Add CLAUDE.md session log

Documents SSH setup, bug fixes, UI enhancements, and Giscus
configuration from the 2026-02-24 Claude Code session.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: Null0RM

CLAUDE.md

@@ -0,0 +1,58 @@
+# CLAUDE.md — Session Log
+
+## Session: 2026-02-24
+
+### Environment
+- Repo: `git@github.com:Null0RM/null0rm.github.io.git`
+- Theme: jekyll-theme-chirpy ~> 7.4
+- SSH key: `~/.ssh/github_null0rm` (ed25519, added to GitHub account)
+- Git identity: `Null0RM <junghy2301@gmail.com>`
+
+---
+
+### Bug Fixes (commit: `386e195`)
+
+| File | Bug | Fix |
+|------|-----|-----|
+| `_posts/2025-12-11-AboutEtherHiding.md` | YAML date was `2025-12-09`, mismatched filename | Changed to `2025-12-11` |
+| `_config.yml` | Duplicate `kramdown:` key — `math_engine: mathjax` was silently overridden, breaking MathJax | Merged into single `kramdown:` block |
+| `_config.yml` | Default Chirpy placeholder in `description:` field | Replaced with `"A technical blog covering Web3 security, blockchain internals, and CTF write-ups."` |
+
+---
+
+### UI Enhancements (commit: `644a164`)
+
+File modified: `assets/css/jekyll-theme-chirpy.scss`
+
+- **Accent color tokens** — `--accent: #3b82f6` (light) / `--accent-dark: #60a5fa` (dark)
+- **Dark mode** — GitHub-style deep backgrounds (`#0f1117` main, `#161b22` sidebar/cards)
+- **Links** — accent color, 1px underline, smooth hover transition
+- **h2 headings** — subtle left accent bar in post content
+- **Code blocks** — rounded corners (8px) + border
+- **Inline code** — improved padding and border-radius
+- **Blockquotes** — uniform padding, non-italic, 3px left border
+- **Post cards** — lift 2px on hover with soft shadow
+- **Tags** — pill shape (border-radius: 20px), hover transition
+- **TOC** — colored left border matching accent
+- **Tables** — rounded corners, 0.92em font
+- **Smooth scroll** — `scroll-behavior: smooth` on `html`
+
+---
+
+### Comments (commit: `66fb1ce`)
+
+Giscus configured in `_config.yml`:
+- `provider: giscus`
+- `repo: Null0RM/null0rm.github.io`
+- `repo_id: R_kgDOQRlfUQ`
+- `category: Announcements`
+- `category_id: DIC_kwDOQRlfUc4C3E40`
+- `mapping: pathname`, `reactions_enabled: 1`
+
+---
+
+### Pending / Optional
+
+- **Avatar** — `avatar:` field in `_config.yml` is still empty
+- **Analytics** — all analytics providers unconfigured in `_config.yml`
+- **Social preview image** — `social_preview_image:` still empty