it's organized now

src/app/auth/signin/page.tsx

@@ -78,6 +78,7 @@ export default function SignIn() {
               <Input
                 id="password"
                 type="password"
+                placeholder="****"
                 value={password}
                 onChange={(e) => setPassword(e.target.value)}
                 required

src/components/app-sidebar.tsx

@@ -35,115 +35,170 @@ import { Button } from "@/components/ui/button"
 import { signOut } from "next-auth/react"
 import Link from "next/link"
 
-// Menú para Administrador
-const adminMenuItems = [
+// Menú para Administrador - Agrupado por secciones
+const adminMenuSections = [
   {
-    title: "Dashboard",
-    url: "/admin/dashboard",
-    icon: Home,
+    label: "Principal",
+    items: [
+      {
+        title: "Dashboard",
+        url: "/admin/dashboard",
+        icon: Home,
+      },
+    ],
   },
   {
-    title: "Profesores",
-    url: "/admin/teachers",
-    icon: Users,
+    label: "Gestión de Usuarios",
+    items: [
+      {
+        title: "Profesores",
+        url: "/admin/teachers",
+        icon: Users,
+      },
+      {
+        title: "Estudiantes",
+        url: "/admin/students",
+        icon: GraduationCap,
+      },
+    ],
   },
   {
-    title: "Estudiantes",
-    url: "/admin/students",
-    icon: GraduationCap,
+    label: "Gestión Académica",
+    items: [
+      {
+        title: "Períodos Académicos",
+        url: "/admin/periods",
+        icon: Calendar,
+      },
+      {
+        title: "Clases",
+        url: "/admin/classes",
+        icon: BookOpen,
+      },
+      {
+        title: "Secciones",
+        url: "/admin/sections",
+        icon: School,
+      },
+    ],
   },
   {
-    title: "Períodos Académicos",
-    url: "/admin/periods",
-    icon: Calendar,
+    label: "Asignaciones e Inscripciones",
+    items: [
+      {
+        title: "Asignaciones de Profesores",
+        url: "/admin/teacher-assignments",
+        icon: UserCheck,
+      },
+      {
+        title: "Inscripciones de Estudiantes",
+        url: "/admin/student-enrollments",
+        icon: UserPlus,
+      },
+      {
+        title: "Historial de Inscripciones",
+        url: "/admin/enrollment-history",
+        icon: BarChart3,
+      },
+    ],
   },
   {
-    title: "Clases",
-    url: "/admin/classes",
-    icon: BookOpen,
-  },
-  {
-    title: "Secciones",
-    url: "/admin/sections",
-    icon: School,
-  },
-  {
-    title: "Asignaciones de Profesores",
-    url: "/admin/teacher-assignments",
-    icon: UserCheck,
-  },
-  {
-    title: "Inscripciones de Estudiantes",
-    url: "/admin/student-enrollments",
-    icon: UserPlus,
-  },
-  {
-    title: "Historial de Inscripciones",
-    url: "/admin/enrollment-history",
-    icon: BarChart3,
-  },
-  {
-    title: "Parciales",
-    url: "/admin/partials",
-    icon: Settings,
+    label: "Configuración",
+    items: [
+      {
+        title: "Parciales",
+        url: "/admin/partials",
+        icon: Settings,
+      },
+    ],
   },
 ]
 
-// Menú para Profesor
-const teacherMenuItems = [
-  {
-    title: "Dashboard",
-    url: "/teacher",
-    icon: Home,
-  },
-  {
-    title: "Estudiantes",
-    url: "/teacher/students",
-    icon: GraduationCap,
-  },
+// Menú para Profesor - Agrupado por secciones
+const teacherMenuSections = [
   {
-    title: "Tomar Asistencia",
-    url: "/teacher/attendance",
-    icon: UserCheck,
+    label: "Principal",
+    items: [
+      {
+        title: "Dashboard",
+        url: "/teacher",
+        icon: Home,
+      },
+      {
+        title: "Estudiantes",
+        url: "/teacher/students",
+        icon: GraduationCap,
+      },
+    ],
   },
   {
-    title: "Historial de Asistencia",
-    url: "/teacher/attendance-history",
-    icon: ClipboardList,
+    label: "Gestión de Asistencia",
+    items: [
+      {
+        title: "Tomar Asistencia",
+        url: "/teacher/attendance",
+        icon: UserCheck,
+      },
+      {
+        title: "Historial de Asistencia",
+        url: "/teacher/attendance-history",
+        icon: ClipboardList,
+      },
+      {
+        title: "Asistencia por Estudiante",
+        url: "/teacher/student-attendance",
+        icon: Users,
+      },
+    ],
   },
   {
-    title: "Asistencia por Estudiante",
-    url: "/teacher/student-attendance",
-    icon: Users,
-  },
-  {
-    title: "Exportar Reportes",
-    url: "/teacher/export-reports",
-    icon: Download,
+    label: "Reportes",
+    items: [
+      {
+        title: "Exportar Reportes",
+        url: "/teacher/export-reports",
+        icon: Download,
+      },
+    ],
   },
 ]
 
