.is-on {
    position: relative !important;
    transition: all .5s ease;
} 

.is-on::before {
    content: "";
    text-align: center;
    background:#f4f4f4;
    width: 100%;
    height: 100%;
    position: absolute;
    left: 0;
    top: 0;
    z-index: 0;
}

.is-on::after {
    content: "";
    display: inline-block;
    background-image: url("../asset/giphy.gif");
    background-repeat: no-repeat;
    background-size: cover;
    width: 150px;
    height: 150px;
    z-index: 1;
    position: absolute;
    top: 0;
    left: 50%;
    transform: translate(-50%);
}