/* ===================== FULLPAGE LOADING OVERLAY ===================== */

#page-loader {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: #ffffff;
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 999999;
    transition: opacity 0.4s ease, visibility 0.4s ease;
}

/* Loader hình tròn xoay */
#page-loader .loader {
    width: 60px;
    height: 60px;
    border: 6px solid #dddddd;
    border-top: 6px solid #a00000; /* màu đỏ DKHP */
    border-radius: 50%;
    animation: spin 0.9s linear infinite;
}

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

/* Khi trang load xong */
#page-loader.hide {
    opacity: 0;
    visibility: hidden;
}