怎么實現表格中的標題居中
<!DOCTYPE?html>
<html>
<head>
????<meta?charset="UTF-8">
????<title>學習表格標簽</title>
????<style>
????????caption{
???????????text-align:?center;?
????????}
????</style>
</head>
<body>
????<caption>前端三劍客</caption>
????<table?border="1">
????????<tr>
????????????<td>知識點</td>
????????????<td>重要程度</td>
????????????<td>難度</td>
????????????<td>學習周期</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>
2021-03-24
將第一個的<tr></tr>中的所有<td></td>改為<th></th>
2021-03-17
<style>????????caption{???????????text-align:?center;?????????}????</style>