How to write responsive styles in css?

To make website responsive in all device , include following meta tag in header section:

<meta name=”viewport” content=”width=device-width”>

Then include media queries in stylesheet and add responsive styles there:
examples:
@media only screen and (max-width: 767px) and (min-width: 480px){
}
for more details:
http://www.howtofindit.in/responsive-style-media-query-in-stylesheet/