/*常用*/
$family: unquote("Droid+Sans");
@import url("http://fonts.googleapis.com/css?family=#{$family}");
$family: unquote("Droid+Sans+2");
@import url("http://fonts.googleapis.com/css?family=#{$family}");

/*mixin 这里就好像一个组件，给个param让组件赋予样式*/
@mixin firefox-message($selector) {
  body.firefox #{$selector}:before {
    content: "Hi, Firefox users!";
  }
}
@include firefox-message(".header");

/*在p 里设置变量*/
p {
  $font-size: 12px;
  $line-height: 30px;
  font: #{$font-size}/#{$line-height};
}

/*表达式*/
p:before {
  content: "I ate #{5 + 10} pies!";
}

/*這裏可以有包*/
.example {
  color: red;
}
#main {
  @import "example";
}

/*不用刻意把media寫在外面，media 會去外面*/
.sidebar {
  width: 300px;
  @media screen and (orientation: landscape) {
    width: 500px;
  }
}

/*extend 像是組合*/
.error {
  border: 1px #f00;
  background-color: #fdd;
}
.seriousError {
  @extend .error;
  border-width: 3px;
}

/*這不好理解*/
.hoverlink {
  @extend a:hover;
}
.comment a.user:hover {
  font-weight: bold;
}

/*@if， @else if */
$type: monster;
p {
  @if $type == ocean {
    color: blue;
  } @else if $type == matador {
    color: red;
  } @else if $type == monster {
    color: green;
  } @else {
    color: black;
  }
}

/*@for*/
@for $i from 1 through 3 {
  .item-#{$i} { width: 2em * $i; }
}

/*@each*/
@each $animal in puma, sea-slug, egret, salamander {
  .#{$animal}-icon {
    background-image: url(‘/images/#{$animal}.png‘);
  }
}

/*@while*/
$i: 6;
@while $i > 0 {
  .item-#{$i} { width: 2em * $i; }
  $i: $i - 2;
}

/*@mixin pass param， defaut value is 1px*/
@mixin sexy-border($color, $width: 1px) {
  border: {
    color: $color;
    width: $width;
    style: dashed;
  }
}
p { @include sexy-border(blue, 2px); }

/*... like ECMA*/
@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);
}

/*2nd example*/
@mixin colors($text, $background, $border) {
  color: $text;
  background-color: $background;
  border-color: $border;
}
$values: #ff0000, #00ff00, #0000ff;
.primary {
  @include colors($values...);
}

/*function & return */
$grid-width: 40px;
$gutter-width: 10px;

@function grid-width($n) {
  @return $n * $grid-width + ($n - 1) * $gutter-width;
}

#sidebar { width: grid-width(5); }