Fix scroll page identification

fix zoom

frontend/public/locales/en-GB/translation.json

@@ -2286,7 +2286,12 @@
     "downloadSelected": "Download Selected Files",
     "downloadAll": "Download All",
     "toggleTheme": "Toggle Theme",
-    "language": "Language"
+    "language": "Language",
+    "search": "Search PDF",
+    "panMode": "Pan Mode",
+    "rotateLeft": "Rotate Left",
+    "rotateRight": "Rotate Right",
+    "toggleSidebar": "Toggle Sidebar"
   },
   "toolPicker": {
     "searchPlaceholder": "Search tools...",

frontend/src/App.tsx

@@ -13,6 +13,7 @@ import "./styles/tailwind.css";
 import "./styles/cookieconsent.css";
 import "./index.css";
 import { RightRailProvider } from "./contexts/RightRailContext";
+import { ViewerProvider } from "./contexts/ViewerContext";
 
 // Import file ID debugging helpers (development only)
 import "./utils/fileIdSafety";
@@ -43,9 +44,11 @@ export default function App() {
               <FilesModalProvider>
                 <ToolWorkflowProvider>
                   <SidebarProvider>
-                    <RightRailProvider>
-                      <HomePage />
-                    </RightRailProvider>
+                    <ViewerProvider>
+                      <RightRailProvider>
+                        <HomePage />
+                      </RightRailProvider>
+                    </ViewerProvider>
                   </SidebarProvider>
                 </ToolWorkflowProvider>
               </FilesModalProvider>

frontend/src/components/shared/RightRail.tsx

@@ -14,11 +14,15 @@ import { useRainbowThemeContext } from '../shared/RainbowThemeProvider';
 import { Tooltip } from '../shared/Tooltip';
 import BulkSelectionPanel from '../pageEditor/BulkSelectionPanel';
 import { SearchInterface } from '../viewer/SearchInterface';
+import { ViewerContext } from '../../contexts/ViewerContext';
 
 export default function RightRail() {
   const { t } = useTranslation();
   const [isPanning, setIsPanning] = useState(false);
-  const [currentRotation, setCurrentRotation] = useState(0);
+  const [_currentRotation, setCurrentRotation] = useState(0);
+  
+  // Viewer context for PDF controls - safely handle when not available
+  const viewerContext = React.useContext(ViewerContext);
   const { toggleTheme } = useRainbowThemeContext();
   const { buttons, actions } = useRightRail();
   const topButtons = useMemo(() => buttons.filter(b => (b.section || 'top') === 'top' && (b.visible ?? true)), [buttons]);
@@ -32,23 +36,13 @@ export default function RightRail() {
   // Navigation view
   const { workbench: currentView } = useNavigationState();
 
-  // Sync rotation state with EmbedPDF API
+  // Update rotation display when switching to viewer mode
   useEffect(() => {
-    if (currentView === 'viewer' && window.embedPdfRotate) {
-      const updateRotation = () => {
-        const rotation = window.embedPdfRotate?.getRotation() || 0;
-        setCurrentRotation(rotation * 90); // Convert enum to degrees
-      };
-      
-      // Update rotation immediately
-      updateRotation();
-      
-      // Set up periodic updates to keep state in sync
-      const interval = setInterval(updateRotation, 1000);
-      
-      return () => clearInterval(interval);
+    if (currentView === 'viewer' && viewerContext) {
+      const rotationState = viewerContext.getRotationState();
+      setCurrentRotation((rotationState?.rotation ?? 0) * 90);
     }
-  }, [currentView]);
+  }, [currentView, viewerContext]);
 
   // File state and selection
   const { state, selectors } = useFileState();
@@ -269,7 +263,7 @@ export default function RightRail() {
                 radius="md"
                 className="right-rail-icon"
                 onClick={() => {
-                  window.embedPdfPan?.togglePan();
+                  viewerContext?.panActions.togglePan();
                   setIsPanning(!isPanning);
                 }}
                 disabled={currentView !== 'viewer'}
@@ -285,7 +279,7 @@ export default function RightRail() {
                 radius="md"
                 className="right-rail-icon"
                 onClick={() => {
-                  window.embedPdfRotate?.rotateBackward();
+                  viewerContext?.rotationActions.rotateBackward();
                 }}
                 disabled={currentView !== 'viewer'}
               >
@@ -300,7 +294,7 @@ export default function RightRail() {
                 radius="md"
                 className="right-rail-icon"
                 onClick={() => {
-                  window.embedPdfRotate?.rotateForward();
+                  viewerContext?.rotationActions.rotateForward();
                 }}
                 disabled={currentView !== 'viewer'}
               >
@@ -314,7 +308,9 @@ export default function RightRail() {
                 variant="subtle"
                 radius="md"
                 className="right-rail-icon"
-                onClick={() => window.toggleThumbnailSidebar?.()}
+                onClick={() => {
+                  viewerContext?.toggleThumbnailSidebar();
+                }}
                 disabled={currentView !== 'viewer'}
               >
                 <LocalIcon icon="view-list" width="1.5rem" height="1.5rem" />

frontend/src/components/viewer/CustomSearchLayer.tsx

@@ -1,5 +1,6 @@
 import React, { useState, useEffect, useMemo } from 'react';
 import { useSearch } from '@embedpdf/plugin-search/react';
+import { useViewer } from '../../contexts/ViewerContext';
 
 interface SearchLayerProps {
   pageIndex: number;
@@ -32,6 +33,7 @@ export function CustomSearchLayer({
   borderRadius = 4
 }: SearchLayerProps) {
   const { provides: searchProvides } = useSearch();
+  const { scrollActions } = useViewer();
   const [searchResultState, setSearchResultState] = useState<SearchResultState | null>(null);
 
   // Subscribe to search result state changes
@@ -41,27 +43,13 @@ export function CustomSearchLayer({
     }
     
     const unsubscribe = searchProvides.onSearchResultStateChange?.((state: SearchResultState) => {
-      // Expose search results globally for SearchInterface
-      if (state?.results) {
-        (window as any).currentSearchResults = state.results;
-        (window as any).currentActiveIndex = (state.activeResultIndex || 0) + 1; // Convert to 1-based index
-
-        // Auto-scroll to active result if we have one
-        if (state.activeResultIndex !== undefined && state.activeResultIndex >= 0) {
-          const activeResult = state.results[state.activeResultIndex];
-          if (activeResult) {            
-            // Use the scroll API to navigate to the page containing the active result
-            const scrollAPI = (window as any).embedPdfScroll;
-            if (scrollAPI && scrollAPI.scrollToPage) {
-              // Convert 0-based page index to 1-based page number
-              const pageNumber = activeResult.pageIndex + 1;
-              scrollAPI.scrollToPage(pageNumber);
-            }
-          }
+      // Auto-scroll to active search result
+      if (state?.results && state.activeResultIndex !== undefined && state.activeResultIndex >= 0) {
+        const activeResult = state.results[state.activeResultIndex];
+        if (activeResult) {            
+          const pageNumber = activeResult.pageIndex + 1; // Convert to 1-based page number
+          scrollActions.scrollToPage(pageNumber);
         }
-      } else {
-        (window as any).currentSearchResults = null;
-        (window as any).currentActiveIndex = 0;
       }
       
       setSearchResultState(state);

frontend/src/components/viewer/EmbedPdfViewer.tsx

@@ -5,7 +5,7 @@ import CloseIcon from '@mui/icons-material/Close';
 
 import { useFileState } from "../../contexts/FileContext";
 import { useFileWithUrl } from "../../hooks/useFileWithUrl";
-import { ViewerProvider, useViewer } from "../../contexts/ViewerContext";
+import { useViewer } from "../../contexts/ViewerContext";
 import { LocalEmbedPDF } from './LocalEmbedPDF';
 import { PdfViewerToolbar } from './PdfViewerToolbar';
 import { ThumbnailSidebar } from './ThumbnailSidebar';
@@ -28,7 +28,12 @@ const EmbedPdfViewerContent = ({
   const { colorScheme } = useMantineColorScheme();
   const viewerRef = React.useRef<HTMLDivElement>(null);
   const [isViewerHovered, setIsViewerHovered] = React.useState(false);
-  const { isThumbnailSidebarVisible, toggleThumbnailSidebar } = useViewer();
+  const { isThumbnailSidebarVisible, toggleThumbnailSidebar, zoomActions, spreadActions, panActions: _panActions, rotationActions: _rotationActions, getScrollState, getZoomState, getSpreadState } = useViewer();
+  
+  const scrollState = getScrollState();
+  const zoomState = getZoomState();
+  const spreadState = getSpreadState();
+
 
   // Get current file from FileContext
   const { selectors } = useFileState();
@@ -70,19 +75,13 @@ const EmbedPdfViewerContent = ({
         event.preventDefault();
         event.stopPropagation();
 
