CSS transform-style Property - Playground Example

<!DOCTYPE html><html><head><style type="text/css">/* Demo showing transform-style: preserve-3d vs flat */
* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: system-ui, -apple-system, Roboto, Arial, sans-serif;
  background: linear-gradient(180deg,#eef6ff,#f7fbff);
  color: #213;
  display: flex;
  align-items: center;
  justify-content: center;
  height: 100vh;
}

.container {
  display: flex;
  gap: 48px;
  align-items: center;
}

.wrap {
  perspective: 900px; /* Provide perspective so 3D effect is visible */
  text-align: center;
}

.box {
  width: 240px;
  height: 140px;
  position: relative;
  margin: 0 auto;
  transform: rotateX(18deg) rotateY(-22deg);
  transition: transform .45s ease;
}

.box.preserve {
  transform-style: preserve-3d; /* children keep their 3D transforms */
}

.box.flat {
  transform-style: flat; /* children are flattened into the box's plane */
}

.surface {
  position: absolute;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 10px;
  color: #fff;
  font-weight: 600;
  box-shadow: 0 10px 30px rgba(16,24,40,0.12);
}

.surface.base {
  background: linear-gradient(135deg,#6c8cff,#8ae1ff);
}

.surface.pop {
  background: linear-gradient(135deg,#ff9a9e,#fecf8a);
  transform: translateZ(40px); /* this Z translation is preserved only when parent has preserve-3d */
}

.label {
  margin-top: 12px;
  font-size: 14px;
  color: #273447;
}

@media (max-width: 640px) {
  .container {
    flex-direction: column;
    gap: 24px;
  }
}
</style></head><body><div class='container'>
  <div class='wrap'>
    <div class='box preserve'>
      <div class='surface base'>Base</div>
      <div class='surface pop'>Pop-out (preserve-3d)</div>
    </div>
    <div class='label'>transform-style: preserve-3d</div>
  </div>

  <div class='wrap'>
    <div class='box flat'>
      <div class='surface base'>Base</div>
      <div class='surface pop'>Pop-out (flat)</div>
    </div>
    <div class='label'>transform-style: flat</div>
  </div>
</div></body></html>