#particles-js canvas {
  position: absolute;
  width: 100%;
  height: 100vh;
  z-index: 1;
  background: #fa6d7e;
  background: -webkit-linear-gradient(45deg, #fa6d7e, #f98c6b);
  background: -moz-oldlinear-gradient(45deg, #fa6d7e, #f98c6b);
  background: -o-linear-gradient(45deg, #fa6d7e, #f98c6b);
  background: linear-gradient(45deg, #fa6d7e, #f98c6b);
}