页面效果：

 load. wxml

<view class="container">
<view>

  <form class="form" style="position: relative; left: 0rpx; top: -156rpx; width: 551rpx; height: 584rpx; display: flex; box-sizing: border-box">
    <input style="width: 432rpx; height: 94rpx; display: block; box-sizing: border-box; position: relative; left: 0rpx; top: 47rpx" type="text" name="username" placeholder="用户名"/>
    <input style="width: 427rpx; height: 90rpx; display: block; box-sizing: border-box" type="password" name="password" placeholder="密码"/>
    <button type="submit" class="btn" style="position: relative; left: -5rpx; top: 8rpx">登录</button>
    <button type="submit" class="btn" style="position: relative; left: -5rpx; top: -5rpx">注册</button>
  </form>
</view>

load.wxss 

.container {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  height: 100vh;
  background-color: #f2f2f2;
}


.form {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  background-color: #fff;
  padding: 20px;
  border-radius: 5px;
  box-shadow: 0 0 10px rgba(0, 0, 0, 0.2);
}

input {
  display: block;
  width: 100%;
  margin-bottom: 20px;
  padding: 10px;
  border: 1px solid #ccc;
  border-radius: 5px;
  box-sizing: border-box;
  font-size: 16px;
}

button {
  display: block;
  width: 100%;
  margin-bottom: 20px;
  padding: 10px;
  border: none;
  border-radius: 5px;
  background-color: #007aff;
  color: #fff;
  font-size: 16px;
  text-align: center;
  cursor: pointer;
}