Fixes applied to the Barcode scanning

Web/templates/upload_admin.html

@@ -155,6 +155,27 @@
         background-color: #1e7e34;
     }
 
+    /* Quagga Scanner Video Styles */
+    #code4-scanner video, #code4-scanner canvas,
+    #isbn-scanner video, #isbn-scanner canvas {
+        width: 100%;
+        max-width: 640px;
+        height: auto;
+        border-radius: 5px;
+        box-shadow: 0 2px 8px rgba(0,0,0,0.1);
+    }
+    
+    #code4-scanner canvas, #isbn-scanner canvas {
+        position: absolute;
+        top: 0;
+        left: 0;
+    }
+    
+    #code4-scanner, #isbn-scanner {
+        position: relative;
+        overflow: hidden;
+    }
+
     /* ISBN input group styling */
     .isbn-input-group {
         display: flex;
@@ -1125,7 +1146,6 @@
         const scanButton = document.getElementById('scan-code4-btn');
         const scannerBox = document.getElementById('code4-scanner');
         
-        // Scanner stoppen, falls der Modus gewechselt wird und er noch läuft
         if (scannerBox && scannerBox.style.display !== 'none') {
             if (typeof killScannerHardware === 'function') killScannerHardware();
             scannerBox.style.display = 'none';
@@ -1133,11 +1153,10 @@
         }
     
         if (mode === 'range') {
-            rangeGroup.style.display = 'block';
-            if(scanButton) scanButton.style.display = 'none'; // Verstecke Scanner im Range-Modus
+            if(rangeGroup) rangeGroup.style.display = 'block';
+            if(scanButton) scanButton.style.display = 'none'; 
         } else {
-            rangeGroup.style.none = 'none';
-            if(rangeGroup) rangeGroup.style.display = 'none';
+            if(rangeGroup) rangeGroup.style.display = 'none'; // Hier wurde der Fehler korrigiert
             if(scanButton) scanButton.style.display = 'inline-block';
         }
     }
@@ -1884,16 +1903,6 @@
             });
         }
 
-        const scanCodeBtn = document.getElementById('scan-code4-btn');
-        if (scanCodeBtn) {
-            scanCodeBtn.addEventListener('click', startCode4Scanner);
-        }
-
-        const scanIsbnBtn = document.getElementById('scan-isbn-btn');
-        if (scanIsbnBtn) {
-            scanIsbnBtn.addEventListener('click', startIsbnScanner);
-        }
-
         const isbnField = document.getElementById('isbn');
         if (isbnField) {
             isbnField.addEventListener('input', updateIsbnLiveValidation);