--- a/devtools/client/jar.mn
+++ b/devtools/client/jar.mn
@@ -9,17 +9,16 @@ devtools.jar:
     content/shared/widgets/widgets.css (shared/widgets/widgets.css)
     content/shared/widgets/VariablesView.xul (shared/widgets/VariablesView.xul)
     content/projecteditor/chrome/content/projecteditor.xul (projecteditor/chrome/content/projecteditor.xul)
     content/projecteditor/lib/helpers/readdir.js (projecteditor/lib/helpers/readdir.js)
     content/projecteditor/chrome/content/projecteditor-loader.xul (projecteditor/chrome/content/projecteditor-loader.xul)
     content/projecteditor/chrome/content/projecteditor-test.xul (projecteditor/chrome/content/projecteditor-test.xul)
     content/projecteditor/chrome/content/projecteditor-loader.js (projecteditor/chrome/content/projecteditor-loader.js)
     content/netmonitor/netmonitor.xul (netmonitor/netmonitor.xul)
-    content/netmonitor/netmonitor.css (netmonitor/netmonitor.css)
     content/netmonitor/netmonitor-controller.js (netmonitor/netmonitor-controller.js)
     content/netmonitor/netmonitor-view.js (netmonitor/netmonitor-view.js)
     content/webconsole/webconsole.xul (webconsole/webconsole.xul)
 *   content/scratchpad/scratchpad.xul (scratchpad/scratchpad.xul)
     content/scratchpad/scratchpad.js (scratchpad/scratchpad.js)
     content/shared/splitview.css (shared/splitview.css)
     content/shared/theme-switching.js (shared/theme-switching.js)
     content/shared/frame-script-utils.js (shared/frame-script-utils.js)

deleted file mode 100644
--- a/devtools/client/netmonitor/netmonitor.css
+++ /dev/null
@@ -1,47 +0,0 @@
-/* vim:set ts=2 sw=2 sts=2 et: */
-/* This Source Code Form is subject to the terms of the Mozilla Public
- * License, v. 2.0. If a copy of the MPL was not distributed with this
- * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
-
-#toolbar-labels {
-  overflow: hidden;
-}
-
-/**
- * Collapsed details pane needs to be truly hidden to prevent both accessibility
- * tools and keyboard from accessing its contents.
- */
-#details-pane.pane-collapsed {
-  visibility: hidden;
-}
-
-#details-pane-toggle[disabled] {
-  display: none;
-}
-
-#custom-pane {
-  overflow: auto;
-}
-
-#response-content-image-box {
-  overflow: auto;
-}
-
-#network-statistics-charts {
-  overflow: auto;
-}
-
-.cropped-textbox .textbox-input {
-  /* workaround for textbox not supporting the @crop attribute */
-  text-overflow: ellipsis;
-}
-
-/* Responsive sidebar */
-@media (max-width: 700px) {
-  #toolbar-spacer,
-  #details-pane-toggle,
-  .requests-menu-waterfall,
-  #requests-menu-network-summary-button > .toolbarbutton-text {
-    display: none;
-  }
-}

--- a/devtools/client/netmonitor/netmonitor.xul
+++ b/devtools/client/netmonitor/netmonitor.xul
@@ -1,15 +1,14 @@
 <?xml version="1.0" encoding="utf-8"?>
 <!-- This Source Code Form is subject to the terms of the Mozilla Public
    - License, v. 2.0. If a copy of the MPL was not distributed with this
    - file, You can obtain one at http://mozilla.org/MPL/2.0/. -->
 <?xml-stylesheet href="chrome://global/skin/" type="text/css"?>
 <?xml-stylesheet href="chrome://devtools/content/shared/widgets/widgets.css" type="text/css"?>
-<?xml-stylesheet href="chrome://devtools/content/netmonitor/netmonitor.css" type="text/css"?>
 <?xml-stylesheet href="chrome://devtools/skin/widgets.css" type="text/css"?>
 <?xml-stylesheet href="chrome://devtools/skin/netmonitor.css" type="text/css"?>
 <!DOCTYPE window [
   <!ENTITY % netmonitorDTD SYSTEM "chrome://devtools/locale/netmonitor.dtd">
   %netmonitorDTD;
   <!ENTITY % certManagerDTD SYSTEM "chrome://pippki/locale/certManager.dtd">
   %certManagerDTD;
 ]>

--- a/devtools/client/themes/netmonitor.css
+++ b/devtools/client/themes/netmonitor.css
@@ -1,13 +1,56 @@
 /* vim:set ts=2 sw=2 sts=2 et: */
 /* This Source Code Form is subject to the terms of the Mozilla Public
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
+#toolbar-labels {
+  overflow: hidden;
+}
+
+/**
+ * Collapsed details pane needs to be truly hidden to prevent both accessibility
+ * tools and keyboard from accessing its contents.
+ */
+#details-pane.pane-collapsed {
+  visibility: hidden;
+}
+
+#details-pane-toggle[disabled] {
+  display: none;
+}
+
+#custom-pane {
+  overflow: auto;
+}
+
+#response-content-image-box {
+  overflow: auto;
+}
+
+#network-statistics-charts {
+  overflow: auto;
+}
+
+.cropped-textbox .textbox-input {
+  /* workaround for textbox not supporting the @crop attribute */
+  text-overflow: ellipsis;
+}
+
+/* Responsive sidebar */
+@media (max-width: 700px) {
+  #toolbar-spacer,
+  #details-pane-toggle,
+  .requests-menu-waterfall,
+  #requests-menu-network-summary-button > .toolbarbutton-text {
+    display: none;
+  }
+}
+
 :root.theme-dark {
   --table-splitter-color: rgba(255,255,255,0.15);
   --table-zebra-background: rgba(255,255,255,0.05);
 
   --timing-blocked-color: rgba(235, 83, 104, 0.8);
   --timing-dns-color: rgba(223, 128, 255, 0.8); /* pink */
   --timing-connect-color: rgba(217, 102, 41, 0.8); /* orange */
   --timing-send-color: rgba(70, 175, 227, 0.8); /* light blue */