HTMLify

body {
    background-color: #151515;
    display: grid;
    place-items: center;
    height: 100vh;
}

.wandering-cubes {
    width: 4em;
    height: 4em;
    position: relative;
    margin: auto;
}

.wandering-cubes .cube {
    background-color: #33b75d;
    width: 2em;
    height: 2em;
    position: absolute;
    top: 0;
    left: 0;
    animation: wandering-cubes 1.8s ease-in-out -1.8s infinite both;
}

.wandering-cubes .cube-2 {
    animation-delay: -0.9s;
}

@keyframes wandering-cubes {
    0% {
        transform: rotate(0deg);
    }

    25% {
        transform: translateX(3em) rotate(-90deg) scale(0.5);
    }

    50% {
        transform: translateX(3em) translateY(3em) rotate(-179deg);
    }

    50.1% {
        transform: translateX(3em) translateY(3em) rotate(-180deg);
    }

    75% {
        transform: translateX(0) translateY(3em) rotate(-270deg) scale(0.5);
    }

    100% {
        transform: rotate(-360deg);
    }
}