:root{--fg: #1a1a1a;--bg: #fafafa;--accent: #2563eb;--accent-fg: #ffffff;--muted: #6b7280;--legal: #bfdbfe;--border: #d1d5db}*{box-sizing:border-box}body{margin:0;font-family:-apple-system,BlinkMacSystemFont,Segoe UI,Roboto,sans-serif;background:var(--bg);color:var(--fg)}.page{max-width:720px;margin:0 auto;padding:1.5rem}.header{display:flex;justify-content:space-between;align-items:baseline;margin-bottom:1.5rem}.header h1{margin:0}.me{color:var(--muted);font-size:.9rem}button{cursor:pointer;font:inherit;border:1px solid var(--border);background:#fff;padding:.5rem 1rem;border-radius:4px}button:hover:not(:disabled){background:#f3f4f6}button:disabled{opacity:.5;cursor:not-allowed}button.selected,.game-button.selected{background:var(--accent);color:var(--accent-fg);border-color:var(--accent)}.game-buttons{display:flex;gap:.5rem;margin:.5rem 0 1.5rem}.actions{margin-top:1.5rem}.error{margin:1rem 0;padding:.75rem;border:1px solid #fca5a5;background:#fee2e2;color:#7f1d1d;border-radius:4px}.status-bar{margin:0 0 1rem;font-weight:500}.grid-board{display:flex;flex-direction:column;gap:.25rem;margin:1rem 0}.grid-cells{gap:.25rem}.grid-cell{width:3rem;height:3rem;font-size:1.25rem;display:flex;align-items:center;justify-content:center;background:#fff;border:1px solid var(--border);border-radius:4px;padding:0}.grid-cell.legal{background:var(--legal);cursor:pointer}.grid-cell.occupied{cursor:default}.c4-headers{display:flex;gap:.25rem}.c4-header{width:3rem;height:1.5rem;padding:0;font-size:.85rem}.c4-header.legal{background:var(--legal);cursor:pointer}.nim-heaps{display:flex;flex-direction:column;gap:1rem}.nim-pile-row{font-family:monospace;font-size:1.25rem}.nim-pile-stones{margin-left:.5rem}.nim-pile-takes{display:flex;flex-wrap:wrap;gap:.25rem;margin-top:.25rem}.end-banner{margin-top:1.5rem;padding:1rem;background:#fff;border:1px solid var(--border);border-radius:4px;text-align:center}.end-banner h2{margin-top:0}.end-banner-actions{display:flex;justify-content:center;gap:.5rem}