refactor: adjust spacing and styling in compute pages

- Reduced vertical spacing between header and content sections for tighter layout
- Changed border radius from rounded-3xl to rounded-md for consistent styling
- Added hover effect with gradient background to architecture cards

src/pages/compute/ComputeOverview.tsx

@@ -50,7 +50,7 @@ export function ComputeOverview() {
             Deterministic compute fabric for autonomous workloads.
           </SectionHeader>
 
-          <P color="secondary" className="mt-6 text-gray-600">
+          <P color="secondary" className="mt-4 text-gray-600">
             Mycelium Compute delivers predictable, sovereign performance—free
             from lock-in and drift. Deploy any workload with cryptographic
             precision, knowing the platform verifies, scales, and heals itself
@@ -63,7 +63,7 @@ export function ComputeOverview() {
         </div>
 
         {/* ✅ Light Mode Cards */}
-        <div className="mt-16 grid gap-6 lg:grid-cols-2">
+        <div className="mt-12 grid gap-6 lg:grid-cols-2">
           {overviewCards.map((card) => (
             <div
               key={card.title}