body { padding: 20px; background-color: #f8f9fa; }
.container { max-width: 900px; background-color: white; padding: 30px; border-radius: 8px; box-shadow: 0 0 15px rgba(0,0,0,0.1); }
h2 { color: #007bff; }
.btn-success { margin-top: 10px; }
.mt-3 { margin-top: 3px; }
.card { margin-top: 20px; }
#loading-overlay { position: fixed; top: 0; left: 0; width: 100%; height: 100%; background-color: rgba(0, 0, 0, 0.7); z-index: 10000; display: none; justify-content: center; align-items: center; flex-direction: column; color: white; }
#loading-overlay .spinner-border { width: 3rem; height: 3rem; }
#loading-overlay p { margin-top: 20px; font-size: 1.2em; }
@media (max-width: 480px) { body, .container { padding: 10px; } }