box.sass in bulma-sass-0.7.2

- old
+ new

@@ -6,10 +6,10 @@
 
 $box-link-hover-shadow: 0 2px 3px rgba($black, 0.1), 0 0 0 1px $link !default
 $box-link-active-shadow: inset 0 1px 2px rgba($black, 0.2), 0 0 0 1px $link !default
 
 .box
-  +block
+  @extend %block
   background-color: $box-background-color
   border-radius: $box-radius
   box-shadow: $box-shadow
   color: $box-color
   display: block