Mobile device priority
In Bootstrap 2, we added to mobile device-friendly style of certain key parts of the framework. In the Bootstrap 3, we rewrote the entire frame, so that the start of the mobile device-friendly. This is not simply increase the number of alternative styles for mobile devices, but directly integrated into the core framework. In other words, Bootstrap is a priority of the mobile device . For the style of the mobile device integration into every corner of the frame, instead of adding an extra file.
To ensure proper rendering and touch-screen zoom in need <head> among the add viewport meta tag data .
<meta name="viewport" content="width=device-width, initial-scale=1">On a mobile device browser, by setting the meta attribute viewport (the viewport) to user-scalable=no disable scaled (Zooming) function. After this zoom function is disabled, the user can scroll the screen, you can make your site look more like a native application feel. Note that, in this way we do not recommend the use of all sites, will depend on your own circumstances!
<meta name="viewport" content="width=device-width, initial-scale=1, maximum-scale=1, user-scalable=no">