Pseudo-class :lang()

The :lang() CSS pseudo-class matches elements
based on the language they are determined to be
in.

*:lang(en-US) {
  outline: 2px solid deeppink;
}

:lang(en) > q {
  quotes: "\201C" "\201D" "\2018" "\2019";
}

:lang(fr) > q {
  quotes: "« " " »";
}

/* Matches nl and de */
:lang("nl", "de") {
  color: green;
}

/* Omitting quotes & case-insensitive matching */
:lang(EN, FR) {
  color: blue;
}

/* Wildcard matching a language range */
:lang("*-Latn") {
  color: red;
}