caption中的“前端三剑客”怎么居中？
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>学习表格标签</title>
</head>
<body>
<h3 >前端三剑客</h3>
<table border="1" style="text-align:center">
<captiom>前端三剑客</caption>
<tr>
<th>知识点</th>
<th>重要程度</th>
<th>难度</th>
<th>学习周期</th>
</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>
