2px 2px #00000040);width:86%;height:86%}.dot,.ring{pointer-events:none;position:absolute}.dot{background:#14141447;border-radius:50%;width:28%;height:28%}.ring{border:6px solid #14141438;border-radius:50%;inset:6%}.board-overlay{pointer-events:none;position:absolute;inset:0}.promo{background:#0c0f149e;justify-content:center;align-items:center;gap:8px;display:flex;position:absolute;inset:0}.promo button{background:var(--cream);border:0;border-radius:12px;width:56px;height:56px;padding:6px}.row-actions{flex-wrap:wrap;gap:8px;margin-top:12px;display:flex}.row-actions .btn{flex:1;min-width:90px}.move-log{font-variant-numeric:tabular-nums;max-height:88px;color:var(--muted);font-size:.88rem;overflow:auto}.lesson-progress{background:var(--surface-2);border-radius:99px;height:6px;margin:8px 0 14px;overflow:hidden}.lesson-progress>i{background:linear-gradient(90deg,#b8922a,#f0d78c);height:100%;display:block}.list-item{background:var(--surface);border:1px solid var(--line);border-radius:16px;align-items:flex-start;gap:12px;padding:14px;display:flex}.list-item+.list-item{margin-top:10px}.list-item h3{margin:0 0 4px;font-size:1.05rem}.tabs{gap:8px;padding-bottom:8px;display:flex;overflow-x:auto}.search{border:1px solid var(--line);background:var(--surface);width:100%;color:var(--text);border-radius:12px;margin-bottom:12px;padding:12px 14px}select.search{appearance:none;background-image:linear-gradient(45deg, transparent 50%, var(--gold) 50%), linear-gradient(135deg, var(--gold) 50%, transparent 50%);background-position:calc(100% - 18px) calc(50% - 3px),calc(100% - 13px) calc(50% - 3px);background-repeat:no-repeat;background-size:5px 5px,5px 5px;padding-right:32px}.banner{background:var(--surface-2);border-radius:14px;padding:12px 14px}.banner.good{color:var(--good);background:#7dcea01f}.banner.bad{color:var(--bad);background:#e07a6a1f}.banner.warn{color:var(--warn);background:#e7b56a1f}ul.plain{color:var(--muted);margin:8px 0 0;padding-left:18px}.back{color:var(--gold-2);margin-bottom:10px;font-size:.9rem;display:inline-block}.status-line{min-height:1.4em;color:var(--cream);margin:10px 0 0}.diff-scroll{-webkit-overflow-scrolling:touch;scrollbar-width:none;gap:8px;margin:0 -16px 8px;padding:0 16px 12px;display:flex;overflow-x:auto}.diff-scroll::-webkit-scrollbar{display:none}.diff-card{text-align:left;border:1px solid var(--line);background:var(--surface);color:var(--text);cursor:pointer;border-radius:14px;flex:0 0 148px;padding:10px 12px}.diff-card strong{font-size:.92rem;display:block}.diff-card span{color:var(--gold-2);margin:2px 0 6px;font-size:.72rem;display:block}.diff-card em{color:var(--muted);font-size:.7rem;font-style:normal;line-height:1.35;display:block}.diff-card.active{border-color:var(--gold);background:#d4af371f}.tree-branch{text-align:left;cursor:pointer;width:100%;font:inherit;color:inherit}.tree-branch.good-pick{border-color:var(--good)}textarea.search{resize:vertical;min-height:96px}.wd-bar{background:var(--surface-2);border-radius:99px;height:6px;display:flex;overflow:hidden}.wd-bar i{height:100%;display:block}.wd-bar .w{background:var(--good)}.wd-bar .d{background:var(--muted)}.wd-bar .l{background:var(--bad)}.eval-graph{background:var(--surface);border-radius:12px;align-items:flex-end;gap:2px;height:56px;margin:12px 0;padding:8px 4px 0;display:flex;overflow:hidden}.eval-graph i{border-radius:2px 2px 0 0;flex:1;min-width:2px}.eval-graph .up{background:var(--good)}.eval-graph .down{background:var(--bad)}.move-grades{flex-wrap:wrap;gap:6px;margin:12px 0;display:flex}.grade-chip{border:1px solid var(--line);background:var(--surface);color:var(--text);font:inherit;cursor:pointer;border-radius:999px;padding:4px 10px;font-size:.82rem}.grade-chip.on{border-color:var(--gold)}.grade-brilliant{color:#7ec8e3}.grade-great,.grade-best{color:var(--good)}.grade-good{color:var(--cream)}.grade-inacc{color:var(--warn)}.grade-mistake,.grade-blunder{color:var(--bad)}