Remove z-index attribute from _coverpage.styl

Author: mohammedsahl

src/themes/basic/_coverpage.styl

@@ -22,7 +22,6 @@ section.cover
     flex 1
     margin -20px 16px 0
     text-align center
-    z-index 1
 
   a
     color inherit

src/themes/basic/_layout.styl

@@ -423,7 +423,7 @@ body.close
     left - $sidebar-width
     transition transform 250ms ease-out
 
-  .content, .cover
+  .content
     left 0
     max-width 100vw
     position static
@@ -439,7 +439,7 @@ body.close
     padding 30px 30px 10px 10px
 
   body.close
-    .sidebar, .cover
+    .sidebar
       transform translateX($sidebar-width)
 
     .sidebar-toggle