better-auth/docs/app/docs/layout.tsx

import { DocsLayout } from "fumadocs-ui/layouts/docs";
import type { ReactNode } from "react";
import { docsOptions } from "../layout.config";
import ArticleLayout from "@/components/side-bar";
import { DocsNavBarMobile } from "@/components/nav-mobile";

export default function Layout({ children }: { children: ReactNode }) {
	return (
		<DocsLayout
			{...docsOptions}
			sidebar={{
				component: (
					<div className="mr-[--fd-sidebar-width]">
						<ArticleLayout />
					</div>
				),
			}}
		>
			<DocsNavBarMobile />
			{children}
		</DocsLayout>
	);
}