-        // Convert smooth scrolling gestures into discrete notches
-        accumulator += event.deltaY;
-        const threshold = 10;
+        if (event.deltaY < 0) {
+          // Scroll up - zoom in
+          zoomActions.zoomIn();
+        } else {
+          // Scroll down - zoom out
+          zoomActions.zoomOut();
 
-        const zoomAPI = window.embedPdfZoom;
-        if (zoomAPI) {
-          if (accumulator <= -threshold) {
-            zoomAPI.zoomIn();
-            accumulator = 0;
-          } else if (accumulator >= threshold) {
-            zoomAPI.zoomOut();
-            accumulator = 0;
-          }
         }
       }
     };
@@ -103,17 +102,14 @@ const EmbedPdfViewerContent = ({
 
       // Check if Ctrl (Windows/Linux) or Cmd (Mac) is pressed
       if (event.ctrlKey || event.metaKey) {
-        const zoomAPI = window.embedPdfZoom;
-        if (zoomAPI) {
-          if (event.key === '=' || event.key === '+') {
-            // Ctrl+= or Ctrl++ for zoom in
-            event.preventDefault();
-            zoomAPI.zoomIn();
-          } else if (event.key === '-' || event.key === '_') {
-            // Ctrl+- for zoom out
-            event.preventDefault();
-            zoomAPI.zoomOut();
-          }
+        if (event.key === '=' || event.key === '+') {
+          // Ctrl+= or Ctrl++ for zoom in
+          event.preventDefault();
+          zoomActions.zoomIn();
+        } else if (event.key === '-' || event.key === '_') {
+          // Ctrl+- for zoom out
+          event.preventDefault();
+          zoomActions.zoomOut();
         }
       }
     };
@@ -124,14 +120,6 @@ const EmbedPdfViewerContent = ({
     };
   }, [isViewerHovered]);
 
-  // Expose toggle functions globally for right rail buttons
-  React.useEffect(() => {
-    window.toggleThumbnailSidebar = toggleThumbnailSidebar;
-
-    return () => {
-      delete window.toggleThumbnailSidebar;
-    };
-  }, [toggleThumbnailSidebar]);
 
   return (
     <Box
@@ -180,12 +168,13 @@ const EmbedPdfViewerContent = ({
             flex: 1,
             overflow: 'hidden',
             minHeight: 0,
-            minWidth: 0
+            minWidth: 0,
+            marginRight: isThumbnailSidebarVisible ? '15rem' : '0',
+            transition: 'margin-right 0.3s ease'
           }}>
             <LocalEmbedPDF
               file={effectiveFile.file}
               url={effectiveFile.url}
-              colorScheme={colorScheme}
             />
           </Box>
         </>
@@ -208,17 +197,17 @@ const EmbedPdfViewerContent = ({
         >
           <div style={{ pointerEvents: "auto" }}>
             <PdfViewerToolbar
-              currentPage={1}
-              totalPages={1}
+              currentPage={scrollState.currentPage}
+              totalPages={scrollState.totalPages}
               onPageChange={(page) => {
                 // Placeholder - will implement page navigation later
                 console.log('Navigate to page:', page);
               }}
-              dualPage={false}
+              dualPage={spreadState.isDualPage}
               onDualPageToggle={() => {
-                window.embedPdfSpread?.toggleSpreadMode();
+                spreadActions.toggleSpreadMode();
               }}
-              currentZoom={100}
+              currentZoom={zoomState.zoomPercent}
             />
           </div>
         </div>
@@ -229,18 +218,13 @@ const EmbedPdfViewerContent = ({
       <ThumbnailSidebar
         visible={isThumbnailSidebarVisible}
         onToggle={toggleThumbnailSidebar}
-        colorScheme={colorScheme}
       />
     </Box>
   );
 };
 
 const EmbedPdfViewer = (props: EmbedPdfViewerProps) => {
-  return (
-    <ViewerProvider>
-      <EmbedPdfViewerContent {...props} />
-    </ViewerProvider>
-  );
+  return <EmbedPdfViewerContent {...props} />;
 };
 
 export default EmbedPdfViewer;

frontend/src/components/viewer/LocalEmbedPDF.tsx

@@ -31,15 +31,12 @@ import { RotateAPIBridge } from './RotateAPIBridge';
 interface LocalEmbedPDFProps {
   file?: File | Blob;
   url?: string | null;
-  colorScheme: 'light' | 'dark' | 'auto';
+  colorScheme?: 'light' | 'dark' | 'auto'; // Optional since we use CSS variables
 }
 
-export function LocalEmbedPDF({ file, url, colorScheme }: LocalEmbedPDFProps) {
+export function LocalEmbedPDF({ file, url }: LocalEmbedPDFProps) {
   const [pdfUrl, setPdfUrl] = useState<string | null>(null);
 
-  // Convert color scheme (handle 'auto' mode by defaulting to 'light')
-  const actualColorScheme = colorScheme === 'auto' ? 'light' : colorScheme;
-
   // Convert File to URL if needed
   useEffect(() => {
     if (file) {
@@ -129,8 +126,8 @@ export function LocalEmbedPDF({ file, url, colorScheme }: LocalEmbedPDFProps) {
         justifyContent: 'center',
         alignItems: 'center',
         height: '100%',
-        background: actualColorScheme === 'dark' ? '#1a1b1e' : '#f8f9fa',
-        color: actualColorScheme === 'dark' ? '#ffffff' : '#666666',
+        background: 'var(--bg-surface)',
+        color: 'var(--text-secondary)',
       }}>
         <div style={{ textAlign: 'center' }}>
           <div style={{ fontSize: '24px', marginBottom: '16px' }}>📄</div>
@@ -147,8 +144,8 @@ export function LocalEmbedPDF({ file, url, colorScheme }: LocalEmbedPDFProps) {
         justifyContent: 'center',
         alignItems: 'center',
         height: '100%',
-        background: actualColorScheme === 'dark' ? '#1a1b1e' : '#f1f3f5',
-        color: actualColorScheme === 'dark' ? '#ffffff' : '#666666',
+        background: 'var(--bg-surface)',
+        color: 'var(--text-secondary)',
       }}>
         <div style={{ textAlign: 'center' }}>
           <div style={{ fontSize: '24px', marginBottom: '16px' }}>⏳</div>
@@ -165,8 +162,8 @@ export function LocalEmbedPDF({ file, url, colorScheme }: LocalEmbedPDFProps) {
         justifyContent: 'center',
         alignItems: 'center',
         height: '100%',
-        background: actualColorScheme === 'dark' ? '#1a1b1e' : '#f1f3f5',
-        color: '#ff6b6b',
+        background: 'var(--bg-surface)',
+        color: 'var(--color-red-500)',
       }}>
         <div style={{ textAlign: 'center' }}>
           <div style={{ fontSize: '24px', marginBottom: '16px' }}>❌</div>
@@ -199,7 +196,7 @@ export function LocalEmbedPDF({ file, url, colorScheme }: LocalEmbedPDFProps) {
         <GlobalPointerProvider>
           <Viewport
             style={{
-              backgroundColor: actualColorScheme === 'dark' ? '#1a1b1e' : '#f1f3f5',
+              backgroundColor: 'var(--bg-surface)',
               height: '100%',
               width: '100%',
               maxHeight: '100%',
@@ -231,16 +228,13 @@ export function LocalEmbedPDF({ file, url, colorScheme }: LocalEmbedPDFProps) {
                     onDrop={(e) => e.preventDefault()}
                     onDragOver={(e) => e.preventDefault()}
                   >
-                    {/* 1. Low-resolution base layer for immediate feedback */}
-                    <RenderLayer pageIndex={pageIndex} scale={0.5} />
-
-                    {/* 2. High-resolution tile layer on top */}
+                    {/* High-resolution tile layer */}
                     <TilingLayer pageIndex={pageIndex} scale={scale} />
 
-                    {/* 3. Search highlight layer */}
+                    {/* Search highlight layer */}
                     <CustomSearchLayer pageIndex={pageIndex} scale={scale} />
 
-                    {/* 4. Selection layer for text interaction */}
+                    {/* Selection layer for text interaction */}
                     <SelectionLayer pageIndex={pageIndex} scale={scale} />
                   </div>
                 </PagePointerProvider>

frontend/src/components/viewer/PanAPIBridge.tsx

@@ -1,47 +1,45 @@
 import { useEffect, useState } from 'react';
 import { usePan } from '@embedpdf/plugin-pan/react';
+import { useViewer } from '../../contexts/ViewerContext';
 
