id="app">
      <waterfall
        :line="line"
        :line-gap="200"
        :min-line-gap="180"
        :max-line-gap="220"
        :watch="items"
        @reflowed="reflowed"
        ref="waterfall"
      >
        <!-- each component is wrapped by a waterfall slot -->
        <waterfall-slot
          v-for="(item, index) in items"
          :width="item.width"
          :height="item.height"
          :order="index"
          :key="item.index"
          move-class="item-move"
        >
          <div