diff --git a/client/public/index.html b/client/public/index.html
index 2b89f64..075fc78 100644
--- a/client/public/index.html
+++ b/client/public/index.html
@@ -34,6 +34,34 @@
             min-width: 200px;
         }
 
+        /* Alternating row colors for better readability */
+        .ag-row-odd {
+            background-color: #f8f9fa !important;
+        }
+        
+        .ag-row-even {
+            background-color: #ffffff !important;
+        }
+        
+        /* Maintain alternating colors on hover */
+        .ag-row-odd:hover {
+            background-color: #e9ecef !important;
+        }
+        
+        .ag-row-even:hover {
+            background-color: #f1f3f4 !important;
+        }
+        
+        /* Ensure JTL-only rows (red rows) override alternating colors */
+        .ag-row[style*="background-color: rgb(255, 235, 238)"] {
+            background-color: #ffebee !important;
+        }
+
+        /* Selected rows */
+        .ag-row.selected-row {
+            background-color: #e3f2fd !important;
+            color: #1976d2 !important;
+        }
 
     </style>
     <script>
diff --git a/client/src/App.js b/client/src/App.js
index eeb5c07..1306eb3 100644
--- a/client/src/App.js
+++ b/client/src/App.js
@@ -4,6 +4,7 @@ import CssBaseline from '@mui/material/CssBaseline';
 import { Container, AppBar, Toolbar, Typography, Button, Box } from '@mui/material';
 import LoginIcon from '@mui/icons-material/Login';
 import DashboardIcon from '@mui/icons-material/Dashboard';
+import DownloadIcon from '@mui/icons-material/Download';
 import AuthService from './services/AuthService';
 import DataViewer from './components/DataViewer';
 import Login from './components/Login';
@@ -27,6 +28,7 @@ class App extends Component {
       isAuthenticated: false,
       user: null,
       loading: true,
+      exportData: null, // { selectedMonth, canExport, onExport }
     };
     this.authService = new AuthService();
   }
@@ -68,7 +70,11 @@ class App extends Component {
 
   handleLogout = () => {
     localStorage.removeItem('token');
-    this.setState({ isAuthenticated: false, user: null });
+    this.setState({ isAuthenticated: false, user: null, exportData: null });
+  };
+
+  updateExportData = (exportData) => {
+    this.setState({ exportData });
   };
 
   render() {
@@ -107,6 +113,24 @@ class App extends Component {
                 >
                   Willkommen, {user.name}
                 </Typography>
+                {this.state.exportData && (
+                  <Button 
+                    color="inherit" 
+                    onClick={this.state.exportData.onExport}
+                    disabled={!this.state.exportData.canExport}
+                    size="small"
+                    sx={{ 
+                      mr: { xs: 1, sm: 2 },
+                      minWidth: { xs: 'auto', sm: 'auto' },
+                      px: { xs: 1, sm: 2 }
+                    }}
+                  >
+                    <DownloadIcon sx={{ mr: { xs: 0, sm: 1 } }} />
+                    <Box component="span" sx={{ display: { xs: 'none', sm: 'inline' } }}>
+                      DATEV Export
+                    </Box>
+                  </Button>
+                )}
                 <Button 
                   color="inherit" 
                   onClick={this.handleLogout}
@@ -127,9 +151,9 @@ class App extends Component {
         </AppBar>
 
         <Box sx={{ height: 'calc(100vh - 64px)', display: 'flex', flexDirection: 'column' }}>
-          <Container maxWidth="xl" sx={{ mt: 4, flex: 1, minHeight: 0, display: 'flex', flexDirection: 'column' }}>
+          <Container maxWidth={false} sx={{ mt: 4, flex: 1, minHeight: 0, display: 'flex', flexDirection: 'column', width: '100%' }}>
             {isAuthenticated ? (
-              <DataViewer user={user} />
+              <DataViewer user={user} onUpdateExportData={this.updateExportData} />
             ) : (
               <Login onLogin={this.handleLogin} />
             )}
diff --git a/client/src/components/DataViewer.js b/client/src/components/DataViewer.js
index 7b657f8..40328ea 100644
--- a/client/src/components/DataViewer.js
+++ b/client/src/components/DataViewer.js
@@ -24,6 +24,13 @@ class DataViewer extends Component {
 
   componentDidMount() {
     this.loadMonths();
+    this.updateExportData();
+  }
+
+  componentDidUpdate(prevProps, prevState) {
+    if (prevState.loading !== this.state.loading || prevState.selectedMonth !== this.state.selectedMonth) {
+      this.updateExportData();
+    }
   }
 
   loadMonths = async () => {
@@ -70,6 +77,7 @@ class DataViewer extends Component {
     const monthYear = event.target.value;
     this.setState({ selectedMonth: monthYear });
     this.loadTransactions(monthYear);
+    this.updateExportData(monthYear);
   };
 
 
@@ -98,6 +106,16 @@ class DataViewer extends Component {
     }
   };
 
+  updateExportData = (selectedMonth = this.state.selectedMonth) => {
+    if (this.props.onUpdateExportData) {
+      this.props.onUpdateExportData({
+        selectedMonth,
+        canExport: !!selectedMonth && !this.state.loading,
+        onExport: this.downloadDatev
+      });
+    }
+  };
+
   render() {
     const { months, selectedMonth, transactions, summary, loading, error } = this.state;
 
@@ -126,7 +144,6 @@ class DataViewer extends Component {
             summary={summary}
             loading={loading}
             onMonthChange={this.handleMonthChange}
-            onDownloadDatev={this.downloadDatev}
           />
         </Box>
         
diff --git a/client/src/components/SummaryHeader.js b/client/src/components/SummaryHeader.js
index 1d7a139..999c6e3 100644
--- a/client/src/components/SummaryHeader.js
+++ b/client/src/components/SummaryHeader.js
@@ -95,8 +95,7 @@ class SummaryHeader extends Component {
       selectedMonth, 
       summary, 
       loading, 
-      onMonthChange, 
-      onDownloadDatev 
+      onMonthChange 
     } = this.props;
 
     if (!summary) return null;
@@ -249,23 +248,19 @@ class SummaryHeader extends Component {
           <Grid item xs={6} sm={4} md={1}>
             <Box textAlign="center">
               <Typography variant="caption" color="textSecondary">JTL ✓</Typography>
-              <Typography variant="h6" sx={{ fontWeight: 'bold', color: '#388e3c', fontSize: { xs: '0.9rem', sm: '1.25rem' } }}>
-                {summary.jtlMatches || 0}
+              <Typography 
+                variant="h6" 
+                sx={{ 
+                  fontWeight: 'bold', 
+                  color: summary.jtlMatches === undefined ? '#856404' : '#388e3c', 
+                  fontSize: { xs: '0.9rem', sm: '1.25rem' } 
+                }}
+              >
+                {summary.jtlMatches === undefined ? '?' : summary.jtlMatches}
               </Typography>
             </Box>
           </Grid>
-          <Grid item xs={12} sm={4} md={2}>
-            <Button
-              variant="contained"
-              startIcon={<DownloadIcon />}
-              onClick={onDownloadDatev}
-              disabled={!selectedMonth || loading}
-              size="small"
-              sx={{ height: 'fit-content' }}
-            >
-              DATEV Export
-            </Button>
-          </Grid>
+
         </Grid>
       </Paper>
     );
diff --git a/client/src/components/TransactionsTable.js b/client/src/components/TransactionsTable.js
index 7b04cac..805d385 100644
--- a/client/src/components/TransactionsTable.js
+++ b/client/src/components/TransactionsTable.js
@@ -9,9 +9,12 @@ import {
   Paper,
   Typography,
   CircularProgress,
+  IconButton,
+  Tooltip,
 } from '@mui/material';
+import { Clear as ClearIcon } from '@mui/icons-material';
 import { getColumnDefs, defaultColDef, gridOptions } from './config/gridConfig';
-import { processTransactionData, getRowStyle, getSelectedDisplayName } from './utils/dataUtils';
+import { processTransactionData, getRowStyle, getRowClass, getSelectedDisplayName } from './utils/dataUtils';
 
 class TransactionsTable extends Component {
   constructor(props) {
@@ -20,20 +23,59 @@ class TransactionsTable extends Component {
     this.state = {
       columnDefs: getColumnDefs(),
       defaultColDef: defaultColDef,
-      gridOptions: gridOptions
+      gridOptions: gridOptions,
+      totalRows: 0,
+      displayedRows: 0,
+      selectedRows: new Set() // Track selected row IDs
     };
+    
+    // Ref for header checkbox to update it directly
+    this.headerCheckboxRef = null;
   }
 
 
 
 
 
