在Bootstrap中使用LESS

使用 LESS 定制与扩展Bootstrap，一个 CSS 预处理器，利用变量， mixins 的优势来创建 Bootstrap 的CSS。

为什么选择 LESS?

Bootstrap is made with LESS at its core, a dynamic stylesheet language created by our good friend, Alexis Sellier. It makes developing systems-based CSS faster, easier, and more fun.

都包含什么?

As an extension of CSS, LESS includes variables, mixins for reusable snippets of code, operations for simple math, nesting, and even color functions.

变量

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.

Mixins

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.

操作

Make your grid, leading, and more super flexible by doing the math on the fly with operations. Multiply, divide, add, and subtract your way to CSS sanity.

超链接

`@linkColor`	#08c	Default link text color
`@linkColorHover`	`darken(@linkColor, 15%)`	Default link text hover color

网格系统

`@gridColumns`	12
`@gridColumnWidth`	60px
`@gridGutterWidth`	20px
`@fluidGridColumnWidth`	6.382978723%
`@fluidGridGutterWidth`	2.127659574%

文字排版

`@baseFontSize`	13px
`@baseFontFamily`	`"Helvetica Neue", Helvetica, Arial, sans-serif`
`@baseLineHeight`	18px

灰度颜色

`@black`	#000
`@grayDarker`	#222
`@grayDark`	#333
`@gray`	#555
`@grayLight`	#999
`@grayLighter`	#eee
`@white`	#fff

Accent colors

`@blue`	#049cdb
`@green`	#46a546
`@red`	#9d261d
`@yellow`	#ffc40d
`@orange`	#f89406
`@pink`	#c3325f
`@purple`	#7a43b6

组件

按钮

`@primaryButtonBackground`	`@linkColor`

表单

`@placeholderText`	`@grayLight`

导航栏

`@navbarHeight`	40px
`@navbarBackground`	`@grayDarker`
`@navbarBackgroundHighlight`	`@grayDark`
`@navbarText`	`@grayLight`
`@navbarLinkColor`	`@grayLight`
`@navbarLinkColorHover`	`@white`

表单状态与警告

`@warningText`	#c09853
`@warningBackground`	#f3edd2
`@errorText`	#b94a48
`@errorBackground`	#f2dede
`@successText`	#468847
`@successBackground`	#dff0d8
`@infoText`	#3a87ad
`@infoBackground`	#d9edf7

关于 mixins

mixins 基础

A basic mixin is essentially an include or a partial for a snippet of CSS. They're written just like a CSS class and can be called anywhere.

.element {
  .clearfix();
}

mixins 参数

A parametric mixin is just like a basic mixin, but it also accepts parameters (hence the name) with optional default values.

.element {
  .border-radius(4px);
}

很容易添加你自己的

Nearly all of Bootstrap's mixins are stored in mixins.less, a wonderful utility .less file that enables you to use a mixin in any of the .less files in the toolkit.

So, go ahead and use the existing ones or feel free to add your own as you need.

包含的 mixins

Utilities

Mixin	参数	用途
`.clearfix()`	none	Add to any parent to clear floats within
`.tab-focus()`	none	Apply the Webkit focus style and round Firefox outline
`.center-block()`	none	Auto center a block-level element using `margin: auto`
`.ie7-inline-block()`	none	Use in addition to regular `display: inline-block` to get IE7 support
`.size()`	`@height: 5px, @width: 5px`	Quickly set the height and width on one line
`.square()`	`@size: 5px`	Builds on `.size()` to set the width and height as same value
`.opacity()`	`@opacity: 100`	Set, in whole numbers, the opacity percentage (e.g., "50" or "75")

表单

Mixin	参数	用途
`.placeholder()`	`@color: @placeholderText`	Set the `placeholder` text color for inputs

文字排版

Mixin	参数	用途
`#font > #family > .serif()`	none	Make an element use a serif font stack
`#font > #family > .sans-serif()`	none	Make an element use a sans-serif font stack
`#font > #family > .monospace()`	none	Make an element use a monospace font stack
`#font > .shorthand()`	`@size: @baseFontSize, @weight: normal, @lineHeight: @baseLineHeight`	Easily set font size, weight, and leading
`#font > .serif()`	`@size: @baseFontSize, @weight: normal, @lineHeight: @baseLineHeight`	Set font family to serif, and control size, weight, and leading
`#font > .sans-serif()`	`@size: @baseFontSize, @weight: normal, @lineHeight: @baseLineHeight`	Set font family to sans-serif, and control size, weight, and leading
`#font > .monospace()`	`@size: @baseFontSize, @weight: normal, @lineHeight: @baseLineHeight`	Set font family to monospace, and control size, weight, and leading

