Add functioning site-wide dark mode

static/js/custom.js

@@ -1,4 +0,0 @@
-function toggleDarkMode() {
-  document.body.classList.toggle("dark-mode");
-}
-

static/js/main.js

@@ -0,0 +1,44 @@
+document.addEventListener("DOMContentLoaded", function() {
+  setDarkMode()
+})
+
+
+function setCookie(cname, cvalue, exdays) {
+  document.cookie = cname + "=" + cvalue + ";path=/";
+}
+
+function getCookie(cname) {
+  let name = cname + "=";
+  let decodedCookie = decodeURIComponent(document.cookie);
+  let ca = decodedCookie.split(';');
+  for(let i = 0; i <ca.length; i++) {
+    let c = ca[i];
+    while (c.charAt(0) == ' ') {
+      c = c.substring(1);
+    }
+    if (c.indexOf(name) == 0) {
+      return c.substring(name.length, c.length);
+    }
+  }
+  return "";
+}
+
+function isStringTrue(val) {
+  return String(val).toLowerCase() === 'true'
+}
+
+function toggleDarkMode() {
+  let darkMode = getCookie("setDarkMode");
+  if(isStringTrue(darkMode))
+    setCookie("setDarkMode", false);
+  else
+    setCookie("setDarkMode", true);
+    document.body.classList.toggle("dark-mode");
+}
+
+
+function setDarkMode() {
+  let darkMode = getCookie("setDarkMode");
+  if(isStringTrue(darkMode))
+    document.body.classList.toggle("dark-mode");
+}