Fix copy and expand

docs/_sass/bootstrap.sass

@@ -46,11 +46,11 @@ $bootstrap-invert: #fff
   p:not(:last-child)
     margin-bottom: 0.5rem
 
-.bd-pro.is-bulma
+.bd-pro.bd-is-bulma
   .icon
     color: $primary
 
-.bd-pro.is-bootstrap
+.bd-pro.bd-is-bootstrap
   .icon
     color: $bootstrap
 
@@ -85,10 +85,10 @@ $bootstrap-invert: #fff
         color: currentColor
         &:hover
           text-decoration: underline
-    .is-empty
+    .bd-is-empty
       background-color: $background
       color: $text-light
-    .is-unique
+    .bd-is-unique
       background-color: rgba($green, 0.25)
       color: $text-strong
       font-weight: $weight-bold

docs/_sass/example.sass

@@ -91,8 +91,8 @@ $structure-invert: $danger-invert
 
 .highlight
   position: relative
-  .copy,
-  .expand
+  .bd-copy,
+  .bd-expand
     +unselectable
     background: $white
     border: solid $border
@@ -106,7 +106,7 @@ $structure-invert: $danger-invert
     &:hover
       border-color: $code
       color: $code
-  .expand
+  .bd-expand
     border-right-width: 1px
     right: 50px
   +tablet