Fix #242

sass/components/tabs.sass

@@ -62,12 +62,12 @@
       padding-bottom: 5px
       padding-top: 5px
       &:hover
-        background: $background
+        background-color: $background
         border-bottom-color: $border
     li
       &.is-active
         a
-          background: $white
+          background-color: $white
           border-color: $border
           border-bottom-color: transparent !important
   &.is-fullwidth
@@ -81,7 +81,7 @@
       padding-top: 5px
       position: relative
       &:hover
-        background: $background
+        background-color: $background
         border-color: $border-hover
         z-index: 2
     li
@@ -93,7 +93,7 @@
         border-radius: 0 $radius $radius 0
       &.is-active
         a
-          background: $primary
+          background-color: $primary
           border-color: $primary
           color: $primary-invert
           z-index: 1