The 设置 button was a layout placeholder from the initial header build — never wired to anything, so clicking it did nothing. Remove it (and its style) rather than leave a dead control; current settings (output dir/format/quality) are editable inline in the export panel. Docs: UI design 4.1 records that no settings entry is provided for now. Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>