导言
CSS不是一门真正意义上的编程语言,很多编程语言理所当然的特性(比如变量),都不被支持。同时再开发模块化的web项目的时候,也要避免相互干扰。为了弥补CSS的这些不足,就产生了CSS预处理器,Sass则是其中的佼佼者。
什么是Sass
Sass是最成熟、稳定、强大、专业的CSS扩展语言(官方解释)。直白点,Sass就是一个非常好用的CSS预处理器,为css引入部分编程语言的特性。
Sass在现阶段,有两种编码的语法,一个是兼容CSS语法的Scss格式文件,一个是Haml、Ruby类似语法的Sass格式文件。一般情况下,我们选用第一种兼容Css语法的Scss文件格式
什么是Compass
Compass是基于Sass的一个css创作框架,其实就是基于Sass提供了很多非常实用的函数,有点类库的概念。
如何安装
Sass是基于Ruby写的,安装Sass需要先安装Ruby:https://www.ruby-lang.org/zh_cn/downloads/。
在Windows上安装Ruby,需要借助RubyInstall工具:http://rubyinstaller.org/
安装好Ruby只有,可以使用cmd:ruby -v 查看ruby的版本,如果有输出,表示ruby安装成功。这个时候,则可以使用ruby gem sass
来安装Sass,ruby gem compass
来安装Compass。
注意事项:由于gem仓库被墙了,如果想使用的话,需要切换镜像地址,国内可以采用淘宝的ruby镜像:http://ruby.taobao.org
。可以通过如下命令实现:
//移除官方gems
gem sources --remove https://rubygems.org/
//添加淘宝的gems
gem sources -a https://ruby.taobao.org/
//查看现有的gems
gem sources -l
命令行
//编译Sass
sass <sass file> <css file>
//Sass与Scss相互转换
sass-convert <.sass file> <.scss file>
sass-convert <.scss file> <.sass file>
//监视Sass文件变更,自动编译(可选输出css的风格,参数为style)
sass --watch <sass file>:<css file> [--style [nested|expanded|compact|compressed]]
//监视文件夹中Sass文件变更,自动编译
sass --watch <sass folder>:<ouput css folder>
//----------------------Compass--------------
//创建Sass工程
compass create
//编译sass文件
compass compile
//监视Sass工程下sass文件变更(可选输出css的风格,参数为output-style)
compass --watch [--output-style [nested|expaned|compact|compressed]]
*:first-child {
margin-top: 0 !important;
}
body>*:last-child {
margin-bottom: 0 !important;
}
/* BLOCKS
=============================================================================*/
p, blockquote, ul, ol, dl, table, pre {
margin: 15px 0;
}
/* HEADERS
=============================================================================*/
h1, h2, h3, h4, h5, h6 {
margin: 20px 0 10px;
padding: 0;
font-weight: bold;
-webkit-font-smoothing: antialiased;
}
h1 tt, h1 code, h2 tt, h2 code, h3 tt, h3 code, h4 tt, h4 code, h5 tt, h5 code, h6 tt, h6 code {
font-size: inherit;
}
h1 {
font-size: 28px;
color: #000;
}
h2 {
font-size: 24px;
border-bottom: 1px solid #ccc;
color: #000;
}
h3 {
font-size: 18px;
}
h4 {
font-size: 16px;
}
h5 {
font-size: 14px;
}
h6 {
color: #777;
font-size: 14px;
}
body>h2:first-child, body>h1:first-child, body>h1:first-child+h2, body>h3:first-child, body>h4:first-child, body>h5:first-child, body>h6:first-child {
margin-top: 0;
padding-top: 0;
}
a:first-child h1, a:first-child h2, a:first-child h3, a:first-child h4, a:first-child h5, a:first-child h6 {
margin-top: 0;
padding-top: 0;
}
h1+p, h2+p, h3+p, h4+p, h5+p, h6+p {
margin-top: 10px;
}
/* LINKS
=============================================================================*/
a {
color: #4183C4;
text-decoration: none;
}
a:hover {
text-decoration: underline;
}
/* LISTS
=============================================================================*/
ul, ol {
padding-left: 30px;
}
ul li > :first-child,
ol li > :first-child,
ul li ul:first-of-type,
ol li ol:first-of-type,
ul li ol:first-of-type,
ol li ul:first-of-type {
margin-top: 0px;
}
ul ul, ul ol, ol ol, ol ul {
margin-bottom: 0;
}
dl {
padding: 0;
}
dl dt {
font-size: 14px;
font-weight: bold;
font-style: italic;
padding: 0;
margin: 15px 0 5px;
}
dl dt:first-child {
padding: 0;
}
dl dt>:first-child {
margin-top: 0px;
}
dl dt>:last-child {
margin-bottom: 0px;
}
dl dd {
margin: 0 0 15px;
padding: 0 15px;
}
dl dd>:first-child {
margin-top: 0px;
}
dl dd>:last-child {
margin-bottom: 0px;
}
/* CODE
=============================================================================*/
pre, code, tt {
font-size: 12px;
font-family: Consolas, "Liberation Mono", Courier, monospace;
}
code, tt {
margin: 0 0px;
padding: 0px 0px;
white-space: nowrap;
border: 1px solid #eaeaea;
background-color: #f8f8f8;
border-radius: 3px;
}
pre>code {
margin: 0;
padding: 0;
white-space: pre;
border: none;
background: transparent;
}
pre {
background-color: #f8f8f8;
border: 1px solid #ccc;
font-size: 13px;
line-height: 19px;
overflow: auto;
padding: 6px 10px;
border-radius: 3px;
}
pre code, pre tt {
background-color: transparent;
border: none;
}
kbd {
-moz-border-bottom-colors: none;
-moz-border-left-colors: none;
-moz-border-right-colors: none;
-moz-border-top-colors: none;
background-color: #DDDDDD;
background-image: linear-gradient(#F1F1F1, #DDDDDD);
background-repeat: repeat-x;
border-color: #DDDDDD #CCCCCC #CCCCCC #DDDDDD;
border-image: none;
border-radius: 2px 2px 2px 2px;
border-style: solid;
border-width: 1px;
font-family: "Helvetica Neue",Helvetica,Arial,sans-serif;
line-height: 10px;
padding: 1px 4px;
}
/* QUOTES
=============================================================================*/
blockquote {
border-left: 4px solid #DDD;
padding: 0 15px;
color: #777;
}
blockquote>:first-child {
margin-top: 0px;
}
blockquote>:last-child {
margin-bottom: 0px;
}
/* HORIZONTAL RULES
=============================================================================*/
hr {
clear: both;
margin: 15px 0;
height: 0px;
overflow: hidden;
border: none;
background: transparent;
border-bottom: 4px solid #ddd;
padding: 0;
}
/* IMAGES
=============================================================================*/
img {
max-width: 100%
}
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