为表格添加边框
<!DOCTYPE html>
<html>
<head>
<style>
table, th, td {
border: 1px solid black;
}
</style>
</head>
<body>
<h1>为表格添加边框：</h1>
<table>
<tr>
<th>Firstname</th>
<th>Lastname</th>
</tr>
<tr>
<td>Bill</td>
<td>Gates</td>
</tr>
<tr>
<td>Steve</td>
<td>Jobs</td>
</tr>
</table>
</body>
</html>
规定表格的width和height属性
<!DOCTYPE html>
<html>
<head>
<style>
table, td, th {
border: 1px solid black;
}
table {
border-collapse: collapse;
width: 100%;
}
th {
height: 30px;
}
</style>
</head>
<body>
<h1>width 和 height 属性</h1>
<p>设置表格的宽度，以及表格标题行的高度：</p>
<table>
<tr>
<th>Firstname</th>
<th>Lastname</th>
<th>Savings</th>
</tr>
<tr>
<td>Bill</td>
<td>Gates</td>
<td>$100</td>
</tr>
<tr>
<td>Steve</td>
<td>Jobs</td>
<td>$150</td>
</tr>
<tr>
<td>Elon</td>
<td>Musk</td>
<td>$300</td>
</tr>
<tr>
<td>Mark</td>
<td>Zuckerberg</td>
<td>$250</td>
</tr>
</table>
</body>
</html>