效果示意图：
模板代码：
[code]<div style="width: 80%; overflow-x: scroll; overflow-y: scroll">
<div style="margin-top: 5px; height: 500px">
<table class="header-table">
<thead>
<tr>
<th style="width: 10% !important">任务</th>
<th style="width: 10% !important">状态</th>
<th style="width: 8% !important">负责人</th>
<th style="width: 7% !important">开始日期</th>
<th style="width: 7% !important">结束日期</th>
<th style="width: 12% !important">任务资料</th>
<th style="width: 10% !important">备注</th>
<th style="width: 12% !important">交付文件</th>
<th style="width: 24% !important">操作</th>
</tr>
</thead>
</table>
<a-collapse
v-model:activeKey="activeKey"
style="background: #f0f0f0; border-radius: 0 !important"
:bordered="false"
>
<a-collapse-panel
v-for="(panel, index) in leftPage"
:key="index"
:header="panel.stageName"
:show-arrow="true"
style="padding: 0; margin: 0"
>
<table
class="expanded-table"
style="table-layout: fixed; width: 100%"
>
<tbody>
<tr
v-for="(item, itemIndex) in panel.tasks"
:key="item.id"
style="background-color: #ffffff"
>
<td style="width: 10% !important">
<a-tooltip placement="topLeft">
<template #title>{{ item.name }}</template>
{{ item.name }}
<span v-if="item.isMilestone"> |
