Fix UI issues and enhance appearance

- Fixed fullscreen buttons with improved CSS visibility
- Repositioned loading bar and progress messages above preprocessed preview
- Improved text visibility in Previous Results tab
- Updated About page with more comprehensive and relevant information
- Fixed styling for document containers and improved text contrast

app.py

@@ -880,33 +880,45 @@ with main_tab3:
     """
     
     st.markdown(f"""
-    ### About This Application
+    ### About Historical Document OCR
     
-    This app uses [Mistral AI's Document OCR](https://docs.mistral.ai/capabilities/document/) to extract text and images from historical documents.
+    This application specializes in processing historical documents using [Mistral AI's Document OCR](https://docs.mistral.ai/capabilities/document/), which is particularly effective for handling challenging textual materials.
     
-    It can process:
-    - Image files (jpg, png, etc.)
-    - PDF documents (multi-page support)
+    #### Document Processing Capabilities
+    - **Historical Images**: Process vintage photographs, scanned historical papers, manuscripts
+    - **Handwritten Documents**: Extract text from letters, journals, notes, and records
+    - **Multi-Page PDFs**: Process historical books, articles, and longer documents
+    - **Mixed Content**: Handle documents with both text and imagery
     
-    The extracted content is processed into structured data based on the document type, combining:
-    - Text extraction with `mistral-ocr-latest`
-    - Analysis with language models
-    - Layout preservation with images
+    #### Key Features
+    - **Advanced Image Preprocessing**
+      - Grayscale conversion optimized for historical documents
+      - Denoising to remove artifacts and improve clarity
+      - Contrast adjustment to enhance faded text
+      - Document rotation for proper orientation
     
-    View results in three formats:
-    - Structured HTML view
-    - Raw JSON (for developers)
-    - Markdown with images (preserves document layout)
+    - **Document Analysis**
+      - Text extraction with `mistral-ocr-latest`
+      - Structured data extraction: dates, names, places, topics
+      - Multi-language support with automatic detection
+      - Handling of period-specific terminology and obsolete language
     
-    **New Features:**
-    - Image preprocessing for better OCR quality
-    - PDF resolution and page controls
-    - Document rotation (90°, 180°, 270°)
-    - Custom instructions for special document analysis
-    - Performance mode selection (Speed/Balance/Quality)
-    - Progress tracking during processing
-    - Previous Results tab to review processed documents
-    - Enhanced rate limit handling with automatic retry
+    - **Flexible Output Formats**
+      - Structured view with organized content sections
+      - Developer JSON for integration with other applications
+      - Visual representation preserving original document layout
+      - Downloadable results in various formats
+    
+    #### Historical Context
+    Add period-specific context to improve analysis:
+    - Historical period selection
+    - Document purpose identification
+    - Custom instructions for specialized terminology
+    
+    #### Data Privacy
+    - All document processing happens through secure AI processing
+    - No documents are permanently stored on the server
+    - Results are only saved in your current session
     {fallback_notice}
     """)
 
@@ -926,6 +938,10 @@ with main_tab1:
         with left_col:
             process_button = st.button("Process Document")
             
+            # Empty container for progress indicators - will be filled during processing
+            # Positioned right after the process button for better visibility
+            progress_placeholder = st.empty()
+            
             # Image preprocessing preview - automatically show only the preprocessed version
             if any(preprocessing_options.values()) and uploaded_file.type.startswith('image/'):
                 st.markdown("**Preprocessed Preview**")
@@ -955,9 +971,6 @@ with main_tab1:
                     st.error(f"Error in preprocessing: {str(e)}")
                     st.info("Try using grayscale preprocessing for PNG images with transparency")
             
-            # Empty container for progress indicators - will be filled during processing
-            progress_placeholder = st.empty()
-            
             # Container for success message (will be filled after processing)
             # No extra spacing needed as it will be managed programmatically
             metadata_placeholder = st.empty()

ui/custom.css

@@ -97,6 +97,25 @@
     border-left: 3px solid #4285f4;
 }
 
+/* Fix fullscreen button styling */
+button[title="View fullscreen"],
+button.streamlit-expanderHeader {
+    z-index: 10 !important;
+    background-color: rgba(255, 255, 255, 0.8) !important;
+    visibility: visible !important;
+    opacity: 1 !important;
+    display: flex !important;
+}
+
+/* Make text visible in Previous Results tab */
+.previous-results-container h3,
+.previous-results-container p,
+.previous-results-container .result-filename,
+.previous-results-container .result-date,
+.previous-results-container .result-tag {
+    color: #212121 !important;
+}
+
 /* Additional image fixes for all containers */
 .document-content img,
 .markdown-text-container img,