EmChart | Ford InteractiveEmChart View Demo Download Zip Using a relative unit such as EM is a great way to maintain the vertical rhythm of a web page when a user resizes text in their browser. Constantly reaching for a calculator to compute the correct EM value to use every time you need to is also a great way to drive yourself mad. Let’s say you have an H3 that’s 24 pixels. It doesn’t matter how the font-size is set (pix
