Mobile-first design means building websites and apps primarily for phones. This...

https://page-wiki.win/index.php/Do_Descriptive_Labels_Matter_on_Mobile_or_Is_Placeholder_Text_Enough%3F

Mobile-first design means building websites and apps primarily for phones. This approach makes everything load faster, so you don’t waste time waiting. Buttons and links are big and easy to tap with your finger, not a mouse