diff --git a/web-demo/css/style.css b/web-demo/css/style.css
index e0d4506..95aa42d 100644
--- a/web-demo/css/style.css
+++ b/web-demo/css/style.css
@@ -218,6 +218,13 @@ body {
     transition: all 0.3s ease;
 }
 
+.btn:disabled,
+.btn[aria-busy="true"] {
+    opacity: 0.7;
+    cursor: not-allowed;
+    pointer-events: none;
+}
+
 .btn-primary {
     background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
     color: white;
diff --git a/web-demo/js/app.js b/web-demo/js/app.js
index 11508de..790cab1 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 originalText = '';
+
+        if (submitBtn) {
+            originalText = submitBtn.innerHTML;
+            submitBtn.disabled = true;
+            submitBtn.setAttribute('aria-busy', 'true');
+            submitBtn.innerHTML = '<span class="loading-spinner">⌛</span> 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.removeAttribute('aria-busy');
+                submitBtn.innerHTML = originalText;
+            }
         }
     }
 
@@ -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 originalText = '';
+
+        if (submitBtn) {
+            originalText = submitBtn.innerHTML;
+            submitBtn.disabled = true;
+            submitBtn.setAttribute('aria-busy', 'true');
+            submitBtn.innerHTML = '<span class="loading-spinner">⌛</span> Creating account...';
+        }
 
         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.removeAttribute('aria-busy');
+                submitBtn.innerHTML = originalText;
+            }
         }
     }