.expend {
    width: 80px;
    height: 80px;
    background-color: limegreen;
    border: none;
    border-radius: 50%;
    position: absolute;
    transition-duration: 200ms;
    transition-timing-function: ease-out;
    animation: expendAnim 0.5s;
    pointer-events: none;
    z-index: 99999;
}
.expend::after {
    content: "";
    width: 80px;
    height: 80px;
    position: absolute;
    background-color: white;
    border: none;
    border-radius: 50%;
    top: 0px;
    left: 0px;
    animation: expendAnim2 0.5s;
}

@keyframes expendAnim {
    from {
        opacity: 1;
        border-radius: 50%;
    }
    to {
        border-radius: 50%;
        opacity: 0;
    }
}
@keyframes expendAnim2 {
    from {
        transform: scale(0.1);
    }
    to {
        transform: scale(1);
    }
}