HTMLify

body {
    background-color: #1d1f20;
    min-height: 100vh;
    display: grid;
    place-content: center;
}

.folding-cube {
    width: 4em;
    height: 4em;
    position: relative;
    margin: auto;
    transform: rotateZ(45deg);
}

.folding-cube .cube {
    float: left;
    width: 50%;
    height: 50%;
    position: relative;
    transform: scale(1.1);
}

.folding-cube .cube::before {
    content: "";
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: #57fcff;
    animation: folding-cube 2.4s infinite linear both;
    transform-origin: 100% 100%;
}

.folding-cube .cube-2 {
    transform: scale(1.1) rotateZ(90deg);
}

.folding-cube .cube-3 {
    transform: scale(1.1) rotateZ(180deg);
}

.folding-cube .cube-4 {
    transform: scale(1.1) rotateZ(270deg);
}

.folding-cube .cube-2::before {
    animation-delay: 0.3s;
}

.folding-cube .cube-3::before {
    animation-delay: 0.6s;
}

.folding-cube .cube-4::before {
    animation-delay: 0.9s;
}

@keyframes folding-cube {

    0%,
    10% {
        transform: perspective(140px) rotateX(-180deg);
        opacity: 0;
    }

    25%,
    75% {
        transform: perspective(140px) rotateX(0deg);
        opacity: 1;
    }

    90%,
    100% {
        transform: perspective(140px) rotateY(180deg);
        opacity: 0;
    }
}