Three CSS fixes for the codemirror-live-markdown live preview:
1. Remove header underlines (border-bottom: none on .cm-heading-line)
2. Heading markers (## etc) positioned absolutely in left gutter area
so they never push heading text horizontally when revealed
3. List bullets always occupy fixed width (font-size: 1em, not collapsed),
showing • when inactive and source char (-) when active
Verified via Playwright: 0px horizontal shift on both headings and bullets.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
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