diff --git a/src/main/gtk-3.0/gtk-dark-solid.css b/src/main/gtk-3.0/gtk-dark-solid.css
index 4eb7a04..7d7f15b 100644
--- a/src/main/gtk-3.0/gtk-dark-solid.css
+++ b/src/main/gtk-3.0/gtk-dark-solid.css
@@ -5852,51 +5852,50 @@ window.background.csd > headerbar.titlebar > leaflet > headerbar:last-child, win
 }
 
 .geary-main-window.background.csd > overlay > box.vertical > paned > .sidebar > searchbar,
-window#GearyMainWindow.background.csd > overlay > box.vertical > paned > .sidebar > searchbar, window.background.csd > hdyleaflet > box.vertical > searchbar {
+window#GearyMainWindow.background.csd > overlay > box.vertical > paned > .sidebar > searchbar, window.background.csd > hdyleaflet > box.vertical > searchbar, window.background.csd > leaflet > box.vertical > searchbar {
   background-color: #333333;
 }
 
 .geary-main-window.background.csd > overlay > box.vertical > paned > .sidebar > searchbar > revealer > box,
-window#GearyMainWindow.background.csd > overlay > box.vertical > paned > .sidebar > searchbar > revealer > box, window.background.csd > hdyleaflet > box.vertical > searchbar > revealer > box {
+window#GearyMainWindow.background.csd > overlay > box.vertical > paned > .sidebar > searchbar > revealer > box, window.background.csd > hdyleaflet > box.vertical > searchbar > revealer > box, window.background.csd > leaflet > box.vertical > searchbar > revealer > box {
   border-color: #0e0e0e;
 }
 
 .geary-main-window.background.csd > overlay > box.vertical > paned > separator,
-window#GearyMainWindow.background.csd > overlay > box.vertical > paned > separator, window.background.csd > box.vertical > paned.horizontal > separator, window.background.csd > overlay > hdyleaflet > separator.sidebar,
-window.background.csd > overlay > leaflet > separator.sidebar, window.background.csd > leaflet > separator.sidebar,
-window.background.csd > hdyleaflet > separator.sidebar,
-window.background.csd > box.horizontal > separator.sidebar, window.background.csd > box.horizontal:not(.titlebar) > separator.vertical, window.background.csd > headerbar.titlebar > box.horizontal > separator.sidebar,
+window#GearyMainWindow.background.csd > overlay > box.vertical > paned > separator, window.background.csd > overlay > hdyleaflet > separator.sidebar,
+window.background.csd > overlay > leaflet > separator.sidebar, box.horizontal > separator.sidebar,
+hdyleaflet > separator.sidebar,
+leaflet > separator.sidebar, window.background.csd > box.horizontal:not(.titlebar) > separator.vertical, window.background.csd > headerbar.titlebar > box.horizontal > separator.sidebar,
 window.background.csd > headerbar.titlebar > hdyleaflet > separator.sidebar,
-window.background.csd > headerbar.titlebar > leaflet > separator.sidebar, .titlebar:not(headerbar) > separator, window.org-gnome-gedit > paned.titlebar > separator, window.org-gnome-gedit > overlay > box.vertical > paned.gedit-side-panel-paned > separator, window.org-gnome-gedit > paned.titlebar > separator:backdrop, window.org-gnome-gedit > overlay > box.vertical > paned.gedit-side-panel-paned > separator:backdrop {
-  min-width: 0;
-  background: none;
-  border-right-color: #0e0e0e;
-  border-bottom-color: #0e0e0e;
+window.background.csd > headerbar.titlebar > leaflet > separator.sidebar, window.background.csd > hdyleaflet > separator.vertical, window.background.csd > leaflet > separator.vertical, .titlebar:not(headerbar) > separator, window.org-gnome-gedit > paned.titlebar > separator, window.org-gnome-gedit > overlay > box.vertical > paned.gedit-side-panel-paned > separator, window.org-gnome-gedit > paned.titlebar > separator:backdrop, window.org-gnome-gedit > overlay > box.vertical > paned.gedit-side-panel-paned > separator:backdrop {
+  background-image: image(#0e0e0e);
+  background-color: transparent;
+  border-right: none;
 }
 
-.tweak-group-startup, list.tweak-group list, hdyleaflet list.frame, leaflet list.frame, hdyleaflet frame.view, leaflet frame.view, hdyleaflet frame:not(.view) list:not(.contacts-contact-list), leaflet frame:not(.view) list:not(.contacts-contact-list) {
+.tweak-group-startup, list.tweak-group list, hdyleaflet list.view, hdyleaflet list.frame, leaflet list.view, leaflet list.frame, hdyleaflet frame.view, leaflet frame.view, hdyleaflet frame:not(.view) list:not(.contacts-contact-list), leaflet frame:not(.view) list:not(.contacts-contact-list) {
   border-radius: 14px;
   box-shadow: inset 0 0 8px rgba(255, 255, 255, 0.03), inset 0 0 3px rgba(255, 255, 255, 0.02), inset 0 0 0 1px rgba(255, 255, 255, 0.04), inset 0 1px rgba(255, 255, 255, 0.06);
   background-color: rgba(255, 255, 255, 0.05);
   border: none;
 }
 
-.tweak-group-startup > separator, list.tweak-group list > separator, hdyleaflet list.frame > separator, leaflet list.frame > separator, hdyleaflet frame.view > separator, leaflet frame.view > separator, hdyleaflet frame:not(.view) list:not(.contacts-contact-list) > separator, leaflet frame:not(.view) list:not(.contacts-contact-list) > separator {
+.tweak-group-startup > separator, list.tweak-group list > separator, hdyleaflet list.view > separator, hdyleaflet list.frame > separator, leaflet list.view > separator, leaflet list.frame > separator, hdyleaflet frame.view > separator, leaflet frame.view > separator, hdyleaflet frame:not(.view) list:not(.contacts-contact-list) > separator, leaflet frame:not(.view) list:not(.contacts-contact-list) > separator {
   background: none;
   min-height: 0;
 }
 
