One way to achieve visual consistency in web design is to use a vertical rhythm. For a website, this would mean that no matter what font-size any text element is, its line-height is always an even multiple of a consistent unit of rhythm. When this is done precisely, you could put a striped background behind your page and each text block (paragraphs, headings, blockquotes, etc) would line up along the lines in that grid.
As you could imagine, setting this up by hand would require a lot of math and typing. If you want to change the proportions of that grid responsively, you’ll redo that work for every breakpoint. Sass, as you might expect, provides a great toolbox to automate all that work and generate a custom type scale with consistent vertical rhythm more easily.
I’ll start off by admitting that there are already some good Sass plugins that help build a custom type scale with consistent vertical rhythm. If you’re just looking to grab a pre-built chunk of code, try Typesetting, Typomatic, or Typecsset.
This one is really good. Took a little time to read through – as i’m not a super trained high-skill “artist” who wears a beret.