Fix before and after selectors

sass/elements/tag.sass

@@ -82,8 +82,8 @@ $tag-delete-margin: 1px !default
     padding: 0
     position: relative
     width: 2em
-    &:before,
-    &:after
+    &::before,
+    &::after
       background-color: currentColor
       content: ""
       display: block
@@ -92,10 +92,10 @@ $tag-delete-margin: 1px !default
       top: 50%
       transform: translateX(-50%) translateY(-50%) rotate(45deg)
       transform-origin: center center
-    &:before
+    &::before
       height: 1px
       width: 50%
-    &:after
+    &::after
       height: 50%
       width: 1px
     &:hover,