CubeTime/style.css

@import url('https://fonts.googleapis.com/css2?family=Poppins:ital,wght@0,100;0,200;0,300;0,400;0,500;0,600;0,700;0,800;0,900;1,100;1,200;1,300;1,400;1,500;1,600;1,700;1,800;1,900&display=swap');
*{
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Poppins', sans-serif;
    user-select: none;
}
body{
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    background: #050505;
}
.cube{
    position: relative;
    width: 300px;
    height: 300px;
    transform-style: preserve-3d;
    animation: animate 12s linear infinite;
}
@keyframes animate{
    from{transform: rotateX(-30deg) rotateY(0deg);}
    to{transform: rotateX(-30deg) rotateY(360deg);}
}
.cube div{
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    transform-style: preserve-3d;
}
.cube div span{
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: linear-gradient(#151515, #00ec00);
    transform: rotateY(calc(90deg * var(--i))) translateZ(150px);
}
.top{
    position: absolute;
    top: 0;
    left: 0;
    width: 300px;
    height: 300px;
    background: #222;
    transform: rotateX(90deg) translateZ(150px);
}
.top::after{
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 300px;
    height: 300px;
    background: #00ec00;
    transform: translateZ(-300px);
}
.top::before{
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 300px;
    height: 300px;
    background: #0f0;
    transform: translateZ(-380px);
    filter: blur(20px);
    box-shadow: 
        0 0 120px rgba(0,255,0,0.2),
        0 0 200px rgba(0,255,0,0.4),
        0 0 300px rgba(0,255,0,0.6),
        0 0 400px rgba(0,255,0,0.8),
        0 0 500px rgba(0,255,0,1);
}
.side{
    color: #fff;
    position: relative;
    width: 100%;
    height: 100%;
    transform: translateZ(50rem);
    text-align: center;
    display: flex;
    justify-content: center;
    align-items: center;
    font-size: 4em;
    text-shadow: 0 0 50px #050505;
}