M3 Expressive top app bars (small, centered, medium and large flexible,
search) that collapse with CSS sticky, docked and floating toolbars,
primary and secondary tabs with a view-transition indicator, section
navigation, the account menu and theme toggles.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01V9NnLxnPp8vaaurb3Z1MFy
