waves.css

.waves-ripple {
    position: absolute;
    border-radius: 100%;
    background-color: rgba(0, 0, 0, 0.15);
    background-clip: padding-box;
    pointer-events: none;
    -webkit-user-select: none;
    -moz-user-select: none;
    -ms-user-select: none;
    user-select: none;
    -webkit-transform: scale(0);
    -ms-transform: scale(0);
    transform: scale(0);
    opacity: 1;
}

.waves-ripple.z-active {
    opacity: 0;
    -webkit-transform: scale(2);
    -ms-transform: scale(2);
    transform: scale(2);
    -webkit-transition: opacity 1.2s ease-out, -webkit-transform 0.6s ease-out;
    transition: opacity 1.2s ease-out, -webkit-transform 0.6s ease-out;
    transition: opacity 1.2s ease-out, transform 0.6s ease-out;
    transition: opacity 1.2s ease-out, transform 0.6s ease-out, -webkit-transform 0.6s ease-out;
}