diff --git a/app/(protected)/teacher/actions.ts b/app/(protected)/teacher/actions.ts
index c6a2193..5b5e629 100644
--- a/app/(protected)/teacher/actions.ts
+++ b/app/(protected)/teacher/actions.ts
@@ -8,6 +8,7 @@ import { ContentStatus, Prisma, ProficiencyLevel } from "@prisma/client";
 import {
   buildLessonDescriptionMeta,
   parseLessonDescriptionMeta,
+  type LessonActivityMeta,
   type LessonContentType,
 } from "@/lib/courses/lessonContent";
 
@@ -186,9 +187,11 @@ export async function updateLesson(lessonId: string, data: {
     title?: string;
     description?: string;
     videoUrl?: string;
-    youtubeUrl?: string;
+    youtubeUrl?: string | null;
     materialUrl?: string;
     contentType?: LessonContentType;
+    lectureContent?: string;
+    activity?: LessonActivityMeta | null;
     estimatedDurationMinutes?: number;
     isPreview?: boolean; // maps to DB field isFreePreview
     isPublished?: boolean; // optional: for later
@@ -200,7 +203,7 @@ export async function updateLesson(lessonId: string, data: {
         const updateData: Prisma.LessonUpdateInput = { updatedAt: new Date() };
         if (data.title !== undefined) updateData.title = data.title;
         if (data.videoUrl !== undefined) updateData.videoUrl = data.videoUrl;
-        if (data.youtubeUrl !== undefined) updateData.youtubeUrl = data.youtubeUrl;
+        if (data.youtubeUrl !== undefined) updateData.youtubeUrl = data.youtubeUrl?.trim() || null;
         if (data.estimatedDurationMinutes !== undefined) {
           const minutes = Math.max(0, Math.round(data.estimatedDurationMinutes));
           updateData.estimatedDuration = minutes * 60;
@@ -208,7 +211,11 @@ export async function updateLesson(lessonId: string, data: {
         if (data.isPreview !== undefined) updateData.isFreePreview = data.isPreview;
 
         const shouldUpdateMeta =
-          data.description !== undefined || data.contentType !== undefined || data.materialUrl !== undefined;
+          data.description !== undefined ||
+          data.contentType !== undefined ||
+          data.materialUrl !== undefined ||
+          data.lectureContent !== undefined ||
+          data.activity !== undefined;
 
         if (shouldUpdateMeta) {
           const lesson = await db.lesson.findUnique({
@@ -221,7 +228,9 @@ export async function updateLesson(lessonId: string, data: {
             text: data.description ?? existingMeta.text,
             contentType: data.contentType ?? existingMeta.contentType,
             materialUrl: data.materialUrl ?? existingMeta.materialUrl,
-          });
+            lectureContent: data.lectureContent ?? existingMeta.lectureContent,
+            activity: data.activity ?? existingMeta.activity,
+          }) as Prisma.InputJsonValue;
         }
 
         await db.lesson.update({
@@ -300,7 +309,7 @@ export async function updateModuleTitle(moduleId: string, title: string) {
 }
 
 // 2. CREATE LESSON
-export async function createLesson(moduleId: string) {
+export async function createLesson(moduleId: string, contentType: LessonContentType = "VIDEO") {
     const user = await requireTeacher();
     if (!user) return { success: false, error: "Unauthorized" };
 
@@ -318,9 +327,11 @@ export async function createLesson(moduleId: string) {
             data: {
                 moduleId,
                 title: "Nueva Lección",
-                description: {
-                  contentType: "VIDEO",
-                },
+                description: buildLessonDescriptionMeta({
+                  text: "",
+                  contentType,
+                  lectureContent: "",
+                }) as Prisma.InputJsonValue,
                 orderIndex: newOrder,
                 estimatedDuration: 0,
                 version: 1,
diff --git a/app/(protected)/teacher/courses/[slug]/edit/page.tsx b/app/(protected)/teacher/courses/[slug]/edit/page.tsx
index 096b849..4ce9056 100755
--- a/app/(protected)/teacher/courses/[slug]/edit/page.tsx
+++ b/app/(protected)/teacher/courses/[slug]/edit/page.tsx
@@ -21,6 +21,11 @@ export default async function CourseEditPage({ params }: { params: Promise<{ slu
         include: {
           lessons: {
             orderBy: { orderIndex: "asc" },
+            select: {
+              id: true,
+              title: true,
+              description: true,
+            },
           },
         },
       },
@@ -42,4 +47,4 @@ export default async function CourseEditPage({ params }: { params: Promise<{ slu
 
   // Key forces remount when course updates so uncontrolled inputs (level, status) show new defaultValues after save + router.refresh()
   return <TeacherEditCourseForm key={`${course.id}-${course.updatedAt.toISOString()}`} course={courseData} />;
-}
\ No newline at end of file
+}
diff --git a/app/(protected)/teacher/courses/[slug]/lessons/[lessonId]/LessonEditorForm.tsx b/app/(protected)/teacher/courses/[slug]/lessons/[lessonId]/LessonEditorForm.tsx
index d08c435..f87831e 100644
--- a/app/(protected)/teacher/courses/[slug]/lessons/[lessonId]/LessonEditorForm.tsx
+++ b/app/(protected)/teacher/courses/[slug]/lessons/[lessonId]/LessonEditorForm.tsx
@@ -1,222 +1,676 @@
 "use client";
 
-import { useState } from "react";
+import { useRef, useState } from "react";
 import { useRouter } from "next/navigation";
 import { toast } from "sonner";
 import { updateLesson } from "@/app/(protected)/teacher/actions";
-import VideoUpload from "@/components/teacher/VideoUpload"; // The component you created earlier
 import { getClientLocale } from "@/lib/i18n/clientLocale";
-import { getLessonContentTypeLabel, lessonContentTypes, type LessonContentType } from "@/lib/courses/lessonContent";
+import { markdownToPlainText, markdownToSafeHtml } from "@/lib/courses/lessonMarkdown";
+import { getLessonContentTypeLabel, lessonContentTypes, type LessonActivityMeta, type LessonContentType, type LessonQuestion, type LessonQuestionKind } from "@/lib/courses/lessonContent";
+import VideoUpload from "@/components/teacher/VideoUpload";
+import FileUpload from "@/components/teacher/FileUpload";
 
 interface LessonEditorFormProps {
-    lesson: {
-        id: string;
-        title: string;
-        description?: string | null;
-        videoUrl?: string | null;
-        youtubeUrl?: string | null;
-        isFreePreview?: boolean;
-        contentType: LessonContentType;
-        materialUrl?: string | null;
-        estimatedDurationMinutes: number;
+  lesson: {
+    id: string;
+    title: string;
+    description?: string | null;
+    videoUrl?: string | null;
+    youtubeUrl?: string | null;
+    materialUrl?: string | null;
+    isFreePreview?: boolean;
+    contentType: LessonContentType;
+    lectureContent: string;
+    activity: LessonActivityMeta | null;
+    estimatedDurationMinutes: number;
+  };
+  courseSlug: string;
+}
+
+type EditableQuestion = LessonQuestion;
+
+function createId(prefix: string): string {
+  if (typeof crypto !== "undefined" && typeof crypto.randomUUID === "function") {
+    return `${prefix}-${crypto.randomUUID()}`;
+  }
+  return `${prefix}-${Math.random().toString(36).slice(2, 10)}`;
+}
+
+function createTrueFalseQuestion(): EditableQuestion {
+  return {
+    id: createId("q"),
+    kind: "TRUE_FALSE",
+    prompt: "",
+    explanation: "",
+    options: [
+      { id: "true", text: "Verdadero", isCorrect: true },
+      { id: "false", text: "Falso", isCorrect: false },
+    ],
+  };
+}
+
+function createMultipleChoiceQuestion(): EditableQuestion {
+  return {
+    id: createId("q"),
+    kind: "MULTIPLE_CHOICE",
+    prompt: "",
+    explanation: "",
+    options: [
+      { id: createId("opt"), text: "", isCorrect: true },
+      { id: createId("opt"), text: "", isCorrect: false },
+    ],
+  };
+}
+
+function normalizeQuestion(question: EditableQuestion): EditableQuestion {
+  if (question.kind === "TRUE_FALSE") {
+    const correctOptionId =
+      question.options.find((option) => option.isCorrect)?.id ?? "true";
+    return {
+      ...question,
+      options: [
+        { id: "true", text: "Verdadero", isCorrect: correctOptionId === "true" },
+        { id: "false", text: "Falso", isCorrect: correctOptionId === "false" },
+      ],
     };
-    courseSlug: string;
+  }
+
+  const filteredOptions = question.options.filter((option) => option.text.trim());
+  const hasCorrect = filteredOptions.some((option) => option.isCorrect);
+
+  return {
+    ...question,
+    options: filteredOptions.map((option, index) => ({
+      ...option,
+      text: option.text.trim(),
+      isCorrect: hasCorrect ? option.isCorrect : index === 0,
+    })),
+  };
+}
+
+function isAssessmentType(contentType: LessonContentType): boolean {
+  return contentType === "ACTIVITY" || contentType === "QUIZ" || contentType === "FINAL_EXAM";
+}
+
+function getYouTubeEmbedUrl(url: string): string | null {
+  const value = url.trim();
+  if (!value) return null;
+  const watchMatch = value.match(/(?:youtube\.com\/watch\?v=)([a-zA-Z0-9_-]+)/);
+  if (watchMatch) return `https://www.youtube.com/embed/${watchMatch[1]}`;
+  const shortMatch = value.match(/(?:youtu\.be\/)([a-zA-Z0-9_-]+)/);
+  if (shortMatch) return `https://www.youtube.com/embed/${shortMatch[1]}`;
+  const embedMatch = value.match(/(?:youtube\.com\/embed\/)([a-zA-Z0-9_-]+)/);
+  if (embedMatch) return value;
+  return null;
 }
 
 export function LessonEditorForm({ lesson, courseSlug }: LessonEditorFormProps) {
-    const router = useRouter();
-    const [loading, setLoading] = useState(false);
-    const [title, setTitle] = useState(lesson.title);
-    const [description, setDescription] = useState(lesson.description ?? "");
-    const [youtubeUrl, setYoutubeUrl] = useState(lesson.youtubeUrl ?? "");
-    const [isFreePreview, setIsFreePreview] = useState(lesson.isFreePreview ?? false);
-    const [contentType, setContentType] = useState<LessonContentType>(lesson.contentType);
-    const [materialUrl, setMaterialUrl] = useState(lesson.materialUrl ?? "");
-    const [durationMinutes, setDurationMinutes] = useState(lesson.estimatedDurationMinutes);
+  const router = useRouter();
+  const lectureRef = useRef<HTMLTextAreaElement | null>(null);
+  const [loading, setLoading] = useState(false);
+  const [title, setTitle] = useState(lesson.title);
+  const [youtubeUrl, setYoutubeUrl] = useState(lesson.youtubeUrl ?? "");
+  const [videoUrl, setVideoUrl] = useState(lesson.videoUrl ?? "");
+  const [materialUrl, setMaterialUrl] = useState(lesson.materialUrl ?? "");
+  const [isFreePreview, setIsFreePreview] = useState(lesson.isFreePreview ?? false);
+  const [contentType, setContentType] = useState<LessonContentType>(lesson.contentType);
+  const [durationMinutes, setDurationMinutes] = useState(lesson.estimatedDurationMinutes);
+  const [lectureContent, setLectureContent] = useState(lesson.lectureContent || lesson.description || "");
+  const [activityInstructions, setActivityInstructions] = useState(
+    lesson.activity?.instructions || lesson.description || "",
+  );
+  const [passingScorePercent, setPassingScorePercent] = useState(lesson.activity?.passingScorePercent ?? 70);
+  const [activityQuestions, setActivityQuestions] = useState<EditableQuestion[]>(
+    lesson.activity?.questions?.length ? lesson.activity.questions : [],
+  );
 
