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src/button/Link.module.css

@@ -6,5 +6,8 @@ Please see LICENSE in the repository root for full details.
 */
 
 .external {
+  /* By default links will be blue/purple (or whatever the user agent does), but
+  in our designs we generally want external links to be the same color as the
+  surrounding text */
   color: inherit;
 }