:root{--bg:#f4f6fb;--surface:#fff;--surface-2:#eef1f8;--border:#d9dee9;--border-strong:#334155;--text:#1f2937;--text-soft:#5b6472;--text-faint:#8b93a3;--primary:#2f6df6;--primary-soft:#dce8ff;--primary-dark:#1b4fd1;--accent:#0ea5a4;--danger:#e23d4b;--danger-soft:#fde4e6;--success:#16a34a;--given:#1f2937;--entered:#2f6df6;--highlight:#e8f0ff;--highlight-peer:#f0f4fc;--highlight-same:#cfe0ff;--shadow:0 1px 3px rgba(16,24,40,.08),0 1px 2px rgba(16,24,40,.04);--shadow-lg:0 12px 32px rgba(16,24,40,.12);--radius:14px;--radius-sm:9px;--maxw:1120px;--font:"Segoe UI",system-ui,-apple-system,"Helvetica Neue",Arial,sans-serif}@media (prefers-color-scheme:dark){:root{--bg:#11151c;--surface:#1a1f28;--surface-2:#222835;--border:#2d3543;--border-strong:#c3cbd9;--text:#e8ecf3;--text-soft:#a9b2c2;--text-faint:#6f7a8c;--primary:#5b8bff;--primary-soft:#223154;--primary-dark:#7aa2ff;--accent:#2dd4bf;--danger:#ff6b76;--danger-soft:#3a1f24;--success:#4ade80;--given:#e8ecf3;--entered:#7aa2ff;--highlight:#1f2b44;--highlight-peer:#1b2230;--highlight-same:#2a3a5e;--shadow:0 1px 3px rgba(0,0,0,.4);--shadow-lg:0 12px 32px rgba(0,0,0,.5)}}*{box-sizing:border-box}body,html{padding:0;margin:0;background:var(--bg);color:var(--text);font-family:var(--font);-webkit-font-smoothing:antialiased;text-rendering:optimizeLegibility;line-height:1.6}a{color:var(--primary);text-decoration:none}a:hover{text-decoration:underline}h1,h2,h3,h4{color:var(--text);line-height:1.25;margin:0 0 .5em}p{margin:0 0 1em}.container{width:100%;max-width:var(--maxw);margin:0 auto;padding:0 20px}.site-header{position:-webkit-sticky;position:sticky;top:0;z-index:50;background:var(--surface);border-bottom:1px solid var(--border);-webkit-backdrop-filter:saturate(180%) blur(6px);backdrop-filter:saturate(180%) blur(6px)}.header-inner{justify-content:space-between;height:64px;gap:16px}.brand,.header-inner{display:flex;align-items:center}.brand{gap:10px;font-weight:800;font-size:1.3rem;color:var(--text);letter-spacing:-.02em}.brand:hover{text-decoration:none}.brand-mark{display:inline-grid;place-items:center;width:34px;height:34px;border-radius:9px;background:var(--primary);color:#fff;font-weight:800;font-size:1.05rem}.brand-mark span{transform:translateY(-1px)}.nav{display:flex;align-items:center;gap:4px}.nav a{color:var(--text-soft);font-size:.94rem;font-weight:600;padding:8px 12px;border-radius:8px}.nav a:hover{background:var(--surface-2);color:var(--text);text-decoration:none}.nav-toggle{display:none;background:none;border:1px solid var(--border);border-radius:8px;padding:8px 10px;cursor:pointer;color:var(--text)}@media (max-width:860px){.nav{display:none;position:absolute;top:64px;left:0;right:0;flex-direction:column;align-items:stretch;background:var(--surface);border-bottom:1px solid var(--border);padding:8px 16px 16px;gap:2px}.nav.open{display:flex}.nav a{padding:12px}.nav-toggle{display:inline-flex}}.site-footer{margin-top:56px;background:var(--surface);border-top:1px solid var(--border);padding:40px 0 28px;color:var(--text-soft);font-size:.92rem}.footer-grid{display:grid;grid-template-columns:1.4fr 1fr 1fr;grid-gap:32px;gap:32px}.footer-grid h4{font-size:.82rem;text-transform:uppercase;letter-spacing:.06em;color:var(--text-faint);margin-bottom:14px}.footer-links{list-style:none;padding:0;margin:0;display:flex;flex-direction:column;gap:9px}.footer-links a{color:var(--text-soft)}.footer-bottom{margin-top:32px;padding-top:20px;border-top:1px solid var(--border);display:flex;justify-content:space-between;flex-wrap:wrap;gap:10px;font-size:.86rem;color:var(--text-faint)}@media (max-width:720px){.footer-grid{grid-template-columns:1fr 1fr;gap:24px}}@media (max-width:460px){.footer-grid{grid-template-columns:1fr}}.game-layout{display:grid;grid-template-columns:minmax(0,560px) 300px;grid-gap:28px;gap:28px;align-items:start;justify-content:center;padding:28px 0 8px}@media (max-width:920px){.game-layout{grid-template-columns:minmax(0,560px)}}.game-main{width:100%}.game-topbar{align-items:center;justify-content:space-between;gap:10px;margin-bottom:14px}.game-topbar,.stat-group{display:flex;flex-wrap:wrap}.stat-group{gap:18px}.stat{display:flex;flex-direction:column;font-size:.74rem;color:var(--text-faint);text-transform:uppercase;letter-spacing:.04em}.stat