table 的边框不可见的错误

Question

我不明白为什么第一个 tbody tr 的 td 的边框不可见。

我认为没有理由不可见边框。

我想出来的是这个。

如果 th 的自然高度高于 i 为 th 固定的高度，则第一个 tbody tr 的 td 可见。
如果没有代码th{height: xxpx; }，首先tbody tr的td可见。

.table {
  border-spacing: 0;
  border-collapse: collapse;
}

.table.summary-style
{
    font-size: 11px;

    width: 100%;

    table-layout: fixed;

    text-align: center;

    color: #666;
    border-bottom: 1px solid #666;
    background: #fff;
}

.table.summary-style caption
{
    font-size: 0;
    line-height: 0;

    display: none;
    overflow: hidden;
    clip: rect(1px 1px 1px 1px);
    /* IE6, IE7 */
    clip: rect(1px, 1px, 1px, 1px);

    width: 0;
    height: 0;
    margin: 0;
    padding: 0;

    opacity: 0;
}

.table.summary-style thead th
{
    font-size: 16px;
    line-height: 1;

    position: relative;

    box-sizing: border-box;
    height: 38px;
    padding: 5px 4px;

    text-align: center;
    vertical-align: middle;

    color: #666;
    background: #ddd;
}

.table.summary-style > tbody > tr > td
{
    font-size: 13px;
    line-height: 1.38;

    box-sizing: border-box;
    height: 36px;
    padding: 4px 10px;

    text-align: left;
    vertical-align: middle;

    color: #666;
    border-top: 1px solid #666;
    background: #fff;
}

<table class="table summary-style">
         
         
        <thead>
            <tr>
                <th scope="col">title</th>
                <th scope="col">title</th>
                <th scope="col">title</th>
            </tr>
        </thead>
        <tbody>
            <tr>
                <td colspan="3">No Data.</td>
            </tr>
            <tr>
                <td>content</td>
                <td>content</td>
                <td>content</td>
            </tr>
            <tr>
                <td>content</td>
                <td>content</td>
                <td>content</td>
            </tr>
            <tr>
                <td>content</td>
                <td>content</td>
                <td>content</td>
            </tr>
        </tbody>
    </table>

Answer 1

发生这种情况是因为 .table.summary-style thead th 上的 position: relative; 导致该行元素出现 'above' 其他元素的边界。尽管 box-sizing: border-box; 已被使用，但 table 元素的边界已折叠在一起。解决方案是删除第一行的 position: relative; 或从 .table.

中删除 border-collapse: collapse;

.table {
  border-spacing: 0;
  border-collapse: collapse;
}

.table.summary-style
{
    font-size: 11px;

    width: 100%;

    table-layout: fixed;

    text-align: center;

    color: #666;
    border-bottom: 1px solid #666;
    background: #fff;
}

.table.summary-style caption
{
    font-size: 0;
    line-height: 0;

    display: none;
    overflow: hidden;
    clip: rect(1px 1px 1px 1px);
    /* IE6, IE7 */
    clip: rect(1px, 1px, 1px, 1px);

    width: 0;
    height: 0;
    margin: 0;
    padding: 0;

    opacity: 0;
}

.table.summary-style thead th
{
    font-size: 16px;
    line-height: 1;

    box-sizing: border-box;
    height: 38px;
    padding: 5px 4px;

    text-align: center;
    vertical-align: middle;

    color: #666;
    background: #ddd;
}

.table.summary-style > tbody > tr > td
{
    font-size: 13px;
    line-height: 1.38;

    box-sizing: border-box;
    height: 36px;
    padding: 4px 10px;

    text-align: left;
    vertical-align: middle;

    color: #666;
    border-top: 1px solid #666;
    background: #fff;
}

<table class="table summary-style">
         
         
        <thead>
            <tr>
                <th scope="col">title</th>
                <th scope="col">title</th>
                <th scope="col">title</th>
            </tr>
        </thead>
        <tbody>
            <tr>
                <td colspan="3">No Data.</td>
            </tr>
            <tr>
                <td>content</td>
                <td>content</td>
                <td>content</td>
            </tr>
            <tr>
                <td>content</td>
                <td>content</td>
                <td>content</td>
            </tr>
            <tr>
                <td>content</td>
                <td>content</td>
                <td>content</td>
            </tr>
        </tbody>
    </table>

Answer 2

尝试：

table,
td,
th {
  border-collapse: collapse;
  padding: 0.5em 1em;
  border: 2px solid black;
}

.table.summary-style {
  font-size: 11px;
  width: 100%;
  table-layout: fixed;
  text-align: center;
  color: #666;
  border-bottom: 1px solid #666;
  background: #fff;
}

.table.summary-style caption {
  font-size: 0;
  line-height: 0;
  display: none;
  overflow: hidden;
  clip: rect(1px 1px 1px 1px);
  /* IE6, IE7 */
  clip: rect(1px, 1px, 1px, 1px);
  width: 0;
  height: 0;
  margin: 0;
  padding: 0;
  opacity: 0;
}

.table.summary-style thead th {
  font-size: 16px;
  line-height: 1;
  position: relative;
  box-sizing: border-box;
  height: 38px;
  padding: 5px 4px;
  text-align: center;
  vertical-align: middle;
  color: #666;
  background: #ddd;
}

.table.summary-style>tbody>tr>td {
  font-size: 13px;
  line-height: 1.38;
  box-sizing: border-box;
  height: 36px;
  padding: 4px 10px;
  text-align: left;
  vertical-align: middle;
  color: #666;
  border-top: 1px solid #666;
  background: #fff;
}

<table class="table summary-style">
        <thead>
            <tr>
                <th scope="col">title</th>
                <th scope="col">title</th>
                <th scope="col">title</th>
            </tr>
        </thead>
        <tbody>
            <tr>
                <td colspan="3">No Data.</td>
            </tr>
            <tr>
                <td>content</td>
                <td>content</td>
                <td>content</td>
            </tr>
            <tr>
                <td>content</td>
                <td>content</td>
                <td>content</td>
            </tr>
            <tr>
                <td>content</td>
                <td>content</td>
                <td>content</td>
            </tr>
        </tbody>
    </table>

table 的边框不可见的错误

bug where the border of the table is not visible

css

html-table

border