chore: move for teachers and for students to the middel and modify dockerfile

Dockerfile

@@ -6,10 +6,18 @@ RUN apk add --no-cache libc6-compat
 WORKDIR /app
 COPY package.json yarn.lock* package-lock.json* pnpm-lock.yaml* ./
 RUN \
-  if [ -f yarn.lock ]; then yarn --frozen-lockfile; \
-  elif [ -f package-lock.json ]; then npm ci; \
-  elif [ -f pnpm-lock.yaml ]; then yarn global add pnpm && pnpm i --frozen-lockfile; \
-  else echo "Lockfile not found." && exit 1; \
+  if [ -f yarn.lock ]; then \
+    echo "Installing dependencies with yarn..." && \
+    yarn --frozen-lockfile || exit 1; \
+  elif [ -f package-lock.json ]; then \
+    echo "Installing dependencies with npm..." && \
+    npm ci || exit 1; \
+  elif [ -f pnpm-lock.yaml ]; then \
+    echo "Installing dependencies with pnpm..." && \
+    yarn global add pnpm && pnpm i --frozen-lockfile || exit 1; \
+  else \
+    echo "No lockfile found. Please provide either yarn.lock, package-lock.json, or pnpm-lock.yaml" && \
+    exit 1; \
   fi
 
 FROM base AS frontend-builder

app/page.tsx

@@ -11,7 +11,7 @@ export default function LandingPage() {
     <div className="min-h-screen bg-background-primary">
       {/* Modern Header */}
       <header className="fixed w-full bg-background-secondary/80 backdrop-blur-sm border-b border-border z-50">
-        <div className="container mx-auto px-4 py-4 flex items-center justify-between">
+        <div className="container mx-auto px-4 py-4 flex items-center">
           <Link href="/" className="text-3xl font-bold">
             <span className="text-[#FF6B6B]">P</span>
             <span className="text-[#4ECDC4]">l</span>
@@ -22,23 +22,20 @@ export default function LandingPage() {
             <span className="ml-2 text-[#45B7D1]">A</span>
             <span className="text-[#FDCB6E]">I</span>
           </Link>
-          <nav className="flex items-center space-x-8">
+          <nav className="flex items-center justify-center flex-1 space-x-8">
             <Link href="/for-teachers" className="text-text-secondary hover:text-primary">
-              For Teachers
+              我是老師
             </Link>
             <Link href="/for-students" className="text-text-secondary hover:text-primary">
-              For Students
+              我是學生
             </Link>
-            <Link href="/community" className="text-text-secondary hover:text-primary">
-              Community
-            </Link>
-            <button 
-              onClick={toggleTheme}
-              className="px-4 py-2 rounded-lg bg-primary text-white hover:bg-primary/90"
-            >
-              {theme === 'light' ? '🌙' : '☀️'}
-            </button>
           </nav>
+          <button
+            onClick={toggleTheme}
+            className="px-4 py-2 rounded-lg bg-primary text-white hover:bg-primary/90"
+          >
+            {theme === 'light' ? '🌙' : '☀️'}
+          </button>
         </div>
       </header>
 
@@ -62,7 +59,7 @@ export default function LandingPage() {
                 <h3 className="text-xl font-semibold mb-2">Interactive Learning</h3>
                 <p className="text-text-secondary">Engage with AI-powered quizzes, projects, and virtual labs</p>
               </div>
-              
+
               <div className="p-6 rounded-xl bg-background-primary">
                 <div className="w-12 h-12 bg-primary/10 rounded-lg flex items-center justify-center mb-4">
                   <svg className="w-6 h-6 text-primary" fill="none" stroke="currentColor" viewBox="0 0 24 24">
@@ -137,7 +134,7 @@ export default function LandingPage() {
               </h3>
               <p className="text-text-secondary">Making learning fun and accessible for everyone</p>
             </div>
-            
+
             <div className="text-center">
               <h3 className="font-semibold mb-4">Learning Resources</h3>
               <ul className="space-y-2">
@@ -146,7 +143,7 @@ export default function LandingPage() {
                 <li><Link href="/blog" className="text-text-secondary hover:text-primary">Educational Blog</Link></li>
               </ul>
             </div>
-            
+
             <div className="text-center md:text-right">
               <h3 className="font-semibold mb-4">Connect With Us</h3>
               <div className="flex justify-center md:justify-end space-x-4">