diff --git a/admin-dashboard.html b/admin-dashboard.html
index 4cc6118..2516a0e 100644
--- a/admin-dashboard.html
+++ b/admin-dashboard.html
@@ -710,7 +710,6 @@
             }
         }
 
-        // Save banner
         async function saveBanner(event) {
             event.preventDefault();
             
@@ -730,15 +729,20 @@
                 formData.append('text', document.getElementById('bannerText').value);
                 formData.append('link', document.getElementById('bannerLink').value);
                 
-                // Add style properties to form data with the correct format
-                formData.append('style.backgroundColor', document.getElementById('bannerBgColor').value);
-                formData.append('style.textColor', document.getElementById('bannerTextColor').value);
-                formData.append('style.textAlign', document.getElementById('bannerTextAlign').value);
-                formData.append('style.fontSize', document.getElementById('bannerFontSize').value);
-                formData.append('style.padding', document.getElementById('bannerPadding').value);
-                formData.append('style.margin', document.getElementById('bannerMargin').value);
-                formData.append('style.borderRadius', document.getElementById('bannerBorderRadius').value);
-                formData.append('style.isVisible', document.getElementById('bannerVisible').checked);
+                // Create style object with default values
+                const style = {
+                    backgroundColor: document.getElementById('bannerBgColor').value,
+                    textColor: document.getElementById('bannerTextColor').value,
+                    textAlign: document.getElementById('bannerTextAlign').value,
+                    fontSize: document.getElementById('bannerFontSize').value || '16px',
+                    padding: document.getElementById('bannerPadding').value || '0px',
+                    margin: document.getElementById('bannerMargin').value || '0px',
+                    borderRadius: document.getElementById('bannerBorderRadius').value || '0px',
+                    isVisible: document.getElementById('bannerVisible').checked
+                };
+        
+                // Convert style object to JSON string and append to form data
+                formData.append('style', JSON.stringify(style));
                 
                 // Log form data for debugging
                 console.log('Odesílám data:');  
@@ -746,7 +750,7 @@
                     console.log(key, value);
                 }
                 
-                // Create a new headers object
+                // Create headers object
                 const headers = {};
                 
                 // Add Authorization header if token exists
@@ -761,9 +765,7 @@
                 const response = await fetch('/api/banner/update', {
                     method: 'POST',
                     headers: headers,
-                    body: formData,
-                    // Don't set Content-Type header manually when using FormData with files
-                    // The browser will set it automatically with the correct boundary
+                    body: formData
                 });
 
                 if (!response.ok) {