#loader {
    position: fixed;
    top: 50%;
    left: 50%;
    width: 50px;
    height: 50px;
    border: 5px solid #f3f3f3;
    border-top: 5px solid #3498db;
    border-radius: 50%;
    animation: spin 2s linear infinite;
    display: none; 
    z-index: 9999; 
}

@keyframes spin {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}

@keyframes fadeIn {
    0% { opacity: 0; }
    100% { opacity: 1; }
}

#overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.5); 
    display: none;
    z-index: 9998; 
    animation: fadeIn 0.5s ease-out forwards;
    pointer-events: all; 
}