.app{max-width:600px;margin:0 auto;padding:2rem;text-align:center}h1{color:#333;margin-bottom:1rem}.card-counter{color:#666;margin-bottom:1.5rem;font-size:.9rem}.card{background:#fff;border:2px solid #ddd;border-radius:8px;padding:3rem 2rem;margin-bottom:2rem;min-height:200px;cursor:pointer;transition:transform .2s}.card:hover{transform:scale(1.02)}.card-content{font-size:1.5rem;color:#333;margin-bottom:1rem}.card-content.flipped{color:#06c}.flip-hint{font-size:.8rem;color:#999;margin-top:1rem}.controls{display:flex;gap:1rem;justify-content:center}button{padding:.75rem 1.5rem;font-size:1rem;border:2px solid #0066cc;background-color:#fff;color:#06c;border-radius:4px;cursor:pointer;transition:all .2s}button:hover{background-color:#06c;color:#fff}button:active{transform:scale(.98)}*{margin:0;padding:0;box-sizing:border-box}body{font-family:-apple-system,BlinkMacSystemFont,Segoe UI,Roboto,Oxygen,Ubuntu,Cantarell,Fira Sans,Droid Sans,Helvetica Neue,sans-serif;-webkit-font-smoothing:antialiased;-moz-osx-font-smoothing:grayscale;background-color:#f5f5f5}