-    const showSavedToast = () => {
-        const isSpanish = getClientLocale() === "es";
-        toast.success(isSpanish ? "Cambios guardados" : "Changes saved", {
-            description: isSpanish
-                ? "Puedes seguir editando o volver al panel de cursos."
-                : "You can keep editing or go back to the courses dashboard.",
-            action: {
-                label: isSpanish ? "Volver a cursos" : "Back to courses",
-                onClick: () => router.push("/teacher"),
-            },
-            cancel: {
-                label: isSpanish ? "Seguir editando" : "Keep editing",
-                onClick: () => {},
-            },
-            duration: 7000,
-        });
-    };
+  const handleVideoUploaded = (url: string) => {
+    setVideoUrl(url);
+    toast.success("Video cargado en el formulario (no olvides Guardar Cambios)");
+  };
 
-    // 1. Auto-save Video URL when upload finishes
-    const handleVideoUploaded = async (url: string) => {
-        toast.loading("Guardando video...");
-        const res = await updateLesson(lesson.id, { videoUrl: url });
+  const handleMaterialUploaded = (url: string) => {
+    setMaterialUrl(url);
+    toast.success("Material cargado en el formulario (no olvides Guardar Cambios)");
+  };
 
-        if (res.success) {
-            toast.dismiss();
-            toast.success("Video guardado correctamente");
-            router.refresh(); // Update the UI to show the new video player
-        } else {
-            toast.error("Error al guardar el video en la base de datos");
+  const showSavedToast = () => {
+    const isSpanish = getClientLocale() === "es";
+    toast.success(isSpanish ? "Cambios guardados" : "Changes saved", {
+      description: isSpanish
+        ? "Puedes seguir editando o volver al panel de cursos."
+        : "You can keep editing or go back to the courses dashboard.",
+      action: {
+        label: isSpanish ? "Volver a cursos" : "Back to courses",
+        onClick: () => router.push("/teacher"),
+      },
+      cancel: {
+        label: isSpanish ? "Seguir editando" : "Keep editing",
+        onClick: () => {},
+      },
+      duration: 7000,
+    });
+  };
+
+  const insertMarkdown = (prefix: string, suffix = "", placeholder = "texto") => {
+    const target = lectureRef.current;
+    if (!target) return;
+    const start = target.selectionStart;
+    const end = target.selectionEnd;
+    const selected = lectureContent.slice(start, end);
+    const replacement = `${prefix}${selected || placeholder}${suffix}`;
+    const nextContent = `${lectureContent.slice(0, start)}${replacement}${lectureContent.slice(end)}`;
+    setLectureContent(nextContent);
+
+    requestAnimationFrame(() => {
+      target.focus();
+      target.setSelectionRange(start + prefix.length, start + prefix.length + (selected || placeholder).length);
+    });
+  };
+
+  const updateQuestion = (questionId: string, updater: (question: EditableQuestion) => EditableQuestion) => {
+    setActivityQuestions((prev) => prev.map((question) => (question.id === questionId ? updater(question) : question)));
+  };
+
+  const changeQuestionKind = (questionId: string, kind: LessonQuestionKind) => {
+    updateQuestion(questionId, (question) => {
+      if (kind === question.kind) return question;
+      if (kind === "TRUE_FALSE") {
+        return {
+          ...createTrueFalseQuestion(),
+          id: question.id,
+          prompt: question.prompt,
+          explanation: question.explanation,
+        };
+      }
+      return {
+        ...createMultipleChoiceQuestion(),
+        id: question.id,
+        prompt: question.prompt,
+        explanation: question.explanation,
+      };
+    });
+  };
+
+  const validateForSave = (): { ok: boolean; normalizedQuestions: EditableQuestion[] } => {
+    if (!title.trim()) {
+      toast.error("El título de la lección es obligatorio.");
+      return { ok: false, normalizedQuestions: [] };
+    }
+
+    if (contentType === "VIDEO") {
+      const hasYouTube = getYouTubeEmbedUrl(youtubeUrl);
+      const hasDirectVideo = videoUrl.trim();
+      
+      if (!hasYouTube && !hasDirectVideo) {
+        toast.error("Para video, sube un archivo o ingresa una URL válida de YouTube.");
+        return { ok: false, normalizedQuestions: [] };
+      }
+    }
+
+    if (contentType === "LECTURE") {
+      const plainLecture = markdownToPlainText(lectureContent);
+      if (plainLecture.length < 20) {
+        toast.error("La lectura necesita contenido con formato (mínimo 20 caracteres).");
+        return { ok: false, normalizedQuestions: [] };
+      }
+    }
+
+    if (isAssessmentType(contentType)) {
+      if (activityQuestions.length === 0) {
+        toast.error("Agrega al menos una pregunta para esta actividad.");
+        return { ok: false, normalizedQuestions: [] };
+      }
+
+      const normalized = activityQuestions.map(normalizeQuestion);
+
+      for (let index = 0; index < normalized.length; index += 1) {
+        const question = normalized[index];
+        if (!question.prompt.trim()) {
+          toast.error(`La pregunta ${index + 1} no tiene enunciado.`);
+          return { ok: false, normalizedQuestions: [] };
         }
-    };
 
-    // 2. Save Text Changes (Title/Desc/YouTube/Preview)
-    const handleSave = async () => {
-        setLoading(true);
-        const res = await updateLesson(lesson.id, {
-            title,
-            description,
-            youtubeUrl: youtubeUrl.trim() || undefined,
-            materialUrl: materialUrl.trim() || undefined,
-            contentType,
-            estimatedDurationMinutes: durationMinutes,
-            isPreview: isFreePreview,
-        });
-        if (res.success) {
-            showSavedToast();
-            router.refresh();
-        } else {
-            toast.error("Error al guardar cambios");
+        if (question.options.length < 2) {
+          toast.error(`La pregunta ${index + 1} debe tener al menos 2 opciones.`);
+          return { ok: false, normalizedQuestions: [] };
         }
-        setLoading(false);
+
+        const correctCount = question.options.filter((option) => option.isCorrect).length;
+        if (correctCount !== 1) {
+          toast.error(`La pregunta ${index + 1} debe tener exactamente 1 respuesta correcta.`);
+          return { ok: false, normalizedQuestions: [] };
+        }
+      }
+
+      return { ok: true, normalizedQuestions: normalized };
+    }
+
+    return { ok: true, normalizedQuestions: [] };
+  };
+
+  const handleSave = async () => {
+    const validation = validateForSave();
+    if (!validation.ok) return;
+
+    setLoading(true);
+    const lectureSummary = markdownToPlainText(lectureContent).slice(0, 240);
+    const activitySummary = activityInstructions.trim().slice(0, 240);
+
+    const payload = {
+      title: title.trim(),
+      contentType,
+      youtubeUrl: contentType === "VIDEO" ? youtubeUrl.trim() : null,
+      videoUrl: contentType === "VIDEO" ? videoUrl.trim() : undefined,
+      materialUrl: materialUrl.trim() || undefined,
+      description:
+        contentType === "LECTURE"
+          ? lectureSummary
+          : isAssessmentType(contentType)
+            ? activitySummary
+            : title.trim(),
+      lectureContent: contentType === "LECTURE" ? lectureContent.trim() : "",
+      activity: isAssessmentType(contentType)
+        ? {
+            instructions: activityInstructions.trim(),
+            passingScorePercent: contentType === "ACTIVITY" ? 0 : passingScorePercent,
+            questions: validation.normalizedQuestions,
+          }
+        : null,
+      estimatedDurationMinutes: durationMinutes,
+      isPreview: isFreePreview,
     };
 
-    return (
-        <div className="grid grid-cols-1 lg:grid-cols-3 gap-8">
+    const res = await updateLesson(lesson.id, payload);
+    if (res.success) {
+      showSavedToast();
+      router.refresh();
+    } else {
+      toast.error("Error al guardar cambios");
+    }
+    setLoading(false);
+  };
 
-            {/* LEFT: Video & Content */}
-            <div className="lg:col-span-2 space-y-6">
+  const lecturePreview = markdownToSafeHtml(lectureContent);
+  const videoEmbedUrl = getYouTubeEmbedUrl(youtubeUrl);
 
-                {/* Video Upload Section */}
-                <section className="bg-white rounded-xl border border-slate-200 shadow-sm overflow-hidden">
-                    <div className="p-6 border-b border-slate-100">
-                        <h2 className="font-semibold text-slate-900">Video del Curso</h2>
-                        <p className="text-sm text-slate-500">Sube el video principal de esta lección.</p>
-                    </div>
-                    <div className="p-6 bg-slate-50/50">
-                        <VideoUpload
-                            lessonId={lesson.id}
-                            currentVideoUrl={lesson.videoUrl}
-                            onUploadComplete={handleVideoUploaded}
-                        />
-                    </div>
-                    <div className="border-t border-slate-100 p-6">
-                        <label className="block text-sm font-medium text-slate-700 mb-1">YouTube URL</label>
-                        <input
-                            type="url"
-                            value={youtubeUrl}
-                            onChange={(e) => setYoutubeUrl(e.target.value)}
-                            placeholder="https://www.youtube.com/watch?v=..."
-                            className="w-full rounded-md border border-slate-300 px-3 py-2 outline-none focus:border-black"
-                        />
-                        <p className="mt-1 text-xs text-slate-500">Si se proporciona, se usará en lugar del video subido en la lección.</p>
-                    </div>
-                </section>
+  return (
+    <div className="grid grid-cols-1 gap-8 lg:grid-cols-3">
+      <div className="space-y-6 lg:col-span-2">
+        <section className="space-y-4 rounded-xl border border-slate-200 bg-white p-6 shadow-sm">
+          <div>
+            <label className="mb-1 block text-sm font-medium text-slate-700">Titulo de la Leccion</label>
+            <input
+              value={title}
+              onChange={(event) => setTitle(event.target.value)}
+              className="w-full rounded-md border border-slate-300 px-3 py-2 outline-none focus:border-black"
+            />
+          </div>
 
