The Buttons panel is for exactly what you’d think it’s for. Every button that LearnDash uses, as well as those used by the third-party plugins that we support, will inherit the styles you set here. I’ll explain the difference between Primary & Standard buttons, as well as provide examples of each.

The Button Border Radius is defined in pixels, and it is used for ALL LearnDash buttons. The default is 24px, which is used by LearnDash. Leave it blank to use the default, or enter your own value.
We define Primary Buttons as those that indicate the primary action on a page or in a particular section of your site.
Examples of primary buttons include:
Quite simply, every button that is not a Primary Button is a Standard Button. These are buttons that denote page actions, navigation, etc., but are usually not the first button your students will use to take an action on a page.
Examples of standard buttons include:
Hover styles for all buttons are prefixed with Hover:. You can set hover styles for both primary & standard buttons. The hover state occurs when a mouse hovers over a button, or when a button is tapped on a touch-enabled device.