Percentage height calculation quirk does not seem to match implementations #28
Description
The percentage height calculation quirk seems to use the initial containing block for the containing block. But actual implementations do something where they take the margins and padding of the <body> and <html> into account, as far as I can tell. This section probably needs more testing of what the actual browser behavior is, especially since some of the tests for this part of the spec are not passed by any browser per https://wpt.fyi/results/quirks/percentage-height-calculation.html