.bg{z-index:-999;background:linear-gradient(#d68c00,#e60050) 0 0/cover no-repeat;height:100vh;transition:background .3s;position:fixed;top:0;left:0;right:0}.bg:not(.is-dark).is-break{background:linear-gradient(#006bd6,#14b84d)}.bg.is-dark{background:linear-gradient(#c24300,#8a0074)}.bg.is-dark.is-break{background:linear-gradient(#4520ac,#2a9d5a)}