/* Hide the warning message by default */
#portrait-warning {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.8);
    color: white;
    text-align: center;
    padding-top: 50vh;
    z-index: 9999;
}

/* Show the warning message for devices with max-width of 767px and in landscape mode */
@media (max-width: 767px) and (orientation: landscape) {
    #portrait-warning {
        display: block;
    }
}