使用微信小程序工具设计一个小程序，主要功能有： 1）用户通过下拉操作，弹出提示对话框； 2）实现3种以上不同页面跳转。 包括js、wxml、wxss代码

以下是一个简单的示例小程序，实现了您提到的功能：

app.js:

//app.js
App({
  globalData: {
    userInfo: null
  }
})

app.json:

{
  "pages": [
    "pages/index/index",
    "pages/page1/page1",
    "pages/page2/page2",
    "pages/page3/page3"
  ],
  "window": {
    "backgroundTextStyle": "light",
    "navigationBarBackgroundColor": "#fff",
    "navigationBarTitleText": "Demo",
    "navigationBarTextStyle": "black"
  },
  "tabBar": {
    "list": [
      {
        "pagePath": "pages/index/index",
        "text": "首页"
      },
      {
        "pagePath": "pages/page1/page1",
        "text": "页面1"
      },
      {
        "pagePath": "pages/page2/page2",
        "text": "页面2"
      },
      {
        "pagePath": "pages/page3/page3",
        "text": "页面3"
      }
    ]
  }
}

index.wxml:

<!--index.wxml-->
<view class="container">
  <view class="title">首页</view>
  <view class="btn" bindtap="showModal">下拉提示框</view>
  <view class="btn" bindtap="navigateToPage1">跳转页面1</view>
  <view class="btn" bindtap="navigateToPage2">跳转页面2</view>
  <view class="btn" bindtap="navigateToPage3">跳转页面3</view>
</view>

index.wxss:

/* index.wxss */
.container {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  height: 100vh;
}

.title {
  font-size: 24px;
  margin-bottom: 20px;
}

.btn {
  display: block;
  width: 200px;
  height: 40px;
  line-height: 40px;
  text-align: center;
  margin-bottom: 20px;
  background-color: #4CAF50;
  color: #fff;
  border-radius: 20px;
  box-shadow: 0 2px 4px rgba(0, 0, 0, 0.2);
}

.btn:hover {
  background-color: #3e8e41;
  cursor: pointer;
}

index.js:

//index.js
const app = getApp()

Page({
  showModal: function () {
    wx.showModal({
      title: '提示',
      content: '这是一个模态弹窗',
      success(res) {
        if (res.confirm) {
          console.log('用户点击确定')
        } else if (res.cancel) {
          console.log('用户点击取消')
        }
      }
    })
  },

  navigateToPage1: function () {
    wx.navigateTo({
      url: '/pages/page1/page1',
    })
  },

  navigateToPage2: function () {
    wx.navigateTo({
      url: '/pages/page2/page2',
    })
  },

  navigateToPage3: function () {
    wx.navigateTo({
      url: '/pages/page3/page3',
    })
  }
})

page1.wxml:

<!--page1.wxml-->
<view class="container">
  <view class="title">页面1</view>
  <view class="btn" bindtap="navigateBack">返回首页</view>
</view>

page1.wxss:

/* page1.wxss */
.container {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  height: 100vh;
}

.title {
  font-size: 24px;
  margin-bottom: 20px;
}

.btn {
  display: block;
  width: 200px;
  height: 40px;
  line-height: 40px;
  text-align: center;
  margin-bottom: 20px;
  background-color: #4CAF50;
  color: #fff;
  border-radius: 20px;
  box-shadow: 0 2px 4px rgba(0, 0, 0, 0.2);
}

.btn:hover {
  background-color: #3e8e41;
  cursor: pointer;
}

page1.js:

//page1.js
Page({
  navigateBack: function () {
    wx.navigateBack({
      delta: 1
    })
  }
})

page2.wxml:

<!--page2.wxml-->
<view class="container">
  <view class="title">页面2</view>
  <view class="btn" bindtap="navigateBack">返回首页</view>
</view>

page2.wxss:

/* page2.wxss */
.container {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  height: 100vh;
}

.title {
  font-size: 24px;
  margin-bottom: 20px;
}

.btn {
  display: block;
  width: 200px;
  height: 40px;
  line-height: 40px;
  text-align: center;
  margin-bottom: 20px;
  background-color: #4CAF50;
  color: #fff;
  border-radius: 20px;
  box-shadow: 0 2px 4px rgba(0, 0, 0, 0.2);
}

.btn:hover {
  background-color: #3e8e41;
  cursor: pointer;
}

page2.js:

//page2.js
Page({
  navigateBack: function () {
    wx.navigateBack({
      delta: 1
    })
  }
})

page3.wxml:

<!--page3.wxml-->
<view class="container">
  <view class="title">页面3</view>
  <view class="btn" bindtap="navigateBack">返回首页</view>
</view>

page3.wxss:

/* page3.wxss */
.container {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  height: 100vh;
}

.title {
  font-size: 24px;
  margin-bottom: 20px;
}

.btn {
  display: block;
  width: 200px;
  height: 40px;
  line-height: 40px;
  text-align: center;
  margin-bottom: 20px;
  background-color: #4CAF50;
  color: #fff;
  border-radius: 20px;
  box-shadow: 0 2px 4px rgba(0, 0, 0, 0.2);
}

.btn:hover {
  background-color: #3e8e41;
  cursor: pointer;
}

page3.js:

//page3.js
Page({
  navigateBack: function () {
    wx.navigateBack({
      delta: 1
    })
  }
})

上述代码实现了一个包含下拉提示框和多个页面跳转的微信小程序。注意：若要在微信小程序中正常运行，需要将代码保存成对应的文件名和文件格式，且需要在微信小程序开发者工具中导入项目并运行。