Update

static/js/theme-mode.js

@@ -0,0 +1,29 @@
+function switchTheme() {
+  const currentStyle = currentTheme();
+
+  if (currentStyle == 'light') {
+    setTheme('dark');
+  }
+  else {
+    setTheme('light');
+  }
+}
+
+function setTheme(style) {
+  console.log(`set theme ${style}`);
+  document.querySelectorAll('.isInitialToggle').forEach(elem => {
+    elem.classList.remove('isInitialToggle');
+  });
+  document.documentElement.setAttribute('data-color-mode', style);
+  localStorage.setItem('data-color-mode', style);
+}
+
+function currentTheme() {
+  const localStyle = localStorage.getItem('data-color-mode');
+  const systemStyle = window.matchMedia && window.matchMedia('(prefers-color-scheme: dark)').matches ? 'dark' : 'light';
+  return localStyle || systemStyle;
+}
+
+(() => {
+  setTheme(currentTheme());
+})();