fix pay center loading speed and style issue. code review by XWG

@@ -158,4 +158,5 @@ function main() {
 
 loading.showLoadingMask();
 
-window.onload = main;
+$(document).ready(main);
+

@@ -45,18 +45,18 @@
     }
 
     .app {
-      width: 40%;
+      width: 35%;
 
-      @include flexbox((flex-basis: 40%));
+      @include flexbox((flex-basis: 35%));
 
       font-size: 32rem / $pxConvertRem;
       color: #414141;
     }
 
     .hint {
-      width: 40%;
+      width: 45%;
 
-      @include flexbox((flex-basis: 40%));
+      @include flexbox((flex-basis: 45%));
 
       font-size: 24rem / $pxConvertRem;
       color: #4b4b4b;