简单版

@for $i from 1 through 6 {
  &:nth-of-type(#{$i}) img {
    transition-delay: calc(0.1 *#{$i}s);//逐次延时效果
  }
}

进阶版

@for $i from 1 through length($数组) {
  $color: nth($数组, $i);
  &:nth-of-type(#{$i}) {
    color: $color;//通常用于序列颜色显示效果
    &:hover {
      color: white;
    }
  }
}

混合版

$bg-color: "blue", "lightBlue", "green", "orange", "yellow", "purple", "pink", "red", "lightRed";
$bgColors: $blue, $lightBlue, $green, $orange, $yellow, $purple, $pink, $red, $lightRed;
@for $i from 1 through length($bg-color) {
//通过颜色属性定位不同节点，制定进行颜色样式设置
  &[bg-color="#{nth($bg-color, $i)}"] {
    color: white;
    background-color: nth($bgColors, $i);
    background-image: url("static/img/v-html/bg/#{nth($bg-color, $i)}.jpg");
  }
}

复杂序列逐帧动画

<style lang='scss' scoped>
.sg-body {
  animation: sg-animate 2s infinite alternate; //在两秒内完成序列png动画图片来回播放，并循环无限次

  $bgPreUrl: "http://www.shuzhiqiang.com/img/bg_"; //序列图路径前缀
  @keyframes sg-animate {
    $len: 75; //逐帧动画画面*75张图
    @for $i from 0 through $len {
      #{ $i * 1% } {
        background-image: url(#{$bgPreUrl}#{$i}.png);
      }
    }
    // 序列图播放完毕那一刻到100%时间（第2s结束那一刻）之间都停留在最后一张序列图静止不动
    #{ $len * 1% },
    100% {
      background-image: url(#{$bgPreUrl}#{$len}.png);
    }
  }
}
</style>

编译后的CSS代码如图

……