refactor: adjust spacing and styling across multiple components for visual consistency

- Increased HomeAurora subtitle margin from mt-4 to mt-6 for better spacing
- Added bg-white to HomeDesign content container for explicit background
- Removed bg-white from HomeTab top separator div
- Reduced network Hero title margin from mt-8 to mt-4 and second paragraph margin from mt-6 to mt-4
- Changed network Hero secondary button variant from cyan to dark
- Reduced NetworkPros title margin from mt-4 to mt-2

src/pages/nodes/NodeHero.tsx

@@ -32,7 +32,7 @@ export function NodeHero() {
                 How it works
               </Button>
               <Button to="#node-architecture" as="a" variant="outline">
-                Explore Docs <span aria-hidden="true">→</span>
+                Explore Docs
               </Button>
             </div>
           </div>