:root{
  --bg:#f6f1e8;
  --panel:#fffaf1;
  --ink:#2c241b;
  --muted:#74685c;
  --accent:#825f3b;
  --accent2:#d8a45f;
  --green:#2f6b4f;
  --shadow:0 14px 40px rgba(60,40,20,.13);
  --radius:22px;
}
*{box-sizing:border-box}
body{
  margin:0;
  font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  color:var(--ink);
  background:
    radial-gradient(circle at top left, rgba(216,164,95,.28), transparent 35%),
    linear-gradient(135deg,#f6f1e8,#efe3d0);
  min-height:100vh;
}
header,main,footer{width:min(1100px,94vw);margin:auto}
header{
  display:flex;justify-content:space-between;align-items:center;gap:16px;
  padding:28px 0 16px;
}
.eyebrow{letter-spacing:.12em;text-transform:uppercase;color:var(--accent);font-weight:700;margin:0 0 4px}
h1{margin:0;font-size:clamp(28px,5vw,48px)}
.lead{color:var(--muted);margin:8px 0 0}
.tabs{
  width:min(1100px,94vw);margin:10px auto 18px;
  display:grid;grid-template-columns:repeat(5,1fr);gap:10px;
}
button{
  border:0;border-radius:999px;padding:12px 16px;
  font-weight:700;cursor:pointer;background:var(--accent);color:white;
  box-shadow:0 5px 14px rgba(80,50,20,.18);
}
button:active{transform:translateY(1px)}
.tab{background:#fffaf1;color:var(--ink);border:1px solid rgba(80,50,20,.12)}
.tab.active{background:var(--ink);color:white}
.ghost{background:transparent;color:var(--accent);border:1px solid rgba(130,95,59,.35);box-shadow:none}
.game{
  display:none;background:rgba(255,250,241,.86);border:1px solid rgba(90,60,30,.12);
  padding:20px;border-radius:var(--radius);box-shadow:var(--shadow);backdrop-filter:blur(8px);
}
.game.active{display:block}
.gameHead{display:flex;align-items:center;justify-content:space-between;gap:16px;margin-bottom:12px}
.gameHead h2{margin:0 0 6px;font-size:26px}
.gameHead p{margin:0;color:var(--muted)}
.status{
  background:#fff;border:1px solid rgba(80,50,20,.12);border-radius:16px;
  padding:12px 14px;margin:12px 0 16px;font-weight:700;color:#493525;
}
.board{margin:auto;touch-action:manipulation}
.othelloBoard{
  width:min(88vw,520px);height:min(88vw,520px);
  display:grid;grid-template-columns:repeat(8,1fr);gap:4px;padding:8px;
  background:#263f32;border-radius:18px;
}
.cell{
  display:flex;align-items:center;justify-content:center;user-select:none;
  border-radius:10px;background:#39805c;position:relative;
}
.disc{width:72%;height:72%;border-radius:50%;box-shadow:inset 0 3px 4px rgba(255,255,255,.25), inset 0 -6px 10px rgba(0,0,0,.25)}
.black{background:#171717}.white{background:#f4efe8}
.hint::after{content:"";width:24%;height:24%;background:rgba(255,255,255,.45);border-radius:50%}
.gomokuBoard{
  width:min(92vw,620px);height:min(92vw,620px);
  display:grid;grid-template-columns:repeat(15,1fr);gap:2px;padding:8px;background:#d5a35d;border-radius:16px;
}
.gomokuBoard .cell{background:#e5bd79;border-radius:5px}
.connect4Board{
  width:min(92vw,560px);display:grid;grid-template-columns:repeat(7,1fr);gap:7px;
  padding:12px;background:#2e62b5;border-radius:20px;
}
.connect4Board .cell{aspect-ratio:1;background:#f6f1e8;border-radius:50%;box-shadow:inset 0 4px 8px rgba(0,0,0,.22)}
.red{background:#e8564a!important}.yellow{background:#ffd45a!important}
.memoryBoard{
  width:min(92vw,520px);display:grid;grid-template-columns:repeat(4,1fr);gap:10px;
}
.card{
  aspect-ratio:1;border-radius:16px;display:flex;align-items:center;justify-content:center;
  font-size:clamp(26px,8vw,48px);background:var(--accent);color:white;cursor:pointer;
  box-shadow:0 6px 14px rgba(70,40,10,.18);user-select:none;
}
.card.open,.card.done{background:#fff;color:var(--ink);border:2px solid rgba(130,95,59,.25)}
.minesBoard{
  width:min(92vw,420px);display:grid;grid-template-columns:repeat(8,1fr);gap:4px;
  background:#c8b08c;padding:8px;border-radius:16px;
}
.mineCell{
  aspect-ratio:1;border-radius:8px;background:#fff8ea;display:flex;align-items:center;justify-content:center;
  font-weight:900;cursor:pointer;box-shadow:inset 0 -3px 0 rgba(0,0,0,.12);user-select:none;
}
.mineCell.closed{background:#8d6c4b;color:transparent}
.mineCell.boom{background:#df5b4f;color:white}
.mineCell.treasure{background:#ffe27a;color:#4b350d}
footer{color:var(--muted);font-size:13px;padding:18px 0 30px;text-align:center}
@media(max-width:700px){
  header{align-items:flex-start;flex-direction:column}
  .tabs{grid-template-columns:repeat(2,1fr)}
  .gameHead{align-items:flex-start;flex-direction:column}
}