-list.tweak-group list row.activatable:first-child, hdyleaflet list.frame row.activatable:first-child, leaflet list.frame row.activatable:first-child, hdyleaflet frame.view list row.activatable:first-child, leaflet frame.view list row.activatable:first-child, hdyleaflet frame:not(.view) list:not(.contacts-contact-list) row.activatable:first-child, leaflet frame:not(.view) list:not(.contacts-contact-list) row.activatable:first-child {
+list.tweak-group list row.activatable:first-child, hdyleaflet list.view row.activatable:first-child, hdyleaflet list.frame row.activatable:first-child, leaflet list.view row.activatable:first-child, leaflet list.frame row.activatable:first-child, hdyleaflet frame.view list row.activatable:first-child, leaflet frame.view list row.activatable:first-child, hdyleaflet frame:not(.view) list:not(.contacts-contact-list) row.activatable:first-child, leaflet frame:not(.view) list:not(.contacts-contact-list) row.activatable:first-child {
   border-top-left-radius: 14px;
   border-top-right-radius: 14px;
 }
 
-list.tweak-group list row.activatable:last-child, hdyleaflet list.frame row.activatable:last-child, leaflet list.frame row.activatable:last-child, hdyleaflet frame.view list row.activatable:last-child, leaflet frame.view list row.activatable:last-child, hdyleaflet frame:not(.view) list:not(.contacts-contact-list) row.activatable:last-child, leaflet frame:not(.view) list:not(.contacts-contact-list) row.activatable:last-child {
+list.tweak-group list row.activatable:last-child, hdyleaflet list.view row.activatable:last-child, hdyleaflet list.frame row.activatable:last-child, leaflet list.view row.activatable:last-child, leaflet list.frame row.activatable:last-child, hdyleaflet frame.view list row.activatable:last-child, leaflet frame.view list row.activatable:last-child, hdyleaflet frame:not(.view) list:not(.contacts-contact-list) row.activatable:last-child, leaflet frame:not(.view) list:not(.contacts-contact-list) row.activatable:last-child {
   border-bottom-left-radius: 14px;
   border-bottom-right-radius: 14px;
 }
 
-list.tweak-group list row.activatable:only-child, hdyleaflet list.frame row.activatable:only-child, leaflet list.frame row.activatable:only-child, hdyleaflet frame.view list row.activatable:only-child, leaflet frame.view list row.activatable:only-child, hdyleaflet frame:not(.view) list:not(.contacts-contact-list) row.activatable:only-child, leaflet frame:not(.view) list:not(.contacts-contact-list) row.activatable:only-child {
+list.tweak-group list row.activatable:only-child, hdyleaflet list.view row.activatable:only-child, hdyleaflet list.frame row.activatable:only-child, leaflet list.view row.activatable:only-child, leaflet list.frame row.activatable:only-child, hdyleaflet frame.view list row.activatable:only-child, leaflet frame.view list row.activatable:only-child, hdyleaflet frame:not(.view) list:not(.contacts-contact-list) row.activatable:only-child, leaflet frame:not(.view) list:not(.contacts-contact-list) row.activatable:only-child {
   border-radius: 14px;
 }
 
@@ -5931,11 +5930,6 @@ hdyleaflet frame.view list > separator, leaflet frame.view list > separator {
   border: none;
 }
 
-window.background.csd > hdyleaflet > separator.vertical {
-  min-width: 1px;
-  background-color: #0e0e0e;
-}
-
 window.background.csd > hdyleaflet > box.vertical > stack.main-container {
   background-color: #242424;
   border-bottom-right-radius: 14px;
@@ -6571,6 +6565,10 @@ window.background.csd > box.vertical > paned.horizontal > scrolledwindow treevie
   background-color: transparent;
 }
 
+window.background.csd > box.vertical > paned.horizontal > separator {
+  background-image: image(#0e0e0e);
+}
+
 window.background.csd > paned.titlebar {
   background-color: #373737;
   box-shadow: inset 0 1px rgba(255, 255, 255, 0.1);
@@ -7132,10 +7130,15 @@ window#GearyMainWindow.background.csd stack#conversation_viewer {
   border-bottom-right-radius: 14px;
 }
 
+.geary-main-window.background.csd stack#conversation_viewer scrolledwindow.geary-conversation-scroller viewport.frame,
+window#GearyMainWindow.background.csd stack#conversation_viewer scrolledwindow.geary-conversation-scroller viewport.frame {
+  background-color: #242424;
+  border-bottom-right-radius: 14px;
+}
+
 .geary-main-window.background.csd stack#conversation_viewer scrolledwindow.geary-conversation-scroller viewport.frame list.conversation-listbox,
 window#GearyMainWindow.background.csd stack#conversation_viewer scrolledwindow.geary-conversation-scroller viewport.frame list.conversation-listbox {
   background-color: transparent;
-  border-bottom-right-radius: 14px;
 }
 
 .geary-main-window.background.csd stack#conversation_viewer searchbar,
diff --git a/src/main/gtk-3.0/gtk-dark.css b/src/main/gtk-3.0/gtk-dark.css
index fa58473..87fb69a 100644
--- a/src/main/gtk-3.0/gtk-dark.css
+++ b/src/main/gtk-3.0/gtk-dark.css
@@ -5848,51 +5848,50 @@ window.background.csd > headerbar.titlebar > leaflet > headerbar:last-child, win
 }
 
