Phabricator's Diffusion is currently handling the Less color coding incorrectly:
https://phabricator.wikimedia.org/source/mediawiki/browse/master/resources/src/mediawiki.ui/components/buttons.less;6960b650ea22607b3901dbb33fb49e3015613df3
Single-line comments (//) are colored using class n and o and look different than a code block using /* */