Plan step 23, containment.md § Missing ("Side sheets: a genuine standard
variant"). `<x-drawer standard>` is M3's other side-sheet variant: from
`expanded` it is co-planar with the content — no scrim, no focus trap,
nothing inert, 0dp elevation, `surface` rather than surface-container-low,
no corner, and an outline-variant rule down its inner edge in place of the
scrim — sitting in the page flow at the window's full height. Below
`expanded` it is the modal sheet, since M3 caps a side sheet at 400dp and
a medium window has too little left beside one. Capped at that 400dp
whatever `width` says, and it always draws the close affordance M3
requires, because nothing else closes it there.
`pane` is untouched and the header and SKILL.md say how the two differ:
pane is the list-detail companion, standard is supplementary content.
Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Qwx5USif3wFFmxtHg5U1g9
