Plan step 36 review of a8c2d88f. error-page.css drew a bare `body`, which
components.css already bundles into every Workbench page and step 37's
all.css would put in every application page: each would take the error
page's background, margin and system font. The rule now matches
body:has(> [data-md-error-page]); the fallback stylesheet, inlined into
the error page alone, keeps its own. A test in the containment harness
and in ErrorPagesTest rejects an unscoped html, body, dialog or :root.
The body's system font stack is gone: the old `font-sans` was the brand
typeface (tokens/theme.css), which the page inherits from the
foundation's html rule, and the header's claim otherwise was wrong. The
shape's slow turn, which moved from the view's inline style into the
stylesheet, is back in the fallback so the no-build page still turns.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Qwx5USif3wFFmxtHg5U1g9