-                {/* Text Content */}
-                <section className="bg-white rounded-xl border border-slate-200 shadow-sm p-6 space-y-4">
-                    <div>
-                        <label className="block text-sm font-medium text-slate-700 mb-1">Título de la Lección</label>
-                        <input
-                            value={title}
-                            onChange={(e) => setTitle(e.target.value)}
-                            className="w-full rounded-md border border-slate-300 px-3 py-2 outline-none focus:border-black"
-                        />
-                    </div>
+          {contentType === "VIDEO" ? (
+            <div className="space-y-4">
+              <label className="block text-sm font-medium text-slate-700">Contenido de Video</label>
+              
+              <div className="rounded-lg border border-slate-200 bg-slate-50 p-4">
+                 <p className="mb-2 text-xs font-semibold text-slate-500 uppercase">Opción 1: Subida directa</p>
+                 <VideoUpload
+                    lessonId={lesson.id}
+                    currentVideoUrl={videoUrl}
+                    onUploadComplete={handleVideoUploaded}
+                 />
+              </div>
 
-                    <div>
-                        <label className="block text-sm font-medium text-slate-700 mb-1">Descripción / Notas</label>
-                        <textarea
-                            rows={6}
-                            value={description}
-                            onChange={(e) => setDescription(e.target.value)}
-                            className="w-full rounded-md border border-slate-300 px-3 py-2 outline-none focus:border-black"
-                            placeholder="Escribe aquí el contenido de la lección..."
-                        />
-                    </div>
+              <div className="rounded-lg border border-slate-200 bg-slate-50 p-4">
+                <p className="mb-2 text-xs font-semibold text-slate-500 uppercase">Opción 2: YouTube URL</p>
+                <input
+                    type="url"
+                    value={youtubeUrl}
+                    onChange={(event) => setYoutubeUrl(event.target.value)}
+                    placeholder="https://www.youtube.com/watch?v=..."
+                    className="w-full rounded-md border border-slate-300 px-3 py-2 outline-none focus:border-black"
+                />
+              </div>
 
-                    <div>
-                        <label className="block text-sm font-medium text-slate-700 mb-1">URL de material (PDF / actividad / lectura)</label>
-                        <input
-                            type="url"
-                            value={materialUrl}
-                            onChange={(e) => setMaterialUrl(e.target.value)}
-                            placeholder="https://.../material.pdf"
-                            className="w-full rounded-md border border-slate-300 px-3 py-2 outline-none focus:border-black"
-                        />
-                        <p className="mt-1 text-xs text-slate-500">Se usará en la vista del alumno como lectura o actividad descargable.</p>
-                    </div>
-                </section>
+              <p className="text-xs text-slate-500 italic">Si ambas están presentes, se priorizará YouTube en la vista del alumno.</p>
+              <div className="overflow-hidden rounded-lg border border-slate-200 bg-slate-100">
+                {videoEmbedUrl ? (
+                  <iframe
+                    className="aspect-video w-full"
+                    src={videoEmbedUrl}
+                    title="Vista previa de YouTube"
+                    allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture"
+                    allowFullScreen
+                  />
+                ) : videoUrl ? (
+                  <div className="flex aspect-video items-center justify-center bg-black text-sm text-white">
+                    <video src={videoUrl} controls className="w-full h-full" />
+                  </div>
+                ) : (
+                  <div className="flex aspect-video items-center justify-center text-sm text-slate-500">
+                    Agrega una URL o sube un video para previsualizar.
+                  </div>
+                )}
+              </div>
             </div>
+          ) : null}
 
-            {/* RIGHT: Settings / Actions */}
-            <div className="space-y-6">
-                <div className="bg-white rounded-xl border border-slate-200 shadow-sm p-6">
-                    <h3 className="font-semibold text-slate-900 mb-4">Tipo de contenido</h3>
-                    <label className="block text-sm text-slate-700 mb-2">Formato de la lección</label>
-                    <select
-                        value={contentType}
-                        onChange={(e) => setContentType(e.target.value as LessonContentType)}
-                        className="w-full rounded-md border border-slate-300 px-3 py-2 outline-none focus:border-black"
+          <section className="mt-8 border-t border-slate-100 pt-6">
+             <h3 className="mb-4 text-lg font-semibold text-slate-900">Material Descargable</h3>
+             <FileUpload
+                lessonId={lesson.id}
+                currentFileUrl={materialUrl}
+                onUploadComplete={handleMaterialUploaded}
+                onRemove={() => setMaterialUrl("")}
+             />
+             <p className="mt-2 text-xs text-slate-500">Este archivo aparecerá como un recurso descargable para el alumno en esta lección.</p>
+          </section>
+
+          {contentType === "LECTURE" ? (
+            <div className="space-y-3">
+              <label className="block text-sm font-medium text-slate-700">Contenido de la lectura</label>
+              <div className="flex flex-wrap gap-2">
+                <button
+                  type="button"
+                  onClick={() => insertMarkdown("## ")}
+                  className="rounded-md border border-slate-300 bg-white px-2 py-1 text-xs font-medium text-slate-700 hover:bg-slate-50"
+                >
+                  Titulo
+                </button>
+                <button
+                  type="button"
+                  onClick={() => insertMarkdown("**", "**")}
+                  className="rounded-md border border-slate-300 bg-white px-2 py-1 text-xs font-medium text-slate-700 hover:bg-slate-50"
+                >
+                  Negrita
+                </button>
+                <button
+                  type="button"
+                  onClick={() => insertMarkdown("*", "*")}
+                  className="rounded-md border border-slate-300 bg-white px-2 py-1 text-xs font-medium text-slate-700 hover:bg-slate-50"
+                >
+                  Cursiva
+                </button>
+                <button
+                  type="button"
+                  onClick={() => insertMarkdown("- ")}
+                  className="rounded-md border border-slate-300 bg-white px-2 py-1 text-xs font-medium text-slate-700 hover:bg-slate-50"
+                >
+                  Lista
+                </button>
+                <button
+                  type="button"
+                  onClick={() => insertMarkdown("[", "](https://...)")}
+                  className="rounded-md border border-slate-300 bg-white px-2 py-1 text-xs font-medium text-slate-700 hover:bg-slate-50"
+                >
+                  Enlace
+                </button>
+              </div>
+              <textarea
+                ref={lectureRef}
+                rows={14}
+                value={lectureContent}
+                onChange={(event) => setLectureContent(event.target.value)}
+                className="w-full rounded-md border border-slate-300 px-3 py-2 font-mono text-sm outline-none focus:border-black"
+                placeholder="Escribe la lectura con formato..."
+              />
+              <p className="text-xs text-slate-500">
+                Usa el toolbar para formato rapido. La vista previa muestra como lo vera el alumno.
+              </p>
+              <div className="rounded-xl border border-slate-200 bg-slate-50 p-5">
+                <p className="mb-3 text-xs font-semibold uppercase tracking-wide text-slate-500">Vista previa</p>
+                <article
+                  className="space-y-4 text-[15px] leading-7 text-slate-800 [&_a]:text-blue-700 [&_a]:underline [&_blockquote]:border-l-4 [&_blockquote]:border-slate-300 [&_blockquote]:pl-3 [&_h1]:mt-5 [&_h1]:text-2xl [&_h1]:font-semibold [&_h2]:mt-4 [&_h2]:text-xl [&_h2]:font-semibold [&_h3]:mt-3 [&_h3]:text-lg [&_h3]:font-semibold [&_ol]:list-decimal [&_ol]:space-y-1 [&_ol]:pl-6 [&_p]:whitespace-pre-wrap [&_ul]:list-disc [&_ul]:space-y-1 [&_ul]:pl-6"
+                  dangerouslySetInnerHTML={{ __html: lecturePreview }}
+                />
+              </div>
+            </div>
+          ) : null}
+
+          {isAssessmentType(contentType) ? (
+            <div className="space-y-4">
+              <div>
+                <label className="mb-1 block text-sm font-medium text-slate-700">Instrucciones de la actividad</label>
+                <textarea
+                  rows={4}
+                  value={activityInstructions}
+                  onChange={(event) => setActivityInstructions(event.target.value)}
+                  className="w-full rounded-md border border-slate-300 px-3 py-2 text-sm outline-none focus:border-black"
+                  placeholder="Ej. Responde cada pregunta y revisa tus respuestas al final."
+                />
+              </div>
+
+              {contentType !== "ACTIVITY" ? (
+                <div>
+                  <label className="mb-1 block text-sm font-medium text-slate-700">Puntaje minimo para aprobar (%)</label>
+                  <input
+                    type="number"
+                    min={0}
+                    max={100}
+                    value={passingScorePercent}
+                    onChange={(event) => setPassingScorePercent(Math.max(0, Math.min(100, Number(event.target.value) || 0)))}
+                    className="w-40 rounded-md border border-slate-300 px-3 py-2 outline-none focus:border-black"
+                  />
+                </div>
+              ) : null}
+
+              <div className="space-y-3 rounded-xl border border-slate-200 bg-slate-50 p-4">
+                <div className="flex flex-wrap items-center justify-between gap-2">
+                  <h3 className="text-sm font-semibold text-slate-900">Preguntas</h3>
+                  <div className="flex flex-wrap gap-2">
+                    <button
+                      type="button"
+                      onClick={() => setActivityQuestions((prev) => [...prev, createTrueFalseQuestion()])}
+                      className="rounded-md border border-slate-300 bg-white px-2.5 py-1 text-xs font-medium text-slate-700 hover:bg-slate-100"
                     >
-                        {lessonContentTypes.map((type) => (
-                            <option key={type} value={type}>
-                                {getLessonContentTypeLabel(type)}
-                            </option>
-                        ))}
-                    </select>
-                    <p className="mt-2 text-xs text-slate-500">
-                        Usa “Evaluación final” para marcar el examen obligatorio del curso.
-                    </p>
+                      + Verdadero/Falso
+                    </button>
+                    <button
+                      type="button"
+                      onClick={() => setActivityQuestions((prev) => [...prev, createMultipleChoiceQuestion()])}
+                      className="rounded-md border border-slate-300 bg-white px-2.5 py-1 text-xs font-medium text-slate-700 hover:bg-slate-100"
+                    >
+                      + Opcion multiple
+                    </button>
+                  </div>
+                </div>
 
