codepens/range-pills/dist/style.css

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

:root {
  --bg: hsl(223,10%,90%);
  --fg: hsl(223,10%,10%);
  --orange: hsl(29,90%,55%);
  --yellow: hsl(43,90%,55%);
  --blue: hsl(198,90%,55%);
  --white: hsl(223,10%,100%);
  font-size: calc(20px + (30 - 20) * (100vw - 320px) / (1280 - 320));
}

body, input {
  font: 1em/1.5 "Jost", system-ui, -apple-system, sans-serif;
}

body {
  background: var(--bg);
  color: var(--fg);
  display: flex;
  height: 100vh;
}

form {
  display: grid;
  grid-gap: 0 1.5em;
  grid-template-columns: repeat(2, 1fr);
  margin: auto;
}

label {
  display: block;
}

.range-pill {
  --pillWidth: 4.5em;
  box-shadow: 0 0.375em 0.375em 0 rgba(0, 0, 0, 0.3);
  display: inline-block;
  overflow: hidden;
  position: relative;
  width: var(--pillWidth);
  height: 1.5em;
}
.range-pill, .range-pill:before, .range-pill__input {
  border-radius: 0.75em;
}
.range-pill:before, .range-pill:after, .range-pill__fill, .range-pill__input, .range-pill__value {
  display: block;
  position: absolute;
}
.range-pill:before, .range-pill__fill, .range-pill__input, .range-pill__value {
  top: 0;
  left: 0;
  height: 100%;
}
.range-pill:before, .range-pill__input, .range-pill__value {
  width: 100%;
}
.range-pill:before, .range-pill:after {
  content: "";
  z-index: 3;
}
.range-pill:before {
  background: radial-gradient(0.5em 0.4em at 0.75em 0.5em, rgba(255, 255, 255, 0.25) 30%, rgba(255, 255, 255, 0) 50%);
  box-shadow: 0.05em -0.025em 0.25em 0.05em rgba(255, 255, 255, 0.4) inset, 0.125em -0.125em 0.15em 0.25em rgba(255, 255, 255, 0.07) inset, 0 -0.75em 0.175em 0 rgba(0, 0, 0, 0.07) inset, 0 -0.4em 0.05em 0.2em rgba(255, 255, 255, 0.07) inset, 0 -0.125em 0.05em 0.2em rgba(255, 255, 255, 0.1) inset;
}
.range-pill:after {
  background: rgba(255, 255, 255, 0.25);
  border-radius: 0.125em;
  box-shadow: 0 0 0.1em 0.1em rgba(255, 255, 255, 0.25);
  top: 0.6em;
  left: 1.25em;
  width: calc(var(--pillWidth) - 1.75em);
  height: 0.1em;
}
.range-pill--orange-track, .range-pill--orange-thumb .range-pill__fill {
  background: var(--orange);
}
.range-pill--yellow-track, .range-pill--yellow-thumb .range-pill__fill {
  background: var(--yellow);
}
.range-pill--blue-track, .range-pill--blue-thumb .range-pill__fill {
  background: var(--blue);
}
.range-pill--white-track, .range-pill--white-thumb .range-pill__fill {
  background: var(--white);
}
.range-pill__fill {
  box-shadow: 0 0 0.1em #17181c, -0.05em 0 0 rgba(255, 255, 255, 0.3) inset;
  z-index: 1;
}
.range-pill__input {
  background: transparent;
  cursor: pointer;
  z-index: 4;
  -webkit-appearance: none;
  -moz-appearance: none;
  appearance: none;
  -webkit-tap-highlight-color: transparent;
}
.range-pill__input:focus {
  outline: transparent;
}
.range-pill__input:focus-visible {
  box-shadow: 0 0 0.125em 0.125em #0b46da inset;
}
.range-pill__input::-moz-focus-outer {
  border: 0;
}
.range-pill__input::-webkit-slider-thumb {
  background: transparent;
  border: 0;
  width: 1px;
  height: 1.5em;
  -webkit-appearance: none;
  -moz-appearance: none;
  appearance: none;
}
.range-pill__input::-moz-range-thumb {
  background: transparent;
  border: 0;
  width: 1px;
  height: 1.5em;
  -webkit-appearance: none;
  -moz-appearance: none;
  appearance: none;
}
.range-pill__value {
  color: #17181c;
  font-size: 0.75em;
  line-height: 2;
  text-align: center;
  text-shadow: 0 0 0.2em rgba(23, 24, 28, 0.3), 0.1em 0.1em 0.1em rgba(23, 24, 28, 0.3);
  z-index: 2;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: hsl(223,10%,20%);
    --fg: hsl(223,10%,90%);
  }

  .range-pill {
    box-shadow: 0 0.375em 0.375em 0 rgba(0, 0, 0, 0.3);
  }
  .range-pill:before {
    background: radial-gradient(0.5em 0.4em at 0.75em 0.5em, rgba(255, 255, 255, 0.2) 30%, rgba(255, 255, 255, 0) 50%);
    box-shadow: 0.05em -0.025em 0.25em 0.05em rgba(46, 49, 56, 0.4) inset, 0.125em -0.125em 0.15em 0.25em rgba(46, 49, 56, 0.07) inset, 0 -0.75em 0.175em 0 rgba(0, 0, 0, 0.07) inset, 0 -0.4em 0.05em 0.2em rgba(46, 49, 56, 0.07) inset, 0 -0.125em 0.05em 0.2em rgba(46, 49, 56, 0.1) inset;
  }
}
@media (min-width: 480px) {
  form {
    grid-template-columns: repeat(3, 1fr);
  }
}
@media (min-width: 768px) {
  form {
    grid-template-columns: repeat(4, 1fr);
  }
}