$colors: (
  #3349f0,
  #3349f0,
  #3349f0,
  #3349f0,
  #3349f0,
  #3349f0,
  #3349f0,
  #3349f0,
  #3349f0,
  #3349f0,
);
$color: nth($colors, random(length($colors)));

html {
  background: radial-gradient(ellipse at center, $color 0%, darken($color, 50%) 100%);
  overflow: hidden;
} 

html {
  background: -webkit-radial-gradient(center, ellipse, #3349f0 0%, #3349f0 100%);
  background: radial-gradient(ellipse at center, #3349f0 0%, #3349f0 100%);
  overflow: hidden;
}