@keyframes floatPure {
    0%   { transform: translateY(0); }
    50%  { transform: translateY(-16px); }
    100% { transform: translateY(0); }
}

.dot.ani {
    animation: floatPure 4s ease-in-out infinite alternate;
}

.dot.ani:hover {
    animation-play-state: paused;
}