w-72 (288 px) listbox can overflow horizontally on a 320 px viewport when the caret sits near the right edge — the existing flip logic only handles vertical overflow. max-w-[calc(100vw-1rem)] adds a defensive horizontal cap so a senior on a 320 px phone never sees the dropdown clip off-screen. Leonie FINDING-MENTION-005 on PR #629. Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>