<html><head><style>input:read-only { background-color: lightgray; border: 0;}</style></head><body><h1>:read-only 演示</h1><p>:read-only 选择器选择带有 "readonly" 属性的元素：</p><form><label for="name">姓名：</label><br><input id="name" name="name" type="text" /><br><label for="email">邮箱：</label><br><input id="email" name="email" type="email" /><br><label for="country">国家：</label><br><input id="country" name="country" type="text" value="中国" readonly /></form></body></html>