help with customising css

[luca_p]

hello, I am trying to modify the starter theme using only css because it is the only language I know how to use a little.

I am trying to set the height equal to the width, which is a persentage. but it is not working, any idea?

online I found this code and tried to use it:
width: calc(100% - 20px)
height: calc((100vw - 20px) * 0.5625) /*16:9 aspect ratio*/

div .product-information{
    width: calc(37.5% - 1px);
    height: calc(37.5vw * (1 / 1));
    background-color: thistle;
    margin: 0 !important;
    padding: 0 !important;
    text-align: left;
    position: absolute;
    top: 90px;
    left: calc(-1px + 62.5%);
    font-size: 3pt;
    border: solid 1px rgba(0, 0, 255, 1);
}