signup.html

<title>注册 Majoring+</title>
<style>
  body {
    background-color: #3498db;
  }

  div {
    background: white;
    max-width: 500px;
    width: 70%;
    padding: 20px;
    position: absolute;
    left: 50%;
    top: 50%;
    transform: translate(-50%, -50%);
    border-radius: 20px;
    min-height: 200px;
    min-width: 400px;
    box-shadow: 0 2.3px 3px rgba(0, 0, 0, 0.015),
      0 5.3px 7.1px rgba(0, 0, 0, 0.022), 0 9.6px 12.7px rgba(0, 0, 0, 0.028),
      0 15.9px 21px rgba(0, 0, 0, 0.032), 0 26.2px 34.7px rgba(0, 0, 0, 0.038),
      0 45.8px 60.6px rgba(0, 0, 0, 0.045), 0 99px 131px rgba(0, 0, 0, 0.06);
  }
  div h3 {
    text-align: center;
    color: #3498db;
    font-family: "Franklin Gothic Medium", "Arial Narrow", Arial, sans-serif;
  }
  div input[type="text"],
  div input[type="password"] {
    width: 100%;
    height: 45px;
    border: 1px solid #ccc;
    padding-left: 10px;
    margin: 10px 0;
    margin-bottom: 25px;
    border-radius: 10px;
  }

  div a button {
    width: 100%;
    height: 35px;
    cursor: pointer;
    background: #2980b9;
    color: white;
    border: 0;
    border-radius: 20px;
    transition: 0.15s;
  }
  div a:hover {
    background-color: #16a085;
  }
  div input[type="text"]:focus {
    outline: 0;
  }
  div input[type="password"]:focus {
    outline: 0;
  }
</style>

<div>
  <h3>注册</h3>
  <input type="text" id="email" name="email" placeholder="学号" />
  <input type="text" id="pass" name="pass" placeholder="密码" />
  <a href="index.html">
    <button onclick="setc()">注册</button>
  </a>
</div>

<script>
  function setc() {
    var inxh = document.getElementById("email").value;
    var inpass = document.getElementById("pass").value;
    if (inxh.length == 9 && inxh.startsWith("20")) {
      localStorage.setItem("acc", inxh);
      localStorage.setItem("pass", inpass);
      alert("注册成功！");
    } else {
      alert("学号格式错误!");
    }
    console.log(document.cookie);
  }
</script>