First Commit

public/js/theme-toggle.js

@@ -0,0 +1,21 @@
+(function () {
+    var STORAGE_KEY = 'bloomfeed-theme';
+
+    function applyTheme(theme) {
+        document.documentElement.setAttribute('data-theme', theme);
+    }
+
+    document.addEventListener('DOMContentLoaded', function () {
+        var toggle = document.querySelector('[data-theme-toggle]');
+        if (!toggle) {
+            return;
+        }
+
+        toggle.addEventListener('click', function () {
+            var current = document.documentElement.getAttribute('data-theme') === 'dark' ? 'dark' : 'light';
+            var next = current === 'dark' ? 'light' : 'dark';
+            applyTheme(next);
+            localStorage.setItem(STORAGE_KEY, next);
+        });
+    });
+})();