How can I achieve same width for pages and blog??

Why are the pages and blog page different how can I get same style across the webpage?

Blog widths can be adjusted between Small, Medium and Large. When editing a blog article, click on Edit Section, and then adjust content width, large should match the rest of your website.

Thanks, but I only got two options, full and inset and text content width which i set to 100% now. Still the blog page is narrower than other normal pages. In addition the text format i different in the blog page full posts than in the single blog posts. I want to have things to look the same