CSS default page style
The default page style is like the blank canvas of a painter (or developer in our case) who hasn't touched it yet. Every browser has its own default style, also known as browser or user-agent (UA) stylesheet, which exists to make any website readable by default if you haven't applied any styles yet.
Default style varies slightly from browser to browser but generally includes some basic settings for buttons, links, padding, margin, borders, different headings, and other useful things. If you want to see browser defaults to make sure they'll comply with your cascading sheets, you can find them online, e.g., Chrome default styles.[1] Some developers use special tools like Meyerweb's CSS reset or Normalize.css to remove those defaults.