function load() {
    const button = document.querySelector(".btn");
  
    // MediaQueryList object
    const useDark = window.matchMedia("(prefers-color-scheme: dark)");
  
    // Toggles the "dark-mode" class based on if the media query matches
    function toggleDarkMode(state) {
      // Older browser don't support the second parameter in the
      // classList.toggle method so you'd need to handle this manually
      // if you need to support older browsers.
      document.documentElement.classList.toggle("dark-mode", state);
    }
  
    // Initial setting
    toggleDarkMode(useDark.matches);
  
    // Listen for changes in the OS settings
    useDark.addListener((evt) => toggleDarkMode(evt.matches));
  
    // Toggles the "dark-mode" class on click
    button.addEventListener("click", () => {
      document.documentElement.classList.toggle("dark-mode");
    });
  }
  
  window.addEventListener("DOMContentLoaded", load);