Plan step 38 (last batch): every example moves onto the layout
components, the md-* text classes and tokens. Wrapper divs that only
sized or grouped a demo (grid/list widths, the divider-and-collapse
stack, the dragged-card scope) become <x-grid>/<x-stack>/<x-row> with
an inline style where a specific px width still matters; a video
thumbnail's Tailwind gradient utility becomes an inline
background/color pair since each list-item's own colours differ. The
standard side sheet demo keeps M3's row-then-column breakpoint through
<x-row stack-below="expanded">, with a data-md-showcase-side-sheet-demo
hook that restores the row's own stretch alignment once it collapses
to a column (an explicit align="start", needed for the row layout,
would otherwise leave it shrink-wrapped).
Every id, data-md-* selector and visible string the Chromium
ContainmentTest reads (#containment, its dialog/sheet/card queries) is
unchanged; no demo content removed.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Qwx5USif3wFFmxtHg5U1g9
