<html>
<body>
<h1>input step 属性</h1>
<p>step 属性指定输入元素的合法数字间隔。</p>
<form action="/action_page.php">
<label for="points">积分:</label>
<input type="number" id="points" name="points" step="3">
<input type="submit" value="提交">
</form>
</body>
</html>