style.css

* {
  box-sizing: border-box;
}
:root {
  --on: 0;
  --bg: hsl(calc(200 - (var(--on) * 160)), calc((20 + (var(--on) * 50)) * 1%), calc((20 + (var(--on) * 60)) * 1%));
  --cord: hsl(0, 0%, calc((60 - (var(--on) * 50)) * 1%));
  --stroke: hsl(0, 0%, calc((60 - (var(--on) * 50)) * 1%));
  --shine: hsla(0, 0%, 100%, calc(0.75 - (var(--on) * 0.5)));
  --cap: hsl(0, 0%, calc((40 + (var(--on) * 30)) * 1%));
  --filament: hsl(45, calc(var(--on) * 80%), calc((25 + (var(--on) * 75)) * 1%));
}
body {
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--bg);
}
.toggle-scene {
  overflow: visible !important;
  height: 50vmin;
  position: absolute;
}
.toggle-scene__cord {
  stroke: var(--cord);
  cursor: move;
}
.toggle-scene__cord:nth-of-type(1) {
  display: none;
}
.toggle-scene__cord:nth-of-type(2),
.toggle-scene__cord:nth-of-type(3),
.toggle-scene__cord:nth-of-type(4),
.toggle-scene__cord:nth-of-type(5) {
  display: none;
}
.toggle-scene__cord-end {
  stroke: var(--cord);
  fill: var(--cord);
}
.toggle-scene__dummy-cord {
  stroke-width: 6;
  stroke: var(--cord);
}
.bulb__filament {
  stroke: var(--filament);
}
.bulb__shine {
  stroke: var(--shine);
}
.bulb__flash {
  stroke: #f5e0a3;  /*#f5e0a3*/
  display: none;
}
.bulb__bulb {
  stroke: var(--stroke);
  fill: hsla(calc(180 - (95 * var(--on))), 80%, 80%, calc(0.1 + (0.4 * var(--on))));
}
.bulb__cap {
  fill: var(--cap);
}
.bulb__cap-shine {
  fill: var(--shine);
}
.bulb__cap-outline {
  stroke: var(--stroke);
}