/* CSS cho màn hình loading */
#loading-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100vw;
    height: 100vh;
    background-color: rgba(0, 0, 0, 0.9);
    z-index: 9999;
    display: flex;
    justify-content: center;
    align-items: center;
}

#loading-overlay img {
    width: 100px;
    height: 100px;
}