i-card 没有样式

[Cloudzp]

以下是我的代码 index.json

{
  "usingComponents": {
    "i-card":"../../dist/card/index",
    "i-panel": "../../dist/panel/index",
    "i-row": "../../dist/row/index",
    "i-col": "../../dist/col/index",
    "i-tab-bar": "../../dist/tab-bar/index",
    "i-tab-bar-item": "../../dist/tab-bar-item/index"
  }
}

index.wxml

<i-card title="卡片标题" extra="额外内容" thumb="https://i.loli.net/2017/08/21/599a521472424.jpg">
  <view slot="content">内容不错</view>
  <view slot="footer">尾部内容</view>
</i-card>

项目目录结构：

[Cloudzp]

dist是用的master分支的代码！