<pclass="lead">Bootstrap has a few easy ways to quickly get started, each one appealing to a different skill level and use case. Read through to see what suits your particular needs.</p>
<p>The fastest way to get Bootstrap is to download the precompiled and minified versions of our CSS, JavaScript, and fonts. No documentation or original source code files are included.</p>
<p>The folks over at <ahref="https://www.netdna.com/">NetDNA</a> graciously provide CDN support for Bootstrap's CSS and JavaScript. Just use these <ahref="http://www.bootstrapcdn.com/">Bootstrap CDN</a> links.</p>
<p>If you work with Bootstrap's uncompiled source code, you need to compile the LESS files to produce usable CSS files. For LESS compilation, we only officially support <ahref="http://twitter.github.io/recess/">Recess</a>, which is Twitter's CSS hinter based on <ahref="http://lesscss.org">less.js</a>.</p>
<pclass="lead">Within the download you'll find the following directories and files, logically grouping common assets and providing both compiled and minified variations.</p>
<p>Once downloaded, unzip the compressed folder to see the structure of (the compiled) Bootstrap. You'll see something like this:</p>
<p>This is the most basic form of Bootstrap: precompiled files for quick drop-in usage in nearly any web project. We provide compiled CSS and JS (<code>bootstrap.*</code>), as well as compiled and minified CSS and JS (<code>bootstrap.min.*</code>). Fonts from Glyphicons are included, as is the optional Bootstrap theme.</p>
<p>Please note that <strong>all JavaScript plugins require jQuery</strong> to be included, as shown in the <ahref="#template">starter template</a>.</p>
<pclass="lead">Build on the basic template above with Bootstrap's many components. See also <ahref="#customizing">Customizing Bootstrap</a> for tips on maintaining your own Bootstrap variants.</p>
<li>Override the <code>width</code> on the <code>.container</code> for each grid tier with a single width, for example <code>width: 970px !important;</code> Be sure that this comes after the default Bootstrap CSS. You can optionally avoid the <code>!important</code> with media queries or some selector-fu.</li>
<li>For grid layouts, use <code>.col-xs-*</code> classes in addition to, or in place of, the medium/large ones. Don't worry, the extra-small device grid scales to all resolutions.</li>
<pclass="lead">Bootstrap 3 is not backwards compatible with v2.x. Folks looking to upgrade to v3 should use this section as a general upgrade guide. We've outlined some of the major changes and provided tables that highlight key changes. For an overview, <ahref="http://blog.getbootstrap.com/2013/08/19/bootstrap-3-released/">read the announcement blog post</a>.</p>
<p>We've made many underlying changes in v3 that are not immediately apparent. Base classes, key styles, and behaviors have been adjusted for flexibility and our mobile first approach.</p>
<li>Text-based form controls are now 100% wide. Wrap inputs inside <code><div class="col-*"></div></code> to control input widths.</li>
<li><code>.badge</code> no longer has contextual (-success,-primary,etc..) classes.</li>
<li><code>.btn</code> must also use <code>.btn-default</code> to get the "default" button.</li>
<li><code>.container</code> and <code>.row</code> are now fluid (percentage-based).</li>
<li>Images are no longer responsive by default. Use <code>.img-responsive</code> for fluid <code><img></code> size.</li>
<li>The icons, now <code>.glyphicon</code>, are now font based. They also require a base and icon class (e.g. <code>.glyphicon .glyphicon-asterisk</code>).</li>
<li>Modal markup has changed significantly. The <code>.modal-header</code>, <code>.modal-body</code>, and <code>.modal-footer</code> sections now get wrapped in <code>.modal-content</code> and <code>.modal-dialog</code> for improved mobile styling and behavior.</li>
<li>JavaScript events are namespaced. For example, to handle the modal "show" event, use <code>'show.bs.modal'</code>. For tabs "shown" use <code>'shown.bs.tab'</code>, etc..</li>
<pclass="lead">Bootstrap is built to work best in the latest desktop and mobile browsers, meaning older and less advanced browsers might receive a less stylized, though fully functional, version of certain components.</p>
<p>Unofficially, Bootstrap should look and behave well enough in Chromium for Linux and Internet Explorer 7, though they are not officially supported.</p>
