body { font-family: Arial, sans-serif; max-width: 800px; margin: auto; padding: 1rem; }
.centered { max-width: 300px; margin: 100px auto; text-align: center; }
input, select { width: 100%; padding: 0.5em; margin: 0.5em 0; }
button { padding: 0.7em 1.2em; background: #0066cc; color: white; border: 0; cursor: pointer; }
button:hover { background: #005bb5; }
.error { color: red; }