.pfButton {
    position: relative;
    overflow: hidden;
}

    .pfButton .circle {
        position: absolute;
        background-color: #fff;
        width: 100px;
        height: 100px;
        border-radius: 50%;
        transform: translate(-50%, -50%) scale(0);
        animation: scale 0.5s ease-out;
    }

@keyframes scale {
    to {
        transform: translate(-50%, -50%) scale(3);
        opacity: 0;
    }
}