feat: add element hover label and refactor to use CSS classes

Add visual feedback for hovered elements:
- Display element selector label (e.g., "p", "h1.title") on hover
- Label positioned at top-left of element with 30% opacity

Refactor all hover/selection styles to use CSS classes instead of inline styles:
- .page-hovered, .page-selected for page states
- .element-hovered, .element-selected for element states
- .element-hover-label for the floating label

This improves maintainability and separation of concerns by moving
styling logic to CSS files instead of JavaScript.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

public/assets/css/pagedjs-interface.css

@@ -144,6 +144,38 @@
   /*--------------------------------------------------------------------------------------*/
 }
 
+/* Hover and selection states for pages and elements */
+.page-hovered {
+  outline: 2px solid #ff8a5050 !important;
+}
+
+.page-selected {
+  outline: 2px solid #ff8a50 !important;
+}
+
+.element-hovered {
+  outline: 2px solid #7136ff50 !important;
+}
+
+.element-selected {
+  outline: 2px dashed #7136ff !important;
+  background-color: #7136ff1a !important;
+}
+
+.element-hover-label {
+  position: absolute;
+  background: #7136ff;
+  color: white;
+  padding: 0.25rem 0.5rem;
+  border-radius: 4px;
+  font-size: 0.875rem;
+  font-weight: 600;
+  opacity: 0.3;
+  pointer-events: none;
+  z-index: 9999;
+  font-family: sans-serif;
+}
+
 /* Marks (to delete when merge in paged.js) */
 
 .pagedjs_marks-crop {

src/App.vue

@@ -65,6 +65,45 @@ const getPagesWithSameTemplate = (page, doc) => {
   );
 };
 
+// Get selector for element (same logic as ElementPopup)
+const getSelectorFromElement = (element) => {
+  if (element.id) {
+    return `#${element.id}`;
+  }
+  const tagName = element.tagName.toLowerCase();
+  const classes = Array.from(element.classList);
+  if (classes.length > 0) {
+    return `${tagName}.${classes[0]}`;
+  }
+  return tagName;
+};
+
+// Create and position element label on hover
+const createElementLabel = (element) => {
+  const doc = element.ownerDocument;
+  const existingLabel = doc.querySelector('.element-hover-label');
+  if (existingLabel) {
+    existingLabel.remove();
+  }
+
+  const label = doc.createElement('div');
+  label.className = 'element-hover-label';
+  label.textContent = getSelectorFromElement(element);
+  label.style.top = `${element.offsetTop}px`;
+  label.style.left = `${element.offsetLeft}px`;
+
+  doc.body.appendChild(label);
+  return label;
+};
+
+// Remove element label
+const removeElementLabel = (doc) => {
+  const label = doc.querySelector('.element-hover-label');
+  if (label) {
+    label.remove();
+  }
+};
+
 // Handle mouse movement in iframe
 const handleIframeMouseMove = (event) => {
   const pages = event.target.ownerDocument.querySelectorAll('.pagedjs_page');
@@ -82,12 +121,12 @@ const handleIframeMouseMove = (event) => {
   if (foundPage !== hoveredPage.value) {
     // Remove highlight from previous page (only if not in selectedPages)
     if (hoveredPage.value && !selectedPages.value.includes(hoveredPage.value)) {
-      hoveredPage.value.style.outline = '';
+      hoveredPage.value.classList.remove('page-hovered');
     }
 
     // Add highlight to new page (only if not already selected)
     if (foundPage && !selectedPages.value.includes(foundPage)) {
-      foundPage.style.outline = `2px solid ${PAGE_HIGHLIGHT_COLOR}50`;
+      foundPage.classList.add('page-hovered');
     }
 
     hoveredPage.value = foundPage;
@@ -96,16 +135,21 @@ const handleIframeMouseMove = (event) => {
   // If not near page edge, check for content element hover
   if (!foundPage) {
     const contentElement = getContentElement(event.target);
+    const doc = event.target.ownerDocument;
 
     if (contentElement !== hoveredElement.value) {
       // Remove highlight from previous element (only if not selected)
       if (hoveredElement.value && hoveredElement.value !== selectedElement.value) {
-        hoveredElement.value.style.outline = '';
+        hoveredElement.value.classList.remove('element-hovered');
       }
 
+      // Remove previous label
+      removeElementLabel(doc);
+
       // Add highlight to new element (only if not already selected)
       if (contentElement && contentElement !== selectedElement.value) {
-        contentElement.style.outline = `2px solid ${ELEMENT_HIGHLIGHT_COLOR}50`;
+        contentElement.classList.add('element-hovered');
+        createElementLabel(contentElement);
       }
 
       hoveredElement.value = contentElement;
@@ -113,16 +157,18 @@ const handleIframeMouseMove = (event) => {
   } else {
     // Clear element hover when hovering page edge
     if (hoveredElement.value && hoveredElement.value !== selectedElement.value) {
-      hoveredElement.value.style.outline = '';
+      hoveredElement.value.classList.remove('element-hovered');
       hoveredElement.value = null;
     }
+    // Remove label when hovering page edge
+    removeElementLabel(event.target.ownerDocument);
   }
 };
 
 // Clear selection highlight from all selected pages
 const clearSelectedPages = () => {
   selectedPages.value.forEach((page) => {
-    page.style.outline = '';
+    page.classList.remove('page-selected');
   });
   selectedPages.value = [];
 };
@@ -153,8 +199,9 @@ const getContentElement = (element) => {
 // Clear selected element highlight
 const clearSelectedElement = () => {
   if (selectedElement.value) {
-    selectedElement.value.style.outline = '';
-    selectedElement.value.style.backgroundColor = '';
+    selectedElement.value.classList.remove('element-selected');
+    const doc = selectedElement.value.ownerDocument;
+    removeElementLabel(doc);
     selectedElement.value = null;
   }
 };
@@ -182,7 +229,7 @@ const handleIframeClick = (event) => {
     const doc = event.target.ownerDocument;
     const sameTemplatePages = getPagesWithSameTemplate(hoveredPage.value, doc);
     sameTemplatePages.forEach((page) => {
-      page.style.outline = `2px solid ${PAGE_HIGHLIGHT_COLOR}`;
+      page.classList.add('page-selected');
     });
     selectedPages.value = sameTemplatePages;
 
@@ -219,8 +266,7 @@ const handleIframeClick = (event) => {
 
   // Select the new element
   selectedElement.value = contentElement;
-  contentElement.style.outline = `2px dashed ${ELEMENT_HIGHLIGHT_COLOR}`;
-  contentElement.style.backgroundColor = `${ELEMENT_HIGHLIGHT_COLOR}1A`; // 10% opacity
+  contentElement.classList.add('element-selected');
 
   // Get count of similar elements
   const doc = event.target.ownerDocument;