Introduction

Get started with Bootstrap, the world’s most popular framework for building responsive, mobile-first sites, with BootstrapCDN and a template starter page.

With the above snippet, nested elements—including generated content via ::before and ::after—will all inherit the specified box-sizing for that .selector-for-some-widget.

Learn more about box model and sizing at CSS Tricks.

Reboot

For improved cross-browser rendering, we use Reboot to correct inconsistencies across browsers and devices while providing slightly more opinionated resets to common HTML elements.

Community

Stay up to date on the development of Bootstrap and reach out to the community with these helpful resources.

• Follow @getbootstrap on Twitter.
• Read and subscribe to The Official Bootstrap Blog.
• Join the official Slack room.
• Chat with fellow Bootstrappers in IRC. On the irc.freenode.net server, in the ##bootstrap channel.
• Implementation help may be found at Stack Overflow (tagged bootstrap-4).
• Developers should use the keyword bootstrap on packages which modify or add to the functionality of Bootstrap when distributing through npm or similar delivery mechanisms for maximum discoverability.

You can also follow @getbootstrap on Twitter for the latest gossip and awesome music videos.