PURE.CSS provides several special classes to create a responsive design :
.pure-u-* : It is used to set the container to occupy required space on any device.
.pure-u-sm-* : It is used to set the container to occupy required space on a devices with width ? 568px.
.pure-u-md-* : It is used to set the container to occupy required space on a devices with width ? 768px.
.pure-u-lg-* : It is used to set the container to occupy required space on a devices with width ? 1024px.
.pure-u-xl-* : It is used to set the container to occupy required space on a devices with width ? 1280px.
