(* ::Package:: *)
values = "
/* <length> values */
text-indent: 3.0mm;
text-indent: 40.0px;
/* <percentage> value
relative to the containing block width */
text-indent: 15%;
/* Keyword values */
text-indent: 5em each-line;
text-indent: 5em hanging;
text-indent: 5em hanging each-line;
/* Global values */
text-indent: inherit;
text-indent: initial;
text-indent: revert;
text-indent: unset;
";
all = Sort@StringCases[
values,
RegularExpression[":\\s*([a-zA-Z0-9-]+);"] :> "$1"
];
"[\"" <> StringRiffle[all, "\",\""] <> "\"].contains(&mode)"