 .geary-main-window.background.csd > overlay > box.vertical > paned > .sidebar > searchbar,
-window#GearyMainWindow.background.csd > overlay > box.vertical > paned > .sidebar > searchbar, window.background.csd > hdyleaflet > box.vertical > searchbar {
+window#GearyMainWindow.background.csd > overlay > box.vertical > paned > .sidebar > searchbar, window.background.csd > hdyleaflet > box.vertical > searchbar, window.background.csd > leaflet > box.vertical > searchbar {
   background-color: #333333;
 }
 
 .geary-main-window.background.csd > overlay > box.vertical > paned > .sidebar > searchbar > revealer > box,
-window#GearyMainWindow.background.csd > overlay > box.vertical > paned > .sidebar > searchbar > revealer > box, window.background.csd > hdyleaflet > box.vertical > searchbar > revealer > box {
+window#GearyMainWindow.background.csd > overlay > box.vertical > paned > .sidebar > searchbar > revealer > box, window.background.csd > hdyleaflet > box.vertical > searchbar > revealer > box, window.background.csd > leaflet > box.vertical > searchbar > revealer > box {
   border-color: #0e0e0e;
 }
 
 .geary-main-window.background.csd > overlay > box.vertical > paned > separator,
-window#GearyMainWindow.background.csd > overlay > box.vertical > paned > separator, window.background.csd > box.vertical > paned.horizontal > separator, window.background.csd > overlay > hdyleaflet > separator.sidebar,
-window.background.csd > overlay > leaflet > separator.sidebar, window.background.csd > leaflet > separator.sidebar,
-window.background.csd > hdyleaflet > separator.sidebar,
-window.background.csd > box.horizontal > separator.sidebar, window.background.csd > box.horizontal:not(.titlebar) > separator.vertical, window.background.csd > headerbar.titlebar > box.horizontal > separator.sidebar,
+window#GearyMainWindow.background.csd > overlay > box.vertical > paned > separator, window.background.csd > overlay > hdyleaflet > separator.sidebar,
+window.background.csd > overlay > leaflet > separator.sidebar, box.horizontal > separator.sidebar,
+hdyleaflet > separator.sidebar,
+leaflet > separator.sidebar, window.background.csd > box.horizontal:not(.titlebar) > separator.vertical, window.background.csd > headerbar.titlebar > box.horizontal > separator.sidebar,
 window.background.csd > headerbar.titlebar > hdyleaflet > separator.sidebar,
-window.background.csd > headerbar.titlebar > leaflet > separator.sidebar, .titlebar:not(headerbar) > separator, window.org-gnome-gedit > paned.titlebar > separator, window.org-gnome-gedit > overlay > box.vertical > paned.gedit-side-panel-paned > separator, window.org-gnome-gedit > paned.titlebar > separator:backdrop, window.org-gnome-gedit > overlay > box.vertical > paned.gedit-side-panel-paned > separator:backdrop {
-  min-width: 0;
-  background: none;
-  border-right-color: #0e0e0e;
-  border-bottom-color: #0e0e0e;
+window.background.csd > headerbar.titlebar > leaflet > separator.sidebar, window.background.csd > hdyleaflet > separator.vertical, window.background.csd > leaflet > separator.vertical, .titlebar:not(headerbar) > separator, window.org-gnome-gedit > paned.titlebar > separator, window.org-gnome-gedit > overlay > box.vertical > paned.gedit-side-panel-paned > separator, window.org-gnome-gedit > paned.titlebar > separator:backdrop, window.org-gnome-gedit > overlay > box.vertical > paned.gedit-side-panel-paned > separator:backdrop {
+  background-image: image(#0e0e0e);
+  background-color: transparent;
+  border-right: none;
 }
 
-.tweak-group-startup, list.tweak-group list, hdyleaflet list.frame, leaflet list.frame, hdyleaflet frame.view, leaflet frame.view, hdyleaflet frame:not(.view) list:not(.contacts-contact-list), leaflet frame:not(.view) list:not(.contacts-contact-list) {
+.tweak-group-startup, list.tweak-group list, hdyleaflet list.view, hdyleaflet list.frame, leaflet list.view, leaflet list.frame, hdyleaflet frame.view, leaflet frame.view, hdyleaflet frame:not(.view) list:not(.contacts-contact-list), leaflet frame:not(.view) list:not(.contacts-contact-list) {
   border-radius: 14px;
   box-shadow: inset 0 0 8px rgba(255, 255, 255, 0.03), inset 0 0 3px rgba(255, 255, 255, 0.02), inset 0 0 0 1px rgba(255, 255, 255, 0.04), inset 0 1px rgba(255, 255, 255, 0.06);
   background-color: rgba(255, 255, 255, 0.05);
   border: none;
 }
 
-.tweak-group-startup > separator, list.tweak-group list > separator, hdyleaflet list.frame > separator, leaflet list.frame > separator, hdyleaflet frame.view > separator, leaflet frame.view > separator, hdyleaflet frame:not(.view) list:not(.contacts-contact-list) > separator, leaflet frame:not(.view) list:not(.contacts-contact-list) > separator {
+.tweak-group-startup > separator, list.tweak-group list > separator, hdyleaflet list.view > separator, hdyleaflet list.frame > separator, leaflet list.view > separator, leaflet list.frame > separator, hdyleaflet frame.view > separator, leaflet frame.view > separator, hdyleaflet frame:not(.view) list:not(.contacts-contact-list) > separator, leaflet frame:not(.view) list:not(.contacts-contact-list) > separator {
   background: none;
   min-height: 0;
 }
 
