fix styling of lineNumber and filename with big sized font

Author: daiyam

browser/components/markdown.styl

@@ -206,11 +206,11 @@ code
   text-decoration none
   margin-right 2px
 pre
-  padding 0.5em !important
+  padding 0.5rem !important
   border solid 1px #D1D1D1
   border-radius 5px
   overflow-x auto
-  margin 0 0 1em
+  margin 0 0 1rem
   display flex
   line-height 1.4em
   code
@@ -226,17 +226,17 @@ pre
       flex 1
       overflow-x auto
   &>span.filename
-    margin -8px 100% 8px -8px
-    padding 2px 6px
+    margin -0.5rem 100% 0.5rem -0.5rem
+    padding 0.125rem 0.375rem
     background-color #777;
     color white
     &:empty
       display none
   &>span.lineNumber
     display none
     font-size 1em
-    padding 0.5em 0
-    margin -0.5em 0.5em -0.5em -0.5em
+    padding 0.5rem 0
+    margin -0.5rem 0.5rem -0.5rem -0.5rem
     border-right 1px solid
     text-align right
     border-top-left-radius 4px