+
+
+  componentDidMount() {
+    // Add window resize listener for auto-resizing columns
+    this.handleResize = () => {
+      if (this.gridApi) {
+        // Small delay to ensure DOM has updated
+        setTimeout(() => {
+          this.gridApi.sizeColumnsToFit();
+        }, 100);
+      }
+    };
+    
+    window.addEventListener('resize', this.handleResize);
+  }
+
+  componentWillUnmount() {
+    // Clean up event listeners
+    if (this.handleResize) {
+      window.removeEventListener('resize', this.handleResize);
+    }
+    
+    if (this.gridApi) {
+      this.gridApi.removeEventListener('modelUpdated', this.onModelUpdated);
+      this.gridApi.removeEventListener('filterChanged', this.onFilterChanged);
+    }
+  }
+
   componentDidUpdate(prevProps) {
     // Update data without recreating grid when transactions change
     if (prevProps.transactions !== this.props.transactions && this.gridApi) {
       const processedTransactions = this.props.transactions ? processTransactionData(this.props.transactions) : [];
       // Use setGridOption to update data while preserving grid state
       this.gridApi.setGridOption('rowData', processedTransactions);
+      // Update total rows count and displayed rows
+      this.setState({ 
+        totalRows: processedTransactions.length,
+        displayedRows: processedTransactions.length 
+      });
     }
   }
 
@@ -51,12 +93,26 @@ class TransactionsTable extends Component {
     this.gridApi = params.api;
     this.gridColumnApi = params.columnApi;
     
+    // Store reference to this component for header access
+    params.api.fibdashComponent = this;
+    params.api.setHeaderCheckboxRef = (ref) => {
+      this.headerCheckboxRef = ref;
+    };
+    
     // Set initial data if available
     if (this.props.transactions) {
       const processedTransactions = processTransactionData(this.props.transactions);
       this.gridApi.setGridOption('rowData', processedTransactions);
+      this.setState({ 
+        totalRows: processedTransactions.length,
+        displayedRows: processedTransactions.length 
+      });
     }
     
+    // Add event listeners for row count updates
+    params.api.addEventListener('modelUpdated', this.onModelUpdated);
+    params.api.addEventListener('filterChanged', this.onFilterChanged);
+    
     // Auto-size columns to fit content
     params.api.sizeColumnsToFit();
     
@@ -64,23 +120,143 @@ class TransactionsTable extends Component {
     this.gridInitialized = true;
   };
 
+  onModelUpdated = () => {
+    if (this.gridApi) {
+      const displayedRows = this.gridApi.getDisplayedRowCount();
+      this.setState({ displayedRows });
+    }
+  };
+
+  onFilterChanged = () => {
+    if (this.gridApi) {
+      const displayedRows = this.gridApi.getDisplayedRowCount();
+      this.setState({ displayedRows });
+    }
+  };
+
+  hasActiveFilters = () => {
+    if (!this.gridApi) return false;
+    const filterModel = this.gridApi.getFilterModel();
+    return filterModel && Object.keys(filterModel).length > 0;
+  };
+
+  clearAllFilters = () => {
+    if (this.gridApi) {
+      this.gridApi.setFilterModel(null);
+    }
+  };
+
+  onCellClicked = (event) => {
+    // Skip selection for specific cells
+    const field = event.colDef.field;
+    
+    // Don't select on selection column or document column (last cell)
+    // Allow IBAN column to trigger selection
+    if (field === 'selection' || field === 'documents') {
+      return;
+    }
+    
+    // Toggle row selection
+    const rowData = event.data;
+    if (!rowData) return;
+    
+    const rowId = rowData.id || event.rowIndex;
+    const isCurrentlySelected = this.state.selectedRows.has(rowId);
+    
+    // Toggle selection
+    this.onSelectionChange(rowId, rowData, !isCurrentlySelected);
+  };
+
+  // Custom selection methods
+  onSelectionChange = (rowId, rowData, isSelected) => {
+    const selectedRows = new Set(this.state.selectedRows);
+    
+    if (isSelected) {
+      selectedRows.add(rowId);
+    } else {
+      selectedRows.delete(rowId);
+    }
+    
+    this.setState({ selectedRows }, () => {
+      // Update only grid context, avoid column definition changes that cause resizing
+      if (this.gridApi) {
+        this.gridApi.setGridOption('context', {
+          selectedRows: selectedRows,
+          onSelectionChange: this.onSelectionChange,
+          onSelectAll: this.onSelectAll,
+          totalRows: this.state.totalRows,
+          displayedRows: this.state.displayedRows
+        });
+        
+        // Refresh only the selection column cells
+        this.gridApi.refreshCells({ columns: ['selection'], force: true });
+        
+        // Refresh row styles to show selection background
+        this.gridApi.redrawRows();
+        
+        // Update header checkbox directly via ref
+        if (this.headerCheckboxRef) {
+          this.headerCheckboxRef.updateState(selectedRows, this.state.displayedRows);
+        }
+      }
+    });
+    console.log('Selected rows:', Array.from(selectedRows));
+  };
+
+  onSelectAll = (selectAll) => {
+    const selectedRows = new Set();
+    
+    if (selectAll && this.gridApi) {
+      // Select all displayed rows
+      this.gridApi.forEachNodeAfterFilter((node) => {
+        if (node.data) {
+          const rowId = node.data.id || node.rowIndex;
+          selectedRows.add(rowId);
+        }
+      });
+    }
+    // If selectAll is false, selectedRows stays empty (clears all)
+    
+    this.setState({ selectedRows }, () => {
+      // Update only grid context, avoid column definition changes that cause resizing
+      if (this.gridApi) {
+        this.gridApi.setGridOption('context', {
+          selectedRows: selectedRows,
+          onSelectionChange: this.onSelectionChange,
+          onSelectAll: this.onSelectAll,
+          totalRows: this.state.totalRows,
+          displayedRows: this.state.displayedRows
+        });
+        
+        // Refresh only the selection column cells
+        this.gridApi.refreshCells({ columns: ['selection'], force: true });
+        
+        // Refresh row styles to show selection background
+        this.gridApi.redrawRows();
+        
+        // Update header checkbox directly via ref
+        if (this.headerCheckboxRef) {
+          this.headerCheckboxRef.updateState(selectedRows, this.state.displayedRows);
+        }
+      }
+    });
+    console.log('Selected rows:', Array.from(selectedRows));
+  };
+
   
 
   render() {
     const { selectedMonth, loading } = this.props;
+    const { totalRows, displayedRows, selectedRows } = this.state;
 
     return (
       <Paper elevation={2} sx={{ 
         m: 0, 
+        width: '100%',
         height: '100%', 
         display: 'flex', 
         flexDirection: 'column' 
       }}>
-        <Box sx={{ p: 1, flexShrink: 0 }}>
-          <Typography variant="h6" component="h2" gutterBottom sx={{ m: 0 }}>
-            Transaktionen für {getSelectedDisplayName(selectedMonth)}
-          </Typography>
-        </Box>
         
