✅ Adaptive Mermaid Rendering - Implemented

Status: Live
Implemented: 2026-02-17
Time: 18 minutes (implementation + testing)

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What Changed

Markdown server now detects device and renders Mermaid diagrams appropriately:

• Desktop/Laptop: Full interactive Mermaid diagram (pan, zoom)
• Mobile/Tablet: Clean list view (no horizontal scroll, touch-friendly)
• AI/Bots: Reads original Mermaid source (unchanged, deterministic)

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Test It Now

Test file created: http://100.72.11.53:9876/test-mermaid.md

Desktop (any computer):

1. Open link above
2. You'll see: Interactive Mermaid diagrams (boxes + arrows)
3. Diagrams are rendered by Mermaid.js (GitHub style)

Mobile (your iPhone):

1. Connect to Tailscale
2. Open same link: http://100.72.11.53:9876/test-mermaid.md
3. You'll see: Structured lists with arrows (→ and ⇢)
4. No horizontal scrolling, easy to read

Example mobile output:

Main Session
  → Dev Agent
  → Ops Agent
  → Sales Agent

Species DNA
  ⇢ Main Session
  ⇢ Dev Agent
  ⇢ Ops Agent

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Real Document Test

Deployment architecture doc:
http://100.72.11.53:9876/working/infrastructure/deployment-architecture.md

• Desktop: Mermaid diagrams stay as-is (we didn't add any yet)
• Mobile: ASCII art renders cleanly (no change)
• Next step: Add Mermaid diagrams to deployment doc, they'll auto-adapt

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Technical Details

Detection:

function isMobile(userAgent) {
  return /Mobile|Android|iPhone|iPad|iPod/i.test(userAgent);
}

Conversion logic:

• Parses Mermaid syntax: A[Label] --> B[Label]
• Extracts nodes and edges
• Builds nested <ul> tree structure
• Solid arrows (-->) become →
• Dashed arrows (-.->) become ⇢

Fallback:

• If parsing fails: Shows "📱 Complex diagram - view on desktop"
• Graceful degradation (never breaks page)

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CSS Added

Mobile list styling:

.diagram-list {
  list-style: none;
  padding: 16px;
  background: #f6f8fa;
  border-radius: 6px;
  font-family: monospace;
}

.diagram-list .arrow {
  color: #0969da;
  font-weight: bold;
}

Desktop Mermaid.js:

• Loaded via CDN (only on desktop)
• Theme: neutral (GitHub-compatible)
• Auto-initializes on page load

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File Modified

tools/markdown-server.js

• Added: isMobile() function
• Added: mermaidToList() converter
• Added: processMarkdown() to handle both modes
• Added: CSS for .diagram-list
• Added: Conditional Mermaid.js loading

Lines added: ~120
No breaking changes: All existing markdown renders identically

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Next Steps

Option 1: Keep ASCII art in deployment-architecture.md

• Pro: Already works great on mobile
• Pro: Simple, no dependencies
• Con: AI parsing less deterministic

Option 2: Convert ASCII to Mermaid

• Pro: AI parsing perfect (structured data)
• Pro: Desktop gets interactive diagrams
• Pro: Mobile auto-converts to list
• Con: 10 min to convert existing ASCII

Option 3: Hybrid (both)

• Use Mermaid for new docs
• Keep ASCII for existing (don't break what works)
• Con: Inconsistent style

Recommendation: Option 3 (hybrid) - Don't touch existing ASCII, use Mermaid for future diagrams.

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Verification Checklist

• Mobile detection working
• Mermaid → list converter working
• Desktop still shows Mermaid.js
• No errors on pages without Mermaid
• CSS mobile-responsive
• Server restarted and live
• Test file created
• Changes committed to git

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Test on your iPhone now: http://100.72.11.53:9876/test-mermaid.md

Feedback welcome. If rendering looks good, we're done. If adjustments needed, let me know.