estilos.css

* {
    box-sizing: border-box;
}

body {
    perspective: 820px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: #DFDFDF;
    min-height: 100vh;
    overflow: hidden;
}

.tirar {
    position: fixed;
    top: 10px;
    left: 10px;
    padding: 7px;
    outline: none;
    border: none;
    border-radius: 4px;
    background: #0f526d;
    color: #fff;
    cursor: pointer;
    font-size: 20px;
    transition: all .5s ease;
}

.tirar:hover, .tirar:focus {
    opacity: 0.8;
}

.cubo {
    height: 150px;
    width: 150px;
    position: relative;
    transform-style: preserve-3d;
    transition: all 2s ease;
}

.lado {
    position: absolute;
    width: 100%;
    height: 100%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 4em;
    font-weight: bold;
    border: 2px solid #000;
    background: #fff;
}

.lado:nth-child(1) {
    transform: translateZ(75px);
}

.lado:nth-child(2) {
    transform: rotateX(90deg) translateZ(75px);
}

.lado:nth-child(2) div:nth-child(1) {
    margin-top: 80px;
    margin-left: 80px;
}

.lado:nth-child(2) div:nth-child(2) {
    margin-bottom: 80px;
    margin-right: 80px;
}

.lado:nth-child(3) {
    transform: rotateY(90deg) translateZ(75px);
}

.lado:nth-child(4) {
    transform: translateZ(-75px);
}

.lado:nth-child(4) div:nth-child(1) {
    margin-top: 50px;
}

.lado:nth-child(4) div:nth-child(2) {
    margin-bottom: 60px;
}

.lado:nth-child(5) {
    transform: rotateX(90deg) translateZ(-75px);
}

.lado:nth-child(5) div:nth-child(1) {
    margin-top: 90px;
    margin-left: 90px;
}

.lado:nth-child(5) div:nth-child(2) {
    margin-top: 90px;
    margin-right: 90px;
}

.lado:nth-child(5) div:nth-child(3) {
    margin-bottom: 90px;
    margin-right: 90px;
}

.lado:nth-child(5) div:nth-child(4) {
    margin-bottom: 90px;
    margin-left: 90px;
}

.lado:nth-child(6) {
    transform: rotateY(90deg) translateZ(-75px);
}

.lado:nth-child(6) div:nth-child(1) {
    margin-top: 90px;
    margin-right: 90px;
}

.lado:nth-child(6) div:nth-child(2) {
    margin-top: 90px;
    margin-left: 90px;
}

.lado:nth-child(6) div:nth-child(3) {
    margin-bottom: 90px;
    margin-left: 90px;
}

.lado:nth-child(6) div:nth-child(4) {
    margin-bottom: 90px;
    margin-right: 90px;
}

.lado div {
    position: absolute;
}