-                    <label className="block text-sm text-slate-700 mb-1 mt-4">Duración estimada (minutos)</label>
-                    <input
-                        type="number"
-                        min={0}
-                        value={durationMinutes}
-                        onChange={(e) => setDurationMinutes(Math.max(0, Number(e.target.value)))}
-                        className="w-full rounded-md border border-slate-300 px-3 py-2 outline-none focus:border-black"
+                {activityQuestions.length === 0 ? (
+                  <p className="rounded-lg border border-dashed border-slate-300 bg-white px-3 py-4 text-sm text-slate-500">
+                    Todavia no hay preguntas. Agrega la primera para construir la actividad.
+                  </p>
+                ) : null}
+
+                {activityQuestions.map((question, index) => (
+                  <div key={question.id} className="space-y-3 rounded-lg border border-slate-200 bg-white p-4">
+                    <div className="flex flex-wrap items-center justify-between gap-2">
+                      <p className="text-sm font-semibold text-slate-900">Pregunta {index + 1}</p>
+                      <div className="flex items-center gap-2">
+                        <select
+                          value={question.kind}
+                          onChange={(event) => changeQuestionKind(question.id, event.target.value as LessonQuestionKind)}
+                          className="rounded-md border border-slate-300 px-2 py-1 text-xs outline-none focus:border-black"
+                        >
+                          <option value="TRUE_FALSE">Verdadero/Falso</option>
+                          <option value="MULTIPLE_CHOICE">Opcion multiple</option>
+                        </select>
+                        <button
+                          type="button"
+                          onClick={() => setActivityQuestions((prev) => prev.filter((item) => item.id !== question.id))}
+                          className="rounded-md border border-rose-300 px-2 py-1 text-xs font-medium text-rose-700 hover:bg-rose-50"
+                        >
+                          Eliminar
+                        </button>
+                      </div>
+                    </div>
+
+                    <textarea
+                      rows={2}
+                      value={question.prompt}
+                      onChange={(event) =>
+                        updateQuestion(question.id, (current) => ({ ...current, prompt: event.target.value }))
+                      }
+                      className="w-full rounded-md border border-slate-300 px-3 py-2 text-sm outline-none focus:border-black"
+                      placeholder="Escribe el enunciado..."
                     />
-                </div>
 
-                <div className="bg-white rounded-xl border border-slate-200 shadow-sm p-6">
-                    <h3 className="font-semibold text-slate-900 mb-4">Vista previa gratuita</h3>
-                    <label className="flex cursor-pointer items-center gap-2">
-                        <input
-                            type="checkbox"
-                            checked={isFreePreview}
-                            onChange={(e) => setIsFreePreview(e.target.checked)}
-                            className="h-4 w-4 rounded border-slate-300"
-                        />
-                        <span className="text-sm text-slate-700">Accesible sin inscripción (teaser)</span>
-                    </label>
-                    <p className="mt-2 text-xs text-slate-500">Los no inscritos podrán ver esta lección sin comprar el curso.</p>
-                </div>
-                <div className="bg-white rounded-xl border border-slate-200 shadow-sm p-6">
-                    <h3 className="font-semibold text-slate-900 mb-4">Acciones</h3>
-                    <button
-                        onClick={handleSave}
-                        disabled={loading}
-                        className="w-full bg-black text-white rounded-lg py-2.5 font-medium hover:bg-slate-800 disabled:opacity-50 transition-colors"
-                    >
-                        {loading ? "Guardando..." : "Guardar Cambios"}
-                    </button>
+                    {question.kind === "TRUE_FALSE" ? (
+                      <div className="space-y-2 rounded-md border border-slate-200 bg-slate-50 p-3">
+                        {question.options.map((option) => (
+                          <label key={option.id} className="flex items-center gap-2 text-sm text-slate-700">
+                            <input
+                              type="radio"
+                              checked={option.isCorrect}
+                              onChange={() =>
+                                updateQuestion(question.id, (current) => ({
+                                  ...current,
+                                  options: current.options.map((item) => ({
+                                    ...item,
+                                    isCorrect: item.id === option.id,
+                                  })),
+                                }))
+                              }
+                            />
+                            <span>{option.text}</span>
+                          </label>
+                        ))}
+                      </div>
+                    ) : (
+                      <div className="space-y-2 rounded-md border border-slate-200 bg-slate-50 p-3">
+                        {question.options.map((option) => (
+                          <div key={option.id} className="flex items-center gap-2">
+                            <input
+                              type="radio"
+                              checked={option.isCorrect}
+                              onChange={() =>
+                                updateQuestion(question.id, (current) => ({
+                                  ...current,
+                                  options: current.options.map((item) => ({
+                                    ...item,
+                                    isCorrect: item.id === option.id,
+                                  })),
+                                }))
+                              }
+                            />
+                            <input
+                              value={option.text}
+                              onChange={(event) =>
+                                updateQuestion(question.id, (current) => ({
+                                  ...current,
+                                  options: current.options.map((item) =>
+                                    item.id === option.id ? { ...item, text: event.target.value } : item,
+                                  ),
+                                }))
+                              }
+                              className="flex-1 rounded-md border border-slate-300 px-2 py-1 text-sm outline-none focus:border-black"
+                              placeholder="Texto de la opcion"
+                            />
+                            <button
+                              type="button"
+                              onClick={() =>
+                                updateQuestion(question.id, (current) => ({
+                                  ...current,
+                                  options: current.options.filter((item) => item.id !== option.id),
+                                }))
+                              }
+                              className="rounded border border-slate-300 px-2 py-1 text-xs text-slate-600 hover:bg-slate-100"
+                            >
+                              -
+                            </button>
+                          </div>
+                        ))}
+                        <button
+                          type="button"
+                          onClick={() =>
+                            updateQuestion(question.id, (current) => ({
+                              ...current,
+                              options: [...current.options, { id: createId("opt"), text: "", isCorrect: false }],
+                            }))
+                          }
+                          className="rounded-md border border-slate-300 bg-white px-2.5 py-1 text-xs font-medium text-slate-700 hover:bg-slate-100"
+                        >
+                          + Agregar opcion
+                        </button>
+                      </div>
+                    )}
 
-                    <button
-                        onClick={() => router.push(`/teacher/courses/${courseSlug}/edit`)}
-                        className="w-full mt-3 bg-white border border-slate-300 text-slate-700 rounded-lg py-2.5 font-medium hover:bg-slate-50 transition-colors"
-                    >
-                        Volver al Curso
-                    </button>
-                </div>
+                    <input
+                      value={question.explanation}
+                      onChange={(event) =>
+                        updateQuestion(question.id, (current) => ({ ...current, explanation: event.target.value }))
+                      }
+                      className="w-full rounded-md border border-slate-300 px-3 py-2 text-sm outline-none focus:border-black"
+                      placeholder="Explicacion breve (opcional)"
+                    />
+                  </div>
+                ))}
+              </div>
             </div>
+          ) : null}
+        </section>
+      </div>
 
+      <div className="space-y-6">
+        <div className="rounded-xl border border-slate-200 bg-white p-6 shadow-sm">
+          <h3 className="mb-4 font-semibold text-slate-900">Tipo de contenido</h3>
+          <label className="mb-2 block text-sm text-slate-700">Formato de la leccion</label>
+          <select
+            value={contentType}
+            onChange={(event) => setContentType(event.target.value as LessonContentType)}
+            className="w-full rounded-md border border-slate-300 px-3 py-2 outline-none focus:border-black"
+          >
+            {lessonContentTypes.map((type) => (
+              <option key={type} value={type}>
+                {getLessonContentTypeLabel(type)}
+              </option>
+            ))}
+          </select>
+          <p className="mt-2 text-xs text-slate-500">Usa Evaluacion final para marcar el examen obligatorio del curso.</p>
+
+          <label className="mb-1 mt-4 block text-sm text-slate-700">Duracion estimada (minutos)</label>
+          <input
+            type="number"
+            min={0}
+            value={durationMinutes}
+            onChange={(event) => {
+              const parsed = Number(event.target.value);
+              setDurationMinutes(Number.isFinite(parsed) ? Math.max(0, parsed) : 0);
+            }}
+            className="w-full rounded-md border border-slate-300 px-3 py-2 outline-none focus:border-black"
+          />
         </div>
-    );
+
+        <div className="rounded-xl border border-slate-200 bg-white p-6 shadow-sm">
+          <h3 className="mb-4 font-semibold text-slate-900">Vista previa gratuita</h3>
+          <label className="flex cursor-pointer items-center gap-2">
+            <input
+              type="checkbox"
+              checked={isFreePreview}
+              onChange={(event) => setIsFreePreview(event.target.checked)}
+              className="h-4 w-4 rounded border-slate-300"
+            />
+            <span className="text-sm text-slate-700">Accesible sin inscripcion (teaser)</span>
+          </label>
+          <p className="mt-2 text-xs text-slate-500">Los no inscritos podran ver esta leccion sin comprar el curso.</p>
+        </div>
+
+        <div className="rounded-xl border border-slate-200 bg-white p-6 shadow-sm">
+          <h3 className="mb-4 font-semibold text-slate-900">Acciones</h3>
+          <button
+            onClick={handleSave}
+            disabled={loading}
+            className="w-full rounded-lg bg-black py-2.5 font-medium text-white transition-colors hover:bg-slate-800 disabled:opacity-50"
+          >
+            {loading ? "Guardando..." : "Guardar Cambios"}
+          </button>
+
+          <button
+            onClick={() => router.push(`/teacher/courses/${courseSlug}/edit`)}
+            className="mt-3 w-full rounded-lg border border-slate-300 bg-white py-2.5 font-medium text-slate-700 transition-colors hover:bg-slate-50"
+          >
+            Volver al Curso
+          </button>
+        </div>
+      </div>
+    </div>
+  );
 }
diff --git a/app/(protected)/teacher/courses/[slug]/lessons/[lessonId]/page.tsx b/app/(protected)/teacher/courses/[slug]/lessons/[lessonId]/page.tsx
index b0c4ec2..9384d22 100644
--- a/app/(protected)/teacher/courses/[slug]/lessons/[lessonId]/page.tsx
+++ b/app/(protected)/teacher/courses/[slug]/lessons/[lessonId]/page.tsx
@@ -69,6 +69,8 @@ export default async function LessonPage({ params }: PageProps) {
                     title: getText(lesson.title),
                     description: lessonMeta.text,
                     contentType: lessonMeta.contentType,
+                    lectureContent: lessonMeta.lectureContent,
+                    activity: lessonMeta.activity,
                     materialUrl: lessonMeta.materialUrl,
                     estimatedDurationMinutes: Math.max(0, Math.ceil((lesson.estimatedDuration ?? 0) / 60)),
                 }}
diff --git a/app/(public)/courses/[slug]/learn/page.tsx b/app/(public)/courses/[slug]/learn/page.tsx
index 75d00a2..064c8be 100644
--- a/app/(public)/courses/[slug]/learn/page.tsx
+++ b/app/(public)/courses/[slug]/learn/page.tsx
@@ -149,6 +149,8 @@ export default async function CourseLearnPage({ params, searchParams }: PageProp
         title: getText(lesson.title) || "Untitled lesson",
         description: lessonMeta.text,
         contentType: lessonMeta.contentType,
+        lectureContent: lessonMeta.lectureContent,
+        activity: lessonMeta.activity,
         materialUrl: lessonMeta.materialUrl,
         videoUrl: lesson.videoUrl,
         youtubeUrl: lesson.youtubeUrl,
diff --git a/components/courses/StudentClassroomClient.tsx b/components/courses/StudentClassroomClient.tsx
index db64f61..475a1b4 100644
--- a/components/courses/StudentClassroomClient.tsx
+++ b/components/courses/StudentClassroomClient.tsx
@@ -4,14 +4,23 @@ import { useEffect, useMemo, useState, useTransition } from "react";
 import Link from "next/link";
 import { useRouter } from "next/navigation";
 import { Check, CircleDashed, ClipboardCheck, FileText, Lock, PlayCircle } from "lucide-react";
+import { toast } from "sonner";
 import { toggleLessonComplete } from "@/app/(public)/courses/[slug]/learn/actions";
 import ProgressBar from "@/components/ProgressBar";
-import { getLessonContentTypeLabel, isFinalExam, type LessonContentType } from "@/lib/courses/lessonContent";
+import { markdownToSafeHtml } from "@/lib/courses/lessonMarkdown";
+import {
+  getLessonContentTypeLabel,
+  isFinalExam,
+  type LessonActivityMeta,
+  type LessonContentType,
+} from "@/lib/courses/lessonContent";
 
