/* Sudoku - Style */
:root{--bg:#f5f6fa;--card:#fff;--text:#1a1a2e;--muted:#6c7293;--accent:#4361ee;--accent2:#3f37c9;--border:#e0e0e8;--green:#2ecc71;--red:#e74c3c;--blue:#3498db;--given:#2c3e50;--shadow:0 2px 12px rgba(0,0,0,.08)}
[data-theme="dark"]{--bg:#1a1a2e;--card:#16213e;--text:#e8e8f0;--muted:#8b8ba7;--accent:#4361ee;--accent2:#5b6cff;--border:#2a2a4a;--given:#aabbdd;--shadow:0 2px 12px rgba(0,0,0,.3)}
*{margin:0;padding:0;box-sizing:border-box}
body{font-family:'Segoe UI',system-ui,-apple-system,sans-serif;background:var(--bg);color:var(--text);line-height:1.6;transition:background .3s,color .3s}
.wrap{max-width:960px;margin:0 auto;padding:16px}
header{display:flex;justify-content:space-between;align-items:center;padding:12px 0;flex-wrap:wrap;gap:8px}
.logo{font-size:1.6rem;font-weight:800;color:var(--accent);display:flex;align-items:center;gap:6px;text-decoration:none}
.logo svg{width:32px;height:32px}
.lang-sel{position:relative}
.lang-btn{background:var(--card);border:1px solid var(--border);color:var(--text);padding:6px 14px;border-radius:8px;cursor:pointer;font-size:.9rem;display:flex;align-items:center;gap:4px}
.lang-menu{display:none;position:absolute;right:0;top:100%;background:var(--card);border:1px solid var(--border);border-radius:8px;box-shadow:var(--shadow);z-index:100;min-width:140px;overflow:hidden}
.lang-menu a{display:block;padding:8px 16px;color:var(--text);text-decoration:none;font-size:.9rem}
.lang-menu a:hover{background:var(--bg)}
.lang-sel:hover .lang-menu{display:block}
.theme-btn{background:var(--card);border:1px solid var(--border);color:var(--text);width:38px;height:38px;border-radius:8px;cursor:pointer;font-size:1.1rem;display:flex;align-items:center;justify-content:center}
.hero{text-align:center;padding:20px 0}
.hero h1{font-size:2rem;margin-bottom:6px}
.hero p{color:var(--muted);font-size:1.05rem;max-width:640px;margin:0 auto}
.game-area{background:var(--card);border-radius:16px;box-shadow:var(--shadow);padding:20px;margin:20px 0}
.controls{display:flex;gap:8px;flex-wrap:wrap;justify-content:center;margin-bottom:16px}
.btn{background:var(--accent);color:#fff;border:none;padding:8px 18px;border-radius:8px;cursor:pointer;font-size:.9rem;font-weight:600;transition:opacity .2s}
.btn:hover{opacity:.85}
.btn.secondary{background:var(--card);color:var(--text);border:1px solid var(--border)}
.btn.active{background:var(--accent2)}
.diff-row{display:flex;gap:6px;justify-content:center;margin-bottom:12px}
.diff-btn{background:var(--card);color:var(--muted);border:1px solid var(--border);padding:6px 16px;border-radius:6px;cursor:pointer;font-size:.85rem;font-weight:600}
.diff-btn.active{background:var(--accent);color:#fff;border-color:var(--accent)}
#board-wrap{display:flex;justify-content:center;margin:16px 0}
#sudoku-canvas{border:2px solid var(--accent);border-radius:8px;cursor:pointer;max-width:100%;height:auto;background:var(--card);touch-action:none}
.numpad{display:grid;grid-template-columns:repeat(9,1fr);gap:4px;max-width:450px;margin:12px auto}
.numpad button{aspect-ratio:1;background:var(--card);border:1px solid var(--border);color:var(--text);font-size:1.3rem;font-weight:700;border-radius:6px;cursor:pointer;transition:background .15s}
.numpad button:hover{background:var(--bg)}
.numpad button.done{opacity:.35}
.action-row{display:flex;gap:8px;justify-content:center;flex-wrap:wrap;margin-top:12px}
.action-btn{background:var(--card);border:1px solid var(--border);color:var(--text);padding:8px 14px;border-radius:8px;cursor:pointer;font-size:.85rem;display:flex;align-items:center;gap:4px}
.action-btn.active{background:var(--accent);color:#fff;border-color:var(--accent)}
.stats{display:flex;gap:20px;justify-content:center;margin:12px 0;font-size:.95rem;color:var(--muted)}
.stats span{font-weight:600;color:var(--text)}
.msg{text-align:center;font-size:.9rem;padding:6px;border-radius:6px;margin:8px 0;display:none}
.msg.show{display:block}
.msg.err{background:rgba(231,76,60,.15);color:var(--red)}
.msg.ok{background:rgba(46,204,113,.15);color:var(--green)}
.highlights{display:grid;grid-template-columns:repeat(auto-fit,minmax(260px,1fr));gap:16px;margin:24px 0}
.card{background:var(--card);border-radius:12px;box-shadow:var(--shadow);padding:20px;transition:transform .2s}
.card:hover{transform:translateY(-2px)}
.card h3{font-size:1.05rem;color:var(--accent);margin-bottom:6px}
.card p{color:var(--muted);font-size:.9rem}
.faq{margin:24px 0}
.faq details{background:var(--card);border-radius:8px;box-shadow:var(--shadow);margin-bottom:8px;padding:14px 18px;cursor:pointer}
.faq summary{font-weight:600;font-size:.95rem}
.faq details[open] summary{color:var(--accent)}
.faq p{margin-top:8px;color:var(--muted);font-size:.9rem}
footer{text-align:center;padding:24px 0;color:var(--muted);font-size:.85rem}
footer a{color:var(--accent);text-decoration:none;margin:0 8px}
.cookie{position:fixed;bottom:0;left:0;right:0;background:var(--card);border-top:1px solid var(--border);padding:12px 20px;display:flex;justify-content:space-between;align-items:center;flex-wrap:wrap;gap:8px;z-index:200;box-shadow:0 -2px 12px rgba(0,0,0,.1)}
.cookie.hidden{display:none}
.cookie p{font-size:.85rem;color:var(--muted);margin:0}
.cookie button{background:var(--accent);color:#fff;border:none;padding:6px 16px;border-radius:6px;cursor:pointer;font-size:.85rem}
@media(max-width:600px){.hero h1{font-size:1.4rem}.numpad{max-width:100%}.numpad button{font-size:1rem}.stats{gap:12px;font-size:.85rem}.action-row{gap:4px}.action-btn{padding:6px 10px;font-size:.8rem}}