html,body{weight:100%; height:100%;}body{
background: linear-gradient(
to right,#833ab4,#fd1d1d,#fcb045);background-size:400% 400%;
animation: animate-background 10s infinite ease-in-out;}
@keyframes animate-background
{0% {background-position: 0 50%;}
50% {background-position: 100% 50%}
100% {background-position:0 50%;}}