如何用CSS3构建一个具有内外嵌套和粗边框效果的Webpack Logo旋转立方体？

<div class="cube outer">
  <div class="face front"></div>
  <div class="face back"></div>
  <div class="face top"></div>
  <div class="face bottom"></div>
  <div class="face left"></div>
  <div class="face right"></div>
  <div class="cube inner">
    <div class="face front"></div>
    <div class="face back"></div>
    <div class="face top"></div>
    <div class="face bottom"></div>
    <div class="face left"></div>
    <div class="face right"></div>
  </div>
</div>

body {
  background: #2b3a42;
}

:root {
  --depth: 50px;
}

.cube {
  width: 100px;
  height: 100px;
  position: relative;
  transform-style: preserve-3d;
  transform: translate(-50%, -50%) rotateX(-35deg) rotateY(-135deg) translateZ(var(--depth));
  position: absolute;
  top: 50%;
  left: 50%;
}

.face {
  position: absolute;
  width: 100px;
  height: 100px;
  box-sizing: border-box;
  z-index: -1;
}

.front {
  transform: translateZ(var(--depth));
}

.back {
  transform: rotateY(180deg) translateZ(var(--depth));
}

.top {
  transform: rotateX(90deg) translateZ(var(--depth));
}

.bottom {
  transform: rotateX(-90deg) translateZ(var(--depth));
}

.left {
  transform: rotateY(-90deg) translateZ(var(--depth));
}

.right {
  transform: rotateY(90deg) translateZ(var(--depth));
}

.outer > .face {
  background: #75afcc;
  border: 1px solid white;
}

.outer > .back, .outer > .top, .outer > .right { /* 粗边框效果 */
  background: none;
  border-width: 0.5px;
  border-right-width: 5px;
  border-bottom-width: 5px;
  z-index: 100;
}

.inner {
  width: 50px;
  height: 50px;
  transform: translate(-50%, -50%);
}

.inner > .face {
  --depth: 25px;
  width: 50px;
  height: 50px;
  background: #5299c8;
}