利用vue-waterfall做瀑布流的问题？

Question

我用vue-waterfall做瀑布流布局，希望两列布局，两列都紧靠屏幕两边，中间留出空白。上代码：    <waterfall :line-gap='screenW'>      <!-- each component is wrapped by a waterfall slot -->      <waterfall-slot        v-for="(video, index) in videoList"        class='items'        :width='screenW'        :height='video.height * screenW / video.width + 40'        :order='index'        :key='video.auid'      >        <img :src='video.coverurl' alt="">        <div class='user-info-box'>          <img class='userlogo' :src='video.logourl' alt="">          <span class='userName'>{{ video.username }}</span>        </div>      </waterfall-slot>    </waterfall>        data () {        return {          screenW: window.screen.width * 0.49        }    }        这样做出来是两列紧靠在一起，居左，屏幕右边留白了    然后我给index%2===0的加了marginLeft希望把右边的顶过去，才想起来在左边的index不一定是奇数，请问大神我应该咋办