diff --git a/docs/changelog-claude.md b/docs/changelog-claude.md
index 3b80360..a4a5a2c 100644
--- a/docs/changelog-claude.md
+++ b/docs/changelog-claude.md
@@ -4,6 +4,53 @@ This file documents all changes made to this project via Claude Code.
 
 ## [2026-02-05]
 
+### Added
+- Redesigned changelog system to use Python-based structure instead of Markdown:
+  - Created `app/changelog.py` with structured changelog data (21 versions from v0.1.22 to v0.1.2)
+  - Each version contains: version number, date, summary, and structured sections
+  - Sections include: title, type (feature/improvement/fixed/documentation), and list of changes
+  - Removed Gitea dependency for changelog rendering - now fully self-contained
+  - No external dependencies, faster loading, always available
+- New changelog.html template with modern design:
+  - Sidebar navigation with all versions for quick jumping between releases
+  - Sticky sidebar that remains visible during scrolling
+  - Bootstrap cards for each version with gradient blue headers
+  - Color-coded type badges for sections:
+    - Green gradient: Feature
+    - Blue gradient: Improvement
+    - Red gradient: Fixed
+    - Purple gradient: Documentation
+  - Responsive design (sidebar hidden on mobile devices)
+  - Summary section with blue left border highlight
+  - Click-to-expand sections with smooth animations
+- Created `static/css/changelog.css` with comprehensive styling:
+  - Modern gradients for badges and headers
+  - Dark mode support via CSS variables
+  - Hover effects on navigation links and list items
+  - Smooth scrolling to version anchors
+  - Compact spacing optimizations (reduced padding, margins, font sizes)
+  - CSS specificity enhancements with !important flags to override Bootstrap defaults
+- Added `{% block head %}` to base.html template to allow pages to inject custom CSS
+
+### Changed
+- Updated `routes_changelog.py` to load data from `changelog.py` instead of fetching from Gitea
+- Simplified changelog route - removed markdown parsing and external HTTP requests
+- Removed dependency on `markdown` library for changelog rendering
+- Template now receives structured Python data instead of HTML string
+
+### Fixed
+- Fixed module import path in routes_changelog.py (changed from `from app.changelog` to `from ..changelog`)
+- Fixed dictionary key conflict - renamed `items` to `changes` to avoid collision with dict.items() method
+- Added missing `{% block head %}` in base.html that prevented custom CSS from loading
+
+### Technical Details
+- Changelog data structure uses dictionaries with keys: version, date, summary, sections
+- Sections contain: title, type, subsections (optional), changes
+- Subsections contain: subtitle, changes
+- All list items use "changes" key instead of "items" to avoid Python reserved method conflicts
+- CSS uses !important flags and increased specificity (.changelog-nav .changelog-nav-link) to override Bootstrap
+- Compact spacing achieved with: 0.15rem padding, 0.15rem margins, 0.85rem/0.7rem font sizes, 1.1/1.0 line heights
+
 ### Added
 - Autotask customer mapping now auto-searches for similar company names when opening unmapped customers:
   - Automatically populates search box with customer name