.ripple-effect { position: relative; overflow: hidden; }
.ripple {
    position: absolute;
    border-radius: 50%;
    transform: scale(0);
    animation: ripple-animation 0.6s linear;
    background: rgba(0,0,0,0.15);
    pointer-events: none;
}
@keyframes ripple-animation {
    to { transform: scale(4); opacity: 0; }
}