@keyframes cube {
    from {
        transform: scale(0) rotate(0deg) translate(-50%, -50%);
        opacity: 1;
    }
    to {
        transform: scale(20) rotate(960deg) translate(-50%, -50%);
        opacity: 0;
    }
}

.background_animate {
    position: absolute;
    width: 100%;
    height: 100%;
    top: 0;
    left: 0;
    margin: 0;
    padding: 0;
    background: #f5f5f5;
    overflow: hidden;
}
.background_animate li {
    position: absolute;
    left: 32%;
    top: 65%;
    width: 10px;
    height: 10px;
    border: solid 1px #dcdcdc;
    color: transparent;
    transform-origin: top left;
    transform: scale(0) rotate(0deg) translate(-50%, -50%);
    animation: cube 11s ease-in forwards infinite;
}
undefined
.background_animate li:nth-child(0) {
    animation-delay: 0s;
    left: 40%;
    top: 60%;
}

.background_animate li:nth-child(1) {
    animation-delay: 2s;
    left: 0%;
    top: 50%;
    border-color: #ffffff;
}

.background_animate li:nth-child(2) {
    animation-delay: 4s;
    left: 50%;
    top: 0%;
    border-color: #ffffff;
}

.background_animate li:nth-child(3) {
    animation-delay: 6s;
    left: 30%;
    top: 70%;
    border-color: #ffffff;
}

.background_animate li:nth-child(4) {
    animation-delay: 8s;
    left: 40%;
    top: 60%;
    border-color: #ffffff;
}

.background_animate li:nth-child(5) {
    animation-delay: 10s;
    left: 50%;
    top: 50%;
}

.background_animate li:nth-child(6) {
    animation-delay: 12s;
    left: 60%;
    top: 40%;
}

.background_animate li:nth-child(7) {
    animation-delay: 14s;
    left: 70%;
    top: 30%;
    border-color: #ffffff;
}

.background_animate li:nth-child(8) {
    animation-delay: 16s;
    left: 80%;
    top: 20%;
    border-color: #ffffff;
}

.background_animate li:nth-child(9) {
    animation-delay: 18s;
    left: 90%;
    top: 10%;
    border-color: #ffffff;
}

.background_animate li:nth-child(10) {
    animation-delay: 20s;
    left: 100%;
    top: 0%;
}

.background_animate li:nth-child(11) {
    animation-delay: 22s;
    left: 0%;
    top: 0%;
}

.background_animate li:nth-child(12) {
    animation-delay: 24s;
    left: 100%;
    top: 100%;
    border-color: #ffffff;
}

.background_animate li:nth-child(13) {
    animation-delay: 26s;
    left: 90%;
    top: 90%;
    border-color: #ffffff;
}

.background_animate li:nth-child(14) {
    animation-delay: 28s;
    left: 80%;
    top: 80%;
    border-color: #ffffff;
}

.background_animate li:nth-child(15) {
    animation-delay: 30s;
    left: 70%;
    top: 70%;
}

.background_animate li:nth-child(16) {
    animation-delay: 32s;
    left: 60%;
    top: 60%;
}

.background_animate li:nth-child(17) {
    animation-delay: 34s;
    left: 50%;
    top: 50%;
    border-color: #ffffff;
}

.background_animate li:nth-child(18) {
    animation-delay: 36s;
    left: 40%;
    top: 40%;
    border-color: #ffffff;
}

.background_animate li:nth-child(19) {
    animation-delay: 38s;
    left: 30%;
    top:30%;
}

.background_animate li:nth-child(20) {
    animation-delay: 40s;
    left: 20%;
    top: 20%;
    border-color: #ffffff;
}

.background_animate li:nth-child(21) {
    animation-delay: 42s;
    left: 10%;
    top: 10%;
    border-color: #ffffff;
}