stylus/options/onoffswitch.css

/* On/Off FlipSwitch https://proto.io/freebies/onoff/ */

:root {
  --slider-enabled-bg: hsl(165, 45%, 84%);
  --slider-enabled-border: hsl(165, 45%, 82%);
  --slider-enabled-circle: hsl(171, 96%, 37%);
}

.onoffswitch {
  position: relative;
  margin: 1ex 0;
  -webkit-user-select: none;
  -moz-user-select: none;
  -ms-user-select: none;
}

.onoffswitch input {
  -webkit-appearance: none;
  -moz-appearance: none;
  pointer-events: none;
  position: absolute;
  top: -8px;
  bottom: -10px;
  left: -10px;
  width: calc(100% + 12px);
}

#message-box .onoffswitch input {
  top: -6px;
  left: -6px;
  bottom: 0;
  height: calc(100% + 12px);
}

.onoffswitch span {
  display: block;
  overflow: hidden;
  cursor: pointer;
  height: 12px;
  padding: 0;
  line-height: 12px;
  border: 1px solid var(--gray-lightness-84);
  border-radius: 12px;
  background-color: var(--gray-lightness-87);
  box-shadow: inset 2px 2px 4px var(--black-alpha-15);
}

.onoffswitch span::before {
  content: "";
  display: block;
  width: 18px;
  height: 18px;
  margin: -3px;
  background: var(--gray-lightness-92);
  position: absolute;
  top: 0;
  bottom: 0;
  right: 46px;
  border-radius: 18px;
  box-shadow: 0 3px 13px 0 var(--black-alpha-45);
}

.onoffswitch input:checked + span {
  background-color: var(--slider-enabled-bg);
}

.onoffswitch input:checked + span, .onoffswitch input:checked + span::before {
  border-color: var(--slider-enabled-border);
}

.onoffswitch input:checked + span .onoffswitch-inner {
  margin-left: 0;
}

.onoffswitch input:checked + span::before {
  right: 0;
  background-color: #04BA9F;
  box-shadow: 3px 6px 18px 0 var(--black-alpha-25);
}