Fix #242

sass/layout/footer.sass

@@ -1,5 +1,5 @@
 .footer
-  background: $background
+  background-color: $background
   padding: 40px 20px 80px
   a
     &,

sass/layout/header.sass

@@ -2,7 +2,7 @@ $header-height: 50px !default
 
 .header
   +clearfix
-  background: $white
+  background-color: $white
   display: flex
   line-height: 24px
   min-height: $header-height
@@ -143,7 +143,7 @@ a.header-item
     justify-content: center
 
 .header.is-small
-  background: $background
+  background-color: $background
   box-shadow: none
   height: 40px
   z-index: 1

sass/layout/hero.sass

@@ -49,7 +49,7 @@
 
 .hero
   align-items: stretch
-  background: $white
+  background-color: $white
   display: flex
   flex-direction: column
   justify-content: space-between
@@ -64,7 +64,7 @@
     $color: nth($pair, 1)
     $color-invert: nth($pair, 2)
     &.is-#{$name}
-      background: $color
+      background-color: $color
       color: $color-invert
       .title
         color: $color-invert
@@ -80,7 +80,7 @@
         box-shadow: 0 1px 0 rgba($color-invert, 0.2)
       .nav-menu
         +mobile
-          background: $color
+          background-color: $color
       a.nav-item,
       .nav-item a:not(.button)
         color: rgba($color-invert, 0.5)
@@ -101,11 +101,11 @@
           a
             color: $color-invert
             &:hover
-              background: rgba($black, 0.1)
+              background-color: rgba($black, 0.1)
           li.is-active a
             &,
             &:hover
-              background: $color-invert
+              background-color: $color-invert
               border-color: $color-invert
               color: $color
       // Modifiers
@@ -117,12 +117,12 @@
       +mobile
         .nav-toggle
           span
-            background: $color-invert
+            background-color: $color-invert
           &:hover
-            background: rgba($black, 0.1)
+            background-color: rgba($black, 0.1)
           &.is-active
             span
-              background: $color-invert
+              background-color: $color-invert
         .nav-menu
           .nav-item
             border-top-color: rgba($color-invert, 0.2)

sass/layout/section.sass

@@ -1,5 +1,5 @@
 .section
-  background: $white
+  background-color: $white
   padding: 40px 20px
   // Responsiveness
   +desktop