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HTML

            
              <div class="cube">
    <div class="cube-face  cube-face-front"></div>
    <div class="cube-face  cube-face-back"></div>
    <div class="cube-face  cube-face-left"></div>
    <div class="cube-face  cube-face-right"></div>
    <div class="cube-face  cube-face-top"></div>
    <div class="cube-face  cube-face-bottom"></div>
 </div>
            
          
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CSS

            
              $size: 150px; // cube length
.cube {
  width: $size;
  height: $size;
  position: relative;
}
.cube-face {
  width: inherit;
  height: inherit;
  position: absolute;
  background: red;
  opacity: 0.7;
}
            
          
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JS

            
              
            
          
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