After an HTML link is being clicked, there will be a dotted outline of around the HTML Link <a> just like the following picture.
It can be removed by simply adding the following css style to <a>.
a {
outline: 0px;
}
Try it using the following .html.
<html>
<head>
<style type="text/css">
a {
outline: 0px;
}
</style>
</head>
<body>
<a href="https://ykyuen.wordpress.com" target="_blank">Eureka!</a>
</body>
</html>
Done =)
Reference: Removing Dotted Links
Eureka! 