fix: Update phone input validation pattern

src/scripts/contact-form.js

@@ -88,9 +88,9 @@ form.addEventListener("submit", function(event) {
     }
 
     // Phone — match format: 123-456-7890
-    const phonePattern = /^\d{3}-\d{3}-\d{4}$/;
+    const phonePattern = /^(\(?\d{3}\)?[-.\s]?\d{3}[-.\s]?\d{4})$/;
     if (!phonePattern.test(phone)) {
-        showError("phone", "Phone number must be in the format 123-456-7890.");
+        showError("phone", "Phone number format is invalid.");
         hasErrors = true;
     }