ARIA 角色参考
<!-- 地标角色 -->
<header role="banner">
<nav role="navigation" aria-label="主导航">
<main role="main">
<aside role="complementary">
<footer role="contentinfo">
<!-- 交互角色 -->
<div role="button" tabindex="0" aria-pressed="false">切换</div>
<div role="dialog" aria-modal="true" aria-labelledby="dialog-title">
<h2 id="dialog-title">确认删除</h2>
</div>
<!-- 实时区域 -->
<div role="alert" aria-live="assertive">错误：表单提交失败</div>
<div aria-live="polite" aria-atomic="true">购物车 3 件商品</div>
<!-- 表单无障碍 -->
<label for="email">邮箱地址</label>
<input id="email" type="email" aria-required="true" aria-describedby="email-hint">
<span id="email-hint">我们不会分享您的邮箱</span>