styles.css

#controls {
  position: fixed;
  top: 10px;
  right: 10px;
  z-index: 1;
  padding: 10px;
  opacity: 0.1;
  background: #fff1;
  border-radius: 3px;
  color: #fff5;
  font-size: 12px;
  font-family: sans-serif;
  transition: 0.1s;
}
#controls:hover {
  opacity: 1;
}

.control {
  display: flex;
  align-items: center;
  padding: 5px;
}

label {
  flex: 1;
}

[type='range'] {
  -webkit-appearance: none;
  appearance: none;
  flex: 1;
  height: 3px;
  margin-left: 10px;
  background: #fff1;
  border-radius: 3px;
  outline: none;
}
[type='range']:focus {
  background: #fff5;
}

[type='range']::-webkit-slider-thumb {
  -webkit-appearance: none;
  appearance: none;
  width: 12px;
  height: 12px;
  background: #00fa9a;
  border-radius: 50%;
  cursor: pointer;
}

#reset {
  padding: 0.5em 0.75em;
  cursor: pointer;
  background: transparent;
  border: 1px solid #00fa9a;
  outline: none;
  border-radius: 3px;
  color: #00fa9a;
  font-family: sans-serif;
}
#reset:hover,
#reset:focus {
  background: #00fa9a;
  color: #000;
}

canvas {
  position: fixed;
  top: 0;
  left: 0;
  background: #000;
}