backface-visibility

backface-visibility: visible;

backface-visibility: hidden;

<section class="default-example" id="default-example">
  <div id="example-element">
    <div class="face front">1</div>
    <div class="face back">2</div>
    <div class="face right">3</div>
    <div class="face bottom">6</div>
  </div>
</section>

#default-example {
  background: linear-gradient(skyblue, khaki);
}

#example-element {
  width: 100px;
  height: 100px;
  perspective: 550px;
  perspective-origin: 220% 220%;
  transform-style: preserve-3d;
}

.face {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 100%;
  height: 100%;
  position: absolute;
  backface-visibility: inherit;
  background: rgb(0 0 0 / 0.4);
  font-size: 60px;
  color: white;
}

.front {
  transform: translateZ(50px);
}

.back {
  background: rgb(230 0 0);
  color: white;
  transform: rotateY(180deg) translateZ(50px);
}

.right {
  background: rgb(0 0 0 / 0.6);
  transform: rotateY(90deg) translateZ(50px);
}

.bottom {
  background: rgb(0 0 0 / 0.6);
  transform: rotateX(-90deg) translateZ(50px);
}

/* Keyword values */
backface-visibility: visible;
backface-visibility: hidden;

/* Global values */
backface-visibility: inherit;
backface-visibility: initial;
backface-visibility: revert;
backface-visibility: revert-layer;
backface-visibility: unset;

<table>
  <tr>
    <th><code>backface-visibility: visible;</code></th>
    <th><code>backface-visibility: hidden;</code></th>
  </tr>
  <tr>
    <td>
      <div class="container">
        <div class="cube show-bf">
          <div class="face front">1</div>
          <div class="face back">2</div>
          <div class="face right">3</div>
          <div class="face left">4</div>
          <div class="face top">5</div>
          <div class="face bottom">6</div>
        </div>
      </div>
      <p>
        Since all faces are partially transparent, the back faces (2, 4, 5) are
        visible through the front faces (1, 3, 6).
      </p>
    </td>
    <td>
      <div class="container">
        <div class="cube hide-bf">
          <div class="face front">1</div>
          <div class="face back">2</div>
          <div class="face right">3</div>
          <div class="face left">4</div>
          <div class="face top">5</div>
          <div class="face bottom">6</div>
        </div>
      </div>
      <p>The three back faces (2, 4, 5) are hidden.</p>
    </td>
  </tr>
</table>

/* Classes that will show or hide the
   three back faces of the "cube" */
.show-bf div {
  backface-visibility: visible;
}

.hide-bf div {
  backface-visibility: hidden;
}

/* Define the container div, the cube div, and a generic face */
.container {
  width: 150px;
  height: 150px;
  margin: 75px 0 0 75px;
  border: none;
}

.cube {
  width: 100%;
  height: 100%;
  perspective: 550px;
  perspective-origin: 150% 150%;
  transform-style: preserve-3d;
}

.face {
  display: block;
  position: absolute;
  width: 100px;
  height: 100px;
  border: none;
  line-height: 100px;
  font-family: sans-serif;
  font-size: 60px;
  color: white;
  text-align: center;
}

/* Define each face based on direction */
.front {
  background: rgb(0 0 0 / 30%);
  transform: translateZ(50px);
}

.back {
  background: lime;
  color: black;
  transform: rotateY(180deg) translateZ(50px);
}

.right {
  background: rgb(196 0 0 / 70%);
  transform: rotateY(90deg) translateZ(50px);
}

.left {
  background: rgb(0 0 196 / 70%);
  transform: rotateY(-90deg) translateZ(50px);
}

.top {
  background: rgb(196 196 0 / 70%);
  transform: rotateX(90deg) translateZ(50px);
}

.bottom {
  background: rgb(196 0 196 / 70%);
  transform: rotateX(-90deg) translateZ(50px);
}

/* Make the table a little nicer */
th,
p,
td {
  background-color: #eeeeee;
  margin: 0px;
  padding: 6px;
  font-family: sans-serif;
  text-align: left;
}