*{box-sizing:border-box}html,body{height:100%}body{margin:0;font-family:Inter,system-ui,-apple-system,Segoe UI,Roboto,Ubuntu,Cantarell,"Fira Sans","Droid Sans","Helvetica Neue",Arial,"Noto Sans",sans-serif;background:#0b1020;color:#e5e7eb;-webkit-tap-highlight-color: transparent}
.app{max-width:1100px;margin:0 auto;padding:16px}
.topbar{position:sticky;top:0;z-index:5;padding-bottom:8px;background:linear-gradient(180deg,#0b1020 70%,rgba(11,16,32,0));backdrop-filter:saturate(120%) blur(4px)}
h1{margin:0 0 8px 0;font-weight:700;letter-spacing:.3px;font-size:20px}
.room-controls{display:flex;gap:8px;align-items:center;flex-wrap:wrap}
.room-controls input{flex:1;min-width:180px;padding:12px 14px;border-radius:12px;border:1px solid #2b3245;background:#10182c;color:#e5e7eb}
.btn{padding:12px 14px;border-radius:12px;border:1px solid #334155;background:#111827;color:#e5e7eb;cursor:pointer;touch-action:manipulation}
.btn:active{transform:scale(.98)}
.btn.primary{background:#2563eb;border-color:#1d4ed8}
.btn.primary:active{background:#1d4ed8}
.btn.subtle{background:#0f172a;border-color:#1f2937}
.pill{background:#0f172a;border:1px solid #1f2937;border-radius:999px;padding:6px 10px;display:inline-flex;align-items:center;gap:6px}
.pill-warn{background:#3b0d0d;border-color:#ef4444;color:#fecaca}
.status{display:flex;gap:10px;flex-wrap:wrap;margin-top:8px}

main{display:grid;grid-template-columns:minmax(320px,1fr) 360px;gap:18px;align-items:start}
.board-section{display:block}
.board-wrap{position:relative;display:grid;place-items:center}
.board{position:relative;width:min(92vw,720px);height:min(92vw,720px);max-width:720px;max-height:720px;border-radius:16px;overflow:hidden;box-shadow:0 10px 30px rgba(0,0,0,.45)}
.board::before{content:"";position:absolute;inset:0;background:repeating-linear-gradient( 45deg, #7e5c3a 0 14px, #845f3d 14px 28px )}
.board{display:grid;grid-template-columns:repeat(8,1fr);grid-template-rows:repeat(8,1fr)}
.square{position:relative;display:flex;align-items:center;justify-content:center;font-size:calc(34px + 2.2vw);user-select:none;transition:background .12s ease}
.square.light{background:rgba(245, 222, 179, 0.35)}
.square.dark{background:rgba(67, 46, 28, 0.55)}
.square.highlight{outline:3px solid #f59e0b;z-index:2}
.piece{cursor:pointer;text-shadow:0 2px 3px rgba(0,0,0,.45), 0 0 1px rgba(0,0,0,.3);transform:translateZ(0)}
.square.lastmove{box-shadow:inset 0 0 0 4px rgba(99,102,241,.7)}
.square.hint::after{content:"";width:28%;height:28%;border-radius:50%;background:rgba(255,255,255,.92);box-shadow:0 0 0 4px rgba(0,0,0,.15);position:absolute}
.square.hint-capture{outline:4px solid rgba(239,68,68,.9)}
.coords{position:absolute;pointer-events:none;color:#cbd5e1;font-size:12px;opacity:.85}
.coords-file{display:grid;grid-template-columns:repeat(8,1fr);gap:0;width:100%;padding:4px 10px}
.coords-file.top{top:-24px}
.coords-file.bottom{bottom:-24px}
.coords-rank{display:grid;grid-template-rows:repeat(8,1fr);gap:0;height:100%;padding:10px 4px}
.coords-rank.left{left:-24px}
.coords-rank.right{right:-24px}
.coords .cell{display:flex;align-items:center;justify-content:center}

.card{background:#0c1428;border:1px solid #233047;border-radius:14px;padding:14px;box-shadow:0 6px 20px rgba(0,0,0,.25)}
.side-section .players{display:flex;gap:12px;justify-content:space-between}
.moves-wrap summary{cursor:pointer;margin:6px 0 8px 0;list-style:none}
.moves{max-height:420px;overflow:auto;padding-left:20px;margin:0}

footer{margin-top:14px;color:#94a3b8;text-align:center}

/* Responsive tweaks */
@media (max-width: 980px){
  main{grid-template-columns:1fr;gap:12px}
  .side-section{order:2}
  .board-section{order:1}
  .board{width:min(96vw,720px);height:min(96vw,720px)}
  .square{font-size:calc(30px + 2.5vw)}
  .coords-file.top,.coords-file.bottom{display:none}
  .coords-rank.left,.coords-rank.right{display:none}
}
@media (max-width: 420px){
  .app{padding:12px}
  .room-controls input{min-width:0}
  .square{font-size:calc(28px + 3vw)}
  .btn{padding:10px 12px}
}
@supports (-webkit-touch-callout: none){
  .board{max-width:100vw;max-height:100vw}
}