*{scroll-behavior: smooth;}

.clickable_div_a {
    position: absolute;
    width: 100%;
    height: 100%;
    top: 0;
    left: 0;
    text-decoration: none; /* No underlines on the link */
    z-index: 10; /* Places the link above everything else in the div */
    background-color: #FFF; /* Fix to make div clickable in IE */
    opacity: 0; /* Fix to make div clickable in IE */
    filter: alpha(opacity=1); /* Fix to make div clickable in IE */
}

.clickable_div_a:hover {
    background: lightblue;
    opacity: 0.15;
}