body {
    margin: 0;
    padding: 0;
    background: rgba(0, 0, 0, .9);
}

ul {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    margin: 0;
    padding: 0;
    display: flex;

}

ul li {
    list-style: none;
    width: 40px;
    height: 40px;
    background: #fff;
    border-radius: 50%;
    animation: grow 1.6s ease-in-out infinite;
}

@keyframes grow {

    0%,
    40%,
    100% {
        transform: scale(0.2);
    }

    20% {
        transform: scale(1);

    }
}

ul li:nth-child(1) {
    animation-delay: -1.4s;
    background: #ffff00;
    box-shadow: 0 0 50px #ffff00;

}

ul li:nth-child(2) {
    animation-delay: -1.2s;
    background: #76ff03;
    box-shadow: 0 0 50px #76ff03;

}

ul li:nth-child(3) {
    animation-delay: -1s;
    background: #f06292;
    box-shadow: 0 0 50px #f06292;

}

ul li:nth-child(4) {
    animation-delay: -0.8s;
    background: #4fc3f7;
    box-shadow: 0 0 50px #4fc3f7;

}

ul li:nth-child(5) {
    animation-delay: -0.6s;
    background: #ba68c8;
    box-shadow: 0 0 50px #ba68c8;

}

ul li:nth-child(6) {
    animation-delay: -0.4s;
    background: #f57c00;
    box-shadow: 0 0 50px #f57c00;

}

ul li:nth-child(7) {
    animation-delay: -0.2s;
    background: #673ab7;
    box-shadow: 0 0 50px #673ab7;

}