skymod.css

html {
  height: -webkit-fill-available;
}
body {
  --angle: 270deg;
  --hue1: 40;
  --hue2: 189;
  --hue3: 330;
  --hue4: 270;
  --light: 50%;
  --l: 0.40;
  --r1: oklch(var(--l) 0.1 60 / 0.75);

  background-image:
    linear-gradient(var(--angle), hsl(var(--hue1), 100%, var(--light)), hsl(var(--hue2), 100%, var(--light)));
  font-family: 'Montserrat', sans-serif;
  margin: 0;
  min-height: 100vh;
  min-height: -webkit-fill-available;
  overflow: hidden;
  padding: 1ch;
}

.daynight {
  background-color: hsla(0, 0%, 0%, 0.15);
  border: 1px solid var(--r1);
  border-radius: 3em;
  color: hsla(0, 0%, 100%, 0.8);
  display: grid;
  padding: .65em;
  position: relative;
  width: 100%;
}
/* Espaciado */
.daynight-icons {
  display: flex;
  justify-content: space-between;
  pointer-events: none;
  position: relative;
  z-index: 1;
}

.daynight-icons svg {
  fill: none;
  height: 2em;
  stroke-linecap: round;
  stroke-linejoin: round;
  stroke-width: 1.25;
  stroke: currentColor;
  width: 2em;
}
.daynight-input {
  appearance: none;
  background: transparent;
  inset: 0;
  position: absolute;
}
.daynight-input::-webkit-slider-runnable-track {
  height: 100%;
  width: 100%;
}
.daynight-input::-webkit-slider-thumb {
  appearance: none;
  aspect-ratio: 1 / 1;
  background: var(--r1);
  border-radius: 100%;
  height: 100%;
}

/* -Boton desplazador- */
@-moz-document url-prefix() { 
  .daynight-input {
     height: 100%;
     width: 100%;
  }
}
/* Tamaño */
.daynight-input::-moz-range-track {
  border-radius: 3em;
  height: 100%;
  width: 100%;
}
/* Color */
.daynight-input::-moz-range-thumb {
  appearance: none;
  aspect-ratio: 1 / 1;
  background: hsla(30, 2%, 60%, 0.5);
  border-radius: 100%;
  height: 75%;
  width: 70px;
}

/* Estrellas */
#stars {
  inset: 60px 0 0 0;
  opacity: calc(50% - var(--light));
  position: fixed;
  z-index: -1;
}

#stars circle {
  animation: fade var(--animdur) linear infinite;
}

#stars line {
  opacity: 0.1;
}

@keyframes fade {
  0%, 100% { opacity: 0.25 }
  50% { opacity: 1 }
}

/* Media Query */
@media screen and (max-width: 480px){
  .daynight {
    display: grid;
    padding: .65em;
    position: fixed;
    width: 100%;
  }  
}