The default user-agent stylesheet as used by Firefox, Chrome, Safari and BFO Publisher sets body { margin: 8px }. Any tool that does this will see lesson-deer wrapping onto the second page because you have html, body { height: 100%} , and lesson-account-statement will not be able to fit your left and right-floating tables side-by-side. You need a body { margin: 0 } rule in both.
In lesson-deer, I'd also strongly suggest setting <!DOCTYPE html> at the top of the file, otherwise you're relying on how quirks-mode is implemented in whichever tool you're testing.
The default user-agent stylesheet as used by Firefox, Chrome, Safari and BFO Publisher sets
body { margin: 8px }. Any tool that does this will see lesson-deer wrapping onto the second page because you havehtml, body { height: 100%}, and lesson-account-statement will not be able to fit your left and right-floating tables side-by-side. You need abody { margin: 0 }rule in both.In lesson-deer, I'd also strongly suggest setting
<!DOCTYPE html>at the top of the file, otherwise you're relying on how quirks-mode is implemented in whichever tool you're testing.