网格系统

Mixin	参数	用途
`.container-fixed()`	none	Create a horizontally centered container for holding your content
`#grid > .core()`	`@gridColumnWidth, @gridGutterWidth`	Generate a pixel grid system (container, row, and columns) with n columns and x pixel wide gutter
`#grid > .fluid()`	`@fluidGridColumnWidth, @fluidGridGutterWidth`	Generate a precent grid system with n columns and x % wide gutter

CSS3 属性

Mixin	参数	用途
`.border-radius()`	`@radius: 5px`	Round the corners of an element. Can be a single value or four space-separated values
`.box-shadow()`	`@shadow: 0 1px 3px rgba(0,0,0,.25)`	Add a drop shadow to an element
`.transition()`	`@transition`	Add CSS3 transition effect (e.g., `all .2s linear`)
`.rotate()`	`@degrees`	Rotate an element n degrees
`.scale()`	`@ratio`	Scale an element to n times its original size
`.translate()`	`@x: 0, @y: 0`	Move an element on the x and y planes
`.background-clip()`	`@clip`	Crop the background of an element (useful for `border-radius`)
`.background-size()`	`@size`	Control the size of background images via CSS3
`.box-sizing()`	`@boxmodel`	Change the box model for an element (e.g., `border-box` for a full-width `input`)
`.user-select()`	`@select`	Control cursor selection of text on a page
`.resizable()`	`@direction: both`	Make any element resizable on the right and bottom
`.content-columns()`	`@columnCount, @columnGap: @gridColumnGutter`	Make the content of any element use CSS3 columns

背景与渐变

Mixin	参数	用途
`#translucent > .background()`	`@color: @white, @alpha: 1`	Give an element a translucent background color
`#translucent > .border()`	`@color: @white, @alpha: 1`	Give an element a translucent border color
`#gradient > .vertical()`	`@startColor, @endColor`	Create a cross-browser vertical background gradient
`#gradient > .horizontal()`	`@startColor, @endColor`	Create a cross-browser horizontal background gradient
`#gradient > .directional()`	`@startColor, @endColor, @deg`	Create a cross-browser directional background gradient
`#gradient > .vertical-three-colors()`	`@startColor, @midColor, @colorStop, @endColor`	Create a cross-browser three-color background gradient
`#gradient > .radial()`	`@innerColor, @outerColor`	Create a cross-browser radial background gradient
`#gradient > .striped()`	`@color, @angle`	Create a cross-browser striped background gradient
`#gradientBar()`	`@primaryColor, @secondaryColor`	Used for buttons to assign a gradient and slightly darker border

Note: If you're submitting a pull request to GitHub with modified CSS, you must recompile the CSS via any of these methods.

编译使用的工具

Node with makefile

Install the LESS command line compiler and uglify-js globally with npm by running the following command:

$ npm install -g less uglify-js

Once installed just run make from the root of your bootstrap directory and you're all set.

Additionally, if you have watchr installed, you may run make watch to have bootstrap automatically rebuilt every time you edit a file in the bootstrap lib (this isn't required, just a convenience method).

命令行

Install the LESS command line tool via Node and run the following command:

$ lessc ./lib/bootstrap.less > bootstrap.css

Be sure to include --compress in that command if you're trying to save some bytes!

Javascript

Download the latest Less.js and include the path to it (and Bootstrap) in the <head>.

<link rel="stylesheet/less" href="/path/to/bootstrap.less">
<script src="/path/to/less.js"></script>

To recompile the .less files, just save them and reload your page. Less.js compiles them and stores them in local storage.

非官方 Mac app

The unofficial Mac app watches directories of .less files and compiles the code to local files after every save of a watched .less file.

If you like, you can toggle preferences in the app for automatic minifying and which directory the compiled files end up in.

Built with LESS

为什么选择 LESS?

都包含什么?

阅读更多

变量

Mixins

操作

Bootstrap 变量 LESS 变量，他们的变量与使用指南

超链接

网格系统

文字排版

灰度颜色

Accent colors

组件

按钮

表单

导航栏

表单状态与警告

Bootstrap mixins

关于 mixins

mixins 基础

mixins 参数

很容易添加你自己的

包含的 mixins

Utilities

表单

文字排版

网格系统

CSS3 属性

背景与渐变

使用LESS编译 Bootstrap

编译使用的工具

Node with makefile

命令行

Javascript

非官方 Mac app

更多 Mac apps

Crunch

CodeKit

Simpless