To note: Javascript is not running in this browser environment. Our apologies, but this demo has not yet been updated to support progressive enhancement.
Test purpose
Check that the underline appears (when included) for all fonts, and it can be offset as required.
Check that the underline width (it should be called depth?) works as expected.
Check that the underline is a solid line, breaking only where the text interrupts it.
Check the gap between the underline and any interrupting text is adjustable.
Check the underline expands/contracts as letter and word spacing is adjusted.
Check that the underline stays in its place in relation to the text as scale/roll/flip values change.
Check that the underline style updates as expected, including for gradient and pattern styles.
Make sure that underline positioning is respected across browsers.