MediaWiki:Common.css

/* Background video wrapper takes up full screen */
#bg-video-wrapper {
    position: fixed;
    top: 0;
    left: 0;
    height: 100vh;
    width: 100vw;
    overflow: hidden;
    z-index: -2;
}

/* Video fills wrapper properly and remains scaled */
#bg-video {
    width: 100%;
    height: 100%;
    object-fit: contain;  /* ensure full video is visible */
    object-position: center center;
    pointer-events: none;
    opacity: 0.3;
}