Visible hero headline stays readable
The opening paragraph renders normally, exactly like the real broken sample: the first viewport looks fine while everything below it never appears.
First hidden section
This block waits for an IntersectionObserver that will never construct, because the single script tag below fails to parse. Its text ships in the document but the reveal class never lands, so the reader scrolls through blank space.
Second hidden section
More shipped-but-invisible copy. Together the hidden sections carry well over thirty percent of the character count of the page, which is the failed-reveal signature this fixture exists to reproduce for the detector tests.
Third hidden section
A final block of body copy that stays at opacity zero forever. A healthy page with this exact markup reveals every one of these sections during the detector's reveal sweep; this one cannot, because its JavaScript died at parse time.