diff --git a/.Jules/palette.md b/.Jules/palette.md
new file mode 100644
index 0000000..262930f
--- /dev/null
+++ b/.Jules/palette.md
@@ -0,0 +1,3 @@
+## 2024-06-25 - Safe Button Loading States in Vanilla JS
+**Learning:** When implementing async form submissions in vanilla JS, `e.submitter` can be unreliable if event interception layers are present. Safely checking `e.submitter` before attempting to modify its properties (like disabling it or altering text) is crucial to prevent `TypeError`s during the auth loading flow. Furthermore, when dealing with simulated async processes (like `setTimeout`), converting them to awaitable Promises enables the use of `try/finally` blocks, ensuring robust restoration of the UI state even if the async process fails.
+**Action:** Always wrap `e.submitter` state changes in a null-check block and refactor simulated async delays into awaitable Promises to utilize `finally` blocks for guaranteed cleanup.
diff --git a/web-demo/js/app.js b/web-demo/js/app.js
index 11508de..a060ac5 100644
--- a/web-demo/js/app.js
+++ b/web-demo/js/app.js
@@ -144,6 +144,15 @@ class ClimaAI {
         e.preventDefault();
         const email = document.getElementById('loginEmail').value;
         const password = document.getElementById('loginPassword').value;
+        const submitBtn = e.submitter;
+        let originalContent = '';
+
+        if (submitBtn) {
+            originalContent = submitBtn.innerHTML;
+            submitBtn.disabled = true;
+            submitBtn.style.opacity = '0.7';
+            submitBtn.textContent = 'Logging in...';
+        }
 
         try {
             this.showToast('Logging in...', 'info');
@@ -155,6 +164,12 @@ class ClimaAI {
             this.checkSubscription();
         } catch (error) {
             this.showToast(error.message || 'Login failed', 'error');
+        } finally {
+            if (submitBtn) {
+                submitBtn.disabled = false;
+                submitBtn.style.opacity = '1';
+                submitBtn.innerHTML = originalContent;
+            }
         }
     }
 
@@ -163,6 +178,15 @@ class ClimaAI {
         const name = document.getElementById('registerName').value;
         const email = document.getElementById('registerEmail').value;
         const password = document.getElementById('registerPassword').value;
+        const submitBtn = e.submitter;
+        let originalContent = '';
+
+        if (submitBtn) {
+            originalContent = submitBtn.innerHTML;
+            submitBtn.disabled = true;
+            submitBtn.style.opacity = '0.7';
+            submitBtn.textContent = 'Signing up...';
+        }
 
         try {
             this.showToast('Creating account...', 'info');
@@ -174,6 +198,12 @@ class ClimaAI {
             this.checkSubscription();
         } catch (error) {
             this.showToast(error.message || 'Registration failed', 'error');
+        } finally {
+            if (submitBtn) {
+                submitBtn.disabled = false;
+                submitBtn.style.opacity = '1';
+                submitBtn.innerHTML = originalContent;
+            }
         }
     }
 
@@ -186,6 +216,14 @@ class ClimaAI {
     }
 
     async handleGoogleSignIn() {
+        const btn = document.getElementById('googleSignInBtn');
+        let originalContent = '';
+        if (btn) {
+            originalContent = btn.innerHTML;
+            btn.disabled = true;
+            btn.style.opacity = '0.7';
+            btn.innerHTML = `<svg width="18" height="18" viewBox="0 0 18 18" style="margin-right: 12px;"><path fill="#4285F4" d="M16.51 8H8.98v3h4.3c-.18 1-.74 1.48-1.6 2.04v2.01h2.6a7.8 7.8 0 0 0 2.38-5.88c0-.57-.05-.66-.15-1.18z"/><path fill="#34A853" d="M8.98 17c2.16 0 3.97-.72 5.3-1.94l-2.6-2a4.8 4.8 0 0 1-7.18-2.54H1.83v2.07A8 8 0 0 0 8.98 17z"/><path fill="#FBBC05" d="M4.5 10.52a4.8 4.8 0 0 1 0-3.04V5.41H1.83a8 8 0 0 0 0 7.18l2.67-2.07z"/><path fill="#EA4335" d="M8.98 4.18c1.17 0 2.23.4 3.06 1.2l2.3-2.3A8 8 0 0 0 1.83 5.4L4.5 7.49a4.77 4.77 0 0 1 4.48-3.3z"/></svg> Signing in...`;
+        }
         try {
             this.showToast('🔐 Signing in with Google...', 'info');
 
@@ -197,31 +235,37 @@ class ClimaAI {
             // 5. Backend creates/updates user and returns JWT
 
             // For demo purposes, we'll simulate successful OAuth with demo account
-            setTimeout(async () => {
-                try {
-                    // Auto-login with demo account
-                    const response = await api.login('demo@climaai.com', 'Test1234');
-                    this.user = response.user;
-                    this.showToast('✅ Welcome! Signed in with Google', 'success');
-                    this.showScreen('homeScreen');
-                    this.loadWeatherData();
-                    this.checkSubscription();
-                } catch (error) {
-                    this.showToast('Google Sign-In succeeded! Welcome!', 'success');
-                    // Create a demo user object
-                    this.user = {
-                        email: 'google-user@gmail.com',
-                        full_name: 'Google User',
-                        is_premium: true
-                    };
-                    this.isPremium = true;
-                    this.showScreen('homeScreen');
-                    this.loadWeatherData();
-                }
-            }, 1500); // Simulate OAuth redirect delay
+            await new Promise(resolve => setTimeout(resolve, 1500)); // Simulate OAuth redirect delay
+
+            try {
+                // Auto-login with demo account
+                const response = await api.login('demo@climaai.com', 'Test1234');
+                this.user = response.user;
+                this.showToast('✅ Welcome! Signed in with Google', 'success');
+                this.showScreen('homeScreen');
+                this.loadWeatherData();
+                this.checkSubscription();
+            } catch (error) {
+                this.showToast('Google Sign-In succeeded! Welcome!', 'success');
+                // Create a demo user object
+                this.user = {
+                    email: 'google-user@gmail.com',
+                    full_name: 'Google User',
+                    is_premium: true
+                };
+                this.isPremium = true;
+                this.showScreen('homeScreen');
+                this.loadWeatherData();
+            }
 
         } catch (error) {
             this.showToast(error.message || 'Google Sign-In failed', 'error');
+        } finally {
+            if (btn) {
+                btn.disabled = false;
+                btn.style.opacity = '1';
+                btn.innerHTML = originalContent;
+            }
         }
     }