Add a Dark overlay over image on Hover

[tuanphan]

You can use this CSS code to Custom CSS

div[class*="MediaImage__Container"]:before {
    content: "";
    background-color: rgba(0,0,0,0.5);
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    opacity: 0;
    transition: all 0.3s ease;
    z-index: 999;
}
a:hover div[class*="MediaImage__Container"]:before {
    opacity: 1 !important;
    transition: all 0.3s ease;
}

Result