ar.falsy.cat/assets/darkmode.scss

.darkmode {
  text-align: right;

  & > .toggle {
    display: none;
    box-sizing: border-box;

    &:checked + .toggle-button:after {
      left: 50%;
    }

    & + .toggle-button {
      box-sizing: border-box;
      outline: 0;
      display: inline-block;
      width: 3em;
      height: 1.5em;
      position: relative;
      cursor: pointer;
      border: 2px solid var(--gray);
      user-select: none;
      padding: 2px;
      transition: all 0.2s ease;
      border-radius: 2em;

      &:after, &:before {
        position: relative;
        display: block;
        box-sizing: border-box;
        content: "";
        width: 50%;
        height: 100%;
      }

      &:before {
        display: none;
      }

      &:after {
        left: 0;
        transition: all 0.2s ease;
        background: var(--gray);
        content: "";
        border-radius: 1em;
      }
    }
  }

  & #dayIcon {
    position: relative;
    width: 20px;
    height: 20px;
    top: -1.5px;
    margin: 0 7px;
    fill: var(--gray);
  }

  & #nightIcon {
    position: relative;
    width: 18px;
    height: 18px;
    top: -2px;
    margin: 0 7px;
    fill: var(--gray);
  }
}