Make .cs highlighting legible on dark themes. (#19604)

Author: Eekle

web_src/less/chroma/dark.less

@@ -52,7 +52,7 @@
 .chroma .ch { color: #6a737d; } /* CommentHashbang */
 .chroma .cm { color: #6a737d; } /* CommentMultiline */
 .chroma .c1 { color: #6a737d; } /* CommentSingle */
-.chroma .cs { color: #637d; } /* CommentSpecial */
+.chroma .cs { color: #95ad; } /* CommentSpecial */
 .chroma .cp { color: #fc6; } /* CommentPreproc */
 .chroma .cpf { color: #03dfff; } /* CommentPreprocFile */
 .chroma .gd { color: #fff; background-color: #5f3737; } /* GenericDeleted */