more layout improvements

src/app.css

@@ -44,6 +44,8 @@
 		--sidebar-accent-foreground: 240 5.9% 10%;
 		--sidebar-border: 220 13% 91%;
 		--sidebar-ring: 217.2 91.2% 59.8%;
+
+		--surface: 210 26% 76%;
 	}
 
 	@media (prefers-color-scheme: dark) {
@@ -85,6 +87,8 @@
 			--sidebar-accent-foreground: 240 4.8% 95.9%;
 			--sidebar-border: 240 3.7% 15.9%;
 			--sidebar-ring: 217.2 91.2% 59.8%;
+
+			--surface: 217.2 40.6% 10.5%;
 		}
 	}
 }