Add email provider error checking to login page.

website/pages/login.html

@@ -198,6 +198,10 @@ <h6 style="text-align: center; color: rgb(197 197 197); font-weight: 500; font-s
             const passwordInput = document.getElementById('passwordInput');
             const emailValue = emailInput.value.trim();
             const emailRegex = /^[a-zA-Z0-9._%+-]+@[a-zA-Z0-9.-]+\.[a-zA-Z]{2,}$/;
+
+            // Trusted email domains
+            const trustedDomains = ["gmail.com", "outlook.com", "yahoo.com", "hotmail.com", "protonmail.com", "icloud.com", "tutanota.com"];
+            const emailDomain = emailValue.split('@')[1];
 
             // Make sure to return the password field to the type['password']
             document.querySelector('.password-field').type = 'password';
@@ -206,6 +210,10 @@ <h6 style="text-align: center; color: rgb(197 197 197); font-weight: 500; font-s
                 alert('Invalid email address');
                 return;
             }
+            if(!trustedDomains.includes(emailDomain)) {
+                alert('Please use a valid email address from trusted providers (e.g., Gmail, Outlook, Yahoo) etc.');
+                return;
+            }
             if (passwordInput.value.length === 0) {
                 alert('Please enter your password');
                 return;