table 固定列固定宽度，剩余列给最小宽度

<thead>
              <tr>
                <th rowspan="2" style="width:100px">序号</th>
                <th rowspan="2" style="width:120px">姓名</th>
                <th v-for="date in dates" :key="date.date" style="min-width:80px;">{{date.formatTitle}}
                </th>
              </tr>
              <tr>
                <th v-for="date in dates" :key="date.date">{{date.week}}</th>
              </tr>
            </thead>

效果如下：