The error page's shape turns once a minute (material-error-turn), and
getBoundingClientRect() returns the axis-aligned box of what is drawn,
which is wider than the 240px art box as soon as the turn has begun. The
browser test compared that rect with 240: Chrome sampled it before the
first frame of the animation (currentTime 0) and passed, while Firefox
(33ms, 240.83px) and Safari (4ms, 240.20px) had already turned a fraction
of a degree and failed. The layout itself was right in all three: the
SVG's computed width is 240px.
The test now reads the SVG's computed width, which the rotation does not
touch. It still guards the regression it was written for: with the
inlined layout rules removed, the SVG computes to 1280px in every engine.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
