html, body {
    height: 100%;
    margin: 0;
    padding: 0;
    background: darkslategrey;
}

.catdiv2 {
    display: grid;
    height: 100%;
    text-align: center;
}

.catimg2 {
    max-width: 100vh;
    max-height: 100vh;
    height: min(100vh, 1024px);
    margin: auto;
}

/*.catimg {*/
/*    padding: 0;*/
/*    display: block;*/
/*    margin: 0 auto;*/
/*    max-height: 100%;*/
/*    max-width: 100%;*/
/*    !*position: fixed;*!*/
/*    !*top: 50%;*!*/
/*    !*left: 50%;*!*/
/*    !*transform: translate(-50%, -50%);*!*/
/*}*/