:root{--bg: #f6f7fb;--surface: #ffffff;--surface-2: #eef0f7;--text: #1c1f2e;--muted: #646b82;--border: #dde1ec;--primary: #4f46e5;--primary-text: #ffffff;--good: #16a34a;--bad: #dc2626;--radius: 16px;--shadow: 0 2px 10px rgba(20, 24, 50, .07);color-scheme:light}@media (prefers-color-scheme: dark){:root{--bg: #11131c;--surface: #1b1e2b;--surface-2: #262a3b;--text: #eef0f8;--muted: #9aa1b8;--border: #2f3447;--primary: #7c74ff;--good: #22c55e;--bad: #f87171;--shadow: 0 2px 12px rgba(0, 0, 0, .35);color-scheme:dark}}*{box-sizing:border-box}html,body{margin:0}body{background:var(--bg);color:var(--text);font-family:system-ui,-apple-system,Segoe UI,Roboto,sans-serif;line-height:1.5;-webkit-tap-highlight-color:transparent}button{font:inherit;color:inherit;touch-action:manipulation}a{color:inherit}.app{min-height:100dvh;display:flex;flex-direction:column}.site-header{position:sticky;top:0;z-index:10;background:var(--surface);border-bottom:1px solid var(--border);padding:10px 16px;padding-top:max(10px,env(safe-area-inset-top))}.brand{display:inline-flex;align-items:center;gap:10px;text-decoration:none;font-weight:700;font-size:1.05rem}.brand-badge{display:grid;place-items:center;width:32px;height:32px;border-radius:9px;background:var(--primary);color:var(--primary-text)}.site-main{flex:1;width:100%;max-width:960px;margin:0 auto;padding:16px}.site-footer{text-align:center;color:var(--muted);font-size:.85rem;padding:20px 16px calc(20px + env(safe-area-inset-bottom))}.hero{text-align:center;padding:16px 0 24px}.hero h1{margin:0 0 6px;font-size:clamp(1.8rem,6vw,2.6rem)}.hero p{margin:0;color:var(--muted)}.game-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(min(100%,210px),1fr));gap:14px}.game-card{position:relative;display:flex;flex-direction:column;gap:4px;padding:18px;background:var(--surface);border:1px solid var(--border);border-top:5px solid var(--accent);border-radius:var(--radius);box-shadow:var(--shadow);text-decoration:none;transition:transform .12s ease}.game-card:hover,.game-card:focus-visible{transform:translateY(-3px)}.game-card h2{margin:4px 0 0;font-size:1.25rem}.game-card p{margin:0;color:var(--muted);font-size:.95rem}.game-emoji{font-size:2.2rem;line-height:1}.game-skill{position:absolute;top:14px;right:14px;font-size:.72rem;font-weight:700;text-transform:uppercase;letter-spacing:.05em;color:var(--accent)}.game-best{margin-top:6px;font-size:.85rem;font-weight:600}.game-topbar{display:grid;grid-template-columns:auto 1fr auto;align-items:center;gap:12px;margin-bottom:16px}.game-topbar h1{margin:0;font-size:1.3rem;text-align:center}.back-link{text-decoration:none;color:var(--primary);font-weight:600;padding:6px 0}.game-stats{display:flex;gap:12px}.stat{display:flex;flex-direction:column;align-items:center;min-width:44px}.stat-label{font-size:.7rem;text-transform:uppercase;color:var(--muted);letter-spacing:.05em}.stat-value{font-weight:700;font-size:1.1rem;font-variant-numeric:tabular-nums}@media (max-width: 520px){.game-topbar{grid-template-columns:1fr auto}.game-topbar h1{grid-column:1 / -1;grid-row:2;text-align:left}}.panel{background:var(--surface);border:1px solid var(--border);border-radius:var(--radius);box-shadow:var(--shadow);padding:24px 16px}.center{display:flex;flex-direction:column;align-items:center;text-align:center;gap:14px}.lead{font-size:1.1rem;margin:0}.muted{color:var(--muted);margin:0}.row{display:flex;gap:10px;flex-wrap:wrap;justify-content:center}.btn{min-height:48px;padding:10px 20px;border-radius:12px;border:1px solid var(--border);background:var(--surface-2);font-weight:600;cursor:pointer;transition:transform .06s ease,filter .12s ease}.btn:active:not(:disabled){transform:scale(.96)}.btn:disabled{opacity:.5;cursor:default}.btn.primary{background:var(--primary);border-color:var(--primary);color:var(--primary-text)}.btn.big{font-size:1.2rem;padding:12px 40px}.segmented{display:inline-flex;flex-wrap:wrap;justify-content:center;background:var(--surface-2);border-radius:12px;padding:4px;gap:4px}.segmented button{border:0;background:transparent;padding:10px 12px;min-height:44px;border-radius:9px;white-space:nowrap;font-weight:600;cursor:pointer}.segmented button.active{background:var(--surface);box-shadow:var(--shadow);color:var(--primary)}.big-number{font-size:3.5rem;font-weight:800;margin:0;line-height:1}.badge{margin:0;padding:6px 