         <Box sx={{ flex: 1, width: '100%', minHeight: 0, position: 'relative' }}>
           {loading && (
@@ -103,16 +279,27 @@ class TransactionsTable extends Component {
           )}
           <div style={{ height: '100%', width: '100%' }}>
             <AgGridReact
-              key="transactions-grid" // Stable key prevents recreation
+              key="transactions-grid"
               columnDefs={this.state.columnDefs}
               // Remove rowData prop - data is set via API in componentDidUpdate
               defaultColDef={this.state.defaultColDef}
               gridOptions={this.state.gridOptions}
               onGridReady={this.onGridReady}
-              getRowStyle={getRowStyle}
+              getRowStyle={(params) => getRowStyle(params, this.state.selectedRows)}
+              getRowClass={(params) => getRowClass(params, this.state.selectedRows)}
               suppressRowTransform={true}
               // Use new theming system
               theme={themeQuartz}
+              // Pass selection state through context
+              context={{
+                selectedRows: this.state.selectedRows,
+                onSelectionChange: this.onSelectionChange,
+                onSelectAll: this.onSelectAll,
+                totalRows: this.state.totalRows,
+                displayedRows: this.state.displayedRows
+              }}
+              // Add row click selection
+              onCellClicked={this.onCellClicked}
               // Virtualization settings for performance
               rowBuffer={10}
               suppressRowVirtualisation={false}
@@ -126,6 +313,134 @@ class TransactionsTable extends Component {
             />
           </div>
         </Box>
+        
+        {/* Status Bar */}
+        <Box sx={{ 
+          flexShrink: 0,
+          px: 2, 
+          py: 1, 
+          borderTop: '1px solid #e0e0e0',
+          backgroundColor: '#f8f9fa',
+          display: 'flex',
+          justifyContent: 'space-between',
+          alignItems: 'center'
+        }}>
+          <Box sx={{ display: 'flex', gap: 2, alignItems: 'center' }}>
+            <Typography variant="body2" color="textSecondary">
+              {displayedRows === totalRows 
+                ? `${totalRows} Zeilen angezeigt`
+                : `${displayedRows} von ${totalRows} Zeilen angezeigt`
+              }
+            </Typography>
+            {selectedRows.size > 0 && (
+              <Tooltip title="Auswahl löschen">
+                <Box 
+                  sx={{ 
+                    display: 'flex', 
+                    alignItems: 'center', 
+                    gap: 1,
+                    cursor: 'pointer',
+                    px: 1,
+                    py: 0.5,
+                    borderRadius: 1,
+                    '&:hover': {
+                      backgroundColor: 'primary.light',
+                      '& .selection-text': {
+                        color: 'white'
+                      },
+                      '& .clear-selection-icon': {
+                        color: 'white'
+                      }
+                    }
+                  }}
+                  onClick={() => {
+                    const emptySelection = new Set();
+                    this.setState({ selectedRows: emptySelection }, () => {
+                      if (this.gridApi) {
+                        // Update grid context
+                        this.gridApi.setGridOption('context', {
+                          selectedRows: emptySelection,
+                          onSelectionChange: this.onSelectionChange,
+                          onSelectAll: this.onSelectAll,
+                          totalRows: this.state.totalRows,
+                          displayedRows: this.state.displayedRows
+                        });
+                        
+                        // Refresh cell checkboxes
+                        this.gridApi.refreshCells({ columns: ['selection'], force: true });
+                        
+                        // Refresh row styles to clear selection backgrounds
+                        this.gridApi.redrawRows();
+                        
+                        // Update header checkbox via ref
+                        if (this.headerCheckboxRef) {
+                          this.headerCheckboxRef.updateState(emptySelection, this.state.displayedRows);
+                        }
+                      }
+                    });
+                  }}
+                >
+                  <Typography 
+                    variant="body2" 
+                    color="primary" 
+                    sx={{ fontWeight: 'medium' }}
+                    className="selection-text"
+                  >
+                    {selectedRows.size} ausgewählt
+                  </Typography>
+                  <ClearIcon 
+                    sx={{ 
+                      fontSize: 16,
+                      color: 'primary.main'
+                    }} 
+                    className="clear-selection-icon"
+                  />
+                </Box>
+              </Tooltip>
+            )}
+          </Box>
+          {this.hasActiveFilters() && (
+            <Tooltip title="Alle Filter löschen">
+              <Box 
+                sx={{ 
+                  display: 'flex', 
+                  alignItems: 'center', 
+                  gap: 1,
+                  cursor: 'pointer',
+                  px: 1,
+                  py: 0.5,
+                  borderRadius: 1,
+                  '&:hover': {
+                    backgroundColor: 'primary.light',
+                    '& .filter-text': {
+                      color: 'white'
+                    },
+                    '& .clear-icon': {
+                      color: 'white'
+                    }
+                  }
+                }}
+                onClick={this.clearAllFilters}
+              >
+                <Typography 
+                  variant="body2" 
+                  color="primary" 
+                  sx={{ fontWeight: 'medium' }}
+                  className="filter-text"
+                >
+                  Filter aktiv
+                </Typography>
+                <ClearIcon 
+                  sx={{ 
+                    fontSize: 16,
+                    color: 'primary.main'
+                  }} 
+                  className="clear-icon"
+                />
+              </Box>
+            </Tooltip>
+          )}
+        </Box>
       </Paper>
     );
   }
diff --git a/client/src/components/cellRenderers/DocumentRenderer.js b/client/src/components/cellRenderers/DocumentRenderer.js
new file mode 100644
index 0000000..ef7ac3a
--- /dev/null
+++ b/client/src/components/cellRenderers/DocumentRenderer.js
@@ -0,0 +1,411 @@
+import React, { useState } from 'react';
+import { 
+  Box, 
+  IconButton, 
+  Dialog, 
+  DialogTitle, 
+  DialogContent, 
+  DialogActions, 
+  Button, 
+  List, 
+  ListItem, 
+  ListItemText, 
+  ListItemIcon,
+  Typography,
+  Divider,
+  Tabs,
+  Tab,
+  Alert
+} from '@mui/material';
+import { 
+  PictureAsPdf as PdfIcon, 
+  Link as LinkIcon,
+  Description as DocumentIcon,
+  OpenInNew as OpenIcon,
+  ContentCopy as CopyIcon
+} from '@mui/icons-material';
+import { AgGridReact } from 'ag-grid-react';
+
+const DocumentRenderer = (params) => {
+  // Check for pdfs and links regardless of transaction source
+  const pdfs = params.data.pdfs || [];
+  const links = params.data.links || [];
+  const [dialogOpen, setDialogOpen] = useState(false);
+  const [tabValue, setTabValue] = useState(0);
+  const [error, setError] = useState(null);
+  
+  // Always show something clickable, even if no documents
+  const hasDocuments = pdfs.length > 0 || links.length > 0;
+
+  // Combine PDFs and links since links are also PDFs
+  const allDocuments = [
+    ...pdfs.map(pdf => ({ ...pdf, type: 'pdf' })),
+    ...links.map(link => ({ ...link, type: 'link' }))
+  ];
+
+  const totalCount = allDocuments.length;
+
+  const handleClick = () => {
+    setDialogOpen(true);
+  };
+
+  const handleClose = () => {
+    setDialogOpen(false);
+    setTabValue(0); // Reset to first tab when closing
+    setError(null); // Clear any errors when closing
+  };
+
+  const handleTabChange = (event, newValue) => {
+    setTabValue(newValue);
+  };
+
+  const handleCopyDatevLink = (datevlink) => {
+    if (datevlink) {
+      navigator.clipboard.writeText(datevlink);
+    }
+  };
+
+  const handleOpenPdf = async (document) => {
+    let endpoint = '';
+    
+    if (document.type === 'pdf' && document.kUmsatzBeleg) {
+      // PDF from tUmsatzBeleg table
+      endpoint = `/data/pdf/umsatzbeleg/${document.kUmsatzBeleg}`;
+    } else if (document.type === 'link' && document.kPdfObjekt) {
+      // PDF from tPdfObjekt table (linked documents)
+      endpoint = `/data/pdf/pdfobject/${document.kPdfObjekt}`;
+    } else {
+      console.error('Unable to determine PDF URL for document:', document);
+      return;
+    }
+    
+    try {
+      // Create an authenticated API call
+      const token = localStorage.getItem('token');
+      const response = await fetch(`/api${endpoint}`, {
+        method: 'GET',
+        headers: {
+          'Authorization': `Bearer ${token}`,
+        },
+      });
+      
+      if (!response.ok) {
+        throw new Error(`HTTP ${response.status}: ${response.statusText}`);
+      }
+      
+      // Get the PDF blob
+      const blob = await response.blob();
+      
+      // Create a blob URL and open it in a new tab
+      const blobUrl = URL.createObjectURL(blob);
+      const newWindow = window.open(blobUrl, '_blank');
+      
+      // Clean up the blob URL after a delay to allow the browser to load it
+      setTimeout(() => {
+        URL.revokeObjectURL(blobUrl);
+      }, 1000);
+      
+      // If window.open was blocked, try alternative approach
+      if (!newWindow) {
+        // Create a temporary download link
+        const a = document.createElement('a');
+        a.href = blobUrl;
+        a.target = '_blank';
+        a.download = `document_${document.kUmsatzBeleg || document.kPdfObjekt}.pdf`;
+        document.body.appendChild(a);
+        a.click();
+        document.body.removeChild(a);
+        setTimeout(() => URL.revokeObjectURL(blobUrl), 1000);
+      }
+      
+         } catch (error) {
+       console.error('Error opening PDF:', error);
+       setError('Fehler beim Öffnen des PDFs. Bitte versuchen Sie es erneut.');
+     }
+  };
+
+  // Extract line items from document extraction data
+  const extractLineItems = () => {
+    const lineItems = [];
+    
+    allDocuments.forEach((doc, docIndex) => {
+      if (doc.extraction) {
+        try {
+          const extractionData = JSON.parse(doc.extraction);
+          if (extractionData.net_amounts_and_tax) {
+            extractionData.net_amounts_and_tax.forEach((item, itemIndex) => {
+              lineItems.push({
+                id: `${docIndex}-${itemIndex}`,
+                document: doc.type === 'pdf' ? 'PDF Dokument' : 'Verknüpftes Dokument',
+                documentIndex: docIndex + 1,
+                netAmount: item.net_amount || 0,
+                taxRate: item.tax_rate || 0,
+                taxAmount: item.tax_amount || 0,
+                grossAmount: (item.net_amount || 0) + (item.tax_amount || 0),
+                currency: extractionData.currency || 'EUR',
+                invoiceNumber: extractionData.invoice_number || '',
+                date: extractionData.date || '',
+                sender: extractionData.sender || ''
+              });
+            });
+          }
+        } catch (error) {
+          console.error('Error parsing extraction data:', error);
+        }
+      }
+    });
+    
+    return lineItems;
+  };
+
+  const lineItems = extractLineItems();
+
+  // AG Grid column definitions for line items
+  const columnDefs = [
+    {
+      headerName: 'Dok',
+      field: 'documentIndex',
+      width: 50,
+      cellStyle: { textAlign: 'center' }
+    },
+    {
+      headerName: 'Rechnungsnr.',
+      field: 'invoiceNumber',
+      width: 120
+    },
+    {
+      headerName: 'Datum',
+      field: 'date',
+      width: 100
+    },
+    {
+      headerName: 'Absender',
+      field: 'sender',
+      width: 150,
+      tooltipField: 'sender'
+    },
+    {
+      headerName: 'Netto',
+      field: 'netAmount',
+      width: 80,
+      type: 'rightAligned',
+      valueFormatter: (params) => {
+        return new Intl.NumberFormat('de-DE', {
+          style: 'currency',
+          currency: params.data.currency || 'EUR'
+        }).format(params.value);
+      }
+    },
+    {
+      headerName: 'MwSt %',
+      field: 'taxRate',
+      width: 70,
+      type: 'rightAligned',
+      valueFormatter: (params) => `${params.value}%`
+    },
+    {
+      headerName: 'MwSt',
+      field: 'taxAmount',
+      width: 80,
+      type: 'rightAligned',
+      valueFormatter: (params) => {
+        return new Intl.NumberFormat('de-DE', {
+          style: 'currency',
+          currency: params.data.currency || 'EUR'
+        }).format(params.value);
+      }
+    },
+    {
+      headerName: 'Brutto',
+      field: 'grossAmount',
+      width: 90,
+      type: 'rightAligned',
+      valueFormatter: (params) => {
+        return new Intl.NumberFormat('de-DE', {
+          style: 'currency',
+          currency: params.data.currency || 'EUR'
+        }).format(params.value);
+      }
+    }
+  ];
+
+  const defaultColDef = {
+    sortable: true,
+    filter: false,
+    resizable: true,
+    suppressSizeToFit: false
+  };
+
+  return (
+    <>
+      <Box 
+        sx={{ 
+          display: 'flex', 
+          gap: 0.5, 
+          alignItems: 'center', 
+          height: '100%', 
+          width: '100%',
+          cursor: 'pointer',
+          '&:hover': {
+            backgroundColor: 'rgba(0, 0, 0, 0.04)'
+          }
+        }}
+        onClick={handleClick}
+      >
+        {hasDocuments ? (
+          <>
+            <PdfIcon sx={{ fontSize: 14, color: '#d32f2f' }} />
+            {totalCount > 1 && (
+              <Box sx={{ 
+                fontSize: '8px', 
+                color: '#d32f2f', 
+                fontWeight: 'bold',
+                position: 'relative',
+                backgroundColor: 'white',
+                borderRadius: '50%',
+                width: 12,
+                height: 12,
+                display: 'flex',
+                alignItems: 'center',
+                justifyContent: 'center',
+                border: '1px solid #d32f2f',
+                marginLeft: '-6px'
+              }}>
+                {totalCount}
+              </Box>
+            )}
+          </>
+        ) : (
+          <Box sx={{ 
+            fontSize: '8px', 
+            color: '#999', 
+            fontWeight: 'normal',
+            display: 'flex',
+            alignItems: 'center',
+            justifyContent: 'center'
+          }}>
+            —
+          </Box>
+        )}
+      </Box>
+
+      <Dialog open={dialogOpen} onClose={handleClose} maxWidth="lg" fullWidth>
+        <DialogTitle>
+          {hasDocuments ? `Dokumente (${totalCount})` : 'Dokumentinformationen'}
+        </DialogTitle>
+        <DialogContent sx={{ p: 0 }}>
+          {error && (
+            <Alert severity="error" sx={{ m: 2 }} onClose={() => setError(null)}>
+              {error}
+            </Alert>
+          )}
+          <Box sx={{ borderBottom: 1, borderColor: 'divider' }}>
+            <Tabs value={tabValue} onChange={handleTabChange}>
+              <Tab label="Dokumente" />
+              <Tab label={`Buchungen (${lineItems.length})`} />
+            </Tabs>
+          </Box>
+          
+          {tabValue === 0 && (
+            <Box sx={{ p: 2 }}>
+              {hasDocuments ? (
+                <List>
+                  {allDocuments.map((doc, index) => (
+                    <React.Fragment key={index}>
+                      <ListItem>
+                        <ListItemIcon>
+                          <PdfIcon sx={{ color: '#d32f2f' }} />
+                        </ListItemIcon>
+                        <Box sx={{ flex: 1 }}>
+                          <Typography variant="subtitle2">
+                            {doc.type === 'pdf' ? 'PDF Dokument' : 'Verknüpftes Dokument'} #{index + 1}
+                          </Typography>
+                          {doc.datevlink && (
+                            <Typography variant="body2" color="textSecondary">
+                              DATEV Link: {doc.datevlink}
+                            </Typography>
+                          )}
+                          {doc.note && (
+                            <Typography variant="body2" color="textSecondary">
+                              Notiz: {doc.note}
+                            </Typography>
+                          )}
+                          <Box sx={{ mt: 1, display: 'flex', gap: 1 }}>
+                            <Button
+                              size="small"
+                              startIcon={<OpenIcon />}
+                              onClick={() => handleOpenPdf(doc)}
+                              variant="outlined"
+                            >
+                              PDF öffnen
+                            </Button>
+                            {doc.datevlink && (
+                              <Button
+                                size="small"
+                                startIcon={<CopyIcon />}
+                                onClick={() => handleCopyDatevLink(doc.datevlink)}
+                                variant="outlined"
+                              >
+                                DATEV Link kopieren
+                              </Button>
+                            )}
+                          </Box>
+                        </Box>
+                      </ListItem>
+                      {index < allDocuments.length - 1 && <Divider />}
+                    </React.Fragment>
+                  ))}
+                </List>
+              ) : (
+                <Box sx={{ textAlign: 'center', py: 4 }}>
+                  <PdfIcon sx={{ fontSize: 48, color: '#ccc', mb: 2 }} />
+                  <Typography variant="h6" color="textSecondary" gutterBottom>
+                    Keine Dokumente verfügbar
+                  </Typography>
+                  <Typography variant="body2" color="textSecondary">
+                    Für diese Transaktion sind keine PDF-Dokumente oder Verknüpfungen vorhanden.
+                  </Typography>
+                </Box>
+              )}
+            </Box>
+          )}
+          
+          {tabValue === 1 && (
+            <Box sx={{ p: 2, height: 400 }}>
+              {lineItems.length > 0 ? (
+                <div style={{ height: '100%', width: '100%' }}>
+                  <AgGridReact
+                    columnDefs={columnDefs}
+                    rowData={lineItems}
+                    defaultColDef={defaultColDef}
+                    suppressRowTransform={true}
+                    rowHeight={35}
+                    headerHeight={35}
+                    domLayout="normal"
+                  />
+                </div>
+              ) : (
+                <Box sx={{ textAlign: 'center', py: 4 }}>
+                  <Typography variant="h6" color="textSecondary" gutterBottom>
+                    Keine Buchungsdaten verfügbar
+                  </Typography>
+                  <Typography variant="body2" color="textSecondary">
+                    {hasDocuments 
+                      ? 'In den vorhandenen Dokumenten wurden keine Buchungsdaten gefunden.'
+                      : 'Keine Dokumente vorhanden, daher keine Buchungsdaten verfügbar.'
+                    }
+                  </Typography>
+                </Box>
+              )}
+            </Box>
+          )}
+        </DialogContent>
+        <DialogActions>
+          <Button onClick={handleClose}>Schließen</Button>
+        </DialogActions>
+      </Dialog>
+    </>
+  );
+};
+
+export default DocumentRenderer; 
\ No newline at end of file
diff --git a/client/src/components/cellRenderers/JtlRenderer.js b/client/src/components/cellRenderers/JtlRenderer.js
index 5d12bf7..179841c 100644
--- a/client/src/components/cellRenderers/JtlRenderer.js
+++ b/client/src/components/cellRenderers/JtlRenderer.js
@@ -2,6 +2,30 @@ import React from 'react';
 
