常用布局 @mixin

@mixin center-block() {
  display: block;
  margin-left: auto;
  margin-right: auto;
}

@mixin row($parent-selector, $item-selector, $font-size: 12px, $vertical-align: top) {
  #{$parent-selector} {
    font-size: 0;// 防止子元素的空白元素占据空间
  }
  #{$item-selector} {
    display: inline-block;
    vertical-align: $vertical-align;// 防止子元素高度不同导致的奇怪的对齐
    font-size: $font-size;
  }
}

@mixin row() {
  display: flex;
}

@mixin center-blocks($parent-selector, $item-selector, $font-size: 12px, $vertical-align: top) {
  @include row($parent-selector, $item-selector, $font-size: 12px, $vertical-align: top);
  #{$parent-selector} {
    text-align: center;
  }
}

@mixin center-blocks($parent-selector) {
  #{$parent-selector} {
    @include row;
    justify-content: center;
  }
}

@mixin justify-blocks($parent-selector, $item-selector, $font-size: 12px, $vertical-align: top) {
  @include row($parent-selector, $item-selector, $font-size: 12px, $vertical-align: top);
  #{$parent-selector} {
    text-align: justify;
    &:after {
      content: '';
      display: inline-block;
      width: 100%;
    }
  }
}

@mixin justify-blocks($parent-selector) {
  #{$parent-selector} {
    @include row;
    justify-content: space-between;
  }
}

@mixin item-fill($parent-selector, $item-selector, $fill-item-selector, $vertical-align: top) {
  #{$parent-selector} {
    display: table; // 兼容性相当好。IE8+ 都支持 http://caniuse.com/#feat=css-table
  }
  #{$item-selector} {
    display: table-cell; // 兼容性相当好。IE8+ 都支持 http://caniuse.com/#feat=css-table
    vertical-align: $vertical-align;
  }
  #{$fill-item-selector} {
    width: 100%;
  }
}

@mixin item-fill($parent-selector,  $fill-item-selector) {
  #{$parent-selector} {
    @include row;
  }
  #{$fill-item-selector} {
    -webkit-flex-grow: 1;
    flex-grow: 1;
  }
}