.buy-now-btn img {
    left: 0;
    right: 0;
    top: 50%;
    position: absolute;
    -webkit-transform: translateY(-50%);
    transform: translateY(-50%);
    margin-left: auto;
    margin-right: auto;
}
.buy-now-btn {
    z-index: 9;
    right: 28px;
    width: 50px;
    height: 50px;
    bottom: 100px;
    position: fixed;
    text-align: center;
    border-radius: 50%;
    display: inline-block;
    background-color: #81b441;
    -webkit-box-shadow: rgba(0, 0, 0, .35) 0 5px 15px;
    box-shadow: rgba(0, 0, 0, .35) 0 5px 15px;
    -webkit-animation-name: tada;
    animation-name: tada;
    -webkit-animation-duration: 1s;
    animation-duration: 1s;
    -webkit-animation-fill-mode: both;
    animation-fill-mode: both;
    -webkit-animation-iteration-count: infinite;
    animation-iteration-count: infinite;
}