 const JtlRenderer = (params) => {
   const hasJTL = params.value;
+  
+  // Handle undefined state (database unavailable)
+  if (hasJTL === undefined) {
+    return (
+      <div style={{ display: 'flex', justifyContent: 'center', alignItems: 'center', height: '100%' }}>
+        <div style={{ 
+          width: '12px', 
+          height: '12px', 
+          borderRadius: '50%', 
+          backgroundColor: '#fff3cd', 
+          border: '1px solid #ffc107', 
+          display: 'flex', 
+          alignItems: 'center', 
+          justifyContent: 'center',
+          fontSize: '8px',
+          color: '#856404',
+          fontWeight: 'bold'
+        }}>
+          ?
+        </div>
+      </div>
+    );
+  }
+  
   const backgroundColor = hasJTL ? '#388e3c' : '#f5f5f5';
   const border = hasJTL ? 'none' : '1px solid #ccc';
   
diff --git a/client/src/components/cellRenderers/RecipientRenderer.js b/client/src/components/cellRenderers/RecipientRenderer.js
index f7e319c..9227860 100644
--- a/client/src/components/cellRenderers/RecipientRenderer.js
+++ b/client/src/components/cellRenderers/RecipientRenderer.js
@@ -1,9 +1,39 @@
 import React from 'react';
 
