*{box-sizing:border-box}html,body{margin:0;padding:0;font-family:system-ui,-apple-system,Segoe UI,Roboto,Ubuntu,Cantarell,'Helvetica Neue',Arial,'Noto Sans',sans-serif;line-height:1.5}
:root{
  --bg:#0b1020; --fg:#e2e8f0; --muted:#cbd5e1; --card:#0f172a; --line:#1f2a44;
  --accent:#2563eb; --accent2:#22c55e; --warn:#f59e0b; --danger:#ef4444;
}
body{background:var(--bg);color:var(--fg)}
.hero{padding:28px 16px;text-align:center;background:radial-gradient(1000px 500px at 50% -10%,#1e293b,var(--bg));}
.hero h1{margin:0 0 8px;font-size:30px}
.hero p{max-width:950px;margin:0 auto 12px;color:var(--muted)}
.actions{display:flex;gap:10px;justify-content:center;flex-wrap:wrap}
.btn{display:inline-block;padding:10px 16px;border-radius:12px;background:var(--accent);color:white;text-decoration:none;font-weight:700;border:none;cursor:pointer}
.btn.secondary{background:#334155}
.btn.danger{background:var(--danger)}
.btn.accent{background:var(--accent2)}
.container{max-width:1100px;margin:22px auto;padding:0 16px}
section{background:var(--card);border:1px solid var(--line);border-radius:16px;padding:14px;margin:12px 0}
.setup .row{display:flex;gap:10px;flex-wrap:wrap;margin:8px 0}
.setup input[type=text]{flex:1;min-width:240px;background:#0b132a;color:var(--fg);border:1px solid var(--line);border-radius:10px;padding:8px}
.hint{color:var(--muted);margin:6px 0 0}
.board{display:grid;grid-template-columns:2fr 1fr;gap:12px}
.canvas{background:#0b132a;border:1px solid var(--line);border-radius:14px;min-height:320px;display:flex;align-items:center;justify-content:center;padding:6px}
.controls .moves, .controls .stepper{display:flex;gap:10px;flex-wrap:wrap;margin:8px 0}
.controls input[type=text]{flex:1;min-width:200px;background:#0b132a;color:var(--fg);border:1px solid var(--line);border-radius:10px;padding:8px}
.status .step-title{font-weight:800;font-size:18px;margin-bottom:6px}
.status .algo-box{display:flex;flex-wrap:wrap;gap:8px;margin-top:8px}
.algo-btn{border:1px solid var(--line);background:#0b132a;color:var(--fg);border-radius:10px;padding:8px 12px;cursor:pointer}
.algo-btn:hover{background:#0f172a}
.legend{color:var(--muted);font-size:14px}
.footer-note{color:var(--muted);font-size:14px}
.light{--bg:#f8fafc;--fg:#0b1020;--muted:#334155;--card:#ffffff;--line:#d1d5db}