Message
A chat message with avatar, content, timestamp, and alignment. The open question in a vertical interface is whether bubbles should adapt to the reading axis.
Should chat message bubbles remain horizontal (familiar) or adapt to vertical text orientation (consistent with reading direction)?
Horizontal vs Vertical
Vertical adaptation — each message is a column flowing right-to-left, matching the reading axis. Latest message on the left.
Guidance
- ✓Keep horizontal bubbles for mixed-language interfaces — vertical layout works best for pure CJK content
- ✓In vertical mode, arrange columns RTL: latest message on the left
- ✓Avatars should sit at the top of each message column, matching reading start
- ✗Force vertical bubbles without user control — this is an open UX question, not a resolved decision
- ✗Rotate horizontal bubble text 90° — reflow it properly with writing-mode
- ✗Use vertical messages for long multi-paragraph messages — truncate or expand differently
Accessibility
Each message has aria-label including sender and timestamp. Messages list uses role='log'. New messages announced via aria-live='polite'.
Open Question
This is one of the most contested open questions in vertical UI. Horizontal bubbles are familiar to all users; vertical columns are consistent with reading direction. Which wins? The answer may depend on the content type.