.memory-grid{display:grid;grid-template-columns:repeat(var(--cols),1fr);gap:10px;max-width:600px;margin:0 auto;padding:var(--spacing-md)}.memory-card{aspect-ratio:1;perspective:1000px;cursor:pointer;min-width:60px;min-height:60px}.card-inner{position:relative;width:100%;height:100%;transition:transform .5s;transform-style:preserve-3d}.memory-card.flipped .card-inner{transform:rotateY(180deg)}.card-front,.card-back{position:absolute;width:100%;height:100%;backface-visibility:hidden;border-radius:var(--radius-md);display:flex;align-items:center;justify-content:center;font-size:2rem;padding:var(--spacing-sm);box-sizing:border-box;box-shadow:0 2px 4px #0003}.card-front{background:linear-gradient(135deg,var(--color-card-back) 0%,#1a3a5c 100%);color:#ffffff80;font-weight:700;border:2px solid rgba(255,255,255,.15)}.card-back{background:var(--color-card-bg);transform:rotateY(180deg);font-size:2.5rem;border:2px solid rgba(255,255,255,.1)}.memory-card.matched .card-inner{opacity:.7}.memory-card.matched .card-back{background:#4a9f5a4d;border:2px solid var(--color-accent)}.difficulty-select{padding:var(--spacing-sm) var(--spacing-md);border-radius:var(--radius-md);border:1px solid var(--color-text-muted);background:transparent;color:var(--color-text);font-size:inherit;cursor:pointer;min-height:44px}.difficulty-select:focus{outline:2px solid var(--color-accent);outline-offset:2px}@media (max-width: 500px){.memory-grid{gap:6px;padding:var(--spacing-sm)}.card-front,.card-back{font-size:1.5rem}.card-back{font-size:1.8rem}}.memory-grid[style*="--cols: 6"] .card-front,.memory-grid[style*="--cols: 6"] .card-back{font-size:1.5rem}.memory-grid[style*="--cols: 6"] .card-back{font-size:2rem}@media (max-width: 500px){.memory-grid[style*="--cols: 6"] .card-front,.memory-grid[style*="--cols: 6"] .card-back{font-size:1rem}.memory-grid[style*="--cols: 6"] .card-back{font-size:1.5rem}}