CSS Stage with Light Strings and Stairs

HTML

CSS

@import url('https://fonts.googleapis.com/css2?family=Knewave&display=swap');

*, *::before, *::after {
    padding: 0;
    margin: 0;
    box-sizing: border-box;
}

:root {
  --swingDuration: 32s -28s;
}

body {
  font-family: "Knewave", system-ui;
  background-color: #000;
  color: #fff;
  min-height: 100vh;
  display: grid;
  place-items: center;
  perspective: 50em;
  overflow: hidden;
  
  * {
    transform-style: preserve-3d;
  }
}

.stage {
  position: relative;
  transform: rotateX(90deg) translateZ(-15em);
  animation: stageRotate var(--swingDuration) infinite linear;
  
  * { position: absolute; }
}

@keyframes stageRotate {
  to { rotate: y -360deg; }
}

.floor {
  inset: -100em;
  background:
    radial-gradient(closest-side, transparent, black),
    radial-gradient(#ff0, transparent 0.1em) 0 0 / 7em 4.5em,
    radial-gradient(#ff0, transparent 0.1em) 0 0 / 7.5em 5em,
    radial-gradient(#ff0, transparent 0.1em) 0 0 / 4em 7.5em,
    radial-gradient(#ff0, transparent 0.1em) 0 0 / 4.5em 5em,
    radial-gradient(#ff0, transparent 0.1em) 0 0 / 5em 7.5em,
    radial-gradient(#ff0, transparent 0.1em) 0 0 / 5.5em 4em,
    black;
}

.innerStage {
  inset: -5.75em;
  background-color: #777;
  border-radius: 50%;
  border: 0.25em solid #444;
  transform: translateZ(9em);
}

.innerRing {
  inset: -6em;
  border-radius: 50%;
  box-shadow:
    0 0 0 0.25em white inset,
    0 0 2em white inset;
  transform: translateZ(28em) rotateX(-30deg);
  
  --stringHeight: 36em;
  --w: 6em;
  --h: 6em;
  --rx: -60deg;
  --ro: 6deg;
}

.outerRing {
  inset: -8em -7em;
  border-radius: 50%;
  box-shadow:
    0 0 0 0.25em white inset,
    0 0 2em white inset;
  transform: translateZ(16em) rotateX(-40deg);
  
  --stringHeight: 28em;
  --w: 7em;
  --h: 8em;
  --rx: -50deg;
  --ro: 4deg;
}

.stairsRing {
  inset: -16em -13em;
  transform: translateZ(8em) rotateX(-25deg) rotateZ(180deg);
  
  --stringHeight: 15em;
  --w: 13em;
  --h: 16em;
  --rx: -115deg;
  --ro: 2deg;
  
  &::after {
    content: '';
    position: absolute;
    inset: 0;
    border-radius: 50%;
    box-shadow:
      0 0 0 0.25em white inset,
      0 0 1em white inset;
    clip-path: polygon(0 0, 50% 0, 10% 50%, 50% 100%, 0 100%);
  }
}

.backBar {
  inset: -4em -0.1em;
  background-color: #fff;
  transform: translateZ(14.7em) translateY(-10.5em);
  
  --stringHeight: 15em;
  --rx: -90deg; 
  
  .lightstring {
    left: 0; top: calc(var(--i) * 0.5em);
  }

&::after {
    content: '';
    position: absolute;
    inset: 0;
    background-color: #fff;
    rotate: y 90deg;
    border-radius: 1em;
  }
}

.lightstring {
  left: calc(50% - sin(var(--i) * var(--ro)) * var(--w) - 0.25em);
  top: calc(50% - cos(var(--i) * var(--ro)) * var(--h));
  width: 0.5em; height: var(--stringHeight);
  background-image: radial-gradient(circle at 50% 50%, #fff7, transparent 0.1em);
  background-size: 100% 0.25em;
  transform-origin: top;
  animation: lightstringRotate var(--swingDuration) infinite linear;
  
  &.short {
    height: 2em;
  }
  
  &::after {
    content: '';
    position: absolute;
    left: -2em;
    top: calc(abs(sin(var(--i) * 10deg)) * 100% - 2.25em);
    width: 4.5em; height: 4.5em;
    background-image: radial-gradient(closest-side, var(--_c, #dff), 1%, transparent);
    animation: sparkle 4s calc(abs(sin(var(--i) * 20.5deg)) * -4s) infinite step-end;
  }
  
  &:nth-child(odd) {
    --_c: #ffd;
  }
}

@keyframes lightstringRotate {
  from  { transform: rotateX(var(--rx)) rotateY(0deg); }
  to  { transform: rotateX(var(--rx)) rotateY(360deg); }
}

@keyframes sparkle {
  0%, 10%, 100% { opacity: 0; }
  5% { opacity: 1; }
}

.stair {
  inset: -3em -1em;
  background-color: #444;
  transform-style: flat;
  border: 0.125em solid #777;
  transform:
    rotate(calc(var(--i) * -10deg - 50deg))
    translateY(10em)
    translateZ(calc((var(--i) + 1) * 0.75em));
  
  &:last-child {
    inset: -3em -2em;
    transform:
      rotate(calc(var(--i) * -10deg - 55deg))
      translateY(10em)
      translateZ(calc((var(--i) + 1) * 0.75em));
  }
}

.number {
  inset: -2em;
  display: grid;
  place-items: center;
  transform: rotateX(-90deg) translateY(-2.5em);
  font-size: 6em;
  color: hsl(200 100% 50%);
}

JS

CSS Stage with Light Strings and Stairs

Recommended