body { font-family: -apple-system, system-ui, sans-serif; background: #f4f6f8; display: flex; align-items: center; justify-content: center; height: 100vh; margin: 0; }
.card { background: white; padding: 2rem; border-radius: 8px; box-shadow: 0 4px 12px rgba(0,0,0,0.1); width: 100%; max-width: 400px; text-align: center; }
h2 { margin-top: 0; color: #333; }
input { font-size: 24px; letter-spacing: 2px; text-align: center; width: 100%; padding: 10px; margin: 20px 0; border: 1px solid #ccc; border-radius: 4px; box-sizing: border-box; text-transform: uppercase; }
button { background: #007bff; color: white; border: none; padding: 12px 20px; font-size: 16px; border-radius: 4px; cursor: pointer; width: 100%; transition: background 0.2s; }
button:hover { background: #0056b3; }
.status { margin-top: 15px; font-weight: bold; height: 20px; }
.success { color: #28a745; }
.error { color: #dc3545; }
