.zap {

    position: fixed;
    z-index: 1000;
    bottom: 20px;
    right: 15px;
    width: 63px;
    height: 60px;
    border-radius: 50%;
    cursor: pointer;
    background-color: #08854f;
    transition: .3s;
    background-position: center;
    background-repeat: no-repeat;
    background-image: url("whats.png");
    background-size: 50% auto;

    transition: .5s ease;
    transition-property: background-color, color;

}

.zap:hover {
    background-color: #0dc475;
    opacity: 100%;
}