*
{
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}
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; 
   transform: rotateX(-30deg);
   animation: animate 4s linear infinite;
}
@keyframes animate{
   0% {
    transform: rotateX(-30deg) rotateY(0deg);
   }
   100%{
    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); /* 300 / 2 = 150*/;
   
}
.top{
    position: absolute;
    top: 0;
    left: 0;
    width: 300px;
    height: 300px;
    background-color:#06080a;
    transform: rotateX(90deg) translateZ(150px);
    border: #172917;
    border-radius: 5px;
    border-width: 20px;
    border-style: groove;
}
.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);

}