CSS: Style external links

Question

I want to style all external links in my website (Wordpress). I\'m trying with:

.post p a[href^=\"http://\"]:after

But Wordpress put the entire

Answer 1

This way shows external links ALA Wikipedia:

a[href^="http"]:after {
     content: " " url(data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAoAAAAKCAYAAACNMs+9AAAAVklEQVR4Xn3PgQkAMQhDUXfqTu7kTtkpd5RA8AInfArtQ2iRXFWT2QedAfttj2FsPIOE1eCOlEuoWWjgzYaB/IkeGOrxXhqB+uA9Bfcm0lAZuh+YIeAD+cAqSz4kCMUAAAAASUVORK5CYII=);
}

​An example can be found here: http://jsfiddle.net/ZkbKp/