 type ClassroomLesson = {
   id: string;
   title: string;
   description: string;
+  lectureContent: string;
+  activity: LessonActivityMeta | null;
   contentType: LessonContentType;
   materialUrl: string | null;
   videoUrl: string | null;
@@ -40,6 +49,14 @@ type CompletionCertificate = {
   certificateNumber: string | null;
 };
 
+type ActivityResult = {
+  score: number;
+  correct: number;
+  total: number;
+  passed: boolean;
+  questionResults: Record<string, boolean>;
+};
+
 function getYouTubeEmbedUrl(url: string | null | undefined): string | null {
   if (!url?.trim()) return null;
   const trimmed = url.trim();
@@ -57,6 +74,10 @@ function getIsPdfUrl(url: string | null | undefined): boolean {
   return /\.pdf(?:$|\?)/i.test(url.trim());
 }
 
+function isAssessmentType(contentType: LessonContentType): boolean {
+  return contentType === "ACTIVITY" || contentType === "QUIZ" || contentType === "FINAL_EXAM";
+}
+
 export default function StudentClassroomClient({
   courseSlug,
   courseTitle,
@@ -70,6 +91,8 @@ export default function StudentClassroomClient({
   const [selectedLessonId, setSelectedLessonId] = useState(initialSelectedLessonId);
   const [completedLessonIds, setCompletedLessonIds] = useState(initialCompletedLessonIds);
   const [completionCertificate, setCompletionCertificate] = useState<CompletionCertificate | null>(null);
+  const [activityAnswers, setActivityAnswers] = useState<Record<string, string>>({});
+  const [activityResult, setActivityResult] = useState<ActivityResult | null>(null);
 
   useEffect(() => {
     setSelectedLessonId(initialSelectedLessonId);
@@ -89,10 +112,17 @@ export default function StudentClassroomClient({
   const selectedLesson =
     flatLessons.find((lesson) => lesson.id === selectedLessonId) ?? flatLessons[0] ?? null;
 
+  useEffect(() => {
+    setActivityAnswers({});
+    setActivityResult(null);
+  }, [selectedLesson?.id]);
+
   const selectedLessonTypeLabel = selectedLesson ? getLessonContentTypeLabel(selectedLesson.contentType) : "";
+  const selectedLessonActivity = selectedLesson?.activity?.questions?.length ? selectedLesson.activity : null;
+  const selectedLectureHtml = markdownToSafeHtml(selectedLesson?.lectureContent || selectedLesson?.description || "");
 
   const isRestricted = (lessonId: string) => {
-    if (!isEnrolled) return false; // Non-enrolled can click any lesson (preview shows content, locked shows premium message)
+    if (!isEnrolled) return false;
     const lessonIndex = flatLessons.findIndex((lesson) => lesson.id === lessonId);
     if (lessonIndex <= 0) return false;
     if (completedSet.has(lessonId)) return false;
@@ -109,7 +139,7 @@ export default function StudentClassroomClient({
   };
 
   const handleToggleComplete = async () => {
-    if (!selectedLesson || isSaving) return;
+    if (!selectedLesson || isSaving || !isEnrolled) return;
 
     const lessonId = selectedLesson.id;
     const wasCompleted = completedSet.has(lessonId);
@@ -146,6 +176,40 @@ export default function StudentClassroomClient({
     });
   };
 
+  const submitActivity = async () => {
+    if (!selectedLesson || !selectedLessonActivity) return;
+
+    const total = selectedLessonActivity.questions.length;
+    if (total === 0) return;
+
+    const unanswered = selectedLessonActivity.questions.filter((question) => !activityAnswers[question.id]);
+    if (unanswered.length > 0) {
+      toast.error("Responde todas las preguntas antes de enviar.");
+      return;
+    }
+
+    let correct = 0;
+    const questionResults: Record<string, boolean> = {};
+
+    for (const question of selectedLessonActivity.questions) {
+      const answerId = activityAnswers[question.id];
+      const selectedOption = question.options.find((option) => option.id === answerId);
+      const isCorrect = Boolean(selectedOption?.isCorrect);
+      if (isCorrect) correct += 1;
+      questionResults[question.id] = isCorrect;
+    }
+
+    const score = Math.round((correct / total) * 100);
+    const passingScore = selectedLesson.contentType === "ACTIVITY" ? 0 : selectedLessonActivity.passingScorePercent;
+    const passed = selectedLesson.contentType === "ACTIVITY" ? true : score >= passingScore;
+
+    setActivityResult({ score, correct, total, passed, questionResults });
+
+    if (passed && isEnrolled && !completedSet.has(selectedLesson.id)) {
+      await handleToggleComplete();
+    }
+  };
+
   if (!selectedLesson) {
     return (
       <div className="rounded-xl border border-slate-200 bg-white p-6">
@@ -217,6 +281,7 @@ export default function StudentClassroomClient({
           `}</style>
         </>
       ) : null}
+
       <section className="space-y-4 rounded-xl border border-slate-200 bg-white p-5">
         <Link href={`/courses/${courseSlug}`} className="text-sm font-medium text-slate-600 hover:text-slate-900">
           {"<-"} Back to Course
@@ -255,12 +320,113 @@ export default function StudentClassroomClient({
                 key={`${selectedLesson.id}-${selectedLesson.videoUrl}`}
                 className="h-full w-full"
                 controls
-                onEnded={handleToggleComplete}
+                onEnded={() => {
+                  if (isEnrolled) {
+                    void handleToggleComplete();
+                  }
+                }}
                 src={selectedLesson.videoUrl}
               />
             ) : (
-              <div className="flex h-full items-center justify-center text-sm text-slate-300">Video not available for this lesson</div>
+              <div className="flex h-full items-center justify-center text-sm text-slate-300">
+                Video not available for this lesson
+              </div>
             )
+          ) : selectedLesson.contentType === "LECTURE" ? (
+            <article
+              className="space-y-4 text-[16px] leading-8 text-slate-800 [&_a]:font-medium [&_a]:text-blue-700 [&_a]:underline [&_blockquote]:rounded-r-md [&_blockquote]:border-l-4 [&_blockquote]:border-slate-300 [&_blockquote]:bg-slate-100 [&_blockquote]:px-4 [&_blockquote]:py-2 [&_h1]:mt-6 [&_h1]:text-3xl [&_h1]:font-semibold [&_h2]:mt-5 [&_h2]:text-2xl [&_h2]:font-semibold [&_h3]:mt-4 [&_h3]:text-xl [&_h3]:font-semibold [&_ol]:list-decimal [&_ol]:space-y-2 [&_ol]:pl-7 [&_p]:my-3 [&_ul]:list-disc [&_ul]:space-y-2 [&_ul]:pl-7"
+              dangerouslySetInnerHTML={{ __html: selectedLectureHtml }}
+            />
+          ) : isAssessmentType(selectedLesson.contentType) && selectedLessonActivity ? (
+            <div className="space-y-4">
+              <p className="inline-flex rounded-full border border-slate-300 bg-white px-3 py-1 text-xs font-semibold uppercase tracking-wide text-slate-700">
+                {selectedLessonTypeLabel}
+              </p>
+
+              {selectedLessonActivity.instructions ? (
+                <p className="rounded-lg border border-slate-200 bg-white px-4 py-3 text-sm leading-relaxed text-slate-700">
+                  {selectedLessonActivity.instructions}
+                </p>
+              ) : null}
+
+              <div className="space-y-3">
+                {selectedLessonActivity.questions.map((question, index) => (
+                  <div key={question.id} className="rounded-xl border border-slate-200 bg-white p-4">
+                    <p className="text-sm font-semibold text-slate-900">
+                      {index + 1}. {question.prompt}
+                    </p>
+                    <div className="mt-3 grid gap-2">
+                      {question.options.map((option) => {
+                        const isSelected = activityAnswers[question.id] === option.id;
+                        const showResult = Boolean(activityResult);
+                        const isCorrect = option.isCorrect;
+                        return (
+                          <button
+                            key={option.id}
+                            type="button"
+                            onClick={() =>
+                              setActivityAnswers((prev) => ({
+                                ...prev,
+                                [question.id]: option.id,
+                              }))
+                            }
+                            className={`rounded-lg border px-3 py-2 text-left text-sm transition-colors ${
+                              isSelected ? "border-slate-500 bg-slate-900 text-white" : "border-slate-300 bg-white text-slate-700 hover:bg-slate-50"
+                            } ${
+                              showResult && isCorrect
+                                ? "border-emerald-300 bg-emerald-50 text-emerald-900"
+                                : ""
+                            }`}
+                          >
+                            {option.text}
+                          </button>
+                        );
+                      })}
+                    </div>
+                    {activityResult && question.explanation ? (
+                      <p className="mt-3 rounded-md border border-slate-200 bg-slate-50 px-3 py-2 text-xs text-slate-600">
+                        {question.explanation}
+                      </p>
+                    ) : null}
+                  </div>
+                ))}
+              </div>
+
+              <button
+                type="button"
+                onClick={() => void submitActivity()}
+                className="rounded-md border border-slate-300 bg-slate-900 px-4 py-2 text-sm font-medium text-white hover:bg-slate-800"
+              >
+                Enviar respuestas
+              </button>
+
+              {activityResult ? (
+                <div
+                  className={`rounded-lg border px-4 py-3 text-sm ${
+                    activityResult.passed
+                      ? "border-emerald-200 bg-emerald-50 text-emerald-900"
+                      : "border-amber-200 bg-amber-50 text-amber-900"
+                  }`}
+                >
+                  Resultado: {activityResult.correct}/{activityResult.total} ({activityResult.score}%)
+                  {selectedLesson.contentType !== "ACTIVITY" ? (
+                    <span>
+                      {" "}
+                      | Mínimo: {selectedLessonActivity.passingScorePercent}%{" "}
+                      {activityResult.passed ? "(Aprobado)" : "(No aprobado)"}
+                    </span>
+                  ) : (
+                    <span> | Actividad completada</span>
+                  )}
+                </div>
+              ) : null}
+
+              {isFinalExam(selectedLesson.contentType) ? (
+                <div className="rounded-lg border border-amber-200 bg-amber-50 px-4 py-3 text-sm text-amber-900">
+                  Debes aprobar esta evaluación final para graduarte y emitir el certificado del curso.
+                </div>
+              ) : null}
+            </div>
           ) : (
             <div className="space-y-4">
               <p className="inline-flex rounded-full border border-slate-300 bg-white px-3 py-1 text-xs font-semibold uppercase tracking-wide text-slate-700">
@@ -271,35 +437,29 @@ export default function StudentClassroomClient({
               ) : (
                 <p className="text-sm text-slate-600">Este contenido no tiene descripción adicional.</p>
               )}
-
-              {selectedLesson.materialUrl ? (
-                getIsPdfUrl(selectedLesson.materialUrl) ? (
-                  <iframe
-                    className="h-[430px] w-full rounded-lg border border-slate-200 bg-white"
-                    src={selectedLesson.materialUrl}
-                    title={`${selectedLesson.title} material`}
-                  />
-                ) : (
-                  <a
-                    className="inline-flex rounded-md border border-slate-300 bg-white px-4 py-2 text-sm font-medium text-slate-800 hover:bg-slate-100"
-                    href={selectedLesson.materialUrl}
-                    rel="noreferrer"
-                    target="_blank"
-                  >
-                    Abrir material
-                  </a>
-                )
-              ) : null}
-
-              {isFinalExam(selectedLesson.contentType) ? (
-                <div className="rounded-lg border border-amber-200 bg-amber-50 px-4 py-3 text-sm text-amber-900">
-                  Debes completar esta evaluación final para graduarte y emitir el certificado del curso.
-                </div>
-              ) : null}
             </div>
           )}
         </div>
 
