通过 matchMedia 获取 Web 中系统主题

JavaScript 中的 API

if (window.matchMedia('(prefers-color-scheme)').media !== 'not all') {
  console.log('???? Dark mode is supported');
}

CSS 媒体查询

.day   { background: #eee; color: black; }
.night { background: #333; color: white; }

@media (prefers-color-scheme: dark) {
  .day.dark-scheme   { background:  #333; color: white; }
  .night.dark-scheme { background: black; color:  #ddd; }
}

@media (prefers-color-scheme: light) {
  .day.light-scheme   { background: white; color:  #555; }
  .night.light-scheme { background:  #eee; color: black; }
}

.day, .night {
  display: inline-block;
  padding: 1em;
  width: 7em;
  height: 2em;
  vertical-align: middle;
}

matchMedia 的兼容性

matchMedia 的 polyfill