-list.tweak-group list row.activatable:first-child, hdyleaflet list.frame row.activatable:first-child, leaflet list.frame row.activatable:first-child, hdyleaflet frame.view list row.activatable:first-child, leaflet frame.view list row.activatable:first-child, hdyleaflet frame:not(.view) list:not(.contacts-contact-list) row.activatable:first-child, leaflet frame:not(.view) list:not(.contacts-contact-list) row.activatable:first-child {
+list.tweak-group list row.activatable:first-child, hdyleaflet list.view row.activatable:first-child, hdyleaflet list.frame row.activatable:first-child, leaflet list.view row.activatable:first-child, leaflet list.frame row.activatable:first-child, hdyleaflet frame.view list row.activatable:first-child, leaflet frame.view list row.activatable:first-child, hdyleaflet frame:not(.view) list:not(.contacts-contact-list) row.activatable:first-child, leaflet frame:not(.view) list:not(.contacts-contact-list) row.activatable:first-child {
   border-top-left-radius: 14px;
   border-top-right-radius: 14px;
 }
 
-list.tweak-group list row.activatable:last-child, hdyleaflet list.frame row.activatable:last-child, leaflet list.frame row.activatable:last-child, hdyleaflet frame.view list row.activatable:last-child, leaflet frame.view list row.activatable:last-child, hdyleaflet frame:not(.view) list:not(.contacts-contact-list) row.activatable:last-child, leaflet frame:not(.view) list:not(.contacts-contact-list) row.activatable:last-child {
+list.tweak-group list row.activatable:last-child, hdyleaflet list.view row.activatable:last-child, hdyleaflet list.frame row.activatable:last-child, leaflet list.view row.activatable:last-child, leaflet list.frame row.activatable:last-child, hdyleaflet frame.view list row.activatable:last-child, leaflet frame.view list row.activatable:last-child, hdyleaflet frame:not(.view) list:not(.contacts-contact-list) row.activatable:last-child, leaflet frame:not(.view) list:not(.contacts-contact-list) row.activatable:last-child {
   border-bottom-left-radius: 14px;
   border-bottom-right-radius: 14px;
 }
 
-list.tweak-group list row.activatable:only-child, hdyleaflet list.frame row.activatable:only-child, leaflet list.frame row.activatable:only-child, hdyleaflet frame.view list row.activatable:only-child, leaflet frame.view list row.activatable:only-child, hdyleaflet frame:not(.view) list:not(.contacts-contact-list) row.activatable:only-child, leaflet frame:not(.view) list:not(.contacts-contact-list) row.activatable:only-child {
+list.tweak-group list row.activatable:only-child, hdyleaflet list.view row.activatable:only-child, hdyleaflet list.frame row.activatable:only-child, leaflet list.view row.activatable:only-child, leaflet list.frame row.activatable:only-child, hdyleaflet frame.view list row.activatable:only-child, leaflet frame.view list row.activatable:only-child, hdyleaflet frame:not(.view) list:not(.contacts-contact-list) row.activatable:only-child, leaflet frame:not(.view) list:not(.contacts-contact-list) row.activatable:only-child {
   border-radius: 14px;
 }
 
@@ -5927,11 +5926,6 @@ hdyleaflet frame.view list > separator, leaflet frame.view list > separator {
   border: none;
 }
 
-window.background.csd > hdyleaflet > separator.vertical {
-  min-width: 1px;
-  background-color: #0e0e0e;
-}
-
 window.background.csd > hdyleaflet > box.vertical > stack.main-container {
   background-color: #242424;
   border-bottom-right-radius: 14px;
@@ -6567,6 +6561,10 @@ window.background.csd > box.vertical > paned.horizontal > scrolledwindow treevie
   background-color: transparent;
 }
 
+window.background.csd > box.vertical > paned.horizontal > separator {
+  background-image: image(#0e0e0e);
+}
+
 window.background.csd > paned.titlebar {
   background-color: #373737;
   box-shadow: inset 0 1px rgba(255, 255, 255, 0.1);
@@ -7128,10 +7126,15 @@ window#GearyMainWindow.background.csd stack#conversation_viewer {
   border-bottom-right-radius: 14px;
 }
 
+.geary-main-window.background.csd stack#conversation_viewer scrolledwindow.geary-conversation-scroller viewport.frame,
+window#GearyMainWindow.background.csd stack#conversation_viewer scrolledwindow.geary-conversation-scroller viewport.frame {
+  background-color: #242424;
+  border-bottom-right-radius: 14px;
+}
+
 .geary-main-window.background.csd stack#conversation_viewer scrolledwindow.geary-conversation-scroller viewport.frame list.conversation-listbox,
 window#GearyMainWindow.background.csd stack#conversation_viewer scrolledwindow.geary-conversation-scroller viewport.frame list.conversation-listbox {
   background-color: transparent;
-  border-bottom-right-radius: 14px;
 }
 
 .geary-main-window.background.csd stack#conversation_viewer searchbar,
diff --git a/src/main/gtk-3.0/gtk-light-solid.css b/src/main/gtk-3.0/gtk-light-solid.css
index c5a3dd8..9e0cae2 100644
--- a/src/main/gtk-3.0/gtk-light-solid.css
+++ b/src/main/gtk-3.0/gtk-light-solid.css
@@ -5876,51 +5876,50 @@ window.background.csd > headerbar.titlebar > leaflet > headerbar:last-child, win
 }
 
 .geary-main-window.background.csd > overlay > box.vertical > paned > .sidebar > searchbar,
-window#GearyMainWindow.background.csd > overlay > box.vertical > paned > .sidebar > searchbar, window.background.csd > hdyleaflet > box.vertical > searchbar {
+window#GearyMainWindow.background.csd > overlay > box.vertical > paned > .sidebar > searchbar, window.background.csd > hdyleaflet > box.vertical > searchbar, window.background.csd > leaflet > box.vertical > searchbar {
   background-color: #f0f0f0;
 }
 
