grid.sass in bulma-rails-0.0.12

- old
+ new

@@ -60,13 +60,16 @@
       &.is-#{$i}-desktop
         flex: none
         width: ($i / 12) * 100%
 
 .columns
-  margin-bottom: 10px
   margin-left: -10px
   margin-right: -10px
   margin-top: -10px
+  &:last-child
+    margin-bottom: -10px
+  &:not(:last-child)
+    margin-bottom: 10px
   &.is-mobile
     display: flex
   +tablet
     &:not(.is-desktop)
       display: flex