What about the horizontal scroll bar?

Hello, very, very good day. 🙂

This plugin is very impressive, but I have found a problem.
If you look at the example link (page) and you go to the only box of code that there is (from Mivhak), when you try to copy all the code, you can not completely.
And if you try to move the horizontal scroll bar does not work.

See: https://ibb.co/fF2Fi0

Why does that happen? How can I solve it?

Please help, thanks in advance and a warm hug.

The page I need help with: [log in to see the link]