# HG changeset patch
# User "Matt A. Tobin" <email@mattatobin.com>
# Date 1626109110 14400
# Node ID 0db5f363e7757e1f995784808582aa05865de399
# Parent  cd1042d0923f9bb99c3d213f137c69dd1e7f6bfa
[BINOC] Add a border-bottom to treecols header

diff --git a/toolkit/themes/windows/global/tree.css b/toolkit/themes/windows/global/tree.css
--- a/toolkit/themes/windows/global/tree.css
+++ b/toolkit/themes/windows/global/tree.css
@@ -20,8 +20,18 @@ treecol:not([hideheader="true"]) > .tree
 
 treecol:not([hideheader="true"]) > .treecol-sortdirection[sortDirection="descending"] {
   list-style-image: url("chrome://global/skin/tree/sort-dsc.png");
 }
 
 treecol:not([hideheader="true"]) > .treecol-sortdirection[sortDirection="descending"]:-moz-system-metric(windows-classic) {
   list-style-image: url("chrome://global/skin/tree/sort-dsc-classic.png");
 }
+
+/* ::::: tree columns ::::: */
+
+@media (-moz-os-version: windows-win10) and (-moz-windows-theme: aero) {
+  treecols {
+    /* Windows 10's "aero" msstyle does not provide a complete style for
+       the treecols header so we need to provide a bottom border */
+    border-bottom: 1px solid ThreeDLightShadow;
+  }
+}
\ No newline at end of file
