fix(reader): mount app volume in docker-compose, move popup to body root and add smooth scroll tracking

app/static/js/app.js

@@ -2133,8 +2133,8 @@ document.addEventListener('DOMContentLoaded', () => {
         let top = rect.bottom + 8;
         // If bottom overflows viewport, flip above the word
         if (top + popupHeight > viewportHeight - 12) {
-            if (rect.top - popupHeight - 8 >= 12 || rect.top > viewportHeight / 2) {
-                top = Math.max(12, rect.top - popupHeight - 8);
+            if (rect.top - popupHeight - 8 >= 65 || rect.top > viewportHeight / 2) {
+                top = Math.max(65, rect.top - popupHeight - 8);
             }
         }
 
@@ -2206,6 +2206,34 @@ document.addEventListener('DOMContentLoaded', () => {
         }
     });
 
+    function updatePopupPositionOnScroll() {
+        if (!readerWordPopup || readerWordPopup.classList.contains('hidden')) return;
+        if (!popupCurrentData || !popupCurrentData.targetElement || !popupCurrentData.targetElement.isConnected) {
+            readerWordPopup.classList.add('hidden');
+            return;
+        }
+        const rect = popupCurrentData.targetElement.getBoundingClientRect();
+        const headerOffset = 65; // reader toolbar sticky height
+        if (rect.bottom < headerOffset || rect.top > window.innerHeight) {
+            readerWordPopup.classList.add('hidden');
+            return;
+        }
+        positionWordPopup(popupCurrentData.targetElement);
+    }
+
+    let popupScrollRaf = null;
+    function schedulePopupUpdate() {
+        if (!readerWordPopup || readerWordPopup.classList.contains('hidden')) return;
+        if (popupScrollRaf) return;
+        popupScrollRaf = requestAnimationFrame(() => {
+            popupScrollRaf = null;
+            updatePopupPositionOnScroll();
+        });
+    }
+
+    window.addEventListener('scroll', schedulePopupUpdate, { passive: true, capture: true });
+    window.addEventListener('resize', schedulePopupUpdate, { passive: true });
+
     if (popupSaveBtn) {
         popupSaveBtn.addEventListener('click', async () => {
             if (!popupCurrentData) return;