version compatible with old browser not supporting has

styles/elements/language.css

@@ -1,28 +1,44 @@
-.language {
+label#language_label {
 	position: fixed;
 	margin: 100px;
 }
-.language input {
+input#language {
 	display: none;
 }
 
-.language input:not(:checked) + label #fr {
+
+
+/*
+when not checked
+*/
+input#language:not(:checked) + label #fr {
 	display: inline;
 }
-.language input:not(:checked) + label #en {
+input#language:not(:checked) + label #en {
 	display: none;
 }
-.language:has(input:not(:checked)) ~ * span.en {
-	display: none;
-}
-
-.language input:checked + label #fr {
-	display: none;
-}
-.language input:checked + label #en {
+input#language:not(:checked) ~ * span.en {
 	display: inline;
 }
-.language:has(input:checked) ~ * span.fr {
+input#language:not(:checked) ~ * span.fr {
 	display: none;
 }
 
+
+
+/*
+when checked
+*/
+input#language:checked + label #fr {
+	display: none;
+}
+input#language:checked + label #en {
+	display: inline;
+}
+input#language:checked ~ * span.en {
+	display: none;
+}
+input#language:checked ~ * span.fr {
+	display: inline;
+}
+