Header & working Dark Mode

script.js

@@ -0,0 +1,25 @@
+
+document.addEventListener("DOMContentLoaded", () => {
+    const darkModeButton = document.getElementById("dark-mode-toggle");
+    const body = document.body;
+
+    function toggleDarkMode(save){
+        const isLightMode = body.classList.toggle("light-mode");
+        darkModeButton.textContent = isLightMode ? "☀️" : "🌙";
+    
+        if (save){
+            localStorage.setItem("theme", isLightMode ? "light" : "dark");
+        }
+    }
+
+    // Load Dark Mode preference from cache
+    const theme = localStorage.getItem("theme");
+    if (theme === "dark"){
+        body.classList.remove("light-mode");
+        darkModeButton.textContent = "🌙";
+    }
+
+    darkModeButton.addEventListener("click", () => {
+        toggleDarkMode(true);
+    })    
+})