style.css

#thumbs, #thumbs * {
    padding: 0;
    margin: 0;
    box-sizing: border-box;
}
#thumbs {
    display: flex;
    justify-content: center;
    flex-wrap: wrap;
}
#thumbs li {
    list-style-type: none;
    padding: 10px;
    width: 25%;
}

#thumbs li > span, .hidden {
    display: none !important;
}

#thumbs figure {
    position: relative;
    text-align: center;
}

#thumbs img {
    max-height: 100px;
    max-width: 100px;
}

#thumbs .sidebar-vote.stars {
    transform-origin: top left;
    position: absolute;
    top: 2px;
    left: 2px;
    text-shadow: 0 0 2px black, 0 0 2px black;
    opacity: 0;
    color: white;
    cursor: pointer;
    transition: all .3s;
}
#thumbs figure:hover .sidebar-vote.stars {
    opacity: 1;
    transform: scale(1.2);
}
#thumbs .img {
    background-image: url('https://i.stack.imgur.com/Da7jC.png') !important;
}

#thumbs .sidebar-vote.stars.user-star .vote {
    color: gold;
}