The transform amplified jitter during iOS textarea swipes: visualViewport
scroll events updated --vv-offset-top rapidly, the transform followed,
and the thread juddered then shifted ~300px exposing the body background.
Removing the transform leaves the thread where iOS places it; the
height-shrink to var(--vv-height) still constrains it to the visible
area. Trade-off: on initial focus the thread anchor relies on iOS's
own viewport adjustment instead of explicit compensation, but that
beats the swipe-time jitter.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
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