:root{--bg-primary:#121214;--bg-secondary:#1a1a1e;--board-light:#eeeed2;--board-dark:#769656;--text-primary:#f0f4f8;--text-secondary:#94a3b8;--accent:#3b82f6;--accent-hover:#2563eb;--highlight-last-from:#3b82f640;--highlight-last-to:#22c55e40;--highlight-legal:#22c55e99;--highlight-legal-capture:#ef4444}body{background-color:var(--bg-primary);color:var(--text-primary);justify-content:center;align-items:center;min-height:100vh;margin:0;padding:0;font-family:Inter,system-ui,-apple-system,sans-serif;display:flex}#app{box-sizing:border-box;flex-direction:column;align-items:center;gap:16px;width:100%;max-width:1200px;padding:20px;display:flex}.app-header{text-align:center}.app-header h1{background:linear-gradient(135deg,#f0f4f8,#94a3b8);-webkit-text-fill-color:transparent;letter-spacing:-.025em;-webkit-background-clip:text;margin:0 0 6px;font-size:2.2rem;font-weight:700}.app-header p{color:var(--text-secondary);margin:0;font-size:.95rem}.game-container{flex-direction:column;align-items:center;gap:12px;width:100%;display:flex}.chess-board-svg{width:100%;height:100%;display:block}#board-container{aspect-ratio:1;touch-action:manipulation;border-radius:8px;width:100%;max-width:864px;overflow:hidden;box-shadow:0 10px 30px -5px #0009,0 8px 16px -6px #0009}.chess-piece{-webkit-user-select:none;user-select:none;font-family:system-ui,sans-serif;font-size:44px}.white-piece{fill:#fff;stroke:#222;stroke-width:1.2px;filter:drop-shadow(1px 2px 2px #00000040)}.black-piece{fill:#3b3b3b;stroke:#121212;stroke-width:1.2px;filter:drop-shadow(1px 2px 2px #00000073)}.captured-container{box-sizing:border-box;width:100%;max-width:864px;color:var(--text-secondary);background:#1a1a1e;border-radius:6px;justify-content:space-between;padding:4px 8px;font-size:.9rem;display:flex}.captured-list{gap:4px;font-size:1.2rem;line-height:1;display:flex}.captured-white{color:#a1a1aa}.captured-black{color:#f4f4f5}.control-panel{flex-wrap:wrap;justify-content:center;gap:12px;width:100%;max-width:864px;display:flex}.btn-primary{background-color:var(--bg-secondary);color:var(--text-primary);cursor:pointer;border:1px solid #2e2e33;border-radius:6px;align-items:center;gap:6px;padding:8px 16px;font-size:.9rem;font-weight:500;transition:all .2s;display:flex}.btn-primary:hover{background-color:#27272a;border-color:#3f3f46}.btn-accent{background-color:var(--accent);border-color:var(--accent)}.btn-accent:hover{background-color:var(--accent-hover);border-color:var(--accent-hover)}.btn-primary:focus-visible{outline:2px solid var(--accent);outline-offset:2px}input:focus-visible,select:focus-visible{outline:2px solid var(--accent);outline-offset:1px}#history-container{box-sizing:border-box;background:#1a1a1e;border:1px solid #27272a;border-radius:8px;width:100%;max-width:864px;padding:12px}#history-list{scroll-behavior:smooth;flex-wrap:wrap;gap:8px;min-height:36px;max-height:200px;font-family:monospace;font-size:.9rem;display:flex;overflow-y:auto}@media (width<=600px){.app-header h1{font-size:1.8rem}.btn-primary{padding:6px 12px;font-size:.85rem}.timer-row{padding:4px 12px!important;font-size:.95rem!important}}