Mobile-first design means creating apps and websites that work best on your...

https://www.newpelican.com/articles/why-mobile-first-design-has-become-the-standard-for-modern-digital-services/

Mobile-first design means creating apps and websites that work best on your phone. It’s all about speed—pages load fast, so you’re not stuck waiting. Buttons and links are big enough for easy tapping, making everything feel natural and smooth