FIX: banner topic's max-width & max-height on both mobile & desktop

app/assets/stylesheets/common/components/banner.css.scss

@@ -8,6 +8,7 @@
   background: scale-color($tertiary, $lightness: 90%);
   @include box-shadow(0 1px 2px scale-color($tertiary, $lightness: 70%));
   z-index: 501;
+  overflow: auto;
 
   &.overlay {
     position: fixed;

app/assets/stylesheets/desktop/banner.scss

@@ -4,14 +4,6 @@
 
 #banner {
   margin-bottom: 10px;
-}
-
-@media all
-and (min-width: 1090px) {
-  width: 1090px;
-}
-
-@media all
-and (max-width: 1090px) {
-  width: 100%;
+  max-width: 1090px;
+  max-height: 250px;
 }

app/assets/stylesheets/mobile/banner.scss

@@ -4,4 +4,13 @@
 
 #banner {
   margin: 10px;
+
+  @media all and (max-height: 499px) {
+    max-height: 100px;
+  }
+
+  @media all and (min-height: 500px) {
+    max-height: 180px;
+  }
+
 }