:root{
  --bg:#0b1220;
  --card:#0f1a2e;
  --card2:#0c1629;
  --text:#e6edf7;
  --muted:#9fb0c9;
  --border:rgba(255,255,255,.10);
  --shadow:0 14px 45px rgba(0,0,0,.45);
  --accent:#7c5cff;
  --accent2:#22c55e;
  --danger:#ef4444;
  --sqLight:#e8edf3;
  --sqDark:#7a8aa1;
  --sqLight2:#f6f8fb;
  --sqDark2:#8797ae;
}

*{box-sizing:border-box}
html,body{height:100%}
body{
  margin:0;
  font-family:ui-sans-serif,system-ui,"Segoe UI",Roboto,Helvetica,Arial,"PingFang SC","Microsoft YaHei","Noto Sans CJK SC",sans-serif;
  background: radial-gradient(1200px 800px at 20% 10%, rgba(124,92,255,.25), transparent 55%),
              radial-gradient(900px 600px at 90% 20%, rgba(34,197,94,.20), transparent 55%),
              linear-gradient(180deg, #070b14, var(--bg));
  color:var(--text);
}

.app{max-width:1200px; margin:0 auto; padding:22px 18px 26px}

.topbar{
  display:flex;
  align-items:center;
  justify-content:space-between;
  gap:16px;
  margin-bottom:18px;
}
.brand .title{font-weight:800; font-size:22px; letter-spacing:.5px}
.brand .subtitle{color:var(--muted); font-size:12px; margin-top:4px}
.actions{display:flex; gap:10px}

.btn{
  border:1px solid var(--border);
  background:rgba(255,255,255,.06);
  color:var(--text);
  padding:10px 12px;
  border-radius:10px;
  cursor:pointer;
  box-shadow:0 10px 22px rgba(0,0,0,.25);
}
.btn:hover{background:rgba(255,255,255,.09)}
.btn:active{transform:translateY(1px)}
.btnPrimary{
  border-color:rgba(124,92,255,.55);
  background:linear-gradient(180deg, rgba(124,92,255,.25), rgba(124,92,255,.12));
}

.main{
  display:grid;
  grid-template-columns: minmax(360px, 620px) minmax(260px, 1fr);
  gap:16px;
  align-items:start;
}
@media (max-width: 980px){
  .main{grid-template-columns:1fr}
}

.boardCard, .panel{
  background:linear-gradient(180deg, rgba(255,255,255,.06), rgba(255,255,255,.03));
  border:1px solid var(--border);
  border-radius:16px;
  box-shadow:var(--shadow);
}
.boardCard{padding:14px}

.boardHeader{
  display:flex;
  align-items:center;
  justify-content:space-between;
  gap:12px;
  margin-bottom:12px;
}
.badge{
  display:inline-flex;
  align-items:center;
  gap:8px;
  padding:8px 10px;
  border-radius:999px;
  border:1px solid var(--border);
  background:rgba(255,255,255,.05);
  font-weight:700;
}
.status{color:var(--muted); font-size:13px}

.board{
  width:min(620px, 100%);
  aspect-ratio:1 / 1;
  border-radius:14px;
  overflow:hidden;
  border:1px solid rgba(255,255,255,.14);
  background:rgba(0,0,0,.35);
  display:grid;
  grid-template-columns: repeat(8, 1fr);
}

.sq{
  position:relative;
  display:flex;
  align-items:center;
  justify-content:center;
  user-select:none;
  cursor:pointer;
}
.sq.light{background:linear-gradient(180deg, var(--sqLight2), var(--sqLight))}
.sq.dark{background:linear-gradient(180deg, var(--sqDark2), var(--sqDark))}

.piece{
  font-size: clamp(26px, 4.6vw, 48px);
  line-height:1;
  filter: drop-shadow(0 8px 10px rgba(0,0,0,.35));
}

.sq.selected::after{
  content:"";
  position:absolute; inset:6px;
  border-radius:10px;
  outline:2px solid rgba(124,92,255,.95);
  box-shadow:0 0 0 6px rgba(124,92,255,.20);
}
.sq.legal::before{
  content:"";
  position:absolute;
  width:14px; height:14px;
  border-radius:50%;
  background:rgba(34,197,94,.65);
  box-shadow:0 0 0 6px rgba(34,197,94,.18);
}
.sq.capture::before{
  content:"";
  position:absolute;
  inset:8px;
  border-radius:10px;
  outline:2px solid rgba(239,68,68,.88);
  box-shadow:0 0 0 6px rgba(239,68,68,.18);
}
.sq.checkKing{
  background:linear-gradient(180deg, rgba(239,68,68,.35), rgba(239,68,68,.22)) !important;
}

.coord{
  position:absolute;
  font-size:11px;
  color:rgba(0,0,0,.55);
  font-weight:700;
  letter-spacing:.2px;
}
.sq.dark .coord{color:rgba(255,255,255,.72)}
.coord.file{left:8px; bottom:6px}
.coord.rank{right:8px; top:6px}

.boardFooter{margin-top:12px}
.hint{color:var(--muted); font-size:12px}

.side{display:flex; flex-direction:column; gap:16px}
.panel{padding:14px}
.panelTitle{font-weight:800; margin-bottom:12px}
.field{display:flex; flex-direction:column; gap:8px; margin-bottom:12px}
.label{color:var(--muted); font-size:12px}
.mono{
  width:100%;
  border-radius:12px;
  border:1px solid var(--border);
  padding:10px 12px;
  background:rgba(0,0,0,.20);
  color:var(--text);
  font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono", "Courier New", monospace;
  resize:vertical;
}

.select{
  width:100%;
  border-radius:12px;
  border:1px solid var(--border);
  padding:10px 12px;
  background:rgba(0,0,0,.20);
  color:var(--text);
  outline:none;
}
.select:focus{
  border-color:rgba(124,92,255,.55);
  box-shadow:0 0 0 6px rgba(124,92,255,.14);
}
.row{display:flex; gap:10px}
.rowItem{flex:1; min-width:0}
.sublabel{color:var(--muted); font-size:12px; margin-bottom:8px}
.mutedSmall{color:var(--muted); font-size:12px; margin-top:8px}

.checkbox{
  display:flex;
  align-items:center;
  gap:10px;
  color:var(--text);
  user-select:none;
  margin:8px 0;
}
.checkbox input{width:16px; height:16px}

.footer{margin-top:16px; color:var(--muted); font-size:12px}
.muted{opacity:.95}