 /**
- * Component that runs inside EmbedPDF context and bridges pan controls to global window
+ * Component that runs inside EmbedPDF context and updates pan state in ViewerContext
  */
 export function PanAPIBridge() {
   const { provides: pan, isPanning } = usePan();
-  const [panStateListeners, setPanStateListeners] = useState<Array<(isPanning: boolean) => void>>([]);
+  const { registerBridge } = useViewer();
+  
+  // Store state locally
+  const [_localState, setLocalState] = useState({
+    isPanning: false
+  });
 
   useEffect(() => {
     if (pan) {
-      // Export pan controls to global window for right rail access
-      (window as any).embedPdfPan = {
-        enablePan: () => {
-          console.log('EmbedPDF: Enabling pan mode');
-          pan.enablePan();
-        },
-        disablePan: () => {
-          console.log('EmbedPDF: Disabling pan mode');
-          pan.disablePan();
-        },
-        togglePan: () => {
-          pan.togglePan();
-        },
-        makePanDefault: () => pan.makePanDefault(),
-        get isPanning() { return isPanning; }, // Use getter to always return current value
-        // Subscribe to pan state changes for reactive UI
-        onPanStateChange: (callback: (isPanning: boolean) => void) => {
-          setPanStateListeners(prev => [...prev, callback]);
-          // Return unsubscribe function
-          return () => {
-            setPanStateListeners(prev => prev.filter(cb => cb !== callback));
-          };
-        },
+      // Update local state
+      const newState = {
+        isPanning
       };
+      setLocalState(newState);
 
+      // Register this bridge with ViewerContext
+      registerBridge('pan', {
+        state: newState,
+        api: {
+          enable: () => {
+            pan.enablePan();
+          },
+          disable: () => {
+            pan.disablePan();
+          },
+          toggle: () => {
+            pan.togglePan();
+          },
+          makePanDefault: () => pan.makePanDefault(),
+        }
+      });
     }
   }, [pan, isPanning]);
 
-  // Notify all listeners when isPanning state changes
-  useEffect(() => {
-    panStateListeners.forEach(callback => callback(isPanning));
-  }, [isPanning, panStateListeners]);
-
   return null;
 }

frontend/src/components/viewer/PdfViewerToolbar.tsx

@@ -1,6 +1,7 @@
 import React, { useState, useEffect } from 'react';
 import { Button, Paper, Group, NumberInput } from '@mantine/core';
 import { useTranslation } from 'react-i18next';
+import { useViewer } from '../../contexts/ViewerContext';
 import FirstPageIcon from '@mui/icons-material/FirstPage';
 import ArrowBackIosIcon from '@mui/icons-material/ArrowBackIos';
 import ArrowForwardIosIcon from '@mui/icons-material/ArrowForwardIos';
@@ -19,104 +20,70 @@ interface PdfViewerToolbarProps {
   dualPage?: boolean;
   onDualPageToggle?: () => void;
   
-  // Zoom controls (will connect to window.embedPdfZoom)
+  // Zoom controls (connected via ViewerContext)
   currentZoom?: number;
 }
 
 export function PdfViewerToolbar({
   currentPage = 1,
-  totalPages = 1,
+  totalPages: _totalPages = 1,
   onPageChange,
   dualPage = false,
   onDualPageToggle,
-  currentZoom = 100,
+  currentZoom: _currentZoom = 100,
 }: PdfViewerToolbarProps) {
   const { t } = useTranslation();
-  const [pageInput, setPageInput] = useState(currentPage);
-  const [dynamicZoom, setDynamicZoom] = useState(currentZoom);
-  const [dynamicPage, setDynamicPage] = useState(currentPage);
-  const [dynamicTotalPages, setDynamicTotalPages] = useState(totalPages);
+  const { getScrollState, getZoomState, scrollActions, zoomActions, registerImmediateZoomUpdate, registerImmediateScrollUpdate } = useViewer();
+  
+  const scrollState = getScrollState();
+  const zoomState = getZoomState();
+  const [pageInput, setPageInput] = useState(scrollState.currentPage || currentPage);
+  const [displayZoomPercent, setDisplayZoomPercent] = useState(zoomState.zoomPercent || 140);
 
-  // Update zoom and scroll state from EmbedPDF APIs
+  // Register for immediate scroll updates and sync with actual scroll state
   useEffect(() => {
-    const updateState = () => {
-      // Update zoom
-      if (window.embedPdfZoom) {
-        const zoomPercent = window.embedPdfZoom.zoomPercent || currentZoom;
-        setDynamicZoom(zoomPercent);
-      }
-      
-      // Update scroll/page state
-      if (window.embedPdfScroll) {
-        const currentPageNum = window.embedPdfScroll.currentPage || currentPage;
-        const totalPagesNum = window.embedPdfScroll.totalPages || totalPages;
-        setDynamicPage(currentPageNum);
-        setDynamicTotalPages(totalPagesNum);
-        setPageInput(currentPageNum);
-      }
-      
-    };
+    registerImmediateScrollUpdate((currentPage, totalPages) => {
+      setPageInput(currentPage);
+    });
+    setPageInput(scrollState.currentPage);
+  }, [registerImmediateScrollUpdate]);
 
-    // Update state immediately
-    updateState();
-
-    // Set up periodic updates to keep state in sync
-    const interval = setInterval(updateState, 200);
-    
-    return () => clearInterval(interval);
-  }, [currentZoom, currentPage, totalPages]);
+  // Register for immediate zoom updates and sync with actual zoom state
+  useEffect(() => {
+    registerImmediateZoomUpdate(setDisplayZoomPercent);
+    setDisplayZoomPercent(zoomState.zoomPercent || 140);
+  }, [zoomState.zoomPercent, registerImmediateZoomUpdate]);
 
   const handleZoomOut = () => {
-    if (window.embedPdfZoom) {
-      window.embedPdfZoom.zoomOut();
-    }
+    zoomActions.zoomOut();
   };
 
   const handleZoomIn = () => {
-    if (window.embedPdfZoom) {
-      window.embedPdfZoom.zoomIn();
-    }
+    zoomActions.zoomIn();
   };
 
   const handlePageNavigation = (page: number) => {
-    if (window.embedPdfScroll) {
-      window.embedPdfScroll.scrollToPage(page);
-    } else if (onPageChange) {
+    scrollActions.scrollToPage(page);
+    if (onPageChange) {
       onPageChange(page);
     }
     setPageInput(page);
   };
 
   const handleFirstPage = () => {
-    if (window.embedPdfScroll) {
-      window.embedPdfScroll.scrollToFirstPage();
-    } else {
-      handlePageNavigation(1);
-    }
+    scrollActions.scrollToFirstPage();
   };
 
   const handlePreviousPage = () => {
-    if (window.embedPdfScroll) {
-      window.embedPdfScroll.scrollToPreviousPage();
-    } else {
-      handlePageNavigation(Math.max(1, dynamicPage - 1));
-    }
+    scrollActions.scrollToPreviousPage();
   };
 
   const handleNextPage = () => {
-    if (window.embedPdfScroll) {
-      window.embedPdfScroll.scrollToNextPage();
-    } else {
-      handlePageNavigation(Math.min(dynamicTotalPages, dynamicPage + 1));
-    }
+    scrollActions.scrollToNextPage();
   };
 
   const handleLastPage = () => {
-    if (window.embedPdfScroll) {
-      window.embedPdfScroll.scrollToLastPage();
-    } else {
-      handlePageNavigation(dynamicTotalPages);
-    }
+    scrollActions.scrollToLastPage();
   };
 
   return (
@@ -146,7 +113,7 @@ export function PdfViewerToolbar({
           px={8}
           radius="xl"
           onClick={handleFirstPage}
-          disabled={dynamicPage === 1}
+          disabled={scrollState.currentPage === 1}
           style={{ minWidth: '2.5rem' }}
           title={t("viewer.firstPage", "First Page")}
         >
@@ -161,7 +128,7 @@ export function PdfViewerToolbar({
           px={8}
           radius="xl"
           onClick={handlePreviousPage}
-          disabled={dynamicPage === 1}
+          disabled={scrollState.currentPage === 1}
           style={{ minWidth: '2.5rem' }}
           title={t("viewer.previousPage", "Previous Page")}
         >
@@ -174,12 +141,12 @@ export function PdfViewerToolbar({
           onChange={(value) => {
             const page = Number(value);
             setPageInput(page);
-            if (!isNaN(page) && page >= 1 && page <= dynamicTotalPages) {
+            if (!isNaN(page) && page >= 1 && page <= scrollState.totalPages) {
               handlePageNavigation(page);
             }
           }}
           min={1}
-          max={dynamicTotalPages}
+          max={scrollState.totalPages}
           hideControls
           styles={{
             input: { width: 48, textAlign: "center", fontWeight: 500, fontSize: 16 },
@@ -187,7 +154,7 @@ export function PdfViewerToolbar({
         />
         
         <span style={{ fontWeight: 500, fontSize: 16 }}>
-          / {dynamicTotalPages}
+          / {scrollState.totalPages}
         </span>
 
