下拉图片修改

frontend/saas-portal-web/static/css/invitation_mobile_join.css

@@ -21,7 +21,7 @@ body {
     height: 100%;
     z-index: -1;
     width: 100%;
-    background-size: cover;
+    background-size: 100% 100%;
     background-image: url(../img/invitation_join_background.png);
 	font-family: Microsoft YaHei, 微软雅黑, simhei;
 	font-size: 18px;