Update UI design across multiple pages and components

Several changes have been made to improve the user interface and enhance the user experience. This includes redesigning Auth buttons, modifying website layouts and routing, tweaking heading and text sizes for clarity, and revamping the marketing, documentation, and pricing pages. These changes collectively contribute to a cleaner, more concise and navigable interface.

apps/web/app/(marketing)/_components/site-page-header.tsx

@@ -6,16 +6,18 @@ export function SitePageHeader(props: {
   className?: string;
 }) {
   return (
-    <div
-      className={cn('flex flex-col items-center space-y-4', props.className)}
-    >
-      <h1 className={'text-center text-3xl font-semibold xl:text-4xl'}>
-        {props.title}
-      </h1>
+    <div className={cn('border-b py-8 xl:py-12 2xl:py-14', props.className)}>
+      <div className={'container flex flex-col space-y-4'}>
+        <h1 className={'text-3xl font-semibold xl:text-5xl'}>{props.title}</h1>
 
-      <h2 className={'text-center text-xl text-muted-foreground xl:text-2xl'}>
-        <span className={'font-normal'}>{props.subtitle}</span>
-      </h2>
+        <h2
+          className={
+            'text-base text-secondary-foreground xl:text-lg 2xl:text-xl'
+          }
+        >
+          <span className={'font-normal'}>{props.subtitle}</span>
+        </h2>
+      </div>
     </div>
   );
 }