* {
  position: relative;
}

:root {
  --headerSize: clamp(60px, 10vw, 100px);
  --headerActiveBG: #444;
  --headerActiveText: white;
  --headerOffBG: #ddd;
  --headerOffText: #aaa;
}

body {
  margin: 0;
  font-family: sans-serif;
  background: #ecffed;
}

h1 {
  margin-top: 0px;
  padding-top: 50px;
  text-align: center;
}

.wrapper {
  width: clamp(340px, 80%, 800px);
  margin: auto;
}
.space {
  height: 80vh;
}

p {
  margin: 20px 0 20px 0;
  font-size: clamp(18px, 1.8vw, 30px);
  line-height: 1.6em;
}

.heading-3d-wrapper {
  height: var(--headingSize);
  width: 100%;
  margin-top: 8vw;
}

.heading-3d {
  margin: 0;
  transform-origin: 50% 50% calc(var(--headerSize) / -2);
  height: var(--headerSize);
  transform-style: preserve-3d;
}

.heading-3d div {
  width: 100%;
  position: absolute;
  height: var(--headerSize);
  text-align: center;
}

.heading-3d div h2 {
  text-transform: uppercase;
  font-size: calc(var(--headerSize) / 2);
  line-height: var(--headerSize);
  margin: 0;
  padding: 0;
}

/* top */
.heading-3d div:nth-child(1) {
  transform-origin: 50% 100%;
  transform: translateY(-100%) rotateX(90deg);
  background: var(--headerOffBG);
  color: var(--headerOffText);
}

/* front */
.heading-3d div:nth-child(2) {
  background: var(--headerActiveBG);
  color: var(--headerActiveText);
}

/* bottom */
.heading-3d div:nth-child(3) {
  transform-origin: 0 0;
  transform: translateY(100%) rotateX(-90deg);
  background: var(--headerOffBG);
  color: var(--headerOffText);
}