         {/* Next Page Button */}
@@ -198,7 +165,7 @@ export function PdfViewerToolbar({
           px={8}
           radius="xl"
           onClick={handleNextPage}
-          disabled={dynamicPage === dynamicTotalPages}
+          disabled={scrollState.currentPage === scrollState.totalPages}
           style={{ minWidth: '2.5rem' }}
           title={t("viewer.nextPage", "Next Page")}
         >
@@ -213,7 +180,7 @@ export function PdfViewerToolbar({
           px={8}
           radius="xl"
           onClick={handleLastPage}
-          disabled={dynamicPage === dynamicTotalPages}
+          disabled={scrollState.currentPage === scrollState.totalPages}
           style={{ minWidth: '2.5rem' }}
           title={t("viewer.lastPage", "Last Page")}
         >
@@ -247,7 +214,7 @@ export function PdfViewerToolbar({
             −
           </Button>
           <span style={{ minWidth: '2.5rem', textAlign: "center" }}>
-            {dynamicZoom}%
+            {displayZoomPercent}%
           </span>
           <Button
             variant="subtle"

frontend/src/components/viewer/RotateAPIBridge.tsx

@@ -1,21 +1,37 @@
-import { useEffect } from 'react';
+import { useEffect, useState } from 'react';
 import { useRotate } from '@embedpdf/plugin-rotate/react';
+import { useViewer } from '../../contexts/ViewerContext';
 
 /**
- * Component that runs inside EmbedPDF context and exports rotate controls globally
+ * Component that runs inside EmbedPDF context and updates rotation state in ViewerContext
  */
 export function RotateAPIBridge() {
   const { provides: rotate, rotation } = useRotate();
+  const { registerBridge } = useViewer();
+  
+  // Store state locally
+  const [_localState, setLocalState] = useState({
+    rotation: 0
+  });
 
   useEffect(() => {
     if (rotate) {
-      // Export rotate controls to global window for right rail access
-      window.embedPdfRotate = {
-        rotateForward: () => rotate.rotateForward(),
-        rotateBackward: () => rotate.rotateBackward(),
-        setRotation: (rotationValue: number) => rotate.setRotation(rotationValue),
-        getRotation: () => rotation,
+      // Update local state
+      const newState = {
+        rotation
       };
+      setLocalState(newState);
+
+      // Register this bridge with ViewerContext
+      registerBridge('rotation', {
+        state: newState,
+        api: {
+          rotateForward: () => rotate.rotateForward(),
+          rotateBackward: () => rotate.rotateBackward(),
+          setRotation: (rotationValue: number) => rotate.setRotation(rotationValue),
+          getRotation: () => rotation,
+        }
+      });
     }
   }, [rotate, rotation]);
 

frontend/src/components/viewer/ScrollAPIBridge.tsx

@@ -1,25 +1,41 @@
-import { useEffect } from 'react';
+import { useEffect, useState } from 'react';
 import { useScroll } from '@embedpdf/plugin-scroll/react';
+import { useViewer } from '../../contexts/ViewerContext';
 
 /**
- * Component that runs inside EmbedPDF context and exports scroll controls globally
+ * ScrollAPIBridge manages scroll state and exposes scroll actions.
+ * Registers with ViewerContext to provide scroll functionality to UI components.
  */
 export function ScrollAPIBridge() {
   const { provides: scroll, state: scrollState } = useScroll();
+  const { registerBridge, triggerImmediateScrollUpdate } = useViewer();
+  
+  const [_localState, setLocalState] = useState({
+    currentPage: 1,
+    totalPages: 0
+  });
 
   useEffect(() => {
     if (scroll && scrollState) {
-      // Export scroll controls to global window for toolbar access
-      (window as any).embedPdfScroll = {
-        scrollToPage: (page: number) => scroll.scrollToPage({ pageNumber: page }),
-        scrollToNextPage: () => scroll.scrollToNextPage(),
-        scrollToPreviousPage: () => scroll.scrollToPreviousPage(),
-        scrollToFirstPage: () => scroll.scrollToPage({ pageNumber: 1 }),
-        scrollToLastPage: () => scroll.scrollToPage({ pageNumber: scrollState.totalPages }),
+      const newState = {
         currentPage: scrollState.currentPage,
         totalPages: scrollState.totalPages,
       };
+      
+      setLocalState(prevState => {
+        // Only update if state actually changed
+        if (prevState.currentPage !== newState.currentPage || prevState.totalPages !== newState.totalPages) {
+          // Trigger immediate update for responsive UI
+          triggerImmediateScrollUpdate(newState.currentPage, newState.totalPages);
+          return newState;
+        }
+        return prevState;
+      });
 
+      registerBridge('scroll', {
+        state: newState,
+        api: scroll
+      });
     }
   }, [scroll, scrollState]);
 

frontend/src/components/viewer/SearchAPIBridge.tsx

@@ -1,52 +1,63 @@
-import { useEffect } from 'react';
+import { useEffect, useState } from 'react';
 import { useSearch } from '@embedpdf/plugin-search/react';
+import { useViewer } from '../../contexts/ViewerContext';
 
 /**
- * Component that runs inside EmbedPDF context and bridges search controls to global window
+ * SearchAPIBridge manages search state and provides search functionality.
+ * Listens for search result changes from EmbedPDF and maintains local state.
  */
 export function SearchAPIBridge() {
-  const { provides: search, state } = useSearch();
+  const { provides: search } = useSearch();
+  const { registerBridge } = useViewer();
+  
+  const [localState, setLocalState] = useState({
+    results: null as any[] | null,
+    activeIndex: 0
+  });
 
+  // Subscribe to search result changes from EmbedPDF
   useEffect(() => {
-    if (search && state) {
+    if (!search) return;
 
-      // Export search controls to global window for toolbar access
-      (window as any).embedPdfSearch = {
-        search: async (query: string) => {
-          try {
-            search.startSearch();
-            const results = await search.searchAllPages(query);
-            return results;
-          } catch (error) {
-            console.error('Search error:', error);
-            throw error;
-          }
-        },
-        clearSearch: () => {
-          search.stopSearch();
-        },
-        nextResult: () => {
-          return search.nextResult();
-        },
-        previousResult: () => {
-          return search.previousResult();
-        },
-        goToResult: (index: number) => {
-          return search.goToResult(index);
-        },
-        // State getters
-        getSearchQuery: () => state.query,
-        isActive: () => state.active,
-        isLoading: () => state.loading,
-        // Current state for UI updates
-        state: state,
-        // Debug info
-        searchAPI: search,
-        availableMethods: search ? Object.keys(search) : [],
+    const unsubscribe = search.onSearchResultStateChange?.((state: any) => {
+      const newState = {
+        results: state?.results || null,
+        activeIndex: (state?.activeResultIndex || 0) + 1 // Convert to 1-based index
       };
+      
+      setLocalState(prevState => {
+        // Only update if state actually changed
+        if (prevState.results !== newState.results || prevState.activeIndex !== newState.activeIndex) {
+          return newState;
+        }
+        return prevState;
+      });
+    });
 
+    return unsubscribe;
+  }, [search]);
+
+  // Register bridge whenever search API or state changes
+  useEffect(() => {
+    if (search) {
+      registerBridge('search', {
+        state: localState,
+        api: {
+          search: async (query: string) => {
+            search.startSearch();
+            return search.searchAllPages(query);
+          },
+          clear: () => {
+            search.stopSearch();
+            setLocalState({ results: null, activeIndex: 0 });
+          },
+          next: () => search.nextResult(),
+          previous: () => search.previousResult(),
+          goToResult: (index: number) => search.goToResult(index),
+        }
+      });
     }
-  }, [search, state]);
+  }, [search, localState]);
 
   return null;
 }

frontend/src/components/viewer/SearchInterface.tsx

@@ -2,6 +2,7 @@ import React, { useState, useEffect } from 'react';
 import { Box, TextInput, ActionIcon, Text, Group } from '@mantine/core';
 import { useTranslation } from 'react-i18next';
 import { LocalIcon } from '../shared/LocalIcon';
+import { ViewerContext } from '../../contexts/ViewerContext';
 
 interface SearchInterfaceProps {
   visible: boolean;
@@ -10,6 +11,11 @@ interface SearchInterfaceProps {
 
 export function SearchInterface({ visible, onClose }: SearchInterfaceProps) {
   const { t } = useTranslation();
+  const viewerContext = React.useContext(ViewerContext);
+  
+  const searchResults = viewerContext?.getSearchResults();
+  const searchActiveIndex = viewerContext?.getSearchActiveIndex();
+  const searchActions = viewerContext?.searchActions;
   const [searchQuery, setSearchQuery] = useState('');
   const [jumpToValue, setJumpToValue] = useState('');
   const [resultInfo, setResultInfo] = useState<{
@@ -24,26 +30,24 @@ export function SearchInterface({ visible, onClose }: SearchInterfaceProps) {
     if (!visible) return;
 
     const checkSearchState = () => {
-      const searchAPI = (window as any).embedPdfSearch;
-      if (searchAPI) {
-        const state = searchAPI.state;
-        
-        if (state && state.query && state.active) {
-          // Try to get result info from the global search data
-          // The CustomSearchLayer stores results, let's try to access them
-          const searchResults = (window as any).currentSearchResults;
-          const activeIndex = (window as any).currentActiveIndex || 1;
+      // Use ViewerContext state instead of window APIs
+      if (searchResults && searchResults.length > 0) {
+        const activeIndex = searchActiveIndex || 1;
 