14px;border-radius:999px;background:#fef3c7;color:#92400e;font-weight:700}.feedback{margin:0;font-weight:600;font-size:1.05rem}.feedback.good{color:var(--good)}.feedback.bad{color:var(--bad)}.math-play{display:flex;flex-direction:column;gap:16px;max-width:420px;margin:0 auto}.timer-bar{height:8px;background:var(--surface-2);border-radius:99px;overflow:hidden}.timer-bar div{height:100%;background:var(--primary);transition:width 1s linear}.problem{display:flex;justify-content:center;align-items:center;gap:14px;flex-wrap:wrap;font-size:clamp(2rem,10vw,3rem);font-weight:800;font-variant-numeric:tabular-nums;padding:20px 10px;background:var(--surface);border:2px solid var(--border);border-radius:var(--radius);transition:border-color .15s,background .15s}.problem.right{border-color:var(--good)}.problem.wrong{border-color:var(--bad);animation:shake .25s}.answer-box{min-width:2.5em;padding:0 10px;border-bottom:4px solid var(--primary);text-align:center;color:var(--primary)}.numpad{display:grid;grid-template-columns:repeat(3,1fr);gap:10px}.btn.pad{min-height:60px;font-size:1.5rem}@keyframes shake{25%{transform:translate(-6px)}75%{transform:translate(6px)}}.hint{margin:0;font-size:1.1rem}.slots,.tiles{display:flex;flex-wrap:wrap;justify-content:center;gap:8px}.tiles{min-height:56px}.tile{width:clamp(40px,10vw,54px);height:clamp(48px,12vw,60px);border-radius:10px;border:2px solid var(--border);background:var(--surface-2);font-size:1.5rem;font-weight:800;cursor:pointer}.tile.slot{background:var(--surface);border-style:dashed}.tile.slot:not(:disabled){border-style:solid;border-color:var(--primary)}.slots.right .tile.slot{border-color:var(--good);color:var(--good)}.slots.wrong .tile.slot{border-color:var(--bad);color:var(--bad)}.memory-controls{display:flex;flex-wrap:wrap;align-items:center;justify-content:space-between;gap:10px;margin-bottom:14px}.memory-grid{display:grid;gap:8px;max-width:560px;margin:0 auto}.memory-grid.cols-4{grid-template-columns:repeat(4,1fr)}.memory-grid.cols-6{grid-template-columns:repeat(6,1fr)}@media (max-width: 480px){.memory-grid.cols-6{grid-template-columns:repeat(4,1fr)}}.mem-card{aspect-ratio:1;padding:0;border:0;background:none;cursor:pointer;perspective:600px}.mem-inner{position:relative;display:block;width:100%;height:100%;transition:transform .35s;transform-style:preserve-3d}.mem-card.up .mem-inner{transform:rotateY(180deg)}.mem-front,.mem-back{position:absolute;top:0;right:0;bottom:0;left:0;display:grid;place-items:center;border-radius:12px;backface-visibility:hidden}.mem-front{background:var(--primary);color:var(--primary-text);font-size:clamp(1.4rem,6vw,2rem);font-weight:800}.mem-back{background:var(--surface);border:2px solid var(--border);transform:rotateY(180deg);font-size:clamp(1.8rem,8vw,2.8rem)}.mem-card.matched .mem-back{border-color:var(--good)}.fact-box{display:flex;flex-direction:column;align-items:center;gap:10px;text-align:center;max-width:560px;min-height:72px;margin:16px auto 0;padding:14px;background:var(--surface);border:1px solid var(--border);border-radius:var(--radius)}.quiz-prompt{font-size:clamp(1.6rem,7vw,2.2rem);font-weight:800;margin:0}.choices{display:grid;grid-template-columns:repeat(auto-fit,minmax(min(100%,200px),1fr));gap:10px;width:100%;max-width:480px}.btn.choice.correct{background:var(--good);border-color:var(--good);color:#fff;opacity:1}.btn.choice.incorrect{background:var(--bad);border-color:var(--bad);color:#fff;opacity:1}.btn.choice.dim{opacity:.45}.review{width:100%;max-width:420px;text-align:left}.review ul{margin:6px 0 0;padding-left:20px}.counting{padding:12px;background:var(--surface);border:1px solid var(--border);border-radius:var(--radius);text-align:center}.count-groups{display:flex;align-items:center;justify-content:center;gap:10px}.count-group{display:grid;justify-content:center;gap:2px 4px;padding:6px 8px;border-radius:12px;background:var(--surface-2);font-size:clamp(1.6rem,7vw,2.2rem);line-height:1.2}.count-group .gone{position:relative}.count-group .gone>span{opacity:.35}.count-group .gone:after{content:"✕";position:absolute;top:0;right:0;bottom:0;left:0;display:grid;place-items:center;color:var(--bad);font-weight:900}.count-op{font-size:2rem;font-weight:800}.count-caption{margin:8px 0 0;color:var(--muted);font-weight:600}