[TheIrvin]

Summary

• Rework the conversion landing page into a colorful, modular workspace for converting, organizing, and consulting local documents.
• Clarify the primary drag-and-drop/import action and local privacy behavior.
• Refine responsive layouts for the workspace, library, preview, and cited answers.
• Refresh real desktop and mobile screenshots.

Verification

• dotnet build MarkItDownWeb.slnx --configuration Release --warnaserror — 0 warnings and errors.
• dotnet test MarkItDownWeb.slnx --configuration Release --no-build — 23 passed.
• Visual review at 320 px and 390 px confirmed no horizontal page scrolling.
• git diff --check passed.