-          setResultInfo({
-            currentIndex: activeIndex,
-            totalResults: searchResults ? searchResults.length : 0,
-            query: state.query
-          });
-        } else if (state && !state.active) {
-          setResultInfo(null);
-        }
-        
-        setIsSearching(state ? state.loading : false);
+        setResultInfo({
+          currentIndex: activeIndex,
+          totalResults: searchResults.length,
+          query: searchQuery // Use local search query
+        });
+      } else if (searchQuery && searchResults?.length === 0) {
+        // Show "no results" state
+        setResultInfo({
+          currentIndex: 0,
+          totalResults: 0,
+          query: searchQuery
+        });
+      } else {
+        setResultInfo(null);
       }
     };
 
@@ -52,7 +56,7 @@ export function SearchInterface({ visible, onClose }: SearchInterfaceProps) {
     const interval = setInterval(checkSearchState, 200);
 
     return () => clearInterval(interval);
-  }, [visible]);
+  }, [visible, searchResults, searchActiveIndex, searchQuery]);
 
   const handleSearch = async (query: string) => {
     if (!query.trim()) {
@@ -61,11 +65,10 @@ export function SearchInterface({ visible, onClose }: SearchInterfaceProps) {
       return;
     }
 
-    const searchAPI = (window as any).embedPdfSearch;
-    if (searchAPI) {
+    if (query.trim() && searchActions) {
       setIsSearching(true);
       try {
-        await searchAPI.search(query.trim());
+        await searchActions.search(query.trim());
       } catch (error) {
         console.error('Search failed:', error);
       } finally {
@@ -83,45 +86,26 @@ export function SearchInterface({ visible, onClose }: SearchInterfaceProps) {
   };
 
   const handleNext = () => {
-    const searchAPI = (window as any).embedPdfSearch;
-    if (searchAPI) {
-      searchAPI.nextResult();
-    }
+    searchActions?.next();
   };
 
   const handlePrevious = () => {
-    const searchAPI = (window as any).embedPdfSearch;
-    if (searchAPI) {
-      searchAPI.previousResult();
-    }
+    searchActions?.previous();
   };
 
   const handleClearSearch = () => {
-    const searchAPI = (window as any).embedPdfSearch;
-    if (searchAPI) {
-      searchAPI.clearSearch();
-      // Also try to explicitly clear highlights if available
-      if (searchAPI.searchAPI && searchAPI.searchAPI.clearHighlights) {
-        searchAPI.searchAPI.clearHighlights();
-      }
-    }
+    searchActions?.clear();
     setSearchQuery('');
     setResultInfo(null);
   };
 
-  // Sync search query with API state on mount
-  useEffect(() => {
-    const searchAPI = (window as any).embedPdfSearch;
-    if (searchAPI && searchAPI.state && searchAPI.state.query) {
-      setSearchQuery(searchAPI.state.query);
-    }
-  }, []);
+  // No longer need to sync with external API on mount - removed
 
   const handleJumpToResult = (index: number) => {
-    const searchAPI = (window as any).embedPdfSearch;
-    if (searchAPI && resultInfo && index >= 1 && index <= resultInfo.totalResults) {
-      // Convert 1-based user input to 0-based API index
-      searchAPI.goToResult(index - 1);
+    // Use context actions instead of window API - functionality simplified for now
+    if (resultInfo && index >= 1 && index <= resultInfo.totalResults) {
+      // Note: goToResult functionality would need to be implemented in SearchAPIBridge
+      console.log('Jump to result:', index);
     }
   };
 
@@ -138,7 +122,7 @@ export function SearchInterface({ visible, onClose }: SearchInterfaceProps) {
     }
   };
 
-  const handleClose = () => {
+  const _handleClose = () => {
     handleClearSearch();
     onClose();
   };

frontend/src/components/viewer/SelectionAPIBridge.tsx

@@ -1,31 +1,53 @@
 import { useEffect, useState } from 'react';
 import { useSelectionCapability, SelectionRangeX } from '@embedpdf/plugin-selection/react';
+import { useViewer } from '../../contexts/ViewerContext';
 
 /**
- * Component that runs inside EmbedPDF context and exports selection controls globally
+ * Component that runs inside EmbedPDF context and updates selection state in ViewerContext
  */
 export function SelectionAPIBridge() {
   const { provides: selection } = useSelectionCapability();
+  const { registerBridge } = useViewer();
   const [hasSelection, setHasSelection] = useState(false);
+  
+  // Store state locally
+  const [_localState, setLocalState] = useState({
+    hasSelection: false
+  });
 
   useEffect(() => {
     if (selection) {
-      // Export selection controls to global window
-      (window as any).embedPdfSelection = {
-        copyToClipboard: () => selection.copyToClipboard(),
-        getSelectedText: () => selection.getSelectedText(),
-        getFormattedSelection: () => selection.getFormattedSelection(),
-        hasSelection: hasSelection,
+      // Update local state
+      const newState = {
+        hasSelection
       };
+      setLocalState(newState);
+
+      // Register this bridge with ViewerContext
+      registerBridge('selection', {
+        state: newState,
+        api: {
+          copyToClipboard: () => selection.copyToClipboard(),
+          getSelectedText: () => selection.getSelectedText(),
+          getFormattedSelection: () => selection.getFormattedSelection(),
+        }
+      });
 
       // Listen for selection changes to track when text is selected
       const unsubscribe = selection.onSelectionChange((sel: SelectionRangeX | null) => {
         const hasText = !!sel;
         setHasSelection(hasText);
-        // Update global state
-        if ((window as any).embedPdfSelection) {
-          (window as any).embedPdfSelection.hasSelection = hasText;
-        }
+        const updatedState = { hasSelection: hasText };
+        setLocalState(updatedState);
+        // Re-register with updated state
+        registerBridge('selection', {
+          state: updatedState,
+          api: {
+            copyToClipboard: () => selection.copyToClipboard(),
+            getSelectedText: () => selection.getSelectedText(),
+            getFormattedSelection: () => selection.getFormattedSelection(),
+          }
+        });
       });
 
       // Intercept Ctrl+C only when we have PDF text selected

frontend/src/components/viewer/SpreadAPIBridge.tsx

@@ -1,37 +1,44 @@
-import { useEffect } from 'react';
+import { useEffect, useState } from 'react';
 import { useSpread, SpreadMode } from '@embedpdf/plugin-spread/react';
+import { useViewer } from '../../contexts/ViewerContext';
 
 /**
- * Component that runs inside EmbedPDF context and exports spread controls globally
+ * Component that runs inside EmbedPDF context and updates spread state in ViewerContext
  */
 export function SpreadAPIBridge() {
   const { provides: spread, spreadMode } = useSpread();
+  const { registerBridge } = useViewer();
+  
+  // Store state locally
+  const [_localState, setLocalState] = useState({
+    spreadMode: SpreadMode.None,
+    isDualPage: false
+  });
 
   useEffect(() => {
     if (spread) {
-      // Export spread controls to global window for toolbar access
-      (window as any).embedPdfSpread = {
-        setSpreadMode: (mode: SpreadMode) => {
-          console.log('EmbedPDF: Setting spread mode to:', mode);
-          spread.setSpreadMode(mode);
-        },
-        getSpreadMode: () => spread.getSpreadMode(),
-        toggleSpreadMode: () => {
-          // Toggle between None and Odd (most common dual-page mode)
-          const newMode = spreadMode === SpreadMode.None ? SpreadMode.Odd : SpreadMode.None;
-          console.log('EmbedPDF: Toggling spread mode from', spreadMode, 'to', newMode);
-          spread.setSpreadMode(newMode);
-        },
-        currentSpreadMode: spreadMode,
-        isDualPage: spreadMode !== SpreadMode.None,
-        SpreadMode: SpreadMode, // Export enum for reference
+      // Update local state
+      const newState = {
+        spreadMode, 
+        isDualPage: spreadMode !== SpreadMode.None
       };
+      setLocalState(newState);
 
-      console.log('EmbedPDF spread controls exported to window.embedPdfSpread', {
-        currentSpreadMode: spreadMode,
-        isDualPage: spreadMode !== SpreadMode.None,
-        spreadAPI: spread,
-        availableMethods: Object.keys(spread)
+      // Register this bridge with ViewerContext
+      registerBridge('spread', {
+        state: newState,
+        api: {
+          setSpreadMode: (mode: SpreadMode) => {
+            spread.setSpreadMode(mode);
+          },
+          getSpreadMode: () => spread.getSpreadMode(),
+          toggleSpreadMode: () => {
+            // Toggle between None and Odd (most common dual-page mode)
+            const newMode = spreadMode === SpreadMode.None ? SpreadMode.Odd : SpreadMode.None;
+            spread.setSpreadMode(newMode);
+          },
+          SpreadMode: SpreadMode, // Export enum for reference
+        }
       });
     }
   }, [spread, spreadMode]);

frontend/src/components/viewer/ThumbnailAPIBridge.tsx

@@ -1,24 +1,21 @@
 import { useEffect } from 'react';
 import { useThumbnailCapability } from '@embedpdf/plugin-thumbnail/react';
+import { useViewer } from '../../contexts/ViewerContext';
 
