Gradient banner overlay

Change div ID or class to apply overlay to correct container.

#div {
  width: 100%;
  height: 100%;
  &:before {
    content: '';
    position: absolute;
    top: 0;
    right: 0;
    bottom: 0;
    left: 0;
    background-image: linear-gradient(to top left,#3d59e6,#00188f);
    opacity: .75; 
  }
}