Font Size Changes And ems

Use the mouse wheel (Control + Mouse Wheel) to adjust the font size. The tests below should adapt to the new font size as well.

As fonts changes size, the following box should change size and the text inside it should not get bigger than the box. The line height should adjust as well, text should never overlap itself.

This should fit in the square.
There should be a gap between the next to lines that are the same height as this line of text.
There should be a gap between the previous to lines that are the same height as this line of text.
The next line should be the same height as this line of text.