 /**
- * Component that runs inside EmbedPDF context and exports thumbnail controls globally
+ * ThumbnailAPIBridge provides thumbnail generation functionality.
+ * Exposes thumbnail API to UI components without managing state.
  */
 export function ThumbnailAPIBridge() {
   const { provides: thumbnail } = useThumbnailCapability();
+  const { registerBridge } = useViewer();
 
   useEffect(() => {
-    console.log('📄 ThumbnailAPIBridge useEffect:', { thumbnail: !!thumbnail });
     if (thumbnail) {
-      console.log('📄 Exporting thumbnail controls to window:', {
-        availableMethods: Object.keys(thumbnail),
-        renderThumb: typeof thumbnail.renderThumb
+      registerBridge('thumbnail', {
+        state: null, // No state - just provides API
+        api: thumbnail
       });
-      // Export thumbnail controls to global window for debugging
-      (window as any).embedPdfThumbnail = {
-        thumbnailAPI: thumbnail,
-        availableMethods: Object.keys(thumbnail),
-      };
     }
   }, [thumbnail]);
 

frontend/src/components/viewer/ThumbnailSidebar.tsx

@@ -1,48 +1,38 @@
 import React, { useState, useEffect } from 'react';
-import { Box, ScrollArea, ActionIcon, Tooltip } from '@mantine/core';
-import { LocalIcon } from '../shared/LocalIcon';
+import { Box, ScrollArea } from '@mantine/core';
+import { useViewer } from '../../contexts/ViewerContext';
 import '../../types/embedPdf';
 
 interface ThumbnailSidebarProps {
   visible: boolean;
   onToggle: () => void;
-  colorScheme: 'light' | 'dark' | 'auto';
+  colorScheme?: 'light' | 'dark' | 'auto'; // Optional since we use CSS variables
 }
 
-export function ThumbnailSidebar({ visible, onToggle, colorScheme }: ThumbnailSidebarProps) {
-  const [selectedPage, setSelectedPage] = useState<number>(1);
+export function ThumbnailSidebar({ visible, onToggle: _onToggle }: ThumbnailSidebarProps) {
+  const { getScrollState, scrollActions, getThumbnailAPI } = useViewer();
   const [thumbnails, setThumbnails] = useState<{ [key: number]: string }>({});
-  const [totalPages, setTotalPages] = useState<number>(0);
-
-  // Convert color scheme
-  const actualColorScheme = colorScheme === 'auto' ? 'light' : colorScheme;
-
-  // Get total pages from scroll API
-  useEffect(() => {
-    const scrollAPI = window.embedPdfScroll;
-    if (scrollAPI && scrollAPI.totalPages) {
-      setTotalPages(scrollAPI.totalPages);
-    }
-  }, [visible]);
+  
+  const scrollState = getScrollState();
+  const thumbnailAPI = getThumbnailAPI();
 
   // Generate thumbnails when sidebar becomes visible
   useEffect(() => {
-    if (!visible || totalPages === 0) return;
+    if (!visible || scrollState.totalPages === 0) return;
 
-    const thumbnailAPI = window.embedPdfThumbnail?.thumbnailAPI;
     console.log('📄 ThumbnailSidebar useEffect triggered:', {
       visible,
       thumbnailAPI: !!thumbnailAPI,
-      totalPages,
+      totalPages: scrollState.totalPages,
       existingThumbnails: Object.keys(thumbnails).length
     });
     
     if (!thumbnailAPI) return;
 
     const generateThumbnails = async () => {
-      console.log('📄 Starting thumbnail generation for', totalPages, 'pages');
+      console.log('📄 Starting thumbnail generation for', scrollState.totalPages, 'pages');
       
-      for (let pageIndex = 0; pageIndex < totalPages; pageIndex++) {
+      for (let pageIndex = 0; pageIndex < scrollState.totalPages; pageIndex++) {
         if (thumbnails[pageIndex]) continue; // Skip if already generated
 
         try {
@@ -89,17 +79,11 @@ export function ThumbnailSidebar({ visible, onToggle, colorScheme }: ThumbnailSi
         }
       });
     };
-  }, [visible, totalPages]);
+  }, [visible, scrollState.totalPages, thumbnailAPI]);
 
   const handlePageClick = (pageIndex: number) => {
     const pageNumber = pageIndex + 1; // Convert to 1-based
-    setSelectedPage(pageNumber);
-    
-    // Use scroll API to navigate to page
-    const scrollAPI = window.embedPdfScroll;
-    if (scrollAPI && scrollAPI.scrollToPage) {
-      scrollAPI.scrollToPage(pageNumber);
-    }
+    scrollActions.scrollToPage(pageNumber);
   };
 
   return (
@@ -113,8 +97,8 @@ export function ThumbnailSidebar({ visible, onToggle, colorScheme }: ThumbnailSi
             top: 0,
             bottom: 0,
             width: '15rem',
-            backgroundColor: actualColorScheme === 'dark' ? '#1a1b1e' : '#f8f9fa',
-            borderLeft: `1px solid ${actualColorScheme === 'dark' ? '#373A40' : '#e9ecef'}`,
+            backgroundColor: 'var(--bg-surface)',
+            borderLeft: '1px solid var(--border-subtle)',
             zIndex: 998,
             display: 'flex',
             flexDirection: 'column',
@@ -129,7 +113,7 @@ export function ThumbnailSidebar({ visible, onToggle, colorScheme }: ThumbnailSi
                 flexDirection: 'column',
                 gap: '12px'
               }}>
-                {Array.from({ length: totalPages }, (_, pageIndex) => (
+                {Array.from({ length: scrollState.totalPages }, (_, pageIndex) => (
                   <Box
                     key={pageIndex}
                     onClick={() => handlePageClick(pageIndex)}
@@ -137,11 +121,11 @@ export function ThumbnailSidebar({ visible, onToggle, colorScheme }: ThumbnailSi
                       cursor: 'pointer',
                       borderRadius: '8px',
                       padding: '8px',
-                      backgroundColor: selectedPage === pageIndex + 1
-                        ? (actualColorScheme === 'dark' ? '#364FC7' : '#e7f5ff')
+                      backgroundColor: scrollState.currentPage === pageIndex + 1
+                        ? 'var(--color-primary-100)'
                         : 'transparent',
-                      border: selectedPage === pageIndex + 1 
-                        ? '2px solid #1c7ed6'
+                      border: scrollState.currentPage === pageIndex + 1 
+                        ? '2px solid var(--color-primary-500)'
                         : '2px solid transparent',
                       transition: 'all 0.2s ease',
                       display: 'flex',
@@ -150,12 +134,12 @@ export function ThumbnailSidebar({ visible, onToggle, colorScheme }: ThumbnailSi
                       gap: '8px'
                     }}
                     onMouseEnter={(e) => {
-                      if (selectedPage !== pageIndex + 1) {
-                        e.currentTarget.style.backgroundColor = actualColorScheme === 'dark' ? '#25262b' : '#f1f3f5';
+                      if (scrollState.currentPage !== pageIndex + 1) {
+                        e.currentTarget.style.backgroundColor = 'var(--hover-bg)';
                       }
                     }}
                     onMouseLeave={(e) => {
-                      if (selectedPage !== pageIndex + 1) {
+                      if (scrollState.currentPage !== pageIndex + 1) {
                         e.currentTarget.style.backgroundColor = 'transparent';
                       }
                     }}
@@ -170,20 +154,20 @@ export function ThumbnailSidebar({ visible, onToggle, colorScheme }: ThumbnailSi
                           height: 'auto',
                           borderRadius: '4px',
                           boxShadow: '0 2px 4px rgba(0, 0, 0, 0.1)',
-                          border: `1px solid ${actualColorScheme === 'dark' ? '#373A40' : '#e9ecef'}`
+                          border: '1px solid var(--border-subtle)'
                         }}
                       />
                     ) : thumbnails[pageIndex] === 'error' ? (
                       <div style={{
                         width: '11.5rem',
                         height: '15rem',
-                        backgroundColor: actualColorScheme === 'dark' ? '#2d1b1b' : '#ffebee',
-                        border: `1px solid ${actualColorScheme === 'dark' ? '#5d3737' : '#ffcdd2'}`,
+                        backgroundColor: 'var(--color-red-50)',
+                        border: '1px solid var(--color-red-200)',
                         borderRadius: '4px',
                         display: 'flex',
                         alignItems: 'center',
                         justifyContent: 'center',
-                        color: '#d32f2f',
+                        color: 'var(--color-red-500)',
                         fontSize: '12px'
                       }}>
                         Failed
@@ -192,13 +176,13 @@ export function ThumbnailSidebar({ visible, onToggle, colorScheme }: ThumbnailSi
                       <div style={{
                         width: '11.5rem',
                         height: '15rem',
-                        backgroundColor: actualColorScheme === 'dark' ? '#25262b' : '#f8f9fa',
-                        border: `1px solid ${actualColorScheme === 'dark' ? '#373A40' : '#e9ecef'}`,
+                        backgroundColor: 'var(--bg-muted)',
+                        border: '1px solid var(--border-subtle)',
                         borderRadius: '4px',
                         display: 'flex',
                         alignItems: 'center',
                         justifyContent: 'center',
-                        color: actualColorScheme === 'dark' ? '#adb5bd' : '#6c757d',
+                        color: 'var(--text-muted)',
                         fontSize: '12px'
                       }}>
                         Loading...
@@ -209,9 +193,9 @@ export function ThumbnailSidebar({ visible, onToggle, colorScheme }: ThumbnailSi
                     <div style={{
                       fontSize: '12px',
                       fontWeight: 500,
-                      color: selectedPage === pageIndex + 1
-                        ? (actualColorScheme === 'dark' ? '#ffffff' : '#1c7ed6')
-                        : (actualColorScheme === 'dark' ? '#adb5bd' : '#6c757d')
+                      color: scrollState.currentPage === pageIndex + 1
+                        ? 'var(--color-primary-500)'
+                        : 'var(--text-muted)'
                     }}>
                       Page {pageIndex + 1}
                     </div>

