Greasy Fork

I don't know how to code CSS but luckily I have ADHD timeblindness and accidentally spent all night hyperfixated on quality of life edits. The sun has come up and I regret nothing. If you want to perfectly center the text (i hope... i pulled out an irl ruler because pixel division was getting me nowhere) and get rid of that weird share bar, replace lines 30 through 33 of the original code with these instead:

insertCss('#sticky-end{width:960px;margin-right:136px}')
insertCss('.col-md-offset-2{margin-left:0px;}')
insertCss('.panel.panel-reading{margin-left:-29px;}')
insertCss('.panel-reading{width:1000px;}')
insertCss('.right-rail{display:none;}')
insertCss('.left-rail{display:none;}')
insertCss('.modal-open{overflow:inherit;}')

Also, yes I know the comment buttons make the text look uncentered but it truly is centered. I would know, I used a whole damn ruler ;-;
If it really bothers you then idk what to tell you, i only realized this issue until after 6 in the morning so unfortunately im go sleep.

I tried your suggested CSS, but they seem to be highly specific to your browser/screen size/how you use the site, compared to mine.

With your changes (left) and without (right), side-by-side on the one screen: https://i.imgur.com/s9bT2ZF.png

With your changes fullscreen: https://i.imgur.com/yfKyvuI.png
Without your changes fullscreen: https://i.imgur.com/mVT8nJo.png

I appreciate that my CSS styling selections have room for improvement, and I'm happy your changes work for you.
But I would not consider my script itself to have any bugs (it changes the CSS on the page like we both tell it to), and I unfortunately would consider your suggested CSS styling changes worse than what I've got now for anyone other than you, so I won't be changing anything at this stage (since I don't really use WattPad anymore either).