Reapply style after adding content with JavaScript

Question

I will try to expand my problem:

I have a link:

Display

I have some

Answer 1

That's the problem was talking about in my comment. You are calling document.write(MyHtml) after the document was fully loaded.

It will completely replace the document (see the documentation). Inspect it, you will see that there is an empty head (also see this and this example).

Use other methods to manipulate the DOM.