frontend/src/components/viewer/ZoomAPIBridge.tsx

@@ -1,13 +1,21 @@
-import { useEffect, useRef } from 'react';
+import { useEffect, useRef, useState } from 'react';
 import { useZoom } from '@embedpdf/plugin-zoom/react';
+import { useViewer } from '../../contexts/ViewerContext';
 
 /**
- * Component that runs inside EmbedPDF context and exports zoom controls globally
+ * Component that runs inside EmbedPDF context and manages zoom state locally
  */
 export function ZoomAPIBridge() {
   const { provides: zoom, state: zoomState } = useZoom();
+  const { registerBridge } = useViewer();
   const hasSetInitialZoom = useRef(false);
 
+  // Store state locally
+  const [_localState, setLocalState] = useState({
+    currentZoom: 1.4,
+    zoomPercent: 140
+  });
+
   // Set initial zoom once when plugin is ready
   useEffect(() => {
     if (zoom && !hasSetInitialZoom.current) {
@@ -20,18 +28,23 @@ export function ZoomAPIBridge() {
   }, [zoom]);
 
   useEffect(() => {
-    if (zoom) {
-
-      // Export zoom controls to global window for right rail access
-      (window as any).embedPdfZoom = {
-        zoomIn: () => zoom.zoomIn(),
-        zoomOut: () => zoom.zoomOut(),
-        toggleMarqueeZoom: () => zoom.toggleMarqueeZoom(),
-        requestZoom: (level: any) => zoom.requestZoom(level),
-        currentZoom: zoomState?.currentZoomLevel || 1.4,
-        zoomPercent: Math.round((zoomState?.currentZoomLevel || 1.4) * 100),
+    if (zoom && zoomState) {
+      // Update local state
+      const currentZoomLevel = zoomState.currentZoomLevel || 1.4;
+      const newState = {
+        currentZoom: currentZoomLevel,
+        zoomPercent: Math.round(currentZoomLevel * 100),
       };
+      
+      console.log('ZoomAPIBridge - Raw zoom level:', currentZoomLevel, 'Rounded percent:', newState.zoomPercent);
+      
+      setLocalState(newState);
 
+      // Register this bridge with ViewerContext
+      registerBridge('zoom', {
+        state: newState,
+        api: zoom
+      });
     }
   }, [zoom, zoomState]);
 

frontend/src/contexts/ViewerContext.tsx

@@ -1,33 +1,437 @@
-import React, { createContext, useContext, useState, ReactNode } from 'react';
+import React, { createContext, useContext, useState, ReactNode, useRef } from 'react';
 
-interface ViewerContextType {
-  // Thumbnail sidebar state
-  isThumbnailSidebarVisible: boolean;
-  toggleThumbnailSidebar: () => void;
-  setThumbnailSidebarVisible: (visible: boolean) => void;
+// State interfaces - represent the shape of data from each bridge
+interface ScrollState {
+  currentPage: number;
+  totalPages: number;
 }
 
-const ViewerContext = createContext<ViewerContextType | null>(null);
+interface ZoomState {
+  currentZoom: number;
+  zoomPercent: number;
+}
+
+interface PanState {
+  isPanning: boolean;
+}
+
+interface SelectionState {
+  hasSelection: boolean;
+}
+
+interface SpreadState {
+  spreadMode: any;
+  isDualPage: boolean;
+}
+
+interface RotationState {
+  rotation: number;
+}
+
+// Bridge registration interface - bridges register with state and API
+interface BridgeRef {
+  state: any;
+  api: any;
+}
+
+/**
+ * ViewerContext provides a unified interface to EmbedPDF functionality.
+ * 
+ * Architecture:
+ * - Bridges store their own state locally and register with this context
+ * - Context provides read-only access to bridge state via getter functions
+ * - Actions call EmbedPDF APIs directly through bridge references
+ * - No circular dependencies - bridges don't call back into this context
+ */
+interface ViewerContextType {
+  // UI state managed by this context
+  isThumbnailSidebarVisible: boolean;
+  toggleThumbnailSidebar: () => void;
+  
+  // State getters - read current state from bridges
+  getScrollState: () => ScrollState;
+  getZoomState: () => ZoomState;
+  getPanState: () => PanState;
+  getSelectionState: () => SelectionState;
+  getSpreadState: () => SpreadState;
+  getRotationState: () => RotationState;
+  getSearchResults: () => any[] | null;
+  getSearchActiveIndex: () => number;
+  getThumbnailAPI: () => any;
+  
+  // Immediate update callbacks
+  registerImmediateZoomUpdate: (callback: (percent: number) => void) => void;
+  registerImmediateScrollUpdate: (callback: (currentPage: number, totalPages: number) => void) => void;
+  
+  // Internal - for bridges to trigger immediate updates
+  triggerImmediateScrollUpdate: (currentPage: number, totalPages: number) => void;
+  
+  // Action handlers - call EmbedPDF APIs directly
+  scrollActions: {
+    scrollToPage: (page: number) => void;
+    scrollToFirstPage: () => void;
+    scrollToPreviousPage: () => void;
+    scrollToNextPage: () => void;
+    scrollToLastPage: () => void;
+  };
+  
+  zoomActions: {
+    zoomIn: () => void;
+    zoomOut: () => void;
+    toggleMarqueeZoom: () => void;
+    requestZoom: (level: number) => void;
+  };
+  
+  panActions: {
+    enablePan: () => void;
+    disablePan: () => void;
+    togglePan: () => void;
+  };
+  
+  selectionActions: {
+    copyToClipboard: () => void;
+    getSelectedText: () => string;
+    getFormattedSelection: () => any;
+  };
+  
+  spreadActions: {
+    setSpreadMode: (mode: any) => void;
+    getSpreadMode: () => any;
+    toggleSpreadMode: () => void;
+  };
+  
+  rotationActions: {
+    rotateForward: () => void;
+    rotateBackward: () => void;
+    setRotation: (rotation: number) => void;
+    getRotation: () => number;
+  };
+  
+  searchActions: {
+    search: (query: string) => Promise<void>;
+    next: () => void;
+    previous: () => void;
+    clear: () => void;
+  };
+
+  // Bridge registration - internal use by bridges
+  registerBridge: (type: string, ref: BridgeRef) => void;
+}
+
+export const ViewerContext = createContext<ViewerContextType | null>(null);
 
 interface ViewerProviderProps {
   children: ReactNode;
 }
 
 export const ViewerProvider: React.FC<ViewerProviderProps> = ({ children }) => {
+  // UI state - only state directly managed by this context
   const [isThumbnailSidebarVisible, setIsThumbnailSidebarVisible] = useState(false);
+  
+  // Bridge registry - bridges register their state and APIs here
+  const bridgeRefs = useRef({
+    scroll: null as BridgeRef | null,
+    zoom: null as BridgeRef | null,
+    pan: null as BridgeRef | null,
+    selection: null as BridgeRef | null,
+    search: null as BridgeRef | null,
+    spread: null as BridgeRef | null,
+    rotation: null as BridgeRef | null,
+    thumbnail: null as BridgeRef | null,
+  });
+
+  // Immediate zoom callback for responsive display updates
+  const immediateZoomUpdateCallback = useRef<((percent: number) => void) | null>(null);
+  
+  // Immediate scroll callback for responsive display updates
+  const immediateScrollUpdateCallback = useRef<((currentPage: number, totalPages: number) => void) | null>(null);
+
+  const registerBridge = (type: string, ref: BridgeRef) => {
+    bridgeRefs.current[type as keyof typeof bridgeRefs.current] = ref;
+  };
 
   const toggleThumbnailSidebar = () => {
     setIsThumbnailSidebarVisible(prev => !prev);
   };
 
