Bug with highlighting certain combinations of numbers/words

[FWishbringer]

For example, lets assume this falls within syntax highlighting.

With top, bottom, px being a keywords, set to display in red.

h1 {
top: 10px;
top: 10.1px;
bottom: -10px
}

(Yes, 10.1 is 'invalid' for CSS, included for testing-completeness sake)

I believe it should either display px as highlighted or not, and not mixed, or there should be an option for adding - to valid numerals.