/usr/share/source-highlight/css.lang is in libsource-highlight-common 3.1.7-1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 | # language definition for css style sheets
include "c_comment.lang"
selector = '(\.|#)[[:word:]]+'
state cbracket delim "{" "}" multiline begin
include "c_comment.lang"
property = '[[:word:]-]+[[:blank:]]*:'
value = '[.%[:word:]-]+'
string = '#([[:word:]]+)'
end
include "symbols.lang"
|