A Rescript code used to check if a browser is in Dark Mode

matchmedia.re

// https://developer.mozilla.org/en-US/docs/Web/API/MediaQueryList
type mediaQueryList = {
  matches: bool,
  domString: string
}

// https://developer.mozilla.org/en-US/docs/Web/API/Window/matchMedia
@val @scope("window")
external matchMedia: string => mediaQueryList = "matchMedia"

// Check if the browser is in Dark Mode using the MediaQuery
let isInDarkMode = matchMedia("(prefers-color-scheme: dark)").matches

Based on this: https://stackoverflow.com/questions/56393880/how-do-i-detect-dark-mode-using-javascript