 const RecipientRenderer = (params) => {
+  const isIbanColumn = params.colDef.field === 'Kontonummer/IBAN';
+  const value = params.value;
+
+  const handleClick = (event) => {
+    if (isIbanColumn && value && params.api) {
+      // Stop event propagation to prevent row selection
+      event.stopPropagation();
+      
+      // Apply filter to IBAN column using the custom IbanSelectionFilter format
+      const currentFilterModel = params.api.getFilterModel();
+      params.api.setFilterModel({
+        ...currentFilterModel,
+        'Kontonummer/IBAN': {
+          filterType: 'iban-selection',
+          values: [value]
+        }
+      });
+    }
+  };
+
   return (
-    <span style={{ fontSize: '0.7rem', lineHeight: '1.2' }}>
-      {params.value}
+    <span 
+      style={{ 
+        fontSize: '0.7rem', 
+        lineHeight: '1.2',
+        cursor: isIbanColumn && value ? 'pointer' : 'default',
+        color: isIbanColumn && value ? '#1976d2' : 'inherit',
+        textDecoration: isIbanColumn && value ? 'underline' : 'none'
+      }}
+      onClick={isIbanColumn && value ? handleClick : undefined}
+      title={isIbanColumn && value ? `Nach IBAN "${value}" filtern` : undefined}
+    >
+      {value}
     </span>
   );
 };
diff --git a/client/src/components/cellRenderers/SelectionRenderer.js b/client/src/components/cellRenderers/SelectionRenderer.js
new file mode 100644
index 0000000..8b8ae6d
--- /dev/null
+++ b/client/src/components/cellRenderers/SelectionRenderer.js
@@ -0,0 +1,50 @@
+import React from 'react';
+import { Checkbox } from '@mui/material';
+
+const SelectionRenderer = (params) => {
+  const { data } = params;
+  
+  if (!data) return null;
+  
+  // Create a unique row ID (using row index or a unique field)
+  const rowId = data.id || params.rowIndex;
+  
+  // Get selection state and methods from grid context
+  const context = params.context || {};
+  const { selectedRows, onSelectionChange } = context;
+  const isSelected = selectedRows && selectedRows.has && selectedRows.has(rowId);
+  
+  const handleChange = (event) => {
+    event.stopPropagation(); // Prevent row click events
+    if (onSelectionChange) {
+      onSelectionChange(rowId, data, event.target.checked);
+    }
+  };
+  
+  return (
+    <div 
+      style={{ 
+        display: 'flex', 
+        alignItems: 'center', 
+        justifyContent: 'center',
+        height: '100%',
+        width: '100%'
+      }}
+      onClick={(e) => e.stopPropagation()} // Prevent row click events
+    >
+      <Checkbox
+        checked={isSelected || false}
+        onChange={handleChange}
+        size="small"
+        sx={{
+          padding: 0,
+          '& .MuiSvgIcon-root': {
+            fontSize: 18
+          }
+        }}
+      />
+    </div>
+  );
+};
+
+export default SelectionRenderer; 
\ No newline at end of file
diff --git a/client/src/components/config/gridConfig.js b/client/src/components/config/gridConfig.js
index a0d46af..0574eb3 100644
--- a/client/src/components/config/gridConfig.js
+++ b/client/src/components/config/gridConfig.js
@@ -1,10 +1,14 @@
 import CheckboxFilter from '../filters/CheckboxFilter';
+import IbanSelectionFilter from '../filters/IbanSelectionFilter';
 import TextHeaderWithFilter from '../headers/TextHeaderWithFilter';
+import SelectionHeader from '../headers/SelectionHeader';
 import AmountRenderer from '../cellRenderers/AmountRenderer';
 import TypeRenderer from '../cellRenderers/TypeRenderer';
 import JtlRenderer from '../cellRenderers/JtlRenderer';
 import DescriptionRenderer from '../cellRenderers/DescriptionRenderer';
 import RecipientRenderer from '../cellRenderers/RecipientRenderer';
+import DocumentRenderer from '../cellRenderers/DocumentRenderer';
+import SelectionRenderer from '../cellRenderers/SelectionRenderer';
 
 const formatDate = (dateString) => {
   if (!dateString) return '';
@@ -16,6 +20,21 @@ const formatDate = (dateString) => {
 };
 
 export const getColumnDefs = () => [
+  {
+    headerName: '',
+    field: 'selection',
+    width: 50,
+    pinned: 'left',
+    sortable: false,
+    filter: false,
+    resizable: false,
+    suppressMenu: true,
+    cellRenderer: SelectionRenderer,
+    headerComponent: SelectionHeader,
+    headerComponentParams: {
+      // These will be set by the parent component
+    }
+  },
   {
     headerName: 'Datum',
     field: 'Buchungstag',
@@ -50,6 +69,7 @@ export const getColumnDefs = () => [
     field: 'Kontonummer/IBAN',
     width: 180,
     sortable: true,
+    filter: IbanSelectionFilter,
     headerComponent: TextHeaderWithFilter,
     tooltipField: 'Kontonummer/IBAN',
     cellRenderer: RecipientRenderer
@@ -79,7 +99,8 @@ export const getColumnDefs = () => [
     field: 'typeText',
     width: 70,
     cellRenderer: TypeRenderer,
-    sortable: true,
+    sortable: false,
+    suppressSorting: true,
     filter: CheckboxFilter,
     filterParams: {
       filterOptions: [
@@ -115,7 +136,8 @@ export const getColumnDefs = () => [
     field: 'hasJTL',
     width: 70,
     cellRenderer: JtlRenderer,
-    sortable: true,
+    sortable: false,
+    suppressSorting: true,
     filter: CheckboxFilter,
     filterParams: {
       filterOptions: [
@@ -146,11 +168,36 @@ export const getColumnDefs = () => [
             border: '1px solid #ccc'
           },
           condition: (fieldValue) => fieldValue === false
+        },
+        {
+          value: 'undefined',
+          label: 'Unbekannt',
+          color: 'warning',
+          dotStyle: {
+            width: '12px',
+            height: '12px',
+            backgroundColor: '#fff3cd',
+            border: '1px solid #ffc107',
+            fontSize: '8px',
+            color: '#856404',
+            fontWeight: 'bold',
+            content: '?'
+          },
+          condition: (fieldValue) => fieldValue === undefined
         }
       ]
     },
     floatingFilter: false,
     headerComponent: TextHeaderWithFilter
+  },
+  {
+    headerName: 'Dokumente',
+    field: 'documents',
+    width: 90,
+    cellRenderer: DocumentRenderer,
+    sortable: false,
+    filter: false,
+    headerComponent: TextHeaderWithFilter
   }
 ];
 
