You need to specify a unit. There are many units, including real-world measurements (mm, cm, in), pixel-based measurements (px, pc), and relative measurements (%, ex, em). px, em, and % are the units most recommended for something to be displayed on the screen. px is the number of pixels tall to make the font, em is roughly based on the letter "M" in the current font, and % is based on the parent container's font size. So if you want the text to be 80 pixels tall, you need font-size: 80px; Side note: the label's for attribute is not useful in Roll20's character sheets, because it is used to link to a form element's id attribute. IDs are meant to be unique on a page, but as soon as there are two characters in the journal with your character sheet, there will be two copies of the same id .