@keyframes spin {
                0% { transform: rotate(0deg); }
                100% { transform: rotate(360deg); }
            }
            @keyframes fadeIn {
                from { opacity: 0; }
                to { opacity: 1; }
            }
            @keyframes fadeOut {
                from { opacity: 1; }
                to { opacity: 0; }
            }
            .fadeInOverlay {
                animation: fadeIn 400ms ease forwards;
            }
            .fadeOutOverlay {
                animation: fadeOut 400ms ease forwards;
            }
            .spinner {
                width: 60px;
                height: 60px;
                border: 4px solid rgba(255, 255, 255, 0.3);
                border-top: 4px solid #fff;
                border-radius: 50%;
                animation: spin 1s linear infinite;
            }