diff --git a/Web/templates/library_table.html b/Web/templates/library_table.html
index ea8d676..ed183db 100644
--- a/Web/templates/library_table.html
+++ b/Web/templates/library_table.html
@@ -614,6 +614,199 @@
 </div>
 <script src="https://cdn.jsdelivr.net/npm/@ericblade/quagga2/dist/quagga.js"></script>
 <script>
+
+    // =========================================================================
+    // CUSTOM MODAL HELPERS (Replaces native browser alert, confirm & prompt)
+    // =========================================================================
+    function createModalOverlay() {
+        const overlay = document.createElement('div');
+        overlay.style.position = 'fixed';
+        overlay.style.top = '0';
+        overlay.style.left = '0';
+        overlay.style.width = '100vw';
+        overlay.style.height = '100vh';
+        overlay.style.backgroundColor = 'rgba(0, 0, 0, 0.6)';
+        overlay.style.display = 'flex';
+        overlay.style.alignItems = 'center';
+        overlay.style.justifyContent = 'center';
+        overlay.style.zIndex = '999999';
+        return overlay;
+    }
+
+    function createModalBox() {
+        const box = document.createElement('div');
+        box.style.backgroundColor = '#fff';
+        box.style.padding = '24px';
+        box.style.borderRadius = '8px';
+        box.style.boxShadow = '0 10px 25px rgba(0,0,0,0.2)';
+        box.style.fontFamily = 'sans-serif';
+        box.style.minWidth = '320px';
+        box.style.maxWidth = '90%';
+        box.style.textAlign = 'left';
+        box.style.color = '#333';
+        return box;
+    }
+
+    function customAlert(message) {
+        return new Promise((resolve) => {
+            const overlay = createModalOverlay();
+            const box = createModalBox();
+
+            const text = document.createElement('p');
+            text.textContent = message;
+            text.style.marginBottom = '20px';
+            text.style.lineHeight = '1.5';
+            text.style.whiteSpace = 'pre-wrap';
+
+            const btnContainer = document.createElement('div');
+            btnContainer.style.display = 'flex';
+            btnContainer.style.justifyContent = 'flex-end';
+
+            const btn = document.createElement('button');
+            btn.textContent = 'OK';
+            btn.style.padding = '8px 16px';
+            btn.style.cursor = 'pointer';
+            btn.style.border = 'none';
+            btn.style.backgroundColor = '#007bff';
+            btn.style.color = '#fff';
+            btn.style.borderRadius = '4px';
+
+            btn.onclick = () => {
+                document.body.removeChild(overlay);
+                resolve();
+            };
+
+            btnContainer.appendChild(btn);
+            box.appendChild(text);
+            box.appendChild(btnContainer);
+            overlay.appendChild(box);
+            document.body.appendChild(overlay);
+            btn.focus();
+        });
+    }
+
+    function customConfirm(message) {
+        return new Promise((resolve) => {
+            const overlay = createModalOverlay();
+            const box = createModalBox();
+
+            const text = document.createElement('p');
+            text.textContent = message;
+            text.style.marginBottom = '20px';
+            text.style.lineHeight = '1.5';
+            text.style.whiteSpace = 'pre-wrap';
+
+            const btnContainer = document.createElement('div');
+            btnContainer.style.display = 'flex';
+            btnContainer.style.justifyContent = 'flex-end';
+            btnContainer.style.gap = '10px';
+
+            const cancelBtn = document.createElement('button');
+            cancelBtn.textContent = 'Abbrechen';
+            cancelBtn.style.padding = '8px 16px';
+            cancelBtn.style.cursor = 'pointer';
+            cancelBtn.style.border = '1px solid #ccc';
+            cancelBtn.style.backgroundColor = '#f8f9fa';
+            cancelBtn.style.color = '#333';
+            cancelBtn.style.borderRadius = '4px';
+
+            const okBtn = document.createElement('button');
+            okBtn.textContent = 'OK';
+            okBtn.style.padding = '8px 16px';
+            okBtn.style.cursor = 'pointer';
+            okBtn.style.border = 'none';
+            okBtn.style.backgroundColor = '#007bff';
+            okBtn.style.color = '#fff';
+            okBtn.style.borderRadius = '4px';
+
+            const closeAndResolve = (val) => {
+                document.body.removeChild(overlay);
+                resolve(val);
+            };
+
+            cancelBtn.onclick = () => closeAndResolve(false);
+            okBtn.onclick = () => closeAndResolve(true);
+
+            btnContainer.appendChild(cancelBtn);
+            btnContainer.appendChild(okBtn);
+            box.appendChild(text);
+            box.appendChild(btnContainer);
+            overlay.appendChild(box);
+            document.body.appendChild(overlay);
+            okBtn.focus();
+        });
+    }
+
+    function customPrompt(message, defaultValue = '') {
+        return new Promise((resolve) => {
+            const overlay = createModalOverlay();
+            const box = createModalBox();
+
+            const text = document.createElement('p');
+            text.textContent = message;
+            text.style.marginBottom = '15px';
+            text.style.lineHeight = '1.5';
+            text.style.whiteSpace = 'pre-wrap';
+
+            const input = document.createElement('input');
+            input.type = 'text';
+            input.value = defaultValue;
+            input.style.width = '100%';
+            input.style.marginBottom = '20px';
+            input.style.padding = '10px';
+            input.style.boxSizing = 'border-box';
+            input.style.border = '1px solid #ccc';
+            input.style.borderRadius = '4px';
+
+            const btnContainer = document.createElement('div');
+            btnContainer.style.display = 'flex';
+            btnContainer.style.justifyContent = 'flex-end';
+            btnContainer.style.gap = '10px';
+
+            const cancelBtn = document.createElement('button');
+            cancelBtn.textContent = 'Abbrechen';
+            cancelBtn.style.padding = '8px 16px';
+            cancelBtn.style.cursor = 'pointer';
+            cancelBtn.style.border = '1px solid #ccc';
+            cancelBtn.style.backgroundColor = '#f8f9fa';
+            cancelBtn.style.color = '#333';
+            cancelBtn.style.borderRadius = '4px';
+
+            const okBtn = document.createElement('button');
+            okBtn.textContent = 'OK';
+            okBtn.style.padding = '8px 16px';
+            okBtn.style.cursor = 'pointer';
+            okBtn.style.border = 'none';
+            okBtn.style.backgroundColor = '#007bff';
+            okBtn.style.color = '#fff';
+            okBtn.style.borderRadius = '4px';
+
+            const closeAndResolve = (val) => {
+                document.body.removeChild(overlay);
+                resolve(val);
+            };
+
+            cancelBtn.onclick = () => closeAndResolve(null);
+            okBtn.onclick = () => closeAndResolve(input.value);
+
+            input.onkeydown = (e) => {
+                if (e.key === 'Enter') closeAndResolve(input.value);
+                if (e.key === 'Escape') closeAndResolve(null);
+            };
+
+            btnContainer.appendChild(cancelBtn);
+            btnContainer.appendChild(okBtn);
+
+            box.appendChild(text);
+            box.appendChild(input);
+            box.appendChild(btnContainer);
+            overlay.appendChild(box);
+            document.body.appendChild(overlay);
+
+            input.focus();
+            input.select();
+        });
+    }
     // =========================================================================
     // 1. GLOBAL STATE DEFINITIONS
     // =========================================================================