:root{
  --bg:#fafaf8; --ink:#1a1a1a; --muted:#6b6a63; --line:#d9d8d2;
  --tile:#efeee6; --tile-sel:#5a594e; --y:#f9df6d; --g:#a0c35a; --b:#b0c4ef; --p:#ba81c5;
  --max:560px;
}
*{box-sizing:border-box}
body{margin:0;font-family:-apple-system,Segoe UI,Roboto,Helvetica,Arial,sans-serif;background:var(--bg);color:var(--ink);line-height:1.55}
a{color:#3a6ea5;text-decoration:none}
a:hover{text-decoration:underline}

.site-header{display:flex;justify-content:space-between;align-items:center;max-width:var(--max);margin:0 auto;padding:16px 18px;border-bottom:1px solid var(--line)}
.brand{font-weight:800;font-size:1.25rem;color:var(--ink)}
.brand span{color:var(--muted);font-weight:600}
.site-header nav a{margin-left:16px;font-size:.9rem;font-weight:600}

main{max-width:var(--max);margin:0 auto;padding:18px}
.hero h1{font-size:1.55rem;line-height:1.25;margin:.4em 0 .2em}
.hero .sub{color:var(--muted);margin-top:0}

.modes{display:flex;gap:8px;margin:14px 0}
.mode-btn{flex:1;padding:10px;border:1px solid var(--line);background:#fff;border-radius:24px;font-weight:700;cursor:pointer}
.mode-btn.active{background:var(--ink);color:#fff;border-color:var(--ink)}

.game{margin:8px 0 28px}
.solved-groups{display:flex;flex-direction:column;gap:8px;margin-bottom:8px}
.solved-row{padding:12px;border-radius:8px;text-align:center;color:#1a1a1a}
.solved-row strong{display:block;text-transform:uppercase;letter-spacing:.5px;font-size:.85rem}
.solved-row span{font-size:.95rem}
.solved-row.y{background:var(--y)} .solved-row.g{background:var(--g)}
.solved-row.b{background:var(--b)} .solved-row.p{background:var(--p)}

.board{display:grid;grid-template-columns:repeat(4,1fr);gap:8px}
.tile{aspect-ratio:1.3/1;border:none;border-radius:8px;background:var(--tile);font-weight:700;font-size:clamp(.7rem,3.2vw,1rem);text-transform:uppercase;cursor:pointer;padding:4px;transition:transform .05s,background .15s}
.tile:hover{background:#e4e3da}
.tile.sel{background:var(--tile-sel);color:#fff;transform:scale(.96)}
.tile:disabled{cursor:default}

.mistakes{display:flex;align-items:center;justify-content:center;gap:10px;margin:18px 0;color:var(--muted);font-size:.9rem}
.dots{display:inline-flex;gap:8px}
.dot{width:14px;height:14px;border-radius:50%}
.dot.on{background:var(--tile-sel)} .dot.off{background:var(--line)}

.controls{display:flex;gap:10px;justify-content:center;flex-wrap:wrap}
.btn{padding:12px 20px;border:1px solid var(--ink);background:#fff;border-radius:24px;font-weight:700;cursor:pointer}
.btn:disabled{opacity:.35;cursor:default}
.btn.primary{background:var(--ink);color:#fff}

.message{text-align:center;min-height:1.4em;margin:14px 0 0;font-weight:700}
.message.win{color:#3a7d34} .message.near{color:#b8860b}
.message.miss{color:#b23b3b} .message.lose{color:#b23b3b} .message.win{color:#3a7d34}

.content{margin-top:30px;border-top:1px solid var(--line);padding-top:20px}
.content h2{font-size:1.2rem;margin-top:1.4em}
.content ol,.content ul{padding-left:1.2em}
.content li{margin:.35em 0}
.chip{display:inline-block;padding:1px 8px;border-radius:10px;font-size:.8rem;font-weight:700}
.chip.y{background:var(--y)} .chip.g{background:var(--g)} .chip.b{background:var(--b)} .chip.p{background:var(--p)}
details{border:1px solid var(--line);border-radius:8px;padding:10px 12px;margin:8px 0;background:#fff}
summary{font-weight:700;cursor:pointer}

.site-footer{max-width:var(--max);margin:0 auto;padding:22px 18px 40px;color:var(--muted);font-size:.85rem;text-align:center;border-top:1px solid var(--line)}
.site-footer a{margin:0 4px}

/* answer-page typography reuse */
.answer-body{max-width:var(--max);margin:0 auto;padding:18px}
.answer-body h2{margin-top:1.4em}
.answer-body h3{margin-top:1.1em}
.spoiler{background:#222;color:#222;border-radius:6px;padding:2px 6px;cursor:pointer;transition:color .2s}
.spoiler.show,.spoiler:hover{color:#fff}
table{width:100%;border-collapse:collapse;margin:12px 0}
th,td{border:1px solid var(--line);padding:8px;text-align:left;font-size:.95rem}
th{background:var(--tile)}
.note{background:#fff;border:1px solid var(--line);border-left:4px solid var(--p);border-radius:6px;padding:10px 12px;font-size:.92rem}
.op-note{color:var(--muted);font-size:.85rem;background:#fffbe6;border:1px dashed #e0d49a;border-radius:6px;padding:10px 12px}

/* multi-link nav */
.site-header nav{display:flex;flex-wrap:wrap;gap:0}

/* archive list */
.archive-list{list-style:none;padding:0;margin:14px 0}
.archive-list li{border:1px solid var(--line);border-radius:8px;margin:6px 0;background:#fff}
.archive-list a{display:flex;justify-content:space-between;padding:12px 14px;font-weight:600}
.archive-list a:hover{background:var(--tile);text-decoration:none}
.archive-list .puzzle-no{color:var(--muted);font-weight:600}

/* share-result card */
.share{margin:16px 0;text-align:center;border:1px solid var(--line);border-radius:10px;padding:14px;background:#fff}
.share pre{font-size:1.4rem;line-height:1.3;margin:6px 0;font-family:inherit;letter-spacing:2px}
.share .stats{color:var(--muted);font-size:.85rem;margin:8px 0}

/* ad slot box */
.ad-slot{margin:20px auto;max-width:var(--max);min-height:90px;display:flex;align-items:center;justify-content:center;border:1px dashed var(--line);color:var(--muted);font-size:.8rem;border-radius:8px}

/* cookie consent bar */
.cookie-bar{position:fixed;left:0;right:0;bottom:0;background:#1a1a1a;color:#f4f4f0;padding:14px 18px;display:flex;gap:12px;align-items:center;justify-content:center;flex-wrap:wrap;font-size:.85rem;z-index:50}
.cookie-bar a{color:#9ec1ec}
.cookie-bar button{padding:8px 18px;border:none;border-radius:20px;background:#f9df6d;color:#1a1a1a;font-weight:700;cursor:pointer}
.cookie-bar.hidden{display:none}