Background Image Boilerplate

.div::before {
    content: '';
    position: absolute;
    top: 100%; /* top set to zero or 100% anchors conveniently */
    left: 0;
    right: 0;
    width: 100%;
    aspect-ratio: 1/3; /* aspect ratio should match that of the uploaded file */
    background-image: url(/my.svg);
    background-position: center;
    background-size: cover;
    background-repeat: no-repeat;
    z-index: 1;
    display: block;
}