如果在表的内容中控制空格之间的边框，应使用td和th元素的填充属性 - 在线编辑器

<!DOCTYPE html>
<html>
<head>
  <meta charset="utf-8">
  <style>
    table,
    td,
    th {
      border: 1px solid black;
    }

    td {
      padding: 15px;
    }
  </style>
</head>

<body>
  <table>
    <tr>
      <th>Firstname</th>
      <th>Lastname</th>
      <th>Savings</th>
    </tr>
    <tr>
      <td>Peter</td>
      <td>Griffin</td>
      <td>$100</td>
    </tr>
    <tr>
      <td>Lois</td>
      <td>Griffin</td>
      <td>$150</td>
    </tr>
    <tr>
      <td>Joe</td>
      <td>Swanson</td>
      <td>$300</td>
    </tr>
    <tr>
      <td>Cleveland</td>
      <td>Brown</td>
      <td>$250</td>
    </tr>
  </table>
</body>
</html>
​x
 
<!DOCTYPE html>
<html>
<head>
  <meta charset="utf-8">
  <style>
    table,
    td,
    th {
      border: 1px solid black;
    }
​
    td {
      padding: 15px;
    }
  </style>
</head>
​
<body>
  <table>
    <tr>
      <th>Firstname</th>
      <th>Lastname</th>
      <th>Savings</th>
    </tr>