Sidebar out of place

I think I’ve done a comprehensive search on the subject, so if this has already been covered, I apologize in advance.

Basically, I can’t seem to make my sidebar stick to the right side, and it seems to be somehow linked to my tagline – which I have set to rotate every time the page is loaded. The gap between the taglines and the sidebar is the same, so it jumps around depending on which tagline has loaded.

Check it out for yourself – https://www.studiolockdown.com/blog

Refresh or click on the header a couple of times to see what I’m talking about.

I’m using the water-10 theme (https://themes.wordpress.net/columns/2-columns/715/water-10/), and have been tinkering around with it to suit it to my liking. I’m a total coding neophyte, so it’s been a lot of trial and error, and I did something either in the header.php or the style.php, so far as I can tell, but I can’t seem to fix it back.

Using Mozilla Firefox, FYI….

Any help would be appreciated!