@@ -164,10 +211,7 @@ export const defaultColDef = {
 
 export const gridOptions = {
   animateRows: true,
-  rowSelection: {
-    mode: 'singleRow',
-    enableClickSelection: true
-  },
+  rowSelection: false,
   rowBuffer: 10,
   // Enable virtualization (default behavior)
   suppressRowVirtualisation: false,
@@ -179,5 +223,9 @@ export const gridOptions = {
   headerHeight: 40,
   // Pagination (optional - can be removed for infinite scrolling)
   pagination: false,
-  paginationPageSize: 100
+  paginationPageSize: 100,
+  // Disable cell selection
+  suppressCellSelection: true,
+  suppressRowClickSelection: true,
+  suppressCellFocus: true
 }; 
\ No newline at end of file
diff --git a/client/src/components/filters/IbanSelectionFilter.js b/client/src/components/filters/IbanSelectionFilter.js
new file mode 100644
index 0000000..c1138bb
--- /dev/null
+++ b/client/src/components/filters/IbanSelectionFilter.js
@@ -0,0 +1,209 @@
+import React from 'react';
+import { createRoot } from 'react-dom/client';
+import {
+  FormControl,
+  Select,
+  MenuItem,
+  Checkbox,
+  ListItemText,
+  Box,
+  Chip,
+  Button
+} from '@mui/material';
+
+export default class IbanSelectionFilter {
+  constructor() {
+    this.state = {
+      selectedValues: [],
+      availableValues: []
+    };
+    
+    // Create the DOM element that AG Grid expects
+    this.eGui = document.createElement('div');
+    this.eGui.style.minWidth = '250px';
+    this.eGui.style.padding = '8px';
+  }
+
+  init(params) {
+    this.params = params;
+    this.updateAvailableValues();
+    this.renderReactComponent();
+  }
+
+  getGui() {
+    return this.eGui;
+  }
+
+  destroy() {
+    if (this.reactRoot) {
+      this.reactRoot.unmount();
+      this.reactRoot = null;
+    }
+  }
+
+  updateAvailableValues() {
+    if (!this.params || !this.params.api) return;
+
+    // Get all row data
+    const allRowData = [];
+    this.params.api.forEachNode(node => {
+      if (node.data) {
+        allRowData.push(node.data);
+      }
+    });
+
+    // Create a map of IBAN to names, then get unique combinations
+    const ibanToNameMap = new Map();
+    allRowData.forEach(row => {
+      const iban = row['Kontonummer/IBAN'];
+      const name = row['Beguenstigter/Zahlungspflichtiger'];
+      if (iban && iban.trim() !== '' && iban !== '0000000000') {
+        if (!ibanToNameMap.has(iban)) {
+          ibanToNameMap.set(iban, name || '');
+        }
+      }
+    });
+
+    // Convert to array of objects with iban and name
+    this.availableValues = Array.from(ibanToNameMap.entries()).map(([iban, name]) => ({
+      iban,
+      name: name || 'Unbekannt'
+    }));
+  }
+
+  isFilterActive() {
+    return this.state.selectedValues.length > 0;
+  }
+
+  doesFilterPass(params) {
+    const { selectedValues } = this.state;
+    if (selectedValues.length === 0) return true;
+    
+    const value = params.data['Kontonummer/IBAN'];
+    return selectedValues.includes(value);
+  }
+
+  getModel() {
+    if (!this.isFilterActive()) return null;
+    
+    return {
+      filterType: 'iban-selection',
+      values: this.state.selectedValues
+    };
+  }
+
+  setModel(model) {
+    if (!model) {
+      this.state.selectedValues = [];
+    } else {
+      this.state.selectedValues = model.values || [];
+    }
+    this.renderReactComponent();
+  }
+
+  handleSelectionChange = (selectedValues) => {
+    this.state.selectedValues = selectedValues;
+    this.renderReactComponent();
+    
+    // Notify AG Grid that filter changed
+    if (this.params && this.params.filterChangedCallback) {
+      this.params.filterChangedCallback();
+    }
+  };
+
+  clearFilter = () => {
+    this.state.selectedValues = [];
+    this.renderReactComponent();
+    
+    if (this.params && this.params.filterChangedCallback) {
+      this.params.filterChangedCallback();
+    }
+  };
+
+  renderReactComponent() {
+    if (!this.reactRoot) {
+      this.reactRoot = createRoot(this.eGui);
+    }
+
+    const FilterComponent = () => (
+      <Box sx={{ minWidth: 250 }} className="ag-filter-custom">
+        <FormControl fullWidth size="small">
+          <Select
+            multiple
+            value={this.state.selectedValues}
+            onChange={(event) => this.handleSelectionChange(event.target.value)}
+            displayEmpty
+            renderValue={(selected) => {
+              if (selected.length === 0) {
+                return <em>Alle IBANs</em>;
+              }
+              return (
+                                 <Box sx={{ display: 'flex', flexWrap: 'wrap', gap: 0.5 }}>
+                   {selected.slice(0, 2).map((value) => {
+                     const ibanData = this.availableValues.find(item => item.iban === value);
+                     return (
+                       <Chip 
+                         key={value} 
+                         label={ibanData ? `${ibanData.name.slice(0, 15)}...` : value.slice(-4)}
+                         size="small" 
+                         color="primary"
+                         variant="outlined"
+                       />
+                     );
+                   })}
+                   {selected.length > 2 && (
+                     <Chip 
+                       label={`+${selected.length - 2} mehr`}
+                       size="small" 
+                       color="primary"
+                       variant="outlined"
+                     />
+                   )}
+                 </Box>
+              );
+            }}
+            MenuProps={{
+              PaperProps: {
+                style: {
+                  maxHeight: 300,
+                  width: 300,
+                },
+              },
+            }}
+                     >
+             {this.availableValues.map((item) => (
+               <MenuItem key={item.iban} value={item.iban}>
+                 <Checkbox 
+                   checked={this.state.selectedValues.indexOf(item.iban) > -1}
+                   size="small"
+                 />
+                 <ListItemText 
+                   primary={item.name}
+                   secondary={item.iban}
+                   primaryTypographyProps={{ fontSize: '0.8rem' }}
+                   secondaryTypographyProps={{ fontSize: '0.7rem', color: 'text.secondary' }}
+                 />
+               </MenuItem>
+             ))}
+           </Select>
+        </FormControl>
+        
+        {this.state.selectedValues.length > 0 && (
+          <Box sx={{ mt: 1, textAlign: 'right' }}>
+            <Button 
+              onClick={this.clearFilter}
+              size="small"
+              variant="text"
+              color="primary"
+              sx={{ fontSize: '0.75rem' }}
+            >
+              Filter löschen
+            </Button>
+          </Box>
+        )}
+      </Box>
+    );
+
+    this.reactRoot.render(<FilterComponent />);
+  }
+} 
\ No newline at end of file
diff --git a/client/src/components/headers/SelectionHeader.js b/client/src/components/headers/SelectionHeader.js
new file mode 100644
index 0000000..239b398
--- /dev/null
+++ b/client/src/components/headers/SelectionHeader.js
@@ -0,0 +1,64 @@
+import React, { useState, useEffect, useImperativeHandle, forwardRef } from 'react';
+import { Checkbox } from '@mui/material';
+
+const SelectionHeader = forwardRef((params, ref) => {
+  const [checkboxState, setCheckboxState] = useState({ checked: false, indeterminate: false });
+  
+  // Expose updateState method to parent via ref
+  useImperativeHandle(ref, () => ({
+    updateState: (selectedRows, displayedRows) => {
+      const allSelected = displayedRows > 0 && selectedRows.size >= displayedRows;
+      const someSelected = selectedRows.size > 0;
+      const indeterminate = someSelected && !allSelected;
+      setCheckboxState({ checked: allSelected, indeterminate });
+    }
+  }));
+  
+  // Register this component with parent on mount
+  useEffect(() => {
+    if (params.api?.setHeaderCheckboxRef) {
+      params.api.setHeaderCheckboxRef(ref.current || { updateState: (selectedRows, displayedRows) => {
+        const allSelected = displayedRows > 0 && selectedRows.size >= displayedRows;
+        const someSelected = selectedRows.size > 0;
+        const indeterminate = someSelected && !allSelected;
+        setCheckboxState({ checked: allSelected, indeterminate });
+      }});
+    }
+  }, [params.api, ref]);
+  
+  return (
+    <div 
+      style={{ 
+        display: 'flex', 
+        alignItems: 'center', 
+        justifyContent: 'center',
+        height: '100%',
+        width: '100%'
+      }}
+    >
+      <Checkbox
+        size="small"
+        checked={checkboxState.checked}
+        indeterminate={checkboxState.indeterminate}
+        onClick={(event) => {
+          event.stopPropagation();
+          
+          const parentComponent = params.api?.fibdashComponent;
+          if (parentComponent && parentComponent.onSelectAll) {
+            const { selectedRows } = parentComponent.state;
+            const shouldSelectAll = selectedRows.size === 0;
+            parentComponent.onSelectAll(shouldSelectAll);
+          }
+        }}
+        sx={{
+          padding: 0,
+          '& .MuiSvgIcon-root': {
+            fontSize: 18
+          }
+        }}
+      />
+    </div>
+  );
+});
+
+export default SelectionHeader; 
\ No newline at end of file
diff --git a/client/src/components/headers/TextHeaderWithFilter.js b/client/src/components/headers/TextHeaderWithFilter.js
index 9b63dca..50f7318 100644
--- a/client/src/components/headers/TextHeaderWithFilter.js
+++ b/client/src/components/headers/TextHeaderWithFilter.js
@@ -43,6 +43,17 @@ class HeaderComponent extends Component {
   }
 
   onFilterChanged = () => {
+    // Check if this column's filter was cleared and reset local state
+    if (this.props.params && this.props.params.api && this.props.params.column) {
+      const colId = this.props.params.column.colId;
+      const filterModel = this.props.params.api.getFilterModel();
+      
+      // If this column no longer has a filter, clear the local filterValue
+      if (!filterModel || !filterModel[colId]) {
+        this.setState({ filterValue: '' });
+      }
+    }
+    
     // Force re-render to update filter icon color
     this.forceUpdate();
   };
@@ -134,6 +145,9 @@ class HeaderComponent extends Component {
     const isTextColumn = column.colDef.field === 'description' || 
                         column.colDef.field === 'Beguenstigter/Zahlungspflichtiger';
     const showTextFilter = isTextColumn;
+    
+    // Check if sorting is disabled for this column
+    const isSortingDisabled = column.colDef.sortable === false || column.colDef.suppressSorting === true;
 
     return (
       <Box sx={{ 
@@ -153,44 +167,46 @@ class HeaderComponent extends Component {
             fontWeight: 600,
             fontSize: '13px',
             color: '#212529',
-            cursor: 'pointer',
+            cursor: isSortingDisabled ? 'default' : 'pointer',
             minWidth: 'fit-content',
             marginRight: '6px',
             userSelect: 'none',
             '&:hover': {
-              color: '#0969da'
+              color: isSortingDisabled ? '#212529' : '#0969da'
             }
           }}
-          onClick={(e) => this.onSortRequested(sortDirection === 'asc' ? 'desc' : 'asc', e)}
+          onClick={isSortingDisabled ? undefined : (e) => this.onSortRequested(sortDirection === 'asc' ? 'desc' : 'asc', e)}
         >
           {displayName}
         </Typography>
         
-        {/* Sort Icons - Always visible */}
-        <Box sx={{ 
-          display: 'flex', 
-          flexDirection: 'column',
-          alignItems: 'center',
-          marginRight: '6px',
-          gap: 0
-        }}>
-          <SortUpIcon sx={{ 
-            fontSize: '10px', 
-            color: sortDirection === 'asc' ? '#0969da' : '#ccc',
-            opacity: sortDirection === 'asc' ? 1 : 0.5,
-            cursor: 'pointer'
-          }} 
-          onClick={(e) => this.onSortRequested('asc', e)}
-          />
-          <SortDownIcon sx={{ 
-            fontSize: '10px', 
-            color: sortDirection === 'desc' ? '#0969da' : '#ccc',
-            opacity: sortDirection === 'desc' ? 1 : 0.5,
-            cursor: 'pointer'
-          }}
-          onClick={(e) => this.onSortRequested('desc', e)}
-          />
-        </Box>
+        {/* Sort Icons - Only visible when sorting is enabled */}
+        {!isSortingDisabled && (
+          <Box sx={{ 
+            display: 'flex', 
+            flexDirection: 'column',
+            alignItems: 'center',
+            marginRight: '6px',
+            gap: 0
+          }}>
+            <SortUpIcon sx={{ 
+              fontSize: '10px', 
+              color: sortDirection === 'asc' ? '#0969da' : '#ccc',
+              opacity: sortDirection === 'asc' ? 1 : 0.5,
+              cursor: 'pointer'
+            }} 
+            onClick={(e) => this.onSortRequested('asc', e)}
+            />
+            <SortDownIcon sx={{ 
+              fontSize: '10px', 
+              color: sortDirection === 'desc' ? '#0969da' : '#ccc',
+              opacity: sortDirection === 'desc' ? 1 : 0.5,
+              cursor: 'pointer'
+            }}
+            onClick={(e) => this.onSortRequested('desc', e)}
+            />
+          </Box>
+        )}
         