 .geary-main-window.background.csd > overlay > box.vertical > paned > .sidebar > searchbar > revealer > box,
-window#GearyMainWindow.background.csd > overlay > box.vertical > paned > .sidebar > searchbar > revealer > box, window.background.csd > hdyleaflet > box.vertical > searchbar > revealer > box {
+window#GearyMainWindow.background.csd > overlay > box.vertical > paned > .sidebar > searchbar > revealer > box, window.background.csd > hdyleaflet > box.vertical > searchbar > revealer > box, window.background.csd > leaflet > box.vertical > searchbar > revealer > box {
   border-color: #d6d6d6;
 }
 
 .geary-main-window.background.csd > overlay > box.vertical > paned > separator,
-window#GearyMainWindow.background.csd > overlay > box.vertical > paned > separator, window.background.csd > box.vertical > paned.horizontal > separator, window.background.csd > overlay > hdyleaflet > separator.sidebar,
-window.background.csd > overlay > leaflet > separator.sidebar, window.background.csd > leaflet > separator.sidebar,
-window.background.csd > hdyleaflet > separator.sidebar,
-window.background.csd > box.horizontal > separator.sidebar, window.background.csd > box.horizontal:not(.titlebar) > separator.vertical, window.background.csd > headerbar.titlebar > box.horizontal > separator.sidebar,
+window#GearyMainWindow.background.csd > overlay > box.vertical > paned > separator, window.background.csd > overlay > hdyleaflet > separator.sidebar,
+window.background.csd > overlay > leaflet > separator.sidebar, box.horizontal > separator.sidebar,
+hdyleaflet > separator.sidebar,
+leaflet > separator.sidebar, window.background.csd > box.horizontal:not(.titlebar) > separator.vertical, window.background.csd > headerbar.titlebar > box.horizontal > separator.sidebar,
 window.background.csd > headerbar.titlebar > hdyleaflet > separator.sidebar,
-window.background.csd > headerbar.titlebar > leaflet > separator.sidebar, .titlebar:not(headerbar) > separator, window.org-gnome-gedit > paned.titlebar > separator, window.org-gnome-gedit > overlay > box.vertical > paned.gedit-side-panel-paned > separator, window.org-gnome-gedit > paned.titlebar > separator:backdrop, window.org-gnome-gedit > overlay > box.vertical > paned.gedit-side-panel-paned > separator:backdrop {
-  min-width: 0;
-  background: none;
-  border-right-color: #d6d6d6;
-  border-bottom-color: #d6d6d6;
+window.background.csd > headerbar.titlebar > leaflet > separator.sidebar, window.background.csd > hdyleaflet > separator.vertical, window.background.csd > leaflet > separator.vertical, .titlebar:not(headerbar) > separator, window.org-gnome-gedit > paned.titlebar > separator, window.org-gnome-gedit > overlay > box.vertical > paned.gedit-side-panel-paned > separator, window.org-gnome-gedit > paned.titlebar > separator:backdrop, window.org-gnome-gedit > overlay > box.vertical > paned.gedit-side-panel-paned > separator:backdrop {
+  background-image: image(#d6d6d6);
+  background-color: transparent;
+  border-right: none;
 }
 
-.tweak-group-startup, list.tweak-group list, hdyleaflet list.frame, leaflet list.frame, hdyleaflet frame.view, leaflet frame.view, hdyleaflet frame:not(.view) list:not(.contacts-contact-list), leaflet frame:not(.view) list:not(.contacts-contact-list) {
+.tweak-group-startup, list.tweak-group list, hdyleaflet list.view, hdyleaflet list.frame, leaflet list.view, leaflet list.frame, hdyleaflet frame.view, leaflet frame.view, hdyleaflet frame:not(.view) list:not(.contacts-contact-list), leaflet frame:not(.view) list:not(.contacts-contact-list) {
   border-radius: 14px;
   box-shadow: inset 0 0 8px rgba(0, 0, 0, 0.02), inset 0 0 3px rgba(0, 0, 0, 0.01), inset 0 0 0 1px rgba(0, 0, 0, 0.04), inset 0 1px rgba(0, 0, 0, 0.05);
   background-color: rgba(0, 0, 0, 0.03);
   border: none;
 }
 
-.tweak-group-startup > separator, list.tweak-group list > separator, hdyleaflet list.frame > separator, leaflet list.frame > separator, hdyleaflet frame.view > separator, leaflet frame.view > separator, hdyleaflet frame:not(.view) list:not(.contacts-contact-list) > separator, leaflet frame:not(.view) list:not(.contacts-contact-list) > separator {
+.tweak-group-startup > separator, list.tweak-group list > separator, hdyleaflet list.view > separator, hdyleaflet list.frame > separator, leaflet list.view > separator, leaflet list.frame > separator, hdyleaflet frame.view > separator, leaflet frame.view > separator, hdyleaflet frame:not(.view) list:not(.contacts-contact-list) > separator, leaflet frame:not(.view) list:not(.contacts-contact-list) > separator {
   background: none;
   min-height: 0;
 }
 
-list.tweak-group list row.activatable:first-child, hdyleaflet list.frame row.activatable:first-child, leaflet list.frame row.activatable:first-child, hdyleaflet frame.view list row.activatable:first-child, leaflet frame.view list row.activatable:first-child, hdyleaflet frame:not(.view) list:not(.contacts-contact-list) row.activatable:first-child, leaflet frame:not(.view) list:not(.contacts-contact-list) row.activatable:first-child {
+list.tweak-group list row.activatable:first-child, hdyleaflet list.view row.activatable:first-child, hdyleaflet list.frame row.activatable:first-child, leaflet list.view row.activatable:first-child, leaflet list.frame row.activatable:first-child, hdyleaflet frame.view list row.activatable:first-child, leaflet frame.view list row.activatable:first-child, hdyleaflet frame:not(.view) list:not(.contacts-contact-list) row.activatable:first-child, leaflet frame:not(.view) list:not(.contacts-contact-list) row.activatable:first-child {
   border-top-left-radius: 14px;
   border-top-right-radius: 14px;
 }
 
