To avoid that I used the max-width CSS property to specify how wide the #wrap element can become. I could have used pixels to define a maximum width for the layout, but that would have made line lengths increase as text size is reduced and decrease as text is made larger. I wanted line length to be comfortable for reading and stay roughly the same regardless of text size. By using em instead of px as the unit for max-width, the width will depend on font size and line length will be similar no matter what size the text is. — Fixed or fluid width? Elastic!