<pclass="lead">Customize and extend Bootstrap with <ahref="http://lesscss.org"target="_blank">LESS</a>, a CSS preprocessor, to take advantage of the variables, mixins, and more used to build Bootstrap's CSS.</p>
<p>Bootstrap is made with LESS at it's core, a dynamic stylesheet language created by <ahref="http://cloudhead.io">Alexis Sellier</a>. It makes developing systems-based CSS faster, easier, and more fun.</p>
<p>As an extension of CSS, LESS includes variables, mixins for reusable snippets of code, operations for simple math, nesting, and even color functions.</p>
<p>Managing colors and pixel values in CSS can be a bit of a pain, usually full of copy and paste. Not with LESS though—assign colors or pixel values as variables and change them once.</p>
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<h3>Mixins</h3>
<p>Those three border-radius declarations you need to make in regular ol' CSS? Now they're down to one line with the help of mixins, snippets of code you can reuse anywhere.</p>
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<h3>Operations</h3>
<p>Make your grid, leading, and more super flexible by doing the math on the fly with operations. Multiple, divide, add, and subtract your way to CSS sanity.</p>
<h1>Using Bootstrap with Less <small>Supercharge your CSS with variables, mixins, and functions</small></h1>
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<p>Bootstrap was built with <ahref="http://markdotto.com/bootstrap/">Preboot</a>, an open-source pack of mixins and variables to be used in conjunction with <ahref="http://lesscss.org"target="_blank">Less</a>, a CSS preprocessor for faster and easier web development.</p>
<p>Check out how we used Preboot in Bootstrap and how you can make use of it should you choose to run Less on your next project.</p>
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<h2>How to use it</h2>
<p>Use this option to make full use of Bootstrap’s Less variables, mixins, and nesting in CSS via javascript in your browser.</p>
<p>Not feeling the .js solution? <ahref="http://incident57.com/less"target="_blank">Try the Less Mac app</a> or <ahref="http://lesscss.org/#-client-side-usage"target="_blank">use Node.js</a> to compile when you deploy your code.</p>
<h2>What’s included</h2>
<p>Here are some of the highlights of what’s included in Twitter Bootstrap as part of Bootstrap. Head over to the Bootstrap website or Github project page to download and learn more.</p>
<h3>Variables</h3>
<p>Variables in Less are perfect for maintaining and updating your CSS headache free. When you want to change a color value or a frequently used value, update it in one spot and you’re set.</p>
<preclass="prettyprint linenums">
// Links
@linkColor: #8b59c2;
@linkColorHover: darken(@linkColor, 10);
// Grays
@black: #000;
@grayDark: lighten(@black, 25%);
@gray: lighten(@black, 50%);
@grayLight: lighten(@black, 70%);
@grayLighter: lighten(@black, 90%);
@white: #fff;
// Accent Colors
@blue: #08b5fb;
@green: #46a546;
@red: #9d261d;
@yellow: #ffc40d;
@orange: #f89406;
@pink: #c3325f;
@purple: #7a43b6;
// Baseline grid
@basefont: 13px;
@baseline: 18px;
</pre>
<h3>Commenting</h3>
<p>Less also provides another style of commenting in addition to CSS’s normal <code>/* ... */</code> syntax.</p>
<preclass="prettyprint linenums">
// This is a comment
/* This is also a comment */
</pre>
<h3>Mixins up the wazoo</h3>
<p>Mixins are basically includes or partials for CSS, allowing you to combine a block of code into one. They’re great for vendor prefixed properties like <code>box-shadow</code>, cross-browser gradients, font stacks, and more. Below is a sample of the mixins that are included with Bootstrap.</p>
<p>After modifying the <code>.less</code> files in /lib/, you'll need to recompile them in order to regenerate the bootstrap-*.*.*.css and bootstrap-*.*.*.min.css files. If you're submitting a pull request to GitHub, you must always recompile.</p>
<p>Install the less command line compiler with npm by running the following command:</p>
<pre>$ npm install lessc</pre>
<p>Once installed just run <code>make</code> from the root of your bootstrap directory and you're all set.</p>
<p>Additionally, if you have <ahref="https://github.com/mynyml/watchr">watchr</a> installed, you may run <code>make watch</code> to have bootstrap automatically rebuilt every time you edit a file in the bootstrap lib (this isn't required, just a convenience method).</p>
<p><ahref="http://incident57.com/less/">The unofficial Mac app</a> watches directories of .less files and compiles the code to local files after every save of a watched .less file.</p>
<p>If you like, you can toggle preferences in the app for automatic minifying and which directory the compiled files end up in.</p>
<td>Mac, Linux, and PC app for drag and drop compiling of LESS files. Plus, the <ahref="https://github.com/Paratron/SimpLESS"target="_blank">source code is on GitHub</a>.</td>
<p>Designed and built with all the love in the world <ahref="http://twitter.com/twitter"target="_blank">@twitter</a> by <ahref="http://twitter.com/mdo"target="_blank">@mdo</a> and <ahref="http://twitter.com/fat"target="_blank">@fat</a>.</p>
<p>Code licensed under the <ahref="http://www.apache.org/licenses/LICENSE-2.0"target="_blank">Apache License v2.0</a>. Documentation licensed under <ahref="http://creativecommons.org/licenses/by/3.0/">CC BY 3.0</a>.</p>
<p>Icons from <ahref="http://glyphicons.com">Glyphicons Free</a>, licensed under <ahref="http://creativecommons.org/licenses/by/3.0/">CC BY 3.0</a>.</p>
