fix(login): form显示置顶

src/assets/loginmini/style/home.less

@@ -11,6 +11,7 @@
   left: 50%;
   width: 92%;
   height: auto;
+  z-index: 9999;
   -webkit-transform: translateX(-50%) translateY(-50%);
   -moz-transform: translateX(-50%) translateY(-50%);
   -ms-transform: translateX(-50%) translateY(-50%);