<p>Internet Explorer 8 and 9 are also supported, however, please be aware that some CSS3 properties and HTML5 elements are not fully supported by these browsers. In addition, <strong>Internet Explorer 8 requires the use of <ahref="https://github.com/scottjehl/Respond">respond.js</a> to enable media query support.</strong></p>
<p>IE8 does not fully support <code>box-sizing: border-box;</code> when combined with <code>min-width</code>, <code>max-width</code>, <code>min-height</code>, and <code>max-height</code>. For that reason, as of v3.0.1, we have moved from <code>max-width</code> on <code>.container</code>s.</p>
<p>Bootstrap is not supported in the old Internet Explorer compatibility modes. To be sure you're using the latest rendering mode for IE, consider including the appropriate <code><meta></code> tag in your pages:</p>
<p>See <ahref="http://stackoverflow.com/questions/6771258/whats-the-difference-if-meta-http-equiv-x-ua-compatible-content-ie-edge">this StackOverflow question</a> for more information.</p>
<p>Internet Explorer 10 doesn't differentiate device width from viewport width, and thus doesn't properly apply the media queries in Bootstrap's CSS. To address this, you can optionally include the following CSS and JavaScript to work around this problem until Microsoft issues a fix.</p>
{% highlight css %}
@-webkit-viewport { width: device-width; }
@-moz-viewport { width: device-width; }
@-ms-viewport { width: device-width; }
@-o-viewport { width: device-width; }
@viewport { width: device-width; }
{% endhighlight %}
{% highlight js %}
if (navigator.userAgent.match(/IEMobile\/10\.0/)) {
<p>For more information and usage guidelines, read <ahref="http://timkadlec.com/2013/01/windows-phone-8-and-device-width/">Windows Phone 8 and Device-Width</a>.</p>
<p>In the latest Safari for Mac, its rendering engine has a little trouble with the long decimal places of our <code>.col-*-1</code> grid classes, meaning if you have 12 individual columns you'll notice they come up short compared to other rows of columns. We can't do much here (<ahref="https://github.com/twbs/bootstrap/issues/9282">see #9282</a>) but you do have some options:</p>
<p>Support for <code>overflow: hidden</code> on the <code><body></code> element is quite limited in iOS and Android. To that end, when you scroll past the top or bottom of a modal in either of those devices' browsers, the <code><body></code> content will begin to scroll.</p>
<p>Also, note that if you're using inputs in your modal – iOS has a rendering bug that doesn't update the position of fixed elements when the virtual keyboard is triggered. A few work arounds for this include transforming your elements to <code>position: absolute</code> or invoking a timer on focus to try to correct the positioning manually. This is not handled by Bootstrap, so it is up to you to decide which solution is best for your application.</p>
<p>Page zooming inevitably presents rendering artifacts in some components, both in Bootstrap and the rest of the web. Depending on the issue, we may be able to fix it (search first and then open an issue if need be). However, we tend to ignore these as they often have no direct solution other than hacky workarounds.</p>
<pclass="lead">While we don't officially support any third party plugins or add-ons, we do offer some useful advice to help avoid potential issues in your projects.</p>
<p>Some third party software, including Google Maps and Google Custom Search Engine, conflict with Bootstrap due to <code>* { box-sizing: border-box; }</code>, a rule which makes it so <code>padding</code> does not affect the final computed width of an element. Learn more about <ahref="http://css-tricks.com/box-sizing/">box model and sizing at CSS Tricks</a>.</p>
<p>Depending on the context, you may override as-needed (Option 1) or reset the box-sizing for entire regions (Option 2).</p>
<pclass="lead">Bootstrap follows common web standards, and with minimal extra effort, can be used to create sites that are accessibile to those using <abbrtitle="Assistive Technology"class="initialism">AT</abbr>.</p>
<p>If your navigation contains many links and comes before the main content in the DOM, add a <code>Skip to content</code> link immediately after your opening <code><body></code> tag. <ahref="http://a11yproject.com/posts/skip-nav-links/">(read why)</a></p>
<p>When nesting headings (<code><h1></code> - <code><h6></code>), your primary document header should be an <code><h1></code>. Subsequent headings should make logical use of <code><h2></code> - <code><h6></code> such that screen readers can construct a table of contents for your pages.</p>
<p>Learn more at <ahref="http://squizlabs.github.io/HTML_CodeSniffer/Standards/Section508/">HTML CodeSniffer</a> and <ahref="http://accessibility.psu.edu/headings">Penn State's AccessAbility</a>.</p>
