DevTools: make toolbar button click targets square

Source/devtools/front_end/ui/splitWidget.css

Index: Source/devtools/front_end/ui/splitWidget.css
diff --git a/Source/devtools/front_end/ui/splitWidget.css b/Source/devtools/front_end/ui/splitWidget.css
index b32d0009e158363bd6f71a957a3a857ed94c9c2d..77edeb18081b1cd5d4d2849a664d3f5b2c22bf53 100644
--- a/Source/devtools/front_end/ui/splitWidget.css
+++ b/Source/devtools/front_end/ui/splitWidget.css
@@ -108,6 +108,10 @@
     background-color: rgba(0, 0, 0, 0.6);
 }
 
+.shadow-split-widget button.sidebar-show-hide-button:hover {
+    background-color: black;
+}
+
 .shadow-split-widget button.sidebar-show-hide-button:disabled {
     background-color: rgba(0, 0, 0, 0.35);
 }
@@ -120,8 +124,8 @@
 
 .shadow-split-widget button.left-sidebar-show-hide-button,
 .shadow-split-widget button.top-sidebar-show-hide-button {
-    top: 3px;
-    left: 4px;
+    top: 5px;
+    left: 5px;
 }
 
 :host-context(.material) .shadow-split-widget button.left-sidebar-show-hide-button,
@@ -136,8 +140,8 @@
 }
 
 .shadow-split-widget button.right-sidebar-show-hide-button {
-    top: 3px;
-    right:2px;
+    top: 5px;
+    right:4px;
 }
 
 :host-context(.material) .shadow-split-widget button.right-sidebar-show-hide-button {