#clickarea{height:300px;width:100%;max-width:auto;float:left;background-color:#fff;display:block;border-collapse:collapse;text-decoration:none;color:#000;position:relative;overflow:hidden;cursor:pointer;border-radius:10px;border:2px solid #d4d0d0;padding:5px;margin-bottom:15px}
#start{border-radius:10px;background-color:#a3ff00;display:block;user-select:none;width:100%;height:100%;font-size:20px;overflow:hidden}
.ripple{position:absolute;background:#fff;border-radius:50%;width:5px;height:5px;animation:rippleEffect .88s 1;opacity:0}
@keyframes rippleEffect{0%{transform:scale(1);opacity:.4}100%{transform:scale(100);opacity:0}}