怎么实现表格中的标题居中
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>学习表格标签</title>
<style>
caption{
text-align: center;
}
</style>
</head>
<body>
<caption>前端三剑客</caption>
<table border="1">
<tr>
<td>知识点</td>
<td>重要程度</td>
<td>难度</td>
<td>学习周期</td>
</tr>
<tr>
<td>html</td>
<td>5星</td>
<td>3星</td>
<td>7天</td>
</tr>
<tr>
<td>css</td>
<td>5星</td>
<td>4星</td>
<td>10天</td>
</tr>
<tr>
<td>js</td>
<td>5星</td>
<td>5星</td>
<td>20天</td>
</tr>
</table>
</body>
</html>
