Test case of margin by "em"

Both box has width:15em. The righ box has margin-left:15em. Then, both box should be side-by-side.

A quick brown fox jumps over the lazy dog. A quick brown fox jumps over the lazy dog. A quick brown fox jumps over the lazy dog. A quick brown fox jumps over the lazy dog. A quick brown fox jumps over the lazy dog. A quick brown fox jumps over the lazy dog.

overflow:hidden; A quick brown fox jumps over the lazy dog. A quick brown fox jumps over
the lazy dog. A quick brown fox jumps over the lazy dog. A quick brown
fox jumps over the lazy dog.
overflow:visible;A quick brown fox jumps over the lazy dog. A quick brown fox jumps over
the lazy dog. A quick brown fox jumps over the lazy dog. A quick brown
fox jumps over the lazy dog.