b{font-size:1.05rem;color:var(--text);font-feature-settings:"tnum";font-variant-numeric:tabular-nums;letter-spacing:0;text-transform:none}.stat.danger b{color:var(--danger)}.difficulty-bar{display:flex;flex-wrap:wrap;gap:6px;margin-bottom:16px}.difficulty-bar button{border:1px solid var(--border);background:var(--surface);color:var(--text-soft);font-weight:600;font-size:.85rem;padding:7px 13px;border-radius:999px;cursor:pointer;transition:all .12s ease}.difficulty-bar button:hover{border-color:var(--primary);color:var(--primary)}.difficulty-bar button.active{background:var(--primary);border-color:var(--primary);color:#fff}.board-wrap{position:relative;background:var(--surface);border-radius:var(--radius);box-shadow:var(--shadow);padding:12px}.board{display:grid;grid-template-columns:repeat(9,1fr);aspect-ratio:1/1;width:100%;border:2.5px solid var(--border-strong);border-radius:6px;overflow:hidden;background:var(--border);grid-gap:1px;gap:1px}.cell{position:relative;background:var(--surface);display:grid;place-items:center;font-size:clamp(1.1rem,4.6vw,1.9rem);font-weight:600;color:var(--entered);cursor:pointer;-webkit-user-select:none;-moz-user-select:none;user-select:none;transition:background .1s ease}.cell.given{color:var(--given);font-weight:700}.cell.peer{background:var(--highlight-peer)}.cell.same-value{background:var(--highlight-same)}.cell.selected{background:var(--highlight);box-shadow:inset 0 0 0 2px var(--primary);z-index:2}.cell.conflict{color:var(--danger)}.cell.conflict.selected{box-shadow:inset 0 0 0 2px var(--danger)}.cell:nth-child(3n):not(:nth-child(9n)){border-right:2px solid var(--border-strong)}.board>.cell:nth-child(n+19):nth-child(-n+27),.board>.cell:nth-child(n+46):nth-child(-n+54){border-bottom:2px solid var(--border-strong)}.cell-notes{display:grid;grid-template-columns:repeat(3,1fr);width:100%;height:100%;padding:2px}.cell-note{display:grid;place-items:center;font-size:clamp(.5rem,1.7vw,.72rem);font-weight:600;color:var(--text-faint);line-height:1}.controls{margin-top:18px}.action-row{display:grid;grid-template-columns:repeat(5,1fr);grid-gap:8px;gap:8px;margin-bottom:14px}.action-btn{display:flex;flex-direction:column;align-items:center;gap:3px;background:var(--surface);border:1px solid var(--border);border-radius:var(--radius-sm);padding:10px 4px;cursor:pointer;color:var(--text-soft);font-size:.74rem;font-weight:600;transition:all .12s ease}.action-btn:hover:not(:disabled){border-color:var(--primary);color:var(--primary)}.action-btn:disabled{opacity:.4;cursor:not-allowed}.action-btn .ico{font-size:1.25rem;line-height:1}.action-btn .badge{position:absolute;margin-top:-8px;margin-left:22px;border-radius:999px;font-size:.6rem;padding:1px 5px}.action-btn .badge,.action-btn.on{background:var(--primary);color:#fff}.action-btn.on{border-color:var(--primary)}.keypad{display:grid;grid-template-columns:repeat(9,1fr);grid-gap:7px;gap:7px}@media (max-width:420px){.keypad{grid-template-columns:repeat(5,1fr)}}.key{position:relative;aspect-ratio:1/1.15;border:1px solid var(--border);background:var(--surface);color:var(--primary);border-radius:var(--radius-sm);font-size:1.5rem;font-weight:600;cursor:pointer;transition:all .1s ease}.key:hover:not(:disabled){background:var(--primary-soft)}.key:disabled{opacity:.3;cursor:not-allowed}.key .count{position:absolute;bottom:3px;left:0;right:0;font-size:.6rem;font-weight:600;color:var(--text-faint)}.side-panel{display:flex;flex-direction:column;gap:18px}.panel-card{background:var(--surface);border:1px solid var(--border);border-radius:var(--radius);padding:18px;box-shadow:var(--shadow)}.panel-card h3{font-size:.78rem;text-transform:uppercase;letter-spacing:.05em;color:var(--text-faint);margin-bottom:12px}.btn{display:inline-flex;align-items:center;justify-content:center;gap:8px;background:var(--primary);color:#fff;border:none;border-radius:var(--radius-sm);padding:11px 18px;font-size:.95rem;font-weight:700;cursor:pointer;width:100%;transition:background .12s