diff --git a/static/css/theme.css b/static/css/theme.css
index 4e4e08366a..428670ac6b 100644
--- a/static/css/theme.css
+++ b/static/css/theme.css
@@ -357,21 +357,24 @@ th {
         width: calc( 1300px - 300px - 2 * 3.25rem );
         max-width: calc( 1300px - 300px - 2 * 3.25rem );
     }
+    #body .narrow .flex-block-wrapper {
+        min-width: calc( 1300px - 300px - 2 * 9.75rem );
+        width: calc( 1300px - 300px - 2 * 9.75rem );
+        max-width: calc( 1300px - 300px - 2 * 9.75rem );
+    }
 }
 
 #body-inner.narrow {
-    margin-left: auto;
-    margin-right: auto;
     padding: 2rem 9.75rem;
 }
 @media screen and (max-width: 59.938em) {
     #body-inner.narrow {
-        padding: 15px 6.5rem 15px 6.5rem;
+        padding: 15px 6.5rem;
     }
 }
 @media screen and (max-width: 47.938em) {
     #body-inner.narrow {
-        padding: 5px 3.25rem 5px 3.25rem;
+        padding: 5px 3.25rem;
     }
 }