size and font

That I do not understand in a Web application is supposed not matter if it is developed on Windows, Mac, Linux’s Font should not change or size.

always looks different

If you use a font that is not available on the end users computer you can get substitutions

but when I open the projector and edit in windows I open it in mac and all the labels change Reverse or lose the last position.

Cant say I’ve seen that myself
File a bug report with steps or a sample and we’ll look at it & see whats up