Divi section, add an overlay to the video background

When you change from image to video or decide to use just video in a DIVI section as background, you will realize that the gradient overlay is NOT working.
So, you must go to Advanced tab > Custom CSS > Before field and past the CSS below:

content:"";
    display: block;
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0,0,0,0.5);
    z-index: 8;