修改登录页面配置

learnOnline/pages/login/index.json

 {
+  "navigationBarTextStyle": "white",
+  "navigationBarBackgroundColor": "#414141",
+  "disableScroll": true,
   "usingComponents": {
     "bind-account": "./components/bindAccount/index",
     "bind-phone": "./components/bindPhone/index"