checkbox内容过长自动换行

<el-checkbox-group v-model="checkedBox">
     <el-checkbox>
        <span class="checkbox_content">
            aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
        </span>
      </el-checkbox>
</el-checkbox-group>
<style>
.checkbox_content {
    width: 99%;
    display: inline-grid;
    white-space: pre-line;
    word-wrap: break-word;
    overflow: hidden;
    line-height: 20px;
  }
</style>