SASS stars (with a little JS)

stars.haml

#stars-wrapper
  - 200.times do
    .star

stars.js

$(document).ready(function(){
  $('.star').each(function(){
    var X = 1 + Math.floor(Math.random() * 100);
    var Y = 1 + Math.floor(Math.random() * 100);
    var starSize = 1 + Math.floor(Math.random() * 50);
    $(this).css({'left' : (X + '%'), 'top' : (Y + '%'), 'width' : (starSize + 'px'), 'height' : (starSize + 'px')});
  });
});

stars.sass

=star($size, $color: white)
  width: $size
  height: $size
  +background-image(radial-gradient(rgba($color,0.9) 5%, rgba($color,0.3) 15%, transparent 70%))
  
$colors: #635892 #BB6F93 #AC607C #694865 #C74031 #D1683C #E3A64D #C0C0C0

#stars-wrapper
  position: absolute
  top: 0
  left: 0
  right: 0
  bottom: 0
  background: #333
  overflow: hidden

.star
  +star(30px)
  position: absolute
  @each $color in $colors 
    $i: index($colors, $color)
    &:nth-child(#{$i}), &:nth-child(#{$i*5}), &:nth-child(#{$i*3}), &:nth-child(#{$i*10}), &:nth-child(#{$i*2})
      +star(30px, $color)
      +animation(fadeOut #{$i}s ease-out infinite alternate forwards)
      +animation-delay(#{$i}s)
      opacity: 0.1

+keyframes(fadeOut)
  from
    opacity: 0.1
  to
    opacity: 1

additional mixins are from bourbon.io