Minor change the card styling.

packages/launcher/style/base.css

@@ -111,7 +111,7 @@
   margin: 8px;
   padding: 0px;
   border: 1px solid var(--jp-border-color2);
-  background: var(--jp-layout-color1);
+  background: var(--jp-layout-color0);
   box-shadow: var(--jp-elevation-z2);
   transition: 0.2s box-shadow;
   border-radius: var(--jp-border-radius);
@@ -124,6 +124,7 @@
 
 .jp-LauncherCard:hover {
   box-shadow: var(--jp-elevation-z6);
+  background: var(--jp-layout-color1);
 }
 
 .jp-LauncherCard:active {