Merge branch 'develop/wap' of http://git.dev.yoho.cn/web/yohobuy into develop/wap

-.coupon-area .banner-top {
-    float: left;
+.coupon-area {
+    max-width: 640rem / $pxConvertRem 0;
+    overflow: hidden;
+
+    .banner-top {
+        float: left;
+    }
 }
+
 .just-img{
     width: 100%;
     float: left;

-.coupon-area .banner-top {
-    float: left;
+.coupon-area {
+    max-width: 640px;
+    overflow: hidden;
+
+    .banner-top {
+        float: left;
+    }
 }
+
 .just-img{
     width: 100%;
     float: left;