#webinar_officeserver #banner:before{background-image:url("https://gallery.synology.com/image/z3xBV2g/1x");background-repeat:no-repeat}@media all and (-webkit-min-device-pixel-ratio: 1.5), all and (-o-min-device-pixel-ratio: 3 / 2), all and (min--moz-device-pixel-ratio: 1.5), all and (min-device-pixel-ratio: 1.5){#webinar_officeserver #banner:before{background-image:url("https://gallery.synology.com/image/z3xBV2g/2x")}}