MediaWiki:Common.css

/* CSS placed here will be applied to all skins */

body.page-Main_Page {
    background: url('https://predictive-pulse.com/images/5ean444_winter_cabin_forest_snow_night_sky_stars_peaceful_reali_fc7e7992-0c1e-4564-bf78-2930ff9dc2f9.png') no-repeat center center fixed;
    background-size: cover;
}