:root {
  --bg: #111;
  --fg: #f5e663;
  --face: rgba(245, 230, 99, 0.85);
  --edge: #c9b81e;
  --size: min(40vw, 220px);
}

* {
  box-sizing: border-box;
}

html,
body {
  margin: 0;
  height: 100%;
  background: var(--bg);
  color: var(--fg);
  font-family: ui-monospace, SFMono-Regular, Menlo, monospace;
}

main {
  min-height: 100%;
  display: grid;
  place-items: center;
  align-content: center;
  gap: 2rem;
  padding: 16px;
  user-select: none;
}

h1 {
  margin: 0;
  font-size: clamp(2rem, 8vw, 4rem);
  letter-spacing: 0.1em;
}

.hint {
  margin: 0;
  opacity: 0.5;
}

.scene {
  width: var(--size);
  height: var(--size);
  perspective: calc(var(--size) * 4);
  cursor: grab;
  touch-action: none;
}

.scene:active {
  cursor: grabbing;
}

.cube {
  position: relative;
  width: 100%;
  height: 100%;
  transform-style: preserve-3d;
}

.face {
  position: absolute;
  inset: 0;
  background: var(--face);
  border: 2px solid var(--edge);
  box-shadow: inset 0 0 40px rgba(255, 255, 255, 0.35);
}

.front  { transform: translateZ(calc(var(--size) / 2)); }
.back   { transform: rotateY(180deg) translateZ(calc(var(--size) / 2)); }
.right  { transform: rotateY(90deg) translateZ(calc(var(--size) / 2)); }
.left   { transform: rotateY(-90deg) translateZ(calc(var(--size) / 2)); }
.top    { transform: rotateX(90deg) translateZ(calc(var(--size) / 2)); }
.bottom { transform: rotateX(-90deg) translateZ(calc(var(--size) / 2)); }