*,:before,:after{box-sizing:border-box;margin:0;padding:0}:root{--bg:#f8f8f8;--bg-card:#fff;--fg:#111;--fg-muted:#666;--border:#ddd;--accent:#1a1a1a;--accent-hover:#333;--cell-empty:#eee;--cell-hover:#d8d8d8;--radius:4px;--gap:4px;--font:"Courier New", Courier, monospace}[data-theme=dark]{--bg:#111;--bg-card:#1e1e1e;--fg:#f0f0f0;--fg-muted:#888;--border:#333;--accent:#f0f0f0;--accent-hover:#ccc;--cell-empty:#2a2a2a;--cell-hover:#3a3a3a}html,body{height:100%;font-family:var(--font);background:var(--bg);color:var(--fg);transition:background .2s,color .2s}a{color:inherit;text-decoration:none}button{cursor:pointer;border:1px solid var(--border);background:var(--bg-card);color:var(--fg);border-radius:var(--radius);padding:.4em .8em;font-family:inherit;transition:background .15s}button:hover{background:var(--cell-hover)}.site-header{border-bottom:1px solid var(--border);justify-content:space-between;align-items:center;padding:.75rem 1.25rem;display:flex}.site-header .logo{letter-spacing:.05em;text-transform:uppercase;font-size:1rem;font-weight:700}.site-header nav{gap:1rem;display:flex}.site-header nav a{color:var(--fg-muted);font-size:.85rem}.site-header nav a:hover{color:var(--fg)}.theme-toggle{border:1px solid var(--border);border-radius:var(--radius);background:0 0;padding:.25em .5em;font-size:.85rem}main{max-width:900px;margin:0 auto;padding:1.5rem 1.25rem}.grid-board{gap:var(--gap);display:grid}.cell{background:var(--cell-empty);border-radius:var(--radius);cursor:pointer;aspect-ratio:1;-webkit-user-select:none;user-select:none;justify-content:center;align-items:center;font-size:1.4rem;transition:background .1s;display:flex}.cell:hover{background:var(--cell-hover)}.cell.taken{cursor:default}.page-title{letter-spacing:.08em;text-transform:uppercase;margin-bottom:1rem;font-size:1.1rem}.status{color:var(--fg-muted);min-height:1.4em;margin:.75rem 0;font-size:.9rem}.btn-row{gap:.5rem;margin-top:1rem;display:flex}