:root{--lightningcss-light:initial;--lightningcss-dark: ;color-scheme:light;--bg:#fef7ff;--surface:#fffaff;--surface-high:#eeeaf3;--text:#1b1b21;--muted:#5b5d72;--primary:#4752c4;--on-primary:#fff;--primary-container:#dee0ff;--border:#c7c5d4;--error:#ba1a1a;background:var(--bg);color:var(--text);font-family:system-ui,-apple-system,BlinkMacSystemFont,Segoe UI,sans-serif}:root[data-theme=dark]{--lightningcss-light: ;--lightningcss-dark:initial;color-scheme:dark;--bg:#131318;--surface:#1d1d25;--surface-high:#2b2b37;--text:#e4e1e9;--muted:#c4c5dd;--primary:#bac3ff;--on-primary:#121f8f;--primary-container:#2e39ab;--border:#585868;--error:#ffb4ab}body[data-game=chess],body[data-game=backgammon],body[data-game=reversi]{--bg:#fff8f4;--surface:#fffaf7;--surface-high:#f1e5db;--text:#211a14;--muted:#735943;--primary:#8b5a2b;--on-primary:#fff;--primary-container:#ffdcbb;--border:#cdbbac}:root[data-theme=dark] body[data-game=chess],:root[data-theme=dark] body[data-game=backgammon],:root[data-theme=dark] body[data-game=reversi]{--bg:#18120d;--surface:#231c15;--surface-high:#342a21;--text:#ede0d4;--muted:#e2c0a4;--primary:#ffb77c;--on-primary:#4b2900;--primary-container:#6a3e03;--border:#6e5847}*{box-sizing:border-box}body{background:var(--bg);min-width:280px;min-height:100svh;color:var(--text);margin:0}button,select,input,textarea{font:inherit;color:inherit}button,select,input{min-height:44px}button,select{border:1px solid var(--border);background:var(--surface);border-radius:12px;padding:10px 14px}button{cursor:pointer;touch-action:manipulation}button:hover:not(:disabled),select:hover{background:var(--surface-high)}button:disabled{opacity:.48;cursor:default}input,textarea{border:1px solid var(--border);background:var(--surface);border-radius:10px;min-width:0;max-width:100%;padding:10px}textarea{resize:vertical;width:100%}a{color:var(--primary);text-underline-offset:.2em}:focus-visible{outline:3px solid var(--primary);outline-offset:3px}h1,h2,h3,p{margin-top:0}h1{letter-spacing:-.035em;margin:5px 0 0;font-size:clamp(24px,3.4vw,32px);font-weight:730}h2{font-size:21px}p{line-height:1.6}.app-header{flex-wrap:wrap;justify-content:space-between;align-items:center;gap:12px;max-width:1120px;margin:auto;padding:28px 20px 24px;display:flex}.brand{letter-spacing:.06em;color:var(--muted);font-size:12px;font-weight:650;text-decoration:none}.app-header nav{flex-wrap:wrap;align-items:center;gap:8px;display:flex}.app-header nav a{border-radius:12px;align-items:center;min-height:44px;padding:8px 12px;font-size:14px;font-weight:600;text-decoration:none;display:inline-flex}.app-header nav a:hover{background:var(--surface-high)}#theme{align-items:center;gap:8px;font-size:14px;display:flex}#theme>span:first-child{font-size:22px;line-height:1}#game{outline:none;max-width:1120px;margin:0 auto;padding:0 20px}.app-footer{max-width:1120px;padding:0 20px max(20px, env(safe-area-inset-bottom));color:var(--muted);flex-wrap:wrap;justify-content:space-between;align-items:center;gap:8px 20px;margin:28px auto 0;font-size:12px;display:flex}.text-button{color:var(--muted);background:0 0;border:0;padding:8px 0;font-size:12px}.card{background:var(--surface-high);border-radius:20px;padding:20px}.toolbar{flex-wrap:wrap;gap:8px;display:flex}.button-primary{background:var(--primary);color:var(--on-primary);border-color:#0000;font-weight:650}.button-primary:hover:not(:disabled){background:var(--primary);filter:brightness(.94)}dialog{color:var(--text);background:var(--surface);border:1px solid var(--border);border-radius:24px;width:min(540px,100% - 32px);max-height:calc(100svh - 48px);padding:28px;overflow-y:auto}dialog::backdrop{background:#0008}dialog form{text-align:right}dialog h2{font-size:24px}dialog p{color:var(--muted)}.skip-link{background:var(--surface);z-index:100;border-radius:10px;padding:14px;position:fixed;top:-100px;left:16px}.skip-link:focus{top:12px}.welcome{text-align:center;padding:45px 0 25px}.welcome h2{letter-spacing:-.04em;font-size:clamp(28px,4vw,40px)}.welcome p,.local-note{color:var(--muted)}.game-choices{grid-template-columns:repeat(3,minmax(0,1fr));gap:24px;margin:auto;display:grid}.game-choice{border:1px solid var(--border);color:var(--text);background:var(--surface);border-radius:24px;padding:32px;text-decoration:none}.game-choice:hover{background:var(--surface-high)}.game-choice h2{letter-spacing:-.03em;margin:20px 0 12px;font-size:26px}.game-choice p{color:var(--muted)}.choice-symbol{color:#2e1500;background:#f0d9b5;border-radius:22px;justify-content:center;align-items:center;width:100px;height:100px;font-family:Georgia,serif;font-size:74px;display:flex}.sudoku-symbol{color:#000f5c;text-align:center;white-space:pre;background:#dee0ff;font:600 23px/1.15 system-ui}.reversi-symbol{grid-template-columns:1fr 1fr;gap:6px;padding:18px;display:grid}.reversi-symbol span{aspect-ratio:1;background:#29211a;border:1px solid #62452c;border-radius:50%}.reversi-symbol span:first-child,.reversi-symbol span:last-child{background:#fff3dc}.minesweeper-symbol{color:#000f5c;background:#dee0ff;font-family:system-ui,sans-serif;font-size:62px}.choice-action{color:var(--primary);justify-content:space-between;margin-top:28px;font-weight:650;display:flex}.local-note{text-align:center;margin:28px 0;font-size:13px}@media (width<=900px){.game-choices{grid-template-columns:1fr;max-width:540px}}@media (width<=600px){.app-header{flex-wrap:wrap;padding:18px 12px}#game{padding:0 12px}.app-header nav{gap:0}.app-header nav a{padding:8px}.theme-label{display:none}#theme{padding:8px 11px}.app-footer{padding-left:12px;padding-right:12px}.game-choices{grid-template-columns:1fr;gap:16px}.game-choice{padding:24px}.welcome{padding:22px 4px 12px}}@media (prefers-reduced-motion:reduce){*,:before,:after{scroll-behavior:auto!important;transition:none!important;animation:none!important}}