1、安装Sass

npm install sass -g

2、scss转css

sass demo1.scss demo1.css

3、监视sass

sass --watch demo1.scss:demo1.css

4、取消编译生成的.map文件

sass --watch demo1.scss:demo1.css --no-source-map

5、变量的定义和使用

$variable: value;

/* 定义变量与值 */
$bgcolor: red;
$textcolor: blue;
$fontsize: 18px;

/* 使用变量 */
body {
  background-color: $bgcolor;
  color: $textcolor;
  font-size: $fontsize;
}

6、sass的作用域

$myColor: red;

h1 {
  $myColor: green;   // 只在 h1 里头有用，局部作用域 green
  color: $myColor;
}

p {
  color: $myColor;  // red
}

$myColor: red;

h1 {
  $myColor: green !global;  // 全局作用域 green
  color: $myColor;
}

p {
  color: $myColor;  // green
}

7、sass的嵌套规则和属性

7.1、规则

sass代码

nav {
  ul {
    margin: 0;
    padding: 0;
    list-style: none;
  }
  li {
    display: inline-block;
  }
  a {
    display: block;
    padding: 6px 12px;
    text-decoration: none;
  }
}

css代码

nav ul {
  margin: 0;
  padding: 0;
  list-style: none;
}
nav li {
  display: inline-block;
}
nav a {
  display: block;
  padding: 6px 12px;
  text-decoration: none;
}

7.2、sass 嵌套属性

sass代码

font: {
  family: Helvetica, sans-serif;
  size: 18px;
  weight: bold;
}

text: {
  align: center;
  transform: lowercase;
  overflow: hidden;
}

css代码

font-family: Helvetica, sans-serif;
font-size: 18px;
font-weight: bold;

text-align: center;
text-transform: lowercase;
text-overflow: hidden;

8、sass @mixin与 @include

// 定义混入
@mixin important-text {
  color: red;
  font-size: 25px;
  font-weight: bold;
  border: 1px solid blue;
}

.danger {
  // 使用混入
  @include important-text;
  background-color: green;
}
// 生成css代码
.danger {
  color: red;
  font-size: 25px;
  font-weight: bold;
  border: 1px solid blue;
  background-color: green;
}

混入中也可以包含混入

@mixin special-text {
  @include important-text;
  @include link;
  @include special-border;
}

混入中传递变量

/* 混入接收两个参数 */
@mixin bordered($color, $width) {
  border: $width solid $color;
}

.myArticle {
  @include bordered(blue, 1px);  // 调用混入，并传递两个参数
}

.myNotes {
  @include bordered(red, 2px); // 调用混入，并传递两个参数
}

css代码

.myArticle {
  border: 1px solid blue;
}

.myNotes {
  border: 2px solid red;
}

混入中变量默认值

@mixin sexy-border($color, $width: 1in) {
  border: {
    color: $color;
    width: $width;
    style: dashed;
  }
}
p { @include sexy-border(blue); }
h1 { @include sexy-border(blue, 2in); }

css代码

p {
  border-color: blue;
  border-width: 1in;
  border-style: dashed; }

h1 {
  border-color: blue;
  border-width: 2in;
  border-style: dashed;
}

可变参数

@mixin box-shadow($shadows...) {
      -moz-box-shadow: $shadows;
      -webkit-box-shadow: $shadows;
      box-shadow: $shadows;
}

.shadows {
  @include box-shadow(0px 4px 5px #666, 2px 6px 10px #999);
}

css代码

.shadows {
  -moz-box-shadow: 0px 4px 5px #666, 2px 6px 10px #999;
  -webkit-box-shadow: 0px 4px 5px #666, 2px 6px 10px #999;
  box-shadow: 0px 4px 5px #666, 2px 6px 10px #999;
}

9、sass继承

.button-basic  {
  border: none;
  padding: 15px 30px;
  text-align: center;
  font-size: 16px;
  cursor: pointer;
}

.button-report  {
  @extend .button-basic;
  background-color: red;
}

.button-submit  {
  @extend .button-basic;
  background-color: green;
  color: white;
}

css代码

.button-basic, .button-report, .button-submit {
  border: none;
  padding: 15px 30px;
  text-align: center;
  font-size: 16px;
  cursor: pointer;
}

.button-report  {
  background-color: red;
}

.button-submit  {
  background-color: green;
  color: white;
}

CSDN：https://blog.csdn.net/weixin_45585996/article/details/107252918