Design involves selecting the imagery, the colors, and the fonts that feed into the user interface (UI).
Styling is the process of implementing design choices into the code using CSS or SASS.
At Revelry, we always start a project with a living styleguide on a web or mobile app page that will guide all styling choices as the product is built. While Revelry does offer branding services, if a client comes to us with a brand guideline, we use that as inspiration to bring the product to life.