Set the language
Set font size
36px
Set the font to
Adjust the width of the test box. 400px
If the first letter isn't coloured green, then ::first-letter isn't supported.
CSS for the test box is: #test::first-letter { color:green; font-weight: bold; font-size: 2em; }.
The [Delete 1 code point] button helps speed up some tests were you want to check a series of prepended characters, deleting them as you go. It removes the first character from the input box and refreshes the test.