#popupcontent{
    font: 4vmin Monument;
    background:red;
    height:100vh;
    width:100vw;
    display:flex;
    align-items: center;
}
#popupcontent *{
    overflow:visible;
}

a.imagens {
    position: relative;
    -webkit-text-stroke: 1px black;
    color: transparent;
    cursor: help;
}
a.imagens span {
    position: absolute;
    visibility: hidden;
    overflow: visible;
    bottom: 80%;
    left: 50%;
    z-index: 999999;
}

a:hover.imagens span {
    visibility: visible;
}

span img{
    width: 25vmin;
}