-list.tweak-group list row.activatable:last-child, hdyleaflet list.frame row.activatable:last-child, leaflet list.frame row.activatable:last-child, hdyleaflet frame.view list row.activatable:last-child, leaflet frame.view list row.activatable:last-child, hdyleaflet frame:not(.view) list:not(.contacts-contact-list) row.activatable:last-child, leaflet frame:not(.view) list:not(.contacts-contact-list) row.activatable:last-child {
+list.tweak-group list row.activatable:last-child, hdyleaflet list.view row.activatable:last-child, hdyleaflet list.frame row.activatable:last-child, leaflet list.view row.activatable:last-child, leaflet list.frame row.activatable:last-child, hdyleaflet frame.view list row.activatable:last-child, leaflet frame.view list row.activatable:last-child, hdyleaflet frame:not(.view) list:not(.contacts-contact-list) row.activatable:last-child, leaflet frame:not(.view) list:not(.contacts-contact-list) row.activatable:last-child {
   border-bottom-left-radius: 14px;
   border-bottom-right-radius: 14px;
 }
 
-list.tweak-group list row.activatable:only-child, hdyleaflet list.frame row.activatable:only-child, leaflet list.frame row.activatable:only-child, hdyleaflet frame.view list row.activatable:only-child, leaflet frame.view list row.activatable:only-child, hdyleaflet frame:not(.view) list:not(.contacts-contact-list) row.activatable:only-child, leaflet frame:not(.view) list:not(.contacts-contact-list) row.activatable:only-child {
+list.tweak-group list row.activatable:only-child, hdyleaflet list.view row.activatable:only-child, hdyleaflet list.frame row.activatable:only-child, leaflet list.view row.activatable:only-child, leaflet list.frame row.activatable:only-child, hdyleaflet frame.view list row.activatable:only-child, leaflet frame.view list row.activatable:only-child, hdyleaflet frame:not(.view) list:not(.contacts-contact-list) row.activatable:only-child, leaflet frame:not(.view) list:not(.contacts-contact-list) row.activatable:only-child {
   border-radius: 14px;
 }
 
@@ -5955,11 +5954,6 @@ hdyleaflet frame.view list > separator, leaflet frame.view list > separator {
   border: none;
 }
 
-window.background.csd > hdyleaflet > separator.vertical {
-  min-width: 1px;
-  background-color: #d6d6d6;
-}
-
 window.background.csd > hdyleaflet > box.vertical > stack.main-container {
   background-color: #ffffff;
   border-bottom-right-radius: 14px;
@@ -6588,6 +6582,10 @@ window.background.csd > box.vertical > paned.horizontal > scrolledwindow treevie
   background-color: transparent;
 }
 
+window.background.csd > box.vertical > paned.horizontal > separator {
+  background-image: image(#d6d6d6);
+}
+
 window.background.csd > paned.titlebar {
   background-color: #ffffff;
   box-shadow: inset 0 1px rgba(255, 255, 255, 0.65);
@@ -7149,10 +7147,15 @@ window#GearyMainWindow.background.csd stack#conversation_viewer {
   border-bottom-right-radius: 14px;
 }
 
+.geary-main-window.background.csd stack#conversation_viewer scrolledwindow.geary-conversation-scroller viewport.frame,
+window#GearyMainWindow.background.csd stack#conversation_viewer scrolledwindow.geary-conversation-scroller viewport.frame {
+  background-color: #ffffff;
+  border-bottom-right-radius: 14px;
+}
+
 .geary-main-window.background.csd stack#conversation_viewer scrolledwindow.geary-conversation-scroller viewport.frame list.conversation-listbox,
 window#GearyMainWindow.background.csd stack#conversation_viewer scrolledwindow.geary-conversation-scroller viewport.frame list.conversation-listbox {
   background-color: transparent;
-  border-bottom-right-radius: 14px;
 }
 
 .geary-main-window.background.csd stack#conversation_viewer searchbar,
diff --git a/src/main/gtk-3.0/gtk-light.css b/src/main/gtk-3.0/gtk-light.css
index a428a9a..789437a 100644
--- a/src/main/gtk-3.0/gtk-light.css
+++ b/src/main/gtk-3.0/gtk-light.css
@@ -5872,51 +5872,50 @@ window.background.csd > headerbar.titlebar > leaflet > headerbar:last-child, win
 }
 
 .geary-main-window.background.csd > overlay > box.vertical > paned > .sidebar > searchbar,
-window#GearyMainWindow.background.csd > overlay > box.vertical > paned > .sidebar > searchbar, window.background.csd > hdyleaflet > box.vertical > searchbar {
+window#GearyMainWindow.background.csd > overlay > box.vertical > paned > .sidebar > searchbar, window.background.csd > hdyleaflet > box.vertical > searchbar, window.background.csd > leaflet > box.vertical > searchbar {
   background-color: #f0f0f0;
 }
 
 .geary-main-window.background.csd > overlay > box.vertical > paned > .sidebar > searchbar > revealer > box,
-window#GearyMainWindow.background.csd > overlay > box.vertical > paned > .sidebar > searchbar > revealer > box, window.background.csd > hdyleaflet > box.vertical > searchbar > revealer > box {
+window#GearyMainWindow.background.csd > overlay > box.vertical > paned > .sidebar > searchbar > revealer > box, window.background.csd > hdyleaflet > box.vertical > searchbar > revealer > box, window.background.csd > leaflet > box.vertical > searchbar > revealer > box {
   border-color: #d6d6d6;
 }
 