-// Menú para Estudiante
-const studentMenuItems = [
-  {
-    title: "Dashboard",
-    url: "/student/dashboard",
-    icon: Home,
-  },
+// Menú para Estudiante - Agrupado por secciones
+const studentMenuSections = [
   {
-    title: "Mis Clases",
-    url: "/student/classes",
-    icon: BookOpen,
+    label: "Principal",
+    items: [
+      {
+        title: "Dashboard",
+        url: "/student/dashboard",
+        icon: Home,
+      },
+    ],
   },
   {
-    title: "Mi Asistencia",
-    url: "/student/attendance",
-    icon: ClipboardList,
+    label: "Académico",
+    items: [
+      {
+        title: "Mis Clases",
+        url: "/student/classes",
+        icon: BookOpen,
+      },
+      {
+        title: "Horarios",
+        url: "/student/schedule",
+        icon: Calendar,
+      },
+    ],
   },
   {
-    title: "Horarios",
-    url: "/student/schedule",
-    icon: Calendar,
+    label: "Asistencia",
+    items: [
+      {
+        title: "Mi Asistencia",
+        url: "/student/attendance",
+        icon: ClipboardList,
+      },
+    ],
   },
 ]
 
@@ -161,7 +216,7 @@ export function AppSidebar({ ...props }: React.ComponentProps<typeof Sidebar>) {
   const isAdmin = session.user.role === "admin"
   const isTeacher = session.user.role === "teacher"
   const isStudent = session.user.role === "student"
-  const menuItems = isAdmin ? adminMenuItems : isTeacher ? teacherMenuItems : studentMenuItems
+  const menuSections = isAdmin ? adminMenuSections : isTeacher ? teacherMenuSections : studentMenuSections
   const userInitials = session.user.firstName?.[0] + (session.user.lastName?.[0] || "")
 
   return (
@@ -170,7 +225,7 @@ export function AppSidebar({ ...props }: React.ComponentProps<typeof Sidebar>) {
         <SidebarMenu>
           <SidebarMenuItem>
             <SidebarMenuButton size="lg" asChild>
-              <Link href={isAdmin ? "/admin" : isTeacher ? "/teacher" : "/student"}>
+              <Link href={isAdmin ? "/admin/dashboard" : isTeacher ? "/teacher/dashboard" : "/student/dashboard"}>
                 <div className="flex aspect-square size-8 items-center justify-center rounded-lg bg-sidebar-primary text-sidebar-primary-foreground">
                   <School className="size-4" />
                 </div>
@@ -187,23 +242,25 @@ export function AppSidebar({ ...props }: React.ComponentProps<typeof Sidebar>) {
       </SidebarHeader>
       
       <SidebarContent>
-        <SidebarGroup>
-          <SidebarGroupLabel>Navegación</SidebarGroupLabel>
-          <SidebarGroupContent>
-            <SidebarMenu>
-              {menuItems.map((item) => (
-                <SidebarMenuItem key={item.title}>
-                  <SidebarMenuButton asChild>
-                    <Link href={item.url}>
-                      <item.icon />
-                      <span>{item.title}</span>
-                    </Link>
-                  </SidebarMenuButton>
-                </SidebarMenuItem>
-              ))}
-            </SidebarMenu>
-          </SidebarGroupContent>
-        </SidebarGroup>
+        {menuSections.map((section) => (
+          <SidebarGroup key={section.label}>
+            <SidebarGroupLabel>{section.label}</SidebarGroupLabel>
+            <SidebarGroupContent>
+              <SidebarMenu>
+                {section.items.map((item) => (
+                  <SidebarMenuItem key={item.title}>
+                    <SidebarMenuButton asChild>
+                      <Link href={item.url}>
+                        <item.icon />
+                        <span>{item.title}</span>
+                      </Link>
+                    </SidebarMenuButton>
+                  </SidebarMenuItem>
+                ))}
+              </SidebarMenu>
+            </SidebarGroupContent>
+          </SidebarGroup>
+        ))}
       </SidebarContent>
       
       <SidebarFooter>