$green = #02a774;
$yellow = #F5A100;
$bc = #e4e4e4;

// 一像素下边框
bottom-border-1px($color)
  position relative
  border none
  &:after
    content ''
    position absolute
    left 0
    bottom 0
    width 100%
    height 1px
    background-color $color
    transform scaleY(0.5)

// 一像素上边框
top-border-1px($color)
  position relative
  &::before
    content ''
    position absolute
    z-index 200
    left 0
    top 0
    width 100%
    height 1px
    background-color $color

//根据像素比缩放1px像素边框
@media only screen and (-webkit-device-pixel-ratio: 2 )
  .border-1px
    &::before
      transform scaleY(.5)

@media only screen and (-webkit-device-pixel-ratio: 3 )
  .border-1px
    &::before
      transform scaleY(.333333)

//根据像素比来使用 2x图 3x图
bg-image($url)
  background-image: url($url + "@2x.png")
  @media (-webkit-min-device-pixel-ratio: 3),(min-device-pixel-ratio: 3)
    background-image: url($url + "@3x.png")

//清除浮动
clearFix()
  *zoom 1
  &::after
    content ''
    display block
    clear both

.bottom_tips
  margin-bottom 20px
  height 1px
  border-top 1px solid #ddd
  text-align center
  span
    position relative
    top -8px
    background #f5f5f5
    padding 0 20px
    color #b5b5b5

