fix: dropdown overlap due to word wrapping (close: #359) (#360)

Author: ycmjason

lib/default-theme/DropdownLink.vue

@@ -77,7 +77,6 @@ export default {
           font-size 0.9em
       a
         display block
-        height 1.7rem
         line-height 1.7rem
         position relative
         border-bottom none
@@ -96,7 +95,7 @@ export default {
             border-top 3px solid transparent
             border-bottom 3px solid transparent
             position absolute
-            top calc(50% - 2px)
+            top calc(1rem - 2px)
             left 9px
       &:first-child h4
         margin-top 0
@@ -117,7 +116,6 @@ export default {
           padding-top 0
         h4, & > a
           font-size 15px
-          height 2rem
           line-height 2rem
         .dropdown-subitem
           font-size 14px