Key Takeaways Start with basic concepts like selectors, properties, and box model before moving to layouts.Use online tools ...

For screen sizes up to 1000 pixels the Mobile.css media query will be activated, switching display properties to the value block: @media all and (max-width: 1000px) { .mobi-rvPan, .mobi-rv-leftPan ...

For many developers that means using @media queries to selectively target the device screen size and orientation through CSS. While the @media approach is a good one, it won’t work for every site.

The W3C, the group that helps create web standards, has finished work on CSS Media Queries, turning the cornerstone of responsive web design into an official standard.