The markup for the callout buttons/links on the example page [0] is just <a href="#"><em>Button text</em></a> (for outlined) and <a href="#"><strong>Button text</strong></a> (for filled). That's a pretty creative solution that I definitely haven't seen before.
Giving opinionated styles to unclassed HTML elements is definitely not the right fit for every website. But, given this project's goal of being a minimalist, quick-start stylesheet that requires no classes, I think this use of `a em` and `a strong` selectors to create button-y links is pretty ingenious.
I think it undermines the semanticity of the markup though. A hyperlink isn't supposed to render as a button, or vice versa. If this was just a bolded word in normal inline link text, the button presentation would be very unwelcome.
Giving opinionated styles to unclassed HTML elements is definitely not the right fit for every website. But, given this project's goal of being a minimalist, quick-start stylesheet that requires no classes, I think this use of `a em` and `a strong` selectors to create button-y links is pretty ingenious.
[0]: https://andybrewer.github.io/mvp/