diff --git a/apps/client/src/stylesheets/theme-next/shell.css b/apps/client/src/stylesheets/theme-next/shell.css
index 6fac6af980..fcf7f442c3 100644
--- a/apps/client/src/stylesheets/theme-next/shell.css
+++ b/apps/client/src/stylesheets/theme-next/shell.css
@@ -685,7 +685,7 @@ body.layout-vertical.background-effects div.quick-search .dropdown-menu {
 
 #left-pane span.fancytree-node.fancytree-active {
     position: relative;
-    background: transparent !important;
+    background: transparent;
     color: var(--custom-color, var(--left-pane-item-selected-color));
 }
 
@@ -698,6 +698,14 @@ body.layout-vertical.background-effects div.quick-search .dropdown-menu {
     }
 }
 
+/*
+ * .fancytree-node pseudo-elements:
+ *
+ *      - ::before: the active tree item decorator.
+ *      - ::after:  the selected tree item background. A pseudo-element is used instead of the
+ *                  element's background color, to allow alpha compositing for the hover state.
+ */
+
 #left-pane span.fancytree-node.fancytree-active::before {
     position: absolute;
     content: "";
@@ -712,6 +720,24 @@ body.layout-vertical.background-effects div.quick-search .dropdown-menu {
     z-index: -1;
 }
 
+#left-pane span.fancytree-node.fancytree-selected {
+    --left-pane-item-selected-shadow-size: 4px;
+
+    position: relative;
+    background-color: transparent;
+    border-radius: 0;
+}
+
+#left-pane span.fancytree-node.fancytree-selected::after {
+    display: block;
+    position: absolute;
+    z-index: -2;
+    content: "";
+    inset: 0;
+    background: var(--selection-background-color);
+    animation: left-pane-item-select 100ms ease-out;
+}
+
 #left-pane span.fancytree-node.protected > span.fancytree-custom-icon {
     position: relative;
     filter: unset !important;
diff --git a/apps/client/src/stylesheets/tree.css b/apps/client/src/stylesheets/tree.css
index 8ed03215b1..a4869d674e 100644
--- a/apps/client/src/stylesheets/tree.css
+++ b/apps/client/src/stylesheets/tree.css
@@ -185,7 +185,7 @@ span.fancytree-node.fancytree-active-clone:not(.fancytree-active) .fancytree-tit
 
 span.fancytree-active {
     color: var(--active-item-text-color);
-    background-color: var(--active-item-background-color) !important;
+    background-color: var(--active-item-background-color);
     border-color: transparent; /* invisible border */
     border-radius: 5px;
 }
@@ -195,14 +195,9 @@ span.fancytree-active .fancytree-title {
     border: 0;
 }
 
-span.fancytree-selected {
-    border-color: var(--main-border-color) !important;
-    border-radius: 5px;
-}
-
-span.fancytree-selected .fancytree-title {
-    text-decoration: underline;
-    font-style: italic;
+span.fancytree-node.fancytree-selected {
+    background-color: var(--selection-background-color);
+    border-radius: 0;
 }
 
 span.fancytree-selected .fancytree-custom-icon::before {