.bounce {
    position: relative;
    bottom: 0;
    animation-name: bounce;
    animation-duration: 2s;
    animation-iteration-count: 2;
}
@keyframes bounce {
    0% { bottom: 0; }
    20% { bottom: 20px; }
    40% { bottom: 0; }
    50% { bottom: 10px; }
    60%, 100% { bottom: 0; }
    /*0% { bottom: 0; }
    20% { bottom: 20px; }
    40% { bottom: 0; }
    55% { bottom: 13px; }
    70% { bottom: 0; }
    80% { bottom: 8px; }
    90% { bottom: 0; }
    93% { bottom: 4px; }
    96% { bottom: 0; }
    98% { bottom: 2px; }
    100% { bottom: 0; }*/
}