Problem with external plugin designing

Hey guys.
Im trying to embed a script in my code that allows Accessibility Menu for my users.
I tried to embed the code on the “Header” and in the footer and its work very well.
my only problem its when i embed the code and get inside the website - when im scrolling the page to the top or to the bottom what i see its a “Blue line” at the top and the bottom.
here an example:

<script src=""></script>

Here is my site Read-Only:*