Code to change page width/padding on individual pages

Site URL: http://lindsey-cash.com/journal

Hi, 

I'd like to be able to change the page width/padding on individual pages. Right now I'm having to change my page width/padding on ALL MY PAGES just to make my blog look good. I just made my page width wider and my page padding smaller to make a content page with images look how I wanted it to look, but now my blog looks weird (posts are too wide)! 

I've tried a few codes to make my blog posts less wide but nothing is working. Does anyone have a fix? I'd be fine with a code to either increase width/decrease padding or decrease width/increase padding and would then set my standard width as the opposite. I just want to be able to have variety and not be stuck with one width for all my pages. 

My goal is for my blog be skinny, like the width of the blog in the first image below, and to have individual pages that are the wider--like the width of the second image. But right now I can't have both which is frustrating. 

Thanks so much! 

Add to Home > Design > Custom CSS

.collection-type-blog.view-list section#page {
    max-width: 75%;
}