Responsive css defined

For all the mobile device

Extra small devices (phones, less than 768px)

@media (max-width: @screen-sm-max) { ... }

Small devices (tablets, 768px and up)

@media (min-width: @screen-sm-min) { ... }

For all the PC device

Medium devices (desktops, 992px and up)

@media (min-width: @screen-md-min) { ... }

Large devices (large desktops, 1200px and up)

@media (min-width: @screen-lg-min) { ... }