.loading99 {
    margin: 20px;
    position: relative;
    width: 1px;
    height: 1px;
}

.loading99:before,
.loading99:after {
    position: absolute;
    display: inline-block;
    width: 15px;
    height: 15px;
    content: '';
    border-radius: 100%;
    background-color: #5551ff;
}

.loading99:before {
    left: -15px;
    animation: ball-pulse infinite 0.75s -0.4s cubic-bezier(0.2, 0.68, 0.18, 1.08);
}

.loading99:after {
    right: -15px;
    animation: ball-pulse infinite 0.75s cubic-bezier(0.2, 0.68, 0.18, 1.08);
}

@keyframes ball-pulse {
    0% {
        transform: scale(1);
        opacity: 1;
    }

    50% {
        transform: scale(0.1);
        opacity: 0.6;
    }

    100% {
        transform: scale(1);
        opacity: 1;
    }
}