ease}.btn:hover{background:var(--primary-dark)}.btn.secondary{background:var(--surface-2);color:var(--text)}.btn.secondary:hover{background:var(--border)}.ad-slot{display:flex;align-items:center;justify-content:center;min-height:90px;background:var(--surface-2);border:1px dashed var(--border);border-radius:var(--radius-sm);color:var(--text-faint);font-size:.72rem;text-transform:uppercase;letter-spacing:.08em}.ad-slot.tall{min-height:250px}.overlay{position:absolute;inset:0;display:grid;place-items:center;background:rgba(16,24,40,.55);z-index:20;padding:20px}.overlay,.overlay-card{border-radius:var(--radius)}.overlay-card{background:var(--surface);padding:28px 26px;text-align:center;max-width:320px;box-shadow:var(--shadow-lg)}.overlay-card .emoji{font-size:2.6rem}.overlay-card h2{margin:8px 0 4px}.overlay-card p{color:var(--text-soft);margin-bottom:18px}.loading-spinner{width:34px;height:34px;border:3px solid var(--border);border-top-color:var(--primary);border-radius:50%;animation:spin .8s linear infinite}@keyframes spin{to{transform:rotate(1turn)}}.board-loading{position:absolute;inset:0;display:grid;place-items:center;background:var(--surface);border-radius:var(--radius);z-index:15}.page{padding:36px 0 10px}.page-narrow{max-width:760px;margin:0 auto}.page h1{font-size:clamp(1.7rem,4vw,2.4rem);letter-spacing:-.02em}.page .lead{font-size:1.12rem;color:var(--text-soft);margin-bottom:28px}.page h2{font-size:1.4rem;margin-top:36px}.page h3{font-size:1.12rem;margin-top:24px}.page ol,.page ul{margin:0 0 1em;padding-left:1.3em}.page li{margin-bottom:.5em}.breadcrumb{margin-bottom:14px}.breadcrumb,.meta-note{font-size:.85rem;color:var(--text-faint)}.meta-note{border-top:1px solid var(--border);padding-top:16px;margin-top:36px}.hero{text-align:center;padding:10px 0 4px}.hero h1{font-size:clamp(1.8rem,4.5vw,2.6rem);letter-spacing:-.03em;margin-bottom:8px}.hero p{color:var(--text-soft);max-width:620px;margin:0 auto;font-size:1.05rem}.feature-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(220px,1fr));grid-gap:18px;gap:18px;margin:28px 0}.feature{background:var(--surface);border:1px solid var(--border);border-radius:var(--radius);padding:22px}.feature .fico{font-size:1.6rem;margin-bottom:8px}.feature h3{font-size:1.05rem;margin:0 0 6px}.feature p{color:var(--text-soft);font-size:.94rem;margin:0}.contact-form{gap:14px;background:var(--surface);border:1px solid var(--border);border-radius:var(--radius);padding:24px}.contact-form,.contact-form label{display:flex;flex-direction:column}.contact-form label{font-weight:600;font-size:.9rem;gap:6px}.contact-form input,.contact-form textarea{font-family:inherit;font-size:.95rem;padding:11px 13px;border:1px solid var(--border);border-radius:var(--radius-sm);background:var(--bg);color:var(--text)}.contact-form input:focus,.contact-form textarea:focus{outline:none;border-color:var(--primary)}.form-note{font-size:.85rem;padding:11px 13px;border-radius:var(--radius-sm);background:var(--primary-soft);color:var(--text)}.visually-hidden{position:absolute;width:1px;height:1px;padding:0;margin:-1px;overflow:hidden;clip:rect(0,0,0,0);white-space:nowrap;border:0}.post-list{display:flex;flex-direction:column;gap:16px;margin-top:8px}.post-card{display:block;background:var(--surface);border:1px solid var(--border);border-radius:var(--radius);padding:22px 24px;color:var(--text);box-shadow:var(--shadow);transition:border-color .12s ease,transform .12s ease}.post-card:hover{text-decoration:none;border-color:var(--primary);transform:translateY(-2px)}.post-card h2{font-size:1.25rem;margin:0 0 8px}.post-card p{color:var(--text-soft);font-size:.96rem;margin:0 0 12px}.post-card-meta{font-size:.84rem;color:var(--text-faint)}.post-card-tags{display:flex;flex-wrap:wrap;gap:6px;margin-bottom:10px}.tag{display:inline-block;font-size:.72rem;font-weight:700;text-transform:uppercase;letter-spacing:.04em;color:var(--primary);background:var(--primary-soft);padding:3px 9px;border-radius:999px}.cta-box{background:var(--surface-2);border:1px solid var(--border);border-radius:var(--radius);padding:26px;text-align:center;margin:36px 0}.cta-box h3{margin:0 0 6px;font-size:1.15rem}.cta-box p{color:var(--text-soft);margin:0 0 16px}