         {/* Filter Input - only for text columns */}
         {showTextFilter && (
diff --git a/client/src/components/utils/dataUtils.js b/client/src/components/utils/dataUtils.js
index 129d5a8..b5603d9 100644
--- a/client/src/components/utils/dataUtils.js
+++ b/client/src/components/utils/dataUtils.js
@@ -1,6 +1,7 @@
 export const processTransactionData = (transactions) => {
-  return transactions.map(transaction => ({
+  return transactions.map((transaction, index) => ({
     ...transaction,
+    id: `row-${index}-${transaction.Buchungstag}-${transaction.numericAmount}`, // Unique ID
     description: transaction['Verwendungszweck'] || transaction['Buchungstext'],
     type: transaction.numericAmount >= 0 ? 'Income' : 'Expense',
     isIncome: transaction.numericAmount >= 0,
@@ -8,16 +9,39 @@ export const processTransactionData = (transactions) => {
   }));
 };
 
-export const getRowStyle = (params) => {
+export const getRowStyle = (params, selectedRows) => {
+  const rowId = params.data?.id || params.rowIndex;
+  const isSelected = selectedRows && selectedRows.has && selectedRows.has(rowId);
+  
+  console.log('getRowStyle called for row:', rowId, 'isSelected:', isSelected, 'selectedRows size:', selectedRows?.size);
+  
   if (params.data.isJTLOnly) {
     return {
-      backgroundColor: '#ffebee',
+      backgroundColor: isSelected ? '#e3f2fd' : '#ffebee',
       borderLeft: '4px solid #f44336'
     };
   }
+  
+  if (isSelected) {
+    console.log('Row is selected but using CSS class instead:', rowId);
+    return null; // Don't apply inline styles for selected rows
+  }
+  
+  // Return null to allow CSS classes (ag-row-odd/ag-row-even) to handle alternating colors
   return null;
 };
 
+export const getRowClass = (params, selectedRows) => {
+  const rowId = params.data?.id || params.rowIndex;
+  const isSelected = selectedRows && selectedRows.has && selectedRows.has(rowId);
+  
+  if (isSelected) {
+    return 'selected-row';
+  }
+  
+  return '';
+};
+
 export const getMonthName = (monthYear) => {
   if (!monthYear) return '';
   const [year, month] = monthYear.split('-');
diff --git a/src/middleware/emailAuth.js b/src/middleware/emailAuth.js
index 240f770..ccf39c6 100644
--- a/src/middleware/emailAuth.js
+++ b/src/middleware/emailAuth.js
@@ -1,16 +1,5 @@
-const checkAuthorizedEmail = (req, res, next) => {
-  const authorizedEmails = process.env.AUTHORIZED_EMAILS;
-  
-  // If no authorized emails are configured, deny all users
-  if (!authorizedEmails || authorizedEmails.trim() === '') {
-    return res.status(403).json({ 
-      error: 'Access denied',
-      message: 'No authorized users configured. Contact administrator.'
-    });
-  }
-  
-  const emailList = authorizedEmails.split(',').map(email => email.trim().toLowerCase());
-  const userEmail = req.user?.email?.toLowerCase();
+const checkAuthorizedEmail = async (req, res, next) => {
+  const userEmail = req.user?.email;
   
   if (!userEmail) {
     return res.status(401).json({ 
@@ -19,27 +8,75 @@ const checkAuthorizedEmail = (req, res, next) => {
     });
   }
   
-  if (!emailList.includes(userEmail)) {
-    return res.status(403).json({ 
-      error: 'Access denied',
-      message: 'Your email address is not authorized to access this application'
+  try {
+    const authorized = await isEmailAuthorized(userEmail);
+    
+    if (!authorized) {
+      return res.status(403).json({ 
+        error: 'Access denied',
+        message: 'Your email address is not authorized to access this application'
+      });
+    }
+    
+    next();
+  } catch (error) {
+    console.error('Authorization check failed:', error);
+    return res.status(500).json({ 
+      error: 'Authorization check failed',
+      message: 'Unable to verify authorization. Please try again.'
     });
   }
-  
-  next();
 };
 
-const isEmailAuthorized = (email) => {
+const isEmailAuthorized = async (email) => {
   const authorizedEmails = process.env.AUTHORIZED_EMAILS;
+  const userEmail = email.toLowerCase();
   
-  // If no authorized emails are configured, deny all users
-  if (!authorizedEmails || authorizedEmails.trim() === '') {
-    return false;
+  console.log(`🔍 Checking authorization for email: ${userEmail}`);
+  
+  // First check environment variable
+  if (authorizedEmails && authorizedEmails.trim() !== '') {
+    const emailList = authorizedEmails.split(',').map(e => e.trim().toLowerCase());
+    if (emailList.includes(userEmail)) {
+      console.log(`✅ Email authorized via AUTHORIZED_EMAILS environment variable`);
+      return true;
+    }
+    console.log(`❌ Email not found in AUTHORIZED_EMAILS environment variable`);
+  } else {
+    console.log(`⚠️ No AUTHORIZED_EMAILS configured, checking database...`);
   }
   
-  const emailList = authorizedEmails.split(',').map(e => e.trim().toLowerCase());
-  const userEmail = email.toLowerCase();
-  return emailList.includes(userEmail);
+  // Then check database
+  console.log(`🗄️ Checking database authorization for: ${userEmail}`);
+  try {
+    const { executeQuery } = require('../config/database');
+    
+    const query = `
+      SELECT TOP 1 1 as authorized 
+      FROM dbo.tAdresse 
+      WHERE cMail = @email 
+      AND kKunde IN (
+        SELECT [kKunde] 
+        FROM [Kunde].[tKundeEigenesFeld] 
+        WHERE kAttribut = 219 OR kAttribut = 220 AND nWertInt = 1
+      )
+    `;
+    
+    const result = await executeQuery(query, { email: userEmail });
+    const isAuthorized = result.recordset && result.recordset.length > 0;
+    
+    if (isAuthorized) {
+      console.log(`✅ Email authorized via database (tKundeEigenesFeld with kAttribut 219/220)`);
+      return true;
+    } else {
+      console.log(`❌ Email not authorized via database`);
+      return false;
+    }
+    
+  } catch (error) {
+    console.error(`💥 Database authorization check failed for ${userEmail}:`, error.message);
+    return false;
+  }
 };
 
 module.exports = {
diff --git a/src/routes/auth.js b/src/routes/auth.js
index 3936138..fe6e3ef 100644
--- a/src/routes/auth.js
+++ b/src/routes/auth.js
@@ -35,7 +35,7 @@ router.post('/google', async (req, res) => {
     console.log(`👤 Google token verified for: ${email}`);
 
     // Check if email is authorized
-    const authorized = isEmailAuthorized(email);
+    const authorized = await isEmailAuthorized(email);
     console.log(`🔒 Email authorization check for ${email}: ${authorized ? 'ALLOWED' : 'DENIED'}`);
     
     if (!authorized) {
@@ -46,50 +46,15 @@ router.post('/google', async (req, res) => {
       });
     }
 
-    // Check if user exists in database (optional - auth works without DB)
-    let user;
-    try {
-      // Only try database operations if DB is configured
-      if (process.env.DB_SERVER) {
-        const userResult = await executeQuery(
-          'SELECT * FROM Users WHERE email = @email',
-          { email }
-        );
-
-        if (userResult.recordset.length > 0) {
-          // User exists, update last login
-          user = userResult.recordset[0];
-          await executeQuery(
-            'UPDATE Users SET last_login = GETDATE(), picture = @picture WHERE id = @id',
-            { picture, id: user.id }
-          );
-        } else {
-          // Create new user
-          const insertResult = await executeQuery(
-            `INSERT INTO Users (google_id, email, name, picture, created_at, last_login) 
-             OUTPUT INSERTED.* 
-             VALUES (@googleId, @email, @name, @picture, GETDATE(), GETDATE())`,
-            { googleId, email, name, picture }
-          );
-          user = insertResult.recordset[0];
-        }
-        console.log('✅ Database operations completed successfully');
-      } else {
-        console.log('⚠️ No database configured, using fallback user object');
-        throw new Error('No database configured');
-      }
-    } catch (dbError) {
-      console.error('Database error during authentication:', dbError.message);
-      // Fallback: create user object without database
-      user = {
-        id: googleId,
-        email,
-        name,
-        picture,
-        google_id: googleId,
-      };
-      console.log('✅ Using fallback user object (no database)');
-    }
+    // Create user object from Google data (no database storage needed)
+    const user = {
+      id: googleId,
+      email,
+      name,
+      picture,
+      google_id: googleId,
+    };
+    console.log('✅ User object created from Google authentication');
 
