ポートレートモードでiPadで目次を開くと、目次が背景なしでテキストに重なる

When viewing a topic in Documentation and opening the TOC on an iPad in portrait mode, this happens:

The page can still be scrolled, and the links in the TOC clicked.

Browser: Safari

「いいね!」 3

I see the same on Android with Firefox and Chrome

「いいね!」 2

Can confirm. Thanks for the report.