body, html {
    margin: 0;
    padding: 0;
    height: 100%;
    overflow: hidden;
}
#container {
    width: 100%;
    height: 100%;
    position: relative;
}
.fullscreen-item {
    width: 2160px; /* Width of your content */
    height: 3840px; /* Height of your content */
    position: absolute;
    top: 0;
    left: 0;
    opacity: 0; /* Hide all items by default */
    pointer-events: none; /* Disable pointer events for hidden items */
    transition: opacity 1s; /* Add a smooth transition effect to opacity */
}

.fullscreen-item.active {
    opacity: 1; /* Display the current item */
}