     // Generate JWT token
     const jwtToken = generateToken(user);
diff --git a/src/routes/data.js b/src/routes/data.js
index 0e95132..e6ed0c8 100644
--- a/src/routes/data.js
+++ b/src/routes/data.js
@@ -103,10 +103,51 @@ const getJTLTransactions = async () => {
     `;
     
     const result = await executeQuery(query);
-    return result.recordset || [];
+    const transactions = result.recordset || [];
+
+    // Get PDF documents for each transaction
+    const pdfQuery = `SELECT kUmsatzBeleg, kZahlungsabgleichUmsatz, textContent, markDown, extraction, datevlink FROM tUmsatzBeleg`;
+    const pdfResult = await executeQuery(pdfQuery);
+    
+    for(const item of pdfResult.recordset){
+      for(const transaction of transactions){
+        if(item.kZahlungsabgleichUmsatz == transaction.kZahlungsabgleichUmsatz){
+          if(!transaction.pdfs) transaction.pdfs = [];
+          transaction.pdfs.push({
+            kUmsatzBeleg: item.kUmsatzBeleg,
+            content: item.textContent,
+            markDown: item.markDown,
+            extraction: item.extraction,
+            datevlink: item.datevlink
+          });
+        }
+      }
+    }
+
+    // Get links for each transaction
+    const linksQuery = `
+      SELECT kZahlungsabgleichUmsatzLink, kZahlungsabgleichUmsatz, linktarget, linktype, note, 
+             tPdfObjekt.kPdfObjekt, tPdfObjekt.textContent, tPdfObjekt.markDown, 
+             tPdfObjekt.extraction
+      FROM tZahlungsabgleichUmsatzLink
+      LEFT JOIN tPdfObjekt ON (tZahlungsabgleichUmsatzLink.linktarget = tPdfObjekt.kLieferantenbestellung)
+      WHERE linktype = 'kLieferantenBestellung'
+    `;
+    const linksResult = await executeQuery(linksQuery);
+    
+    for(const item of linksResult.recordset){
+      for(const transaction of transactions){
+        if(item.kZahlungsabgleichUmsatz == transaction.kZahlungsabgleichUmsatz){
+          if(!transaction.links) transaction.links = [];
+          transaction.links.push(item);
+        }
+      }
+    }
+
+    return transactions;
   } catch (error) {
     console.error('Error fetching JTL transactions:', error);
-    return [];
+    throw error; // Re-throw the error so the caller knows the database is unavailable
   }
 };
 
@@ -156,10 +197,13 @@ router.get('/transactions/:timeRange', authenticateToken, async (req, res) => {
 
     // Get JTL transactions for comparison
     let jtlTransactions = [];
+    let jtlDatabaseAvailable = false;
     try {
       jtlTransactions = await getJTLTransactions();
+      jtlDatabaseAvailable = true;
     } catch (error) {
       console.log('JTL database not available, continuing without JTL data');
+      jtlDatabaseAvailable = false;
     }
 
     // Filter JTL transactions for the selected time period
@@ -213,9 +257,13 @@ router.get('/transactions/:timeRange', authenticateToken, async (req, res) => {
 
       return {
         ...transaction,
-        hasJTL: !!jtlMatch,
+        hasJTL: jtlDatabaseAvailable ? !!jtlMatch : undefined,
         jtlId: jtlMatch ? jtlMatch.kZahlungsabgleichUmsatz : null,
-        isFromCSV: true
+        isFromCSV: true,
+        jtlDatabaseAvailable,
+        // Include document data from JTL match
+        pdfs: jtlMatch ? jtlMatch.pdfs || [] : [],
+        links: jtlMatch ? jtlMatch.links || [] : []
       };
     });
 
@@ -258,7 +306,10 @@ router.get('/transactions/:timeRange', authenticateToken, async (req, res) => {
         hasJTL: true,
         jtlId: jtl.kZahlungsabgleichUmsatz,
         isFromCSV: false,
-        isJTLOnly: true
+        isJTLOnly: true,
+        // Include document data from JTL transaction
+        pdfs: jtl.pdfs || [],
+        links: jtl.links || []
       }));
 
     // Combine CSV and JTL-only transactions
@@ -275,10 +326,11 @@ router.get('/transactions/:timeRange', authenticateToken, async (req, res) => {
         .filter(t => t.numericAmount < 0)
         .reduce((sum, t) => sum + Math.abs(t.numericAmount), 0),
       netAmount: allTransactions.reduce((sum, t) => sum + t.numericAmount, 0),
-      jtlMatches: allTransactions.filter(t => t.hasJTL && t.isFromCSV).length,
-      jtlMissing: allTransactions.filter(t => !t.hasJTL && t.isFromCSV).length,
-      jtlOnly: allTransactions.filter(t => t.isJTLOnly).length,
-      csvOnly: allTransactions.filter(t => !t.hasJTL && t.isFromCSV).length
+      jtlMatches: jtlDatabaseAvailable ? allTransactions.filter(t => t.hasJTL === true && t.isFromCSV).length : undefined,
+      jtlMissing: jtlDatabaseAvailable ? allTransactions.filter(t => t.hasJTL === false && t.isFromCSV).length : undefined,
+      jtlOnly: jtlDatabaseAvailable ? allTransactions.filter(t => t.isJTLOnly).length : undefined,
+      csvOnly: jtlDatabaseAvailable ? allTransactions.filter(t => t.hasJTL === false && t.isFromCSV).length : undefined,
+      jtlDatabaseAvailable
     };
     
     res.json({ 
@@ -440,4 +492,70 @@ router.get('/datev/:timeRange', authenticateToken, async (req, res) => {
   }
 });
 
+// Get PDF from tUmsatzBeleg
+router.get('/pdf/umsatzbeleg/:kUmsatzBeleg', authenticateToken, async (req, res) => {
+  try {
+    const { kUmsatzBeleg } = req.params;
+    const { executeQuery } = require('../config/database');
+    
+    const query = `
+      SELECT content, datevlink 
+      FROM dbo.tUmsatzBeleg 
+      WHERE kUmsatzBeleg = @kUmsatzBeleg AND content IS NOT NULL
+    `;
+    
+    const result = await executeQuery(query, {
+      kUmsatzBeleg: parseInt(kUmsatzBeleg)
+    });
+    
+    if (!result.recordset || result.recordset.length === 0) {
+      return res.status(404).json({ error: 'PDF not found' });
+    }
+    
+    const pdfData = result.recordset[0];
+    const filename = `Umsatzbeleg_${kUmsatzBeleg}_${pdfData.datevlink || 'document'}.pdf`;
+    
+    res.setHeader('Content-Type', 'application/pdf');
+    res.setHeader('Content-Disposition', `inline; filename="${filename}"`);
+    res.send(pdfData.content);
+    
+  } catch (error) {
+    console.error('Error fetching PDF from tUmsatzBeleg:', error);
+    res.status(500).json({ error: 'Failed to fetch PDF' });
+  }
+});
+
+// Get PDF from tPdfObjekt
+router.get('/pdf/pdfobject/:kPdfObjekt', authenticateToken, async (req, res) => {
+  try {
+    const { kPdfObjekt } = req.params;
+    const { executeQuery } = require('../config/database');
+    
+    const query = `
+      SELECT content, datevlink, kLieferantenbestellung
+      FROM dbo.tPdfObjekt 
+      WHERE kPdfObjekt = @kPdfObjekt AND content IS NOT NULL
+    `;
+    
+    const result = await executeQuery(query, {
+      kPdfObjekt: parseInt(kPdfObjekt)
+    });
+    
+    if (!result.recordset || result.recordset.length === 0) {
+      return res.status(404).json({ error: 'PDF not found' });
+    }
+    
+    const pdfData = result.recordset[0];
+    const filename = `PdfObjekt_${kPdfObjekt}_LB${pdfData.kLieferantenbestellung}_${pdfData.datevlink || 'document'}.pdf`;
+    
+    res.setHeader('Content-Type', 'application/pdf');
+    res.setHeader('Content-Disposition', `inline; filename="${filename}"`);
+    res.send(pdfData.content);
+    
+  } catch (error) {
+    console.error('Error fetching PDF from tPdfObjekt:', error);
+    res.status(500).json({ error: 'Failed to fetch PDF' });
+  }
+});
+
 module.exports = router; 
\ No newline at end of file
diff --git a/webpack.prod.config.js b/webpack.prod.config.js
index e452279..36a58a5 100644
--- a/webpack.prod.config.js
+++ b/webpack.prod.config.js
@@ -72,6 +72,24 @@ module.exports = {
   resolve: {
     extensions: ['.js', '.jsx'],
   },
+  devServer: {
+    port: 5001,
+    host: '0.0.0.0',
+    allowedHosts: 'all',
+    historyApiFallback: true,
+    hot: false,
+    liveReload: false,
+    client: false,
+    static: {
+      directory: path.join(__dirname, 'client/public'),
+    },
+    proxy: {
+      '/api': {
+        target: 'http://localhost:5000',
+        changeOrigin: true,
+      },
+    },
+  },
   performance: {
     maxAssetSize: 512000,
     maxEntrypointSize: 512000,