til/css/apply-styles-based-on-dark-mode-preferences.md

Apply Styles Based On Dark-Mode Preferences

There is a CSS media query for whether a user prefers a Dark-Mode or Light-Mode color scheme. If you're site is able to provide styling for both modes, then you can hook into those preferences like so:

@media (prefers-color-scheme: dark) {
  /* dark-mode styles */
  /* perhaps changing some custom properties */
}

@media (prefers-color-scheme: light) {
  /* light-mode styles */
  /* perhaps changing some custom properties */
}

As of this writing, prefers-color-scheme is still in a draft state, but it already has decent browser support.

source