 .geary-main-window.background.csd > overlay > box.vertical > paned > separator,
-window#GearyMainWindow.background.csd > overlay > box.vertical > paned > separator, window.background.csd > box.vertical > paned.horizontal > separator, window.background.csd > overlay > hdyleaflet > separator.sidebar,
-window.background.csd > overlay > leaflet > separator.sidebar, window.background.csd > leaflet > separator.sidebar,
-window.background.csd > hdyleaflet > separator.sidebar,
-window.background.csd > box.horizontal > separator.sidebar, window.background.csd > box.horizontal:not(.titlebar) > separator.vertical, window.background.csd > headerbar.titlebar > box.horizontal > separator.sidebar,
+window#GearyMainWindow.background.csd > overlay > box.vertical > paned > separator, window.background.csd > overlay > hdyleaflet > separator.sidebar,
+window.background.csd > overlay > leaflet > separator.sidebar, box.horizontal > separator.sidebar,
+hdyleaflet > separator.sidebar,
+leaflet > separator.sidebar, window.background.csd > box.horizontal:not(.titlebar) > separator.vertical, window.background.csd > headerbar.titlebar > box.horizontal > separator.sidebar,
 window.background.csd > headerbar.titlebar > hdyleaflet > separator.sidebar,
-window.background.csd > headerbar.titlebar > leaflet > separator.sidebar, .titlebar:not(headerbar) > separator, window.org-gnome-gedit > paned.titlebar > separator, window.org-gnome-gedit > overlay > box.vertical > paned.gedit-side-panel-paned > separator, window.org-gnome-gedit > paned.titlebar > separator:backdrop, window.org-gnome-gedit > overlay > box.vertical > paned.gedit-side-panel-paned > separator:backdrop {
-  min-width: 0;
-  background: none;
-  border-right-color: #d6d6d6;
-  border-bottom-color: #d6d6d6;
+window.background.csd > headerbar.titlebar > leaflet > separator.sidebar, window.background.csd > hdyleaflet > separator.vertical, window.background.csd > leaflet > separator.vertical, .titlebar:not(headerbar) > separator, window.org-gnome-gedit > paned.titlebar > separator, window.org-gnome-gedit > overlay > box.vertical > paned.gedit-side-panel-paned > separator, window.org-gnome-gedit > paned.titlebar > separator:backdrop, window.org-gnome-gedit > overlay > box.vertical > paned.gedit-side-panel-paned > separator:backdrop {
+  background-image: image(#d6d6d6);
+  background-color: transparent;
+  border-right: none;
 }
 
-.tweak-group-startup, list.tweak-group list, hdyleaflet list.frame, leaflet list.frame, hdyleaflet frame.view, leaflet frame.view, hdyleaflet frame:not(.view) list:not(.contacts-contact-list), leaflet frame:not(.view) list:not(.contacts-contact-list) {
+.tweak-group-startup, list.tweak-group list, hdyleaflet list.view, hdyleaflet list.frame, leaflet list.view, leaflet list.frame, hdyleaflet frame.view, leaflet frame.view, hdyleaflet frame:not(.view) list:not(.contacts-contact-list), leaflet frame:not(.view) list:not(.contacts-contact-list) {
   border-radius: 14px;
   box-shadow: inset 0 0 8px rgba(0, 0, 0, 0.02), inset 0 0 3px rgba(0, 0, 0, 0.01), inset 0 0 0 1px rgba(0, 0, 0, 0.04), inset 0 1px rgba(0, 0, 0, 0.05);
   background-color: rgba(0, 0, 0, 0.03);
   border: none;
 }
 
-.tweak-group-startup > separator, list.tweak-group list > separator, hdyleaflet list.frame > separator, leaflet list.frame > separator, hdyleaflet frame.view > separator, leaflet frame.view > separator, hdyleaflet frame:not(.view) list:not(.contacts-contact-list) > separator, leaflet frame:not(.view) list:not(.contacts-contact-list) > separator {
+.tweak-group-startup > separator, list.tweak-group list > separator, hdyleaflet list.view > separator, hdyleaflet list.frame > separator, leaflet list.view > separator, leaflet list.frame > separator, hdyleaflet frame.view > separator, leaflet frame.view > separator, hdyleaflet frame:not(.view) list:not(.contacts-contact-list) > separator, leaflet frame:not(.view) list:not(.contacts-contact-list) > separator {
   background: none;
   min-height: 0;
 }
 
-list.tweak-group list row.activatable:first-child, hdyleaflet list.frame row.activatable:first-child, leaflet list.frame row.activatable:first-child, hdyleaflet frame.view list row.activatable:first-child, leaflet frame.view list row.activatable:first-child, hdyleaflet frame:not(.view) list:not(.contacts-contact-list) row.activatable:first-child, leaflet frame:not(.view) list:not(.contacts-contact-list) row.activatable:first-child {
+list.tweak-group list row.activatable:first-child, hdyleaflet list.view row.activatable:first-child, hdyleaflet list.frame row.activatable:first-child, leaflet list.view row.activatable:first-child, leaflet list.frame row.activatable:first-child, hdyleaflet frame.view list row.activatable:first-child, leaflet frame.view list row.activatable:first-child, hdyleaflet frame:not(.view) list:not(.contacts-contact-list) row.activatable:first-child, leaflet frame:not(.view) list:not(.contacts-contact-list) row.activatable:first-child {
   border-top-left-radius: 14px;
   border-top-right-radius: 14px;
 }
 
-list.tweak-group list row.activatable:last-child, hdyleaflet list.frame row.activatable:last-child, leaflet list.frame row.activatable:last-child, hdyleaflet frame.view list row.activatable:last-child, leaflet frame.view list row.activatable:last-child, hdyleaflet frame:not(.view) list:not(.contacts-contact-list) row.activatable:last-child, leaflet frame:not(.view) list:not(.contacts-contact-list) row.activatable:last-child {
+list.tweak-group list row.activatable:last-child, hdyleaflet list.view row.activatable:last-child, hdyleaflet list.frame row.activatable:last-child, leaflet list.view row.activatable:last-child, leaflet list.frame row.activatable:last-child, hdyleaflet frame.view list row.activatable:last-child, leaflet frame.view list row.activatable:last-child, hdyleaflet frame:not(.view) list:not(.contacts-contact-list) row.activatable:last-child, leaflet frame:not(.view) list:not(.contacts-contact-list) row.activatable:last-child {
   border-bottom-left-radius: 14px;
   border-bottom-right-radius: 14px;
 }
 
