refactor: update UI styling and download link to point to GitHub releases

src/components/About.tsx

@@ -6,10 +6,10 @@ export function About() {
   return (
     <section
       id="about"
-      className="relative overflow-hidden bg-black py-20 sm:py-28"
+      className="relative overflow-hidden bg-gray-900 py-20 sm:py-28"
     >
       <div className="absolute top-1/2 left-20 -translate-y-1/2 sm:left-1/2 sm:-translate-x-1/2">
-        <CircleBackground color="#fff" />
+        <CircleBackground color="#fff" className="animate-spin-slower" />
       </div>
       <Container className="relative">
         <div className="mx-auto max-w-3xl sm:text-center">

src/components/DownloadLink.tsx

@@ -4,8 +4,10 @@ import { ArrowDownTrayIcon } from '@heroicons/react/24/solid'
 export function DownloadLink() {
   return (
     <Link
-      href="#"
+      href="https://github.com/threefoldtech/mycelium/releases"
       aria-label="Download Mycelium"
+      target="_blank"
+      rel="noopener noreferrer"
       className="inline-flex items-center rounded-lg bg-cyan-500 px-4 py-2 text-sm font-semibold text-white hover:bg-cyan-600 transition-colors"
     >
       <ArrowDownTrayIcon className="h-5 w-5 mr-2" />

src/components/Header.tsx

@@ -126,7 +126,7 @@ export function Header() {
                             <Button href="https://docs.ourworld.tf/mycelium_cloud/docs/" variant="outline">
                               Docs
                             </Button>
-                            <Button variant="solid" color="cyan" href="https://www.mycelium.threefold.io/download/">Get Mycelium</Button>
+                            <Button variant="solid" color="cyan" href="/download/">Get Mycelium</Button>
                           </div>
                         </PopoverPanel>
                       </>

src/components/Hero.tsx

@@ -98,7 +98,7 @@ function PlayIcon(props: React.ComponentPropsWithoutRef<'svg'>) {
 
 export function Hero() {
   return (
-    <div className="overflow-hidden py-20 sm:py-32 lg:pb-32 xl:pb-36">
+    <div className="overflow-hidden py-32">
       <Container>
         <div className="lg:grid lg:grid-cols-12 lg:gap-x-8 lg:gap-y-20">
           <div className="relative z-10 mx-auto max-w-2xl lg:col-span-7 lg:max-w-none lg:pt-6 xl:col-span-6">