Page trying to rescaling when using typewriter code

Hi new to this page and to code I am trying to use a typewriter effect on my page which works on a larger screen but when I scale down to 1440 wide the video in the background trying to rescale causing the screen to jump back and forth and create a left to the right scrollbar. I am sure there may be a simple solution but I cant work this out. any help would be grand. The page is
Please let me know if there are any solutions or alternatives you can offer or if you need any other info.
Thanks in advance.

UPDATE i have managed to stop the weird scaling issue but now have a left and right scroll bar?