​x
 
<!DOCTYPE html>
<html>
<head>
<style>
/* 默认的 CSS 值 */
form {
  display: block;
  margin-top: 0em;
}
</style>
</head>
<body>
​
<p>默认情况下，form 元素会这样显示：</p>
​
<form action="demo_form.asp">
  First name: <input type="text" name="FirstName" value="Mickey"><br>
  Last name: <input type="text" name="LastName" value="Mouse"><br>
  <input type="submit" value="Submit">
</form>
​
<p>自定义的 form 元素（更改 margin-top）：</p>
​
<form action="demo_form.asp" style="margin-top:50px;">
  First name: <input type="text" name="FirstName" value="Mickey"><br>
  Last name: <input type="text" name="LastName" value="Mouse"><br>
  <input type="submit" value="Submit">
</form>
​
</body>
</html>
​