+        {selectedLesson.materialUrl ? (
+          getIsPdfUrl(selectedLesson.materialUrl) ? (
+            <iframe
+              className="h-[430px] w-full rounded-lg border border-slate-200 bg-white"
+              src={selectedLesson.materialUrl}
+              title={`${selectedLesson.title} material`}
+            />
+          ) : (
+            <a
+              className="inline-flex rounded-md border border-slate-300 bg-white px-4 py-2 text-sm font-medium text-slate-800 hover:bg-slate-100"
+              href={selectedLesson.materialUrl}
+              rel="noreferrer"
+              target="_blank"
+            >
+              Abrir material
+            </a>
+          )
+        ) : null}
+
         <div className="space-y-2 rounded-xl border border-slate-200 bg-white p-4">
           <h1 className="text-2xl font-semibold text-slate-900">{selectedLesson.title}</h1>
           <p className="inline-flex w-fit rounded-full border border-slate-300 bg-slate-50 px-2.5 py-0.5 text-xs font-semibold text-slate-700">
@@ -313,18 +473,14 @@ export default function StudentClassroomClient({
           </p>
         </div>
 
-        {isEnrolled && (
+        {isEnrolled && !isAssessmentType(selectedLesson.contentType) && (
           <button
             type="button"
-            onClick={handleToggleComplete}
+            onClick={() => void handleToggleComplete()}
             disabled={isSaving}
             className="rounded-md border border-slate-300 bg-slate-900 px-4 py-2 text-sm font-medium text-white hover:bg-slate-800 disabled:opacity-60"
           >
-            {completedSet.has(selectedLesson.id)
-              ? "Marcar como pendiente"
-              : isFinalExam(selectedLesson.contentType)
-                ? "Marcar evaluación final como completada"
-                : "Marcar como completada"}
+            {completedSet.has(selectedLesson.id) ? "Marcar como pendiente" : "Marcar como completada"}
           </button>
         )}
       </section>
diff --git a/components/teacher/FileUpload.tsx b/components/teacher/FileUpload.tsx
new file mode 100644
index 0000000..5a7aecc
--- /dev/null
+++ b/components/teacher/FileUpload.tsx
@@ -0,0 +1,159 @@
+"use client";
+
+import { useState } from "react";
+import { createBrowserClient } from "@supabase/ssr";
+import { toast } from "sonner";
+import { FileDown, Upload, X, Loader2 } from "lucide-react";
+
+interface FileUploadProps {
+    lessonId: string;
+    currentFileUrl?: string | null;
+    onUploadComplete: (url: string) => void;
+    onRemove?: () => void;
+    accept?: string;
+    label?: string;
+}
+
+const ALLOWED_MIMES = [
+    "application/pdf",
+    "application/msword",
+    "application/vnd.openxmlformats-officedocument.wordprocessingml.document",
+    "application/vnd.openxmlformats-officedocument.presentationml.presentation",
+    "text/plain"
+].join(",");
+
+export default function FileUpload({
+    lessonId,
+    currentFileUrl,
+    onUploadComplete,
+    onRemove,
+    accept = ALLOWED_MIMES,
+    label = "Documento / Material"
+}: FileUploadProps) {
+    const [uploading, setUploading] = useState(false);
+
+    const handleFileUpload = async (e: React.ChangeEvent<HTMLInputElement>) => {
+        const file = e.target.files?.[0];
+        if (!file) return;
+
+        setUploading(true);
+
+        const supabase = createBrowserClient(
+            process.env.NEXT_PUBLIC_SUPABASE_URL!,
+            process.env.NEXT_PUBLIC_SUPABASE_ANON_KEY!
+        );
+
+        // 1. Verify session
+        const { data: { user }, error: authError } = await supabase.auth.getUser();
+        if (authError || !user) {
+            toast.error("Error de autenticación: Por favor inicia sesión de nuevo.");
+            setUploading(false);
+            return;
+        }
+
+        // 2. Create a unique file path: lesson_id/timestamp_filename
+        const filePath = `${lessonId}/${Date.now()}_${file.name.replace(/\s+/g, '_')}`;
+
+        // 3. Upload to Supabase Storage (assets bucket)
+        const { error } = await supabase.storage
+            .from("assets")
+            .upload(filePath, file, {
+                upsert: true,
+            });
+
+        if (error) {
+            console.error("Storage upload error:", error);
+            if (error.message.includes("row-level security policy")) {
+                toast.error("Error de permisos: El bucket 'assets' no permite subidas para profesores.");
+            } else {
+                toast.error("Error al subir: " + error.message);
+            }
+            setUploading(false);
+            return;
+        }
+
+        // 4. Get Public URL
+        const { data: { publicUrl } } = supabase.storage
+            .from("assets")
+            .getPublicUrl(filePath);
+
+        onUploadComplete(publicUrl);
+        setUploading(false);
+        toast.success("Archivo subido con éxito");
+    };
+
+    const fileName = currentFileUrl ? currentFileUrl.split('/').pop() : "";
+
+    return (
+        <div className="space-y-2">
+            <label className="block text-sm font-medium text-slate-700">{label}</label>
+            
+            {currentFileUrl ? (
+                <div className="flex items-center gap-3 p-3 border border-slate-200 rounded-lg bg-white group shadow-sm">
+                    <div className="h-10 w-10 bg-slate-100 rounded flex items-center justify-center text-slate-500">
+                        <FileDown className="h-5 w-5" />
+                    </div>
+                    <div className="flex-1 min-w-0">
+                        <p className="text-sm font-medium text-slate-900 truncate">
+                            {decodeURIComponent(fileName || "Archivo adjunto")}
+                        </p>
+                        <a 
+                            href={currentFileUrl} 
+                            target="_blank" 
+                            rel="noopener noreferrer"
+                            className="text-xs text-blue-600 hover:underline"
+                        >
+                            Ver archivo actual
+                        </a>
+                    </div>
+                    <button
+                        onClick={onRemove}
+                        className="p-1.5 text-slate-400 hover:text-red-500 hover:bg-red-50 rounded-md transition-colors"
+                        title="Eliminar archivo"
+                    >
+                        <X className="h-4 w-4" />
+                    </button>
+                    
+                    <div className="relative">
+                         <input
+                            type="file"
+                            accept={accept}
+                            onChange={handleFileUpload}
+                            disabled={uploading}
+                            className="absolute inset-0 w-full h-full opacity-0 cursor-pointer"
+                        />
+                        <button className="text-xs bg-slate-100 text-slate-700 px-2 py-1 rounded border border-slate-200 hover:bg-slate-200">
+                             Cambiar
+                        </button>
+                    </div>
+                </div>
+            ) : (
+                <div className="relative border-2 border-dashed border-slate-300 rounded-lg p-6 hover:border-black hover:bg-slate-50 transition-all cursor-pointer group">
+                    <input
+                        type="file"
+                        accept={accept}
+                        onChange={handleFileUpload}
+                        disabled={uploading}
+                        className="absolute inset-0 w-full h-full opacity-0 cursor-pointer z-10"
+                    />
+                    <div className="flex flex-col items-center justify-center text-center space-y-2">
+                        {uploading ? (
+                            <Loader2 className="h-8 w-8 text-slate-400 animate-spin" />
+                        ) : (
+                            <Upload className="h-8 w-8 text-slate-400 group-hover:text-black" />
+                        )}
+                        <div>
+                            <p className="text-sm font-medium text-slate-900">
+                                {uploading ? "Subiendo archivo..." : "Haz clic o arrastra un archivo aquí"}
+                            </p>
+                            <p className="text-xs text-slate-500 mt-1">
+                                Formatos permitidos: <span className="font-semibold">PDF, Word, PowerPoint o Texto (.txt)</span>
+                            </p>
+                            <p className="text-xs text-slate-400 mt-0.5">Máximo 50MB</p>
+                        </div>
+                    </div>
+                </div>
+            )}
+        </div>
+    );
+}
diff --git a/components/teacher/TeacherEditCourseForm.tsx b/components/teacher/TeacherEditCourseForm.tsx
index b676e16..6d9fbc2 100755
--- a/components/teacher/TeacherEditCourseForm.tsx
+++ b/components/teacher/TeacherEditCourseForm.tsx
@@ -14,6 +14,11 @@ import { useRouter } from "next/navigation";
 import Link from "next/link";
 import { toast } from "sonner";
 import { getClientLocale } from "@/lib/i18n/clientLocale";
+import {
+  getLessonContentTypeLabel,
+  parseLessonDescriptionMeta,
+  type LessonContentType,
+} from "@/lib/courses/lessonContent";
 
 import { Prisma } from "@prisma/client";
 
