Edit in JSFiddle

<div class="stage3d" style="--rotY: 30deg;">
   <div class="plane3d">
     <div class="box3d">
       <div class="face faceZ front">front</div>
       <div class="face faceZ back">back</div>
       <div class="face faceX right">right</div>
       <div class="face faceX left">left</div>
       <div class="face faceY top">top</div>
       <div class="face faceY bottom">bottom</div>
     </div>
   </div>
 </div>

@import https://www.mobzystems.com/3dbox.css

.face { color: white; font-size: 50px; text-align: center; }