Project Bestbite; how to properly reference a button to style it with css

How do I properly reference the “Learn More” button in css? My instinct is “a .btn btn-default” or maybe just “.btn-default”

I have no idea how to properly reference this.

In the class “btn btn-default” why is there an extra “btn” in the beginning? What does it mean? How does it differ from “btn-default”

You can pick either .btn or .btn-default to apply styling. btn and btn-default are both bootstrap classes, which this means we have a css file (let’s say it is called bootstrap.css), which both contains a definition for btn and btn-default, to see the difference, i have to go through the bootstrap.css file, do you want me too?