Mobile and desktop view

Question

What is the syntax in HTML and CSS for detection is device phone table or desktop PC laptop
I creating log in page but it is disgusting

Answer 1

What you primarily need is a front end framework with grid system support in order to speed things up. It will make your site appealing and state of art. It makes your site responsive supporting anything from mobile, phablet, tablets, laptops to pc.
Popular frameworks would be
1. Bootstrap
2. Materialize
3. Bulma
4. Foundation
Although 1 & 2 tends to be the most popular.
Alternative if your CSS kong fu knowledge is near average you can use media query. It will increase rendering speed, because you will have a smaller markup and stylesheet.

Answer 2

If i made a watch in html and css then how will i apply that on my mobile home screen? Please someone tell me....