dark-mode via css media query and classes via javascript

dark-mode-via-css-media-query-and-classes-via-javascript.css

/** Common CSS */
html {
  background: #FFFFFF;
}

html.dark-mode {
  filter: invert(100%);
}

html.dark-mode img {
  filter: invert(100%);
}

// Detect if the user has requested the system
// use a light or dark color theme.
// More details about `prefers-color-scheme` in https://web.dev/prefers-color-scheme/
@media (prefers-color-scheme: dark) {
  // Important
  // you should add dark-mode if your html element
  // does not have `.light-mode` class in place
  // so you page can still respect the dark theme configuration 
  // from your user system
  html:not(.light-mode) {
    filter: invert(100%);
  }

  html:not(.light-mode) img {
    filter: invert(100%);
  }
}
/** Common CSS */

/** Switch styles */
.switch-toggle {
  /** The display value will be changes via Javascript.
    So it the browser supports media query manipulation, 
    it shows this option */
  display: none;
  flex-direction: row;
  margin-bottom: 45px;
  margin-top: 20px;
  min-height: 50px;
}

.switch-toggle input[type=checkbox] {
  height: 0;
  width: 0;
  visibility: hidden;
}

.switch-toggle label {
  cursor: pointer;
  text-indent: -9999px;
  width: 100px;
  height: 50px;
  background: #bada55;
  display: block;
  border-radius: 50px;
  position: relative;
}

.switch-toggle label:after {
  content: "";
  position: absolute;
  top: 5px;
  left: 5px;
  width: 40px;
  height: 40px;
  background: #fff;
  border-radius: 40px;
  transition: 0.3s;
}

.switch-toggle input:checked + .active {
  background: #bada55;
}

.switch-toggle input:checked + .active:after {
  left: calc(100% - 5px);
  transform: translateX(-100%);
}

.switch-toggle label:after {
  width: 65px;
}
/** Switch styles */