@@ -35,22 +40,44 @@ type CourseData = {
   modules: {
     id: string;
     title: Prisma.JsonValue;
-    lessons: { id: string; title: Prisma.JsonValue }[];
+    lessons: { id: string; title: Prisma.JsonValue; description: Prisma.JsonValue | null }[];
   }[];
 };
 
+const selectableLessonTypes: LessonContentType[] = [
+  "VIDEO",
+  "LECTURE",
+  "ACTIVITY",
+  "QUIZ",
+  "FINAL_EXAM",
+];
+
+function getLessonTypeBadgeClass(type: LessonContentType): string {
+  if (type === "LECTURE") return "border-indigo-200 bg-indigo-50 text-indigo-700";
+  if (type === "ACTIVITY") return "border-rose-200 bg-rose-50 text-rose-700";
+  if (type === "QUIZ" || type === "FINAL_EXAM") return "border-amber-200 bg-amber-50 text-amber-700";
+  return "border-sky-200 bg-sky-50 text-sky-700";
+}
+
 export default function TeacherEditCourseForm({ course }: { course: CourseData }) {
   const router = useRouter();
   const [loading, setLoading] = useState(false);
   const [optimisticModules, setOptimisticModules] = useState(course.modules);
   const [editingModuleId, setEditingModuleId] = useState<string | null>(null);
   const [editingTitle, setEditingTitle] = useState("");
+  const [newLessonTypeByModule, setNewLessonTypeByModule] = useState<Record<string, LessonContentType>>({});
   const [learningOutcomes, setLearningOutcomes] = useState<string[]>(() =>
     parseLearningOutcomes(course.learningOutcomes)
   );
 
   useEffect(() => {
     setOptimisticModules(course.modules);
+    setNewLessonTypeByModule(
+      course.modules.reduce<Record<string, LessonContentType>>((acc, module) => {
+        acc[module.id] = acc[module.id] ?? "VIDEO";
+        return acc;
+      }, {}),
+    );
   }, [course.modules]);
 
   useEffect(() => {
@@ -134,10 +161,11 @@ export default function TeacherEditCourseForm({ course }: { course: CourseData }
 
   // 3. CREATE NEW LESSON
   const handleAddLesson = async (moduleId: string) => {
+    const selectedType = newLessonTypeByModule[moduleId] ?? "VIDEO";
     setLoading(true);
-    const res = await createLesson(moduleId);
+    const res = await createLesson(moduleId, selectedType);
     if (res.success && res.lessonId) {
-      toast.success("Lección creada");
+      toast.success(`Lección creada (${getLessonContentTypeLabel(selectedType)})`);
       // Redirect immediately to the video upload page
       router.push(`/teacher/courses/${course.slug}/lessons/${res.lessonId}`);
     } else {
@@ -444,61 +472,92 @@ export default function TeacherEditCourseForm({ course }: { course: CourseData }
 
                   {/* Lessons List */}
                   <div className="divide-y divide-slate-100">
-                    {module.lessons.map((lesson, lessonIndex) => (
-                      <div
-                        key={lesson.id}
-                        className="px-4 py-3 flex items-center gap-2 hover:bg-slate-50 transition-colors group"
-                      >
-                        <div className="flex flex-col">
-                          <button
-                            type="button"
-                            onClick={() => handleReorderLesson(moduleIndex, lessonIndex, "up")}
-                            disabled={lessonIndex === 0}
-                            className="p-0.5 rounded text-slate-400 hover:bg-slate-200 hover:text-slate-600 disabled:opacity-30 disabled:cursor-not-allowed disabled:hover:bg-transparent transition-colors"
-                            aria-label="Mover lección arriba"
-                          >
-                            <svg className="w-3 h-3" fill="none" stroke="currentColor" viewBox="0 0 24 24">
-                              <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M5 15l7-7 7 7" />
-                            </svg>
-                          </button>
-                          <button
-                            type="button"
-                            onClick={() => handleReorderLesson(moduleIndex, lessonIndex, "down")}
-                            disabled={lessonIndex === module.lessons.length - 1}
-                            className="p-0.5 rounded text-slate-400 hover:bg-slate-200 hover:text-slate-600 disabled:opacity-30 disabled:cursor-not-allowed disabled:hover:bg-transparent transition-colors"
-                            aria-label="Mover lección abajo"
-                          >
-                            <svg className="w-3 h-3" fill="none" stroke="currentColor" viewBox="0 0 24 24">
-                              <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M19 9l-7 7-7-7" />
-                            </svg>
-                          </button>
-                        </div>
-                        <Link
-                          href={`/teacher/courses/${course.slug}/lessons/${lesson.id}`}
-                          className="flex items-center gap-3 flex-1 min-w-0"
+                    {module.lessons.map((lesson, lessonIndex) => {
+                      const lessonMeta = parseLessonDescriptionMeta(lesson.description);
+                      const lessonType = lessonMeta.contentType;
+                      return (
+                        <div
+                          key={lesson.id}
+                          className="px-4 py-3 flex items-center gap-2 hover:bg-slate-50 transition-colors group"
                         >
-                          <span className="text-slate-400 text-lg group-hover:text-blue-500 flex-shrink-0">▶</span>
-                          <div className="flex-1 min-w-0">
-                            <p className="text-sm font-medium text-slate-700 group-hover:text-slate-900">
-                              {getStr(lesson.title)}
-                            </p>
+                          <div className="flex flex-col">
+                            <button
+                              type="button"
+                              onClick={() => handleReorderLesson(moduleIndex, lessonIndex, "up")}
+                              disabled={lessonIndex === 0}
+                              className="p-0.5 rounded text-slate-400 hover:bg-slate-200 hover:text-slate-600 disabled:opacity-30 disabled:cursor-not-allowed disabled:hover:bg-transparent transition-colors"
+                              aria-label="Mover lección arriba"
+                            >
+                              <svg className="w-3 h-3" fill="none" stroke="currentColor" viewBox="0 0 24 24">
+                                <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M5 15l7-7 7 7" />
+                              </svg>
+                            </button>
+                            <button
+                              type="button"
+                              onClick={() => handleReorderLesson(moduleIndex, lessonIndex, "down")}
+                              disabled={lessonIndex === module.lessons.length - 1}
+                              className="p-0.5 rounded text-slate-400 hover:bg-slate-200 hover:text-slate-600 disabled:opacity-30 disabled:cursor-not-allowed disabled:hover:bg-transparent transition-colors"
+                              aria-label="Mover lección abajo"
+                            >
+                              <svg className="w-3 h-3" fill="none" stroke="currentColor" viewBox="0 0 24 24">
+                                <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M19 9l-7 7-7-7" />
+                              </svg>
+                            </button>
                           </div>
-                          <span className="text-xs text-slate-400 opacity-0 group-hover:opacity-100 border border-slate-200 rounded px-2 py-1 flex-shrink-0">
-                            Editar Contenido
-                          </span>
-                        </Link>
-                      </div>
-                    ))}
+                          <Link
+                            href={`/teacher/courses/${course.slug}/lessons/${lesson.id}`}
+                            className="flex items-center gap-3 flex-1 min-w-0"
+                          >
+                            <span className="text-slate-400 text-lg group-hover:text-blue-500 flex-shrink-0">▶</span>
+                            <div className="flex-1 min-w-0">
+                              <div className="mb-1 flex items-center gap-2">
+                                <span
+                                  className={`inline-flex rounded-full border px-2 py-0.5 text-[11px] font-semibold ${getLessonTypeBadgeClass(
+                                    lessonType,
+                                  )}`}
+                                >
+                                  {getLessonContentTypeLabel(lessonType)}
+                                </span>
+                              </div>
+                              <p className="text-sm font-medium text-slate-700 group-hover:text-slate-900">
+                                {getStr(lesson.title)}
+                              </p>
+                            </div>
+                            <span className="text-xs text-slate-400 opacity-0 group-hover:opacity-100 border border-slate-200 rounded px-2 py-1 flex-shrink-0">
+                              Editar Contenido
+                            </span>
+                          </Link>
+                        </div>
+                      );
+                    })}
 
-                    {/* Add Lesson Button */}
-                    <button
-                      type="button"
-                      onClick={() => handleAddLesson(module.id)}
-                      disabled={loading}
-                      className="w-full text-left px-4 py-3 text-xs text-slate-500 hover:text-blue-600 hover:bg-slate-50 font-medium flex items-center gap-2 transition-colors"
-                    >
-                      <span className="text-lg leading-none">+</span> Agregar Lección
-                    </button>
+                    <div className="flex flex-wrap items-center gap-2 px-4 py-3">
+                      <select
+                        value={newLessonTypeByModule[module.id] ?? "VIDEO"}
+                        onChange={(event) =>
+                          setNewLessonTypeByModule((prev) => ({
+                            ...prev,
+                            [module.id]: event.target.value as LessonContentType,
+                          }))
+                        }
+                        className="rounded-md border border-slate-300 px-2 py-1.5 text-xs text-slate-700 outline-none focus:border-black"
+                      >
+                        {selectableLessonTypes.map((type) => (
+                          <option key={type} value={type}>
+                            {getLessonContentTypeLabel(type)}
+                          </option>
+                        ))}
+                      </select>
+
+                      <button
+                        type="button"
+                        onClick={() => handleAddLesson(module.id)}
+                        disabled={loading}
+                        className="text-xs text-slate-500 hover:text-blue-600 hover:bg-slate-50 font-medium flex items-center gap-2 transition-colors rounded px-2 py-1.5"
+                      >
+                        <span className="text-lg leading-none">+</span> Agregar Lección
+                      </button>
+                    </div>
                   </div>
                 </div>
               ))}
@@ -527,8 +586,8 @@ export default function TeacherEditCourseForm({ course }: { course: CourseData }
             <h3 className="font-semibold text-slate-900 mb-2">💡 Tips</h3>
             <ul className="text-sm text-slate-600 space-y-2 list-disc pl-4">
               <li>Crea módulos para organizar tus temas.</li>
-              <li>Dentro de cada módulo, agrega lecciones.</li>
-              <li>Haz clic en una lección para <strong>subir el video</strong>.</li>
+              <li>Dentro de cada módulo, agrega lecciones con tipo (video, lectura, actividad, quiz).</li>
+              <li>Haz clic en una lección para editar su contenido según el formato elegido.</li>
             </ul>
           </div>
         </div>
diff --git a/components/teacher/VideoUpload.tsx b/components/teacher/VideoUpload.tsx
index 00b06ac..6f95e42 100644
--- a/components/teacher/VideoUpload.tsx
+++ b/components/teacher/VideoUpload.tsx
@@ -14,7 +14,7 @@ export default function VideoUpload({ lessonId, currentVideoUrl, onUploadComplet
     const [uploading, setUploading] = useState(false);
     const [progress, setProgress] = useState(0);
 
