diff --git a/assets/ac_qr_logo.png b/assets/ac_qr_logo.png
index d95f9cb..c8c2e3a 100644
Binary files a/assets/ac_qr_logo.png and b/assets/ac_qr_logo.png differ
diff --git a/assets/js/app.js b/assets/js/app.js
index 9ce9c3e..cc7b557 100644
--- a/assets/js/app.js
+++ b/assets/js/app.js
@@ -1812,19 +1812,33 @@
     }
 
     if (fileForm) {
+      const maxAttachmentBytes = 16 * 1024 * 1024;
       fileForm.addEventListener('submit', function (e) {
         e.preventDefault();
         const fd = new FormData(fileForm);
         fd.append('ticket_id', id);
+        const fileInput = fileForm.querySelector('input[type="file"]');
+        const picked = fileInput && fileInput.files && fileInput.files[0];
+        if (picked && picked.size > maxAttachmentBytes) {
+          if (fileStatus) fileStatus.textContent = 'File too large (max 16 MiB)';
+          return;
+        }
         if (fileStatus) fileStatus.textContent = 'Uploading…';
         const xhr = new XMLHttpRequest();
         xhr.open('POST', basePath() + '/api/ticket_attachments.php', true);
         xhr.onload = function () {
+          if (xhr.status === 413) {
+            if (fileStatus) fileStatus.textContent = 'File too large (max 16 MiB)';
+            return;
+          }
           let data;
           try {
             data = JSON.parse(xhr.responseText);
           } catch {
-            if (fileStatus) fileStatus.textContent = 'Invalid response';
+            if (fileStatus) {
+              fileStatus.textContent =
+                xhr.status >= 400 ? 'Upload failed (HTTP ' + xhr.status + ')' : 'Invalid response';
+            }
             return;
           }
           if (!data.ok) {
@@ -1838,7 +1852,12 @@
           if (fileStatus) fileStatus.textContent = 'Uploaded';
         };
         xhr.onerror = function () {
-          if (fileStatus) fileStatus.textContent = t('reports.network_error');
+          if (fileStatus) {
+            fileStatus.textContent =
+              picked && picked.size > 1024 * 1024
+                ? 'Upload failed — file may exceed server limit (max 16 MiB)'
+                : t('reports.network_error');
+          }
         };
         xhr.send(fd);
       });