Plan step 35: <x-surface level padding corner outlined>, a tonal region
in surface or a surface-container step, padded with a spacing token,
rounded with a corner token and optionally edged in outline-variant. A
pane on a surface keeps its margin again, since the surface is a new edge.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Qwx5USif3wFFmxtHg5U1g9