<pclass="lead">Bootstrap is released under the Apache 2 license and is copyright {{ site.time | date: "%Y" }} Twitter. Boiled down to smaller chunks, it can be described with the following conditions.</p>
<li>Include the source of Bootstrap itself, or of any modifications you may have made to it, in any redistribution you may assemble that includes it</li>
<pclass="lead">Customizing Bootstrap is best accomplished when you treat it as another dependency in your development stack. Doing so ensures future upgrades are as easy as possible while also familiarizing yourself to the intricacies of the framework.</p>
<p>Once you've downloaded and included Bootstrap's CSS into your templates, you can move on to customizing the included components. To do so, create a new stylesheet (LESS, if you like, or just plain CSS) to house your customizations.</p>
<p>Unless you plan on reading a good chunk of the compiled CSS, go with the minified. It's the same code, just compacted. Less bandwidth is good, especially in production environments.</p>
</div>
<p>From there, include whatever Bootstrap components and HTML content you need to get your template setup. It's best to have a rough idea in mind of modifications to make and content to include, so be sure to spend a brief amount of time on that before moving on.</p>
<p>You can customize components to varying degrees, but most fall into two camps: light customizations and complete visual overhauls. Luckily, plenty examples of both are available.</p>
<p>We define light customizations as mostly surface layer changes, things like a color and font changes to existing Bootstrap components. A great example of this is the the <ahref="http://translate.twitter.com">Twitter Translation Center</a> (coded by @mdo). Let's look at how to implement the custom button we wrote for this site, <code>.btn-ttc</code>.</p>
<p>Instead of using the provided Bootstrap buttons, which only require just one class to start, <code>.btn</code>, we'll add our own modifier class, <code>.btn-ttc</code>. This will give us a slightly custom look with minimal effort.</p>
/* An easy hover state is just to move the gradient up a small amount. Add other embellishments as you see fit. */
.btn-ttc:hover {
background-position: 0 -15px;
}
{% endhighlight %}
<p>Customizing Bootstrap components takes time, but should be straightforward. <strong>Look to the source code often and duplicate the selectors you need for your modifications.</strong> Placing them after the Bootstrap source makes for easy overriding without complication. <strong>To recap, here's the basic workflow:</strong></p>
<ul>
<li>For each element you want to customize, find its code in the compiled Bootstrap CSS. Copy and paste the selector for a component as-is. For instance, to customize the navbar background, just snag <code>.navbar</code>.</li>
<li>Add all your custom CSS in a separate stylesheet using the selectors you just copied from the Bootstrap source. No need for prefacing with additional classes or using <code>!important</code> here.</li>
<li>Rinse and repeat until you're happy with your customizations.</li>
</ul>
<p>Going beyond light customizations and into visual overhauls is just as straightforward as the above custom button. For a site like <ahref="http://yourkarma.com">Karma</a>, which uses Bootstrap as a CSS reset with heavy modifications, more extensive work is involved, but well worth it in the end.</p>
<p>While not recommended for folks new to Bootstrap, you may use one of two alternate methods for customization. The first is modifying the source .less files (making upgrades super difficult), and the second is mapping source LESS code to <ahref="http://ruby.bvision.com/blog/please-stop-embedding-bootstrap-classes-in-your-html">your own classes via mixins</a>. For the time being, neither of those options are documented here.</p>
<p>Not all sites and applications need to make use of everything Bootstrap has to offer, especially in production environments where bandwidth literally becomes a financial issue. We encourage folks to remove whatever is unused with our <ahref="../customize/">Customizer</a>.</p>
<p>Using the Customizer, simply uncheck any component, feature, or asset you don't need. Hit download and swap out the default Bootstrap files with these newly customized ones. You'll get vanilla Bootstrap, but without the features *you* deem unnecessary. All custom builds include compiled and minified versions, so use whichever works for you.</p>
