*,:before,:after{box-sizing:border-box}:root{--primary-color:#6366f1;--accent-color:#8b5cf6;--background:#fff;--surface:#f8fafc;--border:#e2e8f0;--text-primary:#1e293b;--text-secondary:#64748b;--tile-background:#fff;--tile-shadow:#0000001a;--tile-hover:#f1f5f9;--success:#10b981}body{-webkit-font-smoothing:antialiased;background:var(--background);color:var(--text-primary);margin:0;font-family:system-ui,-apple-system,Segoe UI,Roboto,sans-serif}.screen{flex-direction:column;align-items:center;min-height:100vh;padding:2rem 1rem;display:flex}.game-container{width:100%;max-width:500px}.header{text-align:center;margin-bottom:2rem}.header h1{color:var(--primary-color);margin:0 0 .5rem;font-size:2rem;font-weight:700}.header p{color:var(--text-secondary);margin:0;font-size:.875rem}.stats{justify-content:space-between;gap:1rem;margin-bottom:1.5rem;display:flex}.stat-card{background:var(--surface);border:1px solid var(--border);text-align:center;border-radius:.75rem;flex:1;padding:1rem}.stat-label{text-transform:uppercase;letter-spacing:.05em;color:var(--text-secondary);margin-bottom:.25rem;font-size:.75rem;font-weight:600;display:block}.stat-value{color:var(--text-primary);font-size:1.5rem;font-weight:700;display:block}.puzzle-grid{background:var(--surface);border:2px solid var(--border);aspect-ratio:1;border-radius:1rem;grid-template-columns:repeat(4,1fr);gap:.5rem;margin-bottom:1.5rem;padding:.5rem;display:grid}.tile{background:var(--tile-background);border:2px solid var(--border);color:var(--primary-color);cursor:pointer;-webkit-user-select:none;user-select:none;box-shadow:0 2px 4px var(--tile-shadow);border-radius:.5rem;justify-content:center;align-items:center;font-size:1.5rem;font-weight:700;transition:all .15s;display:flex}.tile:hover:not(.empty){background:var(--tile-hover);box-shadow:0 4px 8px var(--tile-shadow);transform:scale(1.05)}.tile:active:not(.empty){transform:scale(.95)}.tile.clickable{border-color:var(--primary-color);cursor:pointer}.tile.empty{border:2px dashed var(--border);box-shadow:none;cursor:default;background:0 0}.controls{gap:1rem;display:flex}.button{cursor:pointer;border:none;border-radius:.75rem;flex:1;padding:1rem 1.5rem;font-family:inherit;font-size:1rem;font-weight:600;transition:all .15s}.button-primary{background:var(--primary-color);color:#fff}.button-primary:hover{background:var(--accent-color);transform:translateY(-2px);box-shadow:0 4px 12px #6366f14d}.button-primary:active{transform:translateY(0)}.button-secondary{background:var(--surface);color:var(--primary-color);border:2px solid var(--border)}.button-secondary:hover{background:var(--tile-hover);border-color:var(--primary-color)}.win-banner{background:var(--success);color:#fff;text-align:center;border-radius:.75rem;margin-bottom:1.5rem;padding:1.5rem;animation:.3s slideDown}.win-banner h2{margin:0 0 .5rem;font-size:1.5rem}.win-banner p{opacity:.9;margin:0}@keyframes slideDown{0%{opacity:0;transform:translateY(-20px)}to{opacity:1;transform:translateY(0)}}@media (width<=640px){.screen{padding:1rem .5rem}.header h1{font-size:1.5rem}.stat-value,.tile{font-size:1.25rem}.button{padding:.875rem 1.25rem;font-size:.875rem}}