@ugly: fuchsia; .escape\|random\|char { color: red; } .mixin\!tUp { font-weight: bold; } // class="404" .\34 04 { background: red; strong { color: @ugly; .mixin\!tUp; } } .trailingTest\+ { color: red; } /* This hideous test of hideousness checks for the selector "blockquote" with various permutations of hex escapes */ \62\6c\6f \63 \6B \0071 \000075o\74 e { color: silver; } [ng\:cloak], ng\:form { display: none; } // In Bootstrap v3 .bootstrap { background-color: #000 \9; } textarea { font-family: 'helvetica neue','wenquanyi micro hei',\5FAE\8F6F\96C5\9ED1, \5B8B\4F53, sans-serif; }