-    const handleUpload = async (e: React.ChangeEvent<HTMLInputElement>) => {
+    const handleVideoUpload = async (e: React.ChangeEvent<HTMLInputElement>) => {
         const file = e.target.files?.[0];
         if (!file) return;
 
@@ -26,28 +26,46 @@ export default function VideoUpload({ lessonId, currentVideoUrl, onUploadComplet
             process.env.NEXT_PUBLIC_SUPABASE_ANON_KEY!
         );
 
-        // Create a unique file path: lesson_id/timestamp_filename
+        // 1. Verify session
+        const { data: { user }, error: authError } = await supabase.auth.getUser();
+        if (authError || !user) {
+            toast.error("Authentication error: Please log in again.");
+            setUploading(false);
+            return;
+        }
+
+        console.log("Authenticated User ID:", user.id);
+
+        // 2. Create a unique file path: lesson_id/timestamp_filename
         const filePath = `${lessonId}/${Date.now()}_${file.name}`;
 
+        // 3. Upload to Supabase Storage
         const { error } = await supabase.storage
-            .from("courses") // Make sure this bucket exists!
+            .from("courses")
             .upload(filePath, file, {
                 upsert: true,
             });
 
         if (error) {
-            toast.error("Upload failed: " + error.message);
+            console.error("Storage upload error:", error);
+            // Hint for common RLS issue
+            if (error.message.includes("row-level security policy")) {
+                toast.error("Upload failed: RLS Policy error. Make sure 'courses' bucket allows uploads for authenticated teachers.");
+            } else {
+                toast.error("Upload failed: " + error.message);
+            }
             setUploading(false);
             return;
         }
 
-        // Get Public URL
+        // 4. Get Public URL
         const { data: { publicUrl } } = supabase.storage
             .from("courses")
             .getPublicUrl(filePath);
 
         onUploadComplete(publicUrl);
         setUploading(false);
+        toast.success("Video subido con éxito");
     };
 
     return (
@@ -73,7 +91,7 @@ export default function VideoUpload({ lessonId, currentVideoUrl, onUploadComplet
                     <input
                         type="file"
                         accept="video/*"
-                        onChange={handleUpload}
+                        onChange={handleVideoUpload}
                         disabled={uploading}
                         className="block w-full text-sm text-slate-500
               file:mr-4 file:py-2 file:px-4
diff --git a/db_check.ts b/db_check.ts
new file mode 100644
index 0000000..414a06d
--- /dev/null
+++ b/db_check.ts
@@ -0,0 +1,21 @@
+
+import { Pool } from 'pg'
+
+const connectionString = process.env.DIRECT_URL || process.env.DATABASE_URL
+const pool = new Pool({ connectionString })
+
+async function check() {
+  try {
+    const res = await pool.query("SELECT id, name, public FROM storage.buckets;")
+    console.log("Buckets:", JSON.stringify(res.rows, null, 2))
+    
+    const res2 = await pool.query("SELECT policyname, cmd, qual, with_check FROM pg_policies WHERE tablename = 'objects' AND schemaname = 'storage';")
+    console.log("Policies:", JSON.stringify(res2.rows, null, 2))
+  } catch (e) {
+    console.error(e)
+  } finally {
+    await pool.end()
+  }
+}
+
+check()
diff --git a/lib/courses/lessonContent.ts b/lib/courses/lessonContent.ts
index 932ca3d..e0cda07 100644
--- a/lib/courses/lessonContent.ts
+++ b/lib/courses/lessonContent.ts
@@ -2,10 +2,36 @@ export const lessonContentTypes = ["VIDEO", "LECTURE", "ACTIVITY", "QUIZ", "FINA
 
 export type LessonContentType = (typeof lessonContentTypes)[number];
 
+export const lessonQuestionKinds = ["TRUE_FALSE", "MULTIPLE_CHOICE"] as const;
+
+export type LessonQuestionKind = (typeof lessonQuestionKinds)[number];
+
+export type LessonQuestionOption = {
+  id: string;
+  text: string;
+  isCorrect: boolean;
+};
+
+export type LessonQuestion = {
+  id: string;
+  kind: LessonQuestionKind;
+  prompt: string;
+  explanation: string;
+  options: LessonQuestionOption[];
+};
+
+export type LessonActivityMeta = {
+  instructions: string;
+  passingScorePercent: number;
+  questions: LessonQuestion[];
+};
+
 type LessonDescriptionMeta = {
   text: string;
   contentType: LessonContentType;
   materialUrl: string | null;
+  lectureContent: string;
+  activity: LessonActivityMeta | null;
 };
 
 const lessonTypeAliases: Record<string, LessonContentType> = {
@@ -33,6 +59,15 @@ function asString(value: unknown): string {
   return typeof value === "string" ? value.trim() : "";
 }
 
+function asNumber(value: unknown): number | null {
+  if (typeof value === "number" && Number.isFinite(value)) return value;
+  if (typeof value === "string" && value.trim()) {
+    const parsed = Number(value);
+    if (Number.isFinite(parsed)) return parsed;
+  }
+  return null;
+}
+
 function normalizeType(value: string): LessonContentType {
   const normalized = value.trim().toUpperCase();
   return lessonTypeAliases[normalized] ?? "VIDEO";
@@ -53,12 +88,111 @@ function getDescriptionText(input: unknown): string {
   return "";
 }
 
+function normalizeQuestionKind(value: unknown): LessonQuestionKind {
+  const raw = asString(value).toUpperCase();
+  return raw === "TRUE_FALSE" ? "TRUE_FALSE" : "MULTIPLE_CHOICE";
+}
+
+function parseQuestionOptions(value: unknown, kind: LessonQuestionKind): LessonQuestionOption[] {
+  if (!Array.isArray(value)) {
+    if (kind === "TRUE_FALSE") {
+      return [
+        { id: "true", text: "Verdadero", isCorrect: true },
+        { id: "false", text: "Falso", isCorrect: false },
+      ];
+    }
+    return [];
+  }
+
+  const options = value
+    .map((option, index) => {
+      if (!isRecord(option)) return null;
+      const id = asString(option.id) || `opt-${index + 1}`;
+      const text = asString(option.text);
+      const isCorrect = Boolean(option.isCorrect);
+      if (!text) return null;
+      return { id, text, isCorrect };
+    })
+    .filter((option): option is LessonQuestionOption => option !== null);
+
+  if (kind === "TRUE_FALSE") {
+    const hasTrue = options.find((option) => option.id === "true" || option.text.toLowerCase() === "verdadero");
+    const hasFalse = options.find((option) => option.id === "false" || option.text.toLowerCase() === "falso");
+    if (!hasTrue || !hasFalse) {
+      const correctIndex = options.findIndex((option) => option.isCorrect);
+      return [
+        { id: "true", text: "Verdadero", isCorrect: correctIndex !== 1 },
+        { id: "false", text: "Falso", isCorrect: correctIndex === 1 },
+      ];
+    }
+  }
+
+  return options;
+}
+
+function parseQuestion(value: unknown, index: number): LessonQuestion | null {
+  if (!isRecord(value)) return null;
+  const kind = normalizeQuestionKind(value.kind ?? value.type);
+  const id = asString(value.id) || `q-${index + 1}`;
+  const prompt = asString(value.prompt ?? value.question);
+  const explanation = asString(value.explanation);
+  const options = parseQuestionOptions(value.options, kind);
+
+  if (!prompt) return null;
+  if (options.length < 2) return null;
+
+  const hasCorrect = options.some((option) => option.isCorrect);
+  const normalizedOptions = hasCorrect ? options : options.map((option, optIndex) => ({ ...option, isCorrect: optIndex === 0 }));
+
+  return {
+    id,
+    kind,
+    prompt,
+    explanation,
+    options: normalizedOptions,
+  };
+}
+
+function normalizePassingScore(value: unknown, fallback: number): number {
+  const parsed = asNumber(value);
+  if (parsed == null) return fallback;
+  return Math.max(0, Math.min(100, Math.round(parsed)));
+}
+
+function parseActivityMeta(description: Record<string, unknown>): LessonActivityMeta | null {
+  const activityRaw =
+    (isRecord(description.activity) && description.activity) ||
+    (isRecord(description.quiz) && description.quiz) ||
+    (isRecord(description.exercise) && description.exercise) ||
+    null;
+
+  if (!activityRaw) return null;
+
+  const instructions = asString(activityRaw.instructions ?? activityRaw.intro ?? description.es ?? description.text);
+  const passingScorePercent = normalizePassingScore(activityRaw.passingScorePercent, 70);
+  const questionsRaw = Array.isArray(activityRaw.questions) ? activityRaw.questions : [];
+  const questions = questionsRaw
+    .map((question, index) => parseQuestion(question, index))
+    .filter((question): question is LessonQuestion => question !== null);
+
+  if (questions.length === 0) return null;
+
+  return {
+    instructions,
+    passingScorePercent,
+    questions,
+  };
+}
+
 export function parseLessonDescriptionMeta(description: unknown): LessonDescriptionMeta {
   if (!isRecord(description)) {
+    const fallbackText = getDescriptionText(description);
     return {
-      text: getDescriptionText(description),
+      text: fallbackText,
       contentType: "VIDEO",
       materialUrl: null,
+      lectureContent: fallbackText,
+      activity: null,
     };
   }
 
@@ -69,11 +203,16 @@ export function parseLessonDescriptionMeta(description: unknown): LessonDescript
     asString(description.pdfUrl) ||
     asString(description.attachmentUrl) ||
     "";
+  const text = getDescriptionText(description);
+  const lectureContent = asString(description.lectureContent) || asString(description.content) || text;
+  const activity = parseActivityMeta(description);
 
   return {
-    text: getDescriptionText(description),
+    text,
     contentType: normalizeType(contentTypeRaw || "VIDEO"),
     materialUrl: materialUrl || null,
+    lectureContent,
+    activity,
   };
 }
 
@@ -81,8 +220,10 @@ export function buildLessonDescriptionMeta(input: {
   text: string;
   contentType: LessonContentType;
   materialUrl?: string | null;
-}): Record<string, string> {
-  const payload: Record<string, string> = {
+  lectureContent?: string | null;
+  activity?: LessonActivityMeