feat(auth): introduce immersive split-screen login design

apps/waterfall-wiki/src/components/GuidanceShell.tsx

@@ -1,3 +1,4 @@
+import a from "@/styles/account.module.css";
 import { ThemeToggle } from "./ThemeToggle";
 import { Brand } from "./Brand";
 import Head from "next/head";
@@ -191,11 +192,10 @@ export default function GuidanceShell({
   }
   if (standalone) return (
     <AccountContext.Provider value={{ user, loading, error, refresh }}>
-      <div className={s.accountPage}>
+      <div className={a.page}>
         <Head><title>{`${title} · 啡跃`}</title></Head>
         <a className={s.skipLink} href="#account-content">跳到正文</a>
-        <header className={s.accountHeader}>
-          <Link href="/" aria-label="啡跃首页"><Brand /></Link>
+        <header className={a.header}>
           <div><Link href="/">返回首页</Link><ThemeToggle /></div>
         </header>
         <main id="account-content">{children}</main>