body { font-family: sans-serif; padding: 20px; }
.container { max-width: 600px; margin: 0 auto; border: 1px solid #ccc; padding: 20px; border-radius: 8px; }
button { margin-top: 10px; padding: 10px 20px; cursor: pointer; background: #007bff; color: white; border: none; border-radius: 4px; }
button:disabled { background: #ccc; }