html, body {
    margin: 0;
    padding: 0;
    width: 100%;
    height: 100%;
}
.site-container {
    width: 100%;
    height: 100%;
    background: url(images/saha2024-img.jpeg) no-repeat center center;
    background-size: contain;
    -webkit-animation: fadein 4s; /* Safari and Chrome */
    -moz-animation: fadein 4s; /* Firefox */
    -ms-animation: fadein 4s; /* Internet Explorer */
    -o-animation: fadein 4s; /* Opera */
    animation: fadein 4s;
}
@keyframes fadein {
    from { opacity: 0; }
    to   { opacity: 1; }
}