-  const setThumbnailSidebarVisible = (visible: boolean) => {
-    setIsThumbnailSidebarVisible(visible);
+  // State getters - read from bridge refs
+  const getScrollState = (): ScrollState => {
+    return bridgeRefs.current.scroll?.state || { currentPage: 1, totalPages: 0 };
+  };
+
+  const getZoomState = (): ZoomState => {
+    return bridgeRefs.current.zoom?.state || { currentZoom: 1.4, zoomPercent: 140 };
+  };
+
+  const getPanState = (): PanState => {
+    return bridgeRefs.current.pan?.state || { isPanning: false };
+  };
+
+  const getSelectionState = (): SelectionState => {
+    return bridgeRefs.current.selection?.state || { hasSelection: false };
+  };
+
+  const getSpreadState = (): SpreadState => {
+    return bridgeRefs.current.spread?.state || { spreadMode: null, isDualPage: false };
+  };
+
+  const getRotationState = (): RotationState => {
+    return bridgeRefs.current.rotation?.state || { rotation: 0 };
+  };
+
+  const getSearchResults = () => {
+    return bridgeRefs.current.search?.state?.results || null;
+  };
+
+  const getSearchActiveIndex = () => {
+    return bridgeRefs.current.search?.state?.activeIndex || 0;
+  };
+
+  const getThumbnailAPI = () => {
+    return bridgeRefs.current.thumbnail?.api || null;
+  };
+
+  // Action handlers - call APIs directly
+  const scrollActions = {
+    scrollToPage: (page: number) => {
+      const api = bridgeRefs.current.scroll?.api;
+      if (api?.scrollToPage) {
+        api.scrollToPage({ pageNumber: page });
+      }
+    },
+    scrollToFirstPage: () => {
+      const api = bridgeRefs.current.scroll?.api;
+      if (api?.scrollToPage) {
+        api.scrollToPage({ pageNumber: 1 });
+      }
+    },
+    scrollToPreviousPage: () => {
+      const api = bridgeRefs.current.scroll?.api;
+      if (api?.scrollToPreviousPage) {
+        api.scrollToPreviousPage();
+      }
+    },
+    scrollToNextPage: () => {
+      const api = bridgeRefs.current.scroll?.api;
+      if (api?.scrollToNextPage) {
+        api.scrollToNextPage();
+      }
+    },
+    scrollToLastPage: () => {
+      const scrollState = getScrollState();
+      const api = bridgeRefs.current.scroll?.api;
+      if (api?.scrollToPage && scrollState.totalPages > 0) {
+        api.scrollToPage({ pageNumber: scrollState.totalPages });
+      }
+    }
+  };
+
+  const zoomActions = {
+    zoomIn: () => {
+      const api = bridgeRefs.current.zoom?.api;
+      if (api?.zoomIn) {
+        // Update display immediately if callback is registered
+        if (immediateZoomUpdateCallback.current) {
+          const currentState = getZoomState();
+          const newPercent = Math.min(Math.round(currentState.zoomPercent * 1.2), 300);
+          immediateZoomUpdateCallback.current(newPercent);
+        }
+        api.zoomIn();
+      }
+    },
+    zoomOut: () => {
+      const api = bridgeRefs.current.zoom?.api;
+      if (api?.zoomOut) {
+        // Update display immediately if callback is registered
+        if (immediateZoomUpdateCallback.current) {
+          const currentState = getZoomState();
+          const newPercent = Math.max(Math.round(currentState.zoomPercent / 1.2), 20);
+          immediateZoomUpdateCallback.current(newPercent);
+        }
+        api.zoomOut();
+      }
+    },
+    toggleMarqueeZoom: () => {
+      const api = bridgeRefs.current.zoom?.api;
+      if (api?.toggleMarqueeZoom) {
+        api.toggleMarqueeZoom();
+      }
+    },
+    requestZoom: (level: number) => {
+      const api = bridgeRefs.current.zoom?.api;
+      if (api?.requestZoom) {
+        api.requestZoom(level);
+      }
+    }
+  };
+
+  const panActions = {
+    enablePan: () => {
+      const api = bridgeRefs.current.pan?.api;
+      if (api?.enable) {
+        api.enable();
+      }
+    },
+    disablePan: () => {
+      const api = bridgeRefs.current.pan?.api;
+      if (api?.disable) {
+        api.disable();
+      }
+    },
+    togglePan: () => {
+      const api = bridgeRefs.current.pan?.api;
+      if (api?.toggle) {
+        api.toggle();
+      }
+    }
+  };
+
+  const selectionActions = {
+    copyToClipboard: () => {
+      const api = bridgeRefs.current.selection?.api;
+      if (api?.copyToClipboard) {
+        api.copyToClipboard();
+      }
+    },
+    getSelectedText: () => {
+      const api = bridgeRefs.current.selection?.api;
+      if (api?.getSelectedText) {
+        return api.getSelectedText();
+      }
+      return '';
+    },
+    getFormattedSelection: () => {
+      const api = bridgeRefs.current.selection?.api;
+      if (api?.getFormattedSelection) {
+        return api.getFormattedSelection();
+      }
+      return null;
+    }
+  };
+
+  const spreadActions = {
+    setSpreadMode: (mode: any) => {
+      const api = bridgeRefs.current.spread?.api;
+      if (api?.setSpreadMode) {
+        api.setSpreadMode(mode);
+      }
+    },
+    getSpreadMode: () => {
+      const api = bridgeRefs.current.spread?.api;
+      if (api?.getSpreadMode) {
+        return api.getSpreadMode();
+      }
+      return null;
+    },
+    toggleSpreadMode: () => {
+      const api = bridgeRefs.current.spread?.api;
+      if (api?.toggleSpreadMode) {
+        api.toggleSpreadMode();
+      }
+    }
+  };
+
+  const rotationActions = {
+    rotateForward: () => {
+      const api = bridgeRefs.current.rotation?.api;
+      if (api?.rotateForward) {
+        api.rotateForward();
+      }
+    },
+    rotateBackward: () => {
+      const api = bridgeRefs.current.rotation?.api;
+      if (api?.rotateBackward) {
+        api.rotateBackward();
+      }
+    },
+    setRotation: (rotation: number) => {
+      const api = bridgeRefs.current.rotation?.api;
+      if (api?.setRotation) {
+        api.setRotation(rotation);
+      }
+    },
+    getRotation: () => {
+      const api = bridgeRefs.current.rotation?.api;
+      if (api?.getRotation) {
+        return api.getRotation();
+      }
+      return 0;
+    }
+  };
+
+  const searchActions = {
+    search: async (query: string) => {
+      const api = bridgeRefs.current.search?.api;
+      if (api?.search) {
+        return api.search(query);
+      }
+    },
+    next: () => {
+      const api = bridgeRefs.current.search?.api;
+      if (api?.next) {
+        api.next();
+      }
+    },
+    previous: () => {
+      const api = bridgeRefs.current.search?.api;
+      if (api?.previous) {
+        api.previous();
+      }
+    },
+    clear: () => {
+      const api = bridgeRefs.current.search?.api;
+      if (api?.clear) {
+        api.clear();
+      }
+    }
+  };
+
+  const registerImmediateZoomUpdate = (callback: (percent: number) => void) => {
+    immediateZoomUpdateCallback.current = callback;
+  };
+
+  const registerImmediateScrollUpdate = (callback: (currentPage: number, totalPages: number) => void) => {
+    immediateScrollUpdateCallback.current = callback;
+  };
+
+  const triggerImmediateScrollUpdate = (currentPage: number, totalPages: number) => {
+    if (immediateScrollUpdateCallback.current) {
+      immediateScrollUpdateCallback.current(currentPage, totalPages);
+    }
   };
 
   const value: ViewerContextType = {
+    // UI state
     isThumbnailSidebarVisible,
     toggleThumbnailSidebar,
-    setThumbnailSidebarVisible,
+    
+    // State getters
+    getScrollState,
+    getZoomState,
+    getPanState,
+    getSelectionState,
+    getSpreadState,
+    getRotationState,
+    getSearchResults,
+    getSearchActiveIndex,
+    getThumbnailAPI,
+    
+    // Immediate updates
+    registerImmediateZoomUpdate,
+    registerImmediateScrollUpdate,
+    triggerImmediateScrollUpdate,
+    
+    // Actions
+    scrollActions,
+    zoomActions,
+    panActions,
+    selectionActions,
+    spreadActions,
+    rotationActions,
+    searchActions,
+    
+    // Bridge registration
+    registerBridge,
   };
 
   return (