body { font-family: sans-serif; max-width: 800px; margin: 2rem auto; padding: 0 1rem; }
.container { border: 1px solid #ccc; padding: 2rem; border-radius: 8px; }
.file-list { margin: 1rem 0; padding: 1rem; background: #f9f9f9; border: 1px dashed #999; min-height: 50px; }
button { padding: 10px 20px; cursor: pointer; background-color: #007bff; color: white; border: none; border-radius: 4px; font-size: 16px; }
button:disabled { background-color: #ccc; cursor: not-allowed; }
button:hover:not(:disabled) { background-color: #0056b3; }