JavaScript代码：

document.addEventListener("DOMContentLoaded", function (event) {
  var allow_domains = ["www.baidu.com"];
  document.querySelectorAll("a").forEach((link) => {
    link.addEventListener("click", function (event) {
      if (
            !/^https?:\/\//i.test(link.href) ||
                /[^\s]*\.gov.cn$/i.test(link.hostname) ||
                allow_domains.some(item=>link.hostname.endsWith(item))
      ) {
        return true;
      } else {
        event.preventDefault();
        window.open(
          "/link.htm?target=" + encodeURIComponent(this.href),
          "_blank"
        );
      }
    });
  });
});

Html代码

<!DOCTYPE html>
<html lang="zh-CN">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>跳转提示</title>
    <style>
* {
padding: 0;
margin: 0;
}

html,
body {
width: 100vw;
height: 100vh;
}

body {
display: flex;
justify-content: center;
align-items: center;
}

.middle-page {
border: 1pxsolid#ccc;
max-width: 700px;
}

.logo {
background-color: #2845ac;
padding: 20px;
display: block;
}

.logoimg {
background-color: #2845ac;
max-width: 100%;
display: block;
}

.content {
padding: 20px;
border-bottom: 1pxsolid#ccc;
}

.title {
font-size: 20px;
font-weight: normal;
}

.link-container {
margin: 15px0;
color: #666;
}

.link-content {}

.btn {
all: unset;
border: 1pxsolid#2845ac;
color: #2845ac;
padding: 8px20px;
cursor: pointer;
border-radius: 5px;
float: right;
margin: 15px;
}

.btn:hover {
background-color: #2845ac;
color: #fff;
}
</style>
</head>

<body>
    <div class="middle-page">
        <div class="logo">
            <img src="/images/logo.png" />
        </div>
        <div class="content">
            <p class="title">温馨提示：即将跳转至非党政机关网站，请注意账号财产安全</p>
            <div class="link-container">
                <div class="link-content">
                    <p id="target"></p>
                </div>
            </div>
        </div>
        <button class="btn">继续访问</button>
    </div>
    <script>
constquery = newURLSearchParams(window.location.search);
consturl = query.get('target');
target.innerText = decodeURIComponent(url);
constbtn = document.querySelector(".btn");
btn.addEventListener("click", () =>window.location.replace(decodeURIComponent(url)));
</script>
</body>

</html>