-list.tweak-group list row.activatable:only-child, hdyleaflet list.frame row.activatable:only-child, leaflet list.frame row.activatable:only-child, hdyleaflet frame.view list row.activatable:only-child, leaflet frame.view list row.activatable:only-child, hdyleaflet frame:not(.view) list:not(.contacts-contact-list) row.activatable:only-child, leaflet frame:not(.view) list:not(.contacts-contact-list) row.activatable:only-child {
+list.tweak-group list row.activatable:only-child, hdyleaflet list.view row.activatable:only-child, hdyleaflet list.frame row.activatable:only-child, leaflet list.view row.activatable:only-child, leaflet list.frame row.activatable:only-child, hdyleaflet frame.view list row.activatable:only-child, leaflet frame.view list row.activatable:only-child, hdyleaflet frame:not(.view) list:not(.contacts-contact-list) row.activatable:only-child, leaflet frame:not(.view) list:not(.contacts-contact-list) row.activatable:only-child {
   border-radius: 14px;
 }
 
@@ -5951,11 +5950,6 @@ hdyleaflet frame.view list > separator, leaflet frame.view list > separator {
   border: none;
 }
 
-window.background.csd > hdyleaflet > separator.vertical {
-  min-width: 1px;
-  background-color: #d6d6d6;
-}
-
 window.background.csd > hdyleaflet > box.vertical > stack.main-container {
   background-color: #ffffff;
   border-bottom-right-radius: 14px;
@@ -6584,6 +6578,10 @@ window.background.csd > box.vertical > paned.horizontal > scrolledwindow treevie
   background-color: transparent;
 }
 
+window.background.csd > box.vertical > paned.horizontal > separator {
+  background-image: image(#d6d6d6);
+}
+
 window.background.csd > paned.titlebar {
   background-color: #ffffff;
   box-shadow: inset 0 1px rgba(255, 255, 255, 0.65);
@@ -7145,10 +7143,15 @@ window#GearyMainWindow.background.csd stack#conversation_viewer {
   border-bottom-right-radius: 14px;
 }
 
+.geary-main-window.background.csd stack#conversation_viewer scrolledwindow.geary-conversation-scroller viewport.frame,
+window#GearyMainWindow.background.csd stack#conversation_viewer scrolledwindow.geary-conversation-scroller viewport.frame {
+  background-color: #ffffff;
+  border-bottom-right-radius: 14px;
+}
+
 .geary-main-window.background.csd stack#conversation_viewer scrolledwindow.geary-conversation-scroller viewport.frame list.conversation-listbox,
 window#GearyMainWindow.background.csd stack#conversation_viewer scrolledwindow.geary-conversation-scroller viewport.frame list.conversation-listbox {
   background-color: transparent;
-  border-bottom-right-radius: 14px;
 }
 
 .geary-main-window.background.csd stack#conversation_viewer searchbar,
diff --git a/src/sass/gtk/_applications.scss b/src/sass/gtk/_applications.scss
index 54814c7..235d54e 100644
--- a/src/sass/gtk/_applications.scss
+++ b/src/sass/gtk/_applications.scss
@@ -1295,10 +1295,9 @@ button.documents-favorite:active:hover {
 
 %side_separator {
   &, &:backdrop {
-    min-width: 0;
-    background: none;
-    border-right-color: if($variant == 'light', $solid_borders_color, $header_border);
-    border-bottom-color: if($variant == 'light', $solid_borders_color, $header_border);
+    background-image: if($variant == 'light', image($solid_borders_color), image($header_border));
+    background-color: transparent;
+    border-right: none;
   }
 }
 
@@ -1370,7 +1369,7 @@ hdyleaflet, leaflet {
     }
   }
 
-  list.frame {
+  list.view, list.frame {
     @extend %circular_list;
 
     row.activatable { @extend %circular_row; }
@@ -1405,10 +1404,9 @@ list {
 
 // separator of sidebar on Gnome contol center and Gnome tweaks
 window.background.csd {
-  > hdyleaflet {
+  > hdyleaflet, > leaflet {
     > separator.vertical {
-      min-width: 1px;
-      background-color: if($variant == 'light', $solid_borders_color, $header_border);
+      @extend %side_separator;
     }
 
     > box.vertical {
@@ -1548,12 +1546,12 @@ window.background.csd {
       }
     }
   }
+}
 
-  > leaflet > separator.sidebar,
-  > hdyleaflet > separator.sidebar,
-  > box.horizontal > separator.sidebar {
-    @extend %side_separator;
-  }
+box.horizontal > separator.sidebar,
+hdyleaflet > separator.sidebar,
+leaflet > separator.sidebar { // reset
+  @extend %side_separator;
 }
 
 //
@@ -2205,7 +2203,7 @@ window.background.csd {
     }
 
     > separator {
-      @extend %side_separator;
+      background-image: if($variant == 'light', image($solid_borders_color), image($header_border));
     }
   }
 
@@ -2778,9 +2776,11 @@ window#GearyMainWindow.background.csd {
 
     scrolledwindow.geary-conversation-scroller {
       viewport.frame {
+        background-color: $base_color;
+        border-bottom-right-radius: $wm_radius;
+
         list.conversation-listbox {
           background-color: transparent;
-          border-bottom-right-radius: $wm_radius;
         }
       }
     }