- #mode-select changed from flex column to flex row (desktop + mobile unified)
- Chat/⚡ buttons now sit side-by-side at the same height as the textarea
- Removed stale mode-agent CSS rules (mode removed in prior commit)
- Mobile: simplified override — flex:1 only, direction/align already desktop default
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>