Improve look&feel of external link warning in Kiwix Server

[kelson42]

In Kiwix Server, when a user is about to leave the pages serverd from the ZIM file, then they click on a so called "external link". That means a link which is not served by Kiwix Server, but by a Web server... on the Web.

This is a very normal situation as ZIM file pages have a lot of external links. But of course we want to inform the user about that. This is a matter of transparency and to some extend of security.

Today such a page looks like this:

So basically the page has two functions:

• Inform the user
• Allow the user - with just a click - to jump to the external content.

The current design is really not nice, we would like to have something really better.