Mobile-first design means building websites or apps starting with phones in...

https://blogfreely.net/samuel-wang09/what-is-appropriate-contrast-and-how-do-i-check-it-fast

Mobile-first design means building websites or apps starting with phones in mind. It makes sure pages load fast, buttons are easy to tap, and menus are simple to use. This way, you can find what you need quickly without fuss, even on the smallest screen