changedetection.io/changedetectionio/static/js/toggle-theme.js

/**
 * @file
 * Toggles theme between light and dark mode.
 */
$(document).ready(function () {
  const button = document.getElementById("toggle-light-mode");

  button.onclick = () => {
    const htmlElement = document.getElementsByTagName("html");
    const isDarkMode = htmlElement[0].dataset.darkmode === "true";
    htmlElement[0].dataset.darkmode = !isDarkMode;
    if (isDarkMode) {
      button.classList.remove("dark");
      setCookieValue(false);
    } else {
      button.classList.add("dark");
      setCookieValue(true);
    }
  };

  const setCookieValue = (value) => {
    document.cookie = `css_dark_mode=${value};max-age=31536000;path=/`
  }

  // Search input box behaviour
    const toggle_search = document.getElementById("toggle-search");
  const search_q = document.getElementById("search-q");
  window.addEventListener('keydown', function (e) {

    if (e.altKey == true && e.keyCode == 83)
      search_q.classList.toggle('expanded');
      search_q.focus();
  });


  search_q.onkeydown = (e) => {
    var key = e.keyCode || e.which;
    if (key === 13) {
      document.searchForm.submit();
    }
  };
  toggle_search.onclick = () => {
    // Could be that they want to search something once text is in there
    if (search_q.value.length) {
      document.searchForm.submit();
    } else {
      // If not..
      search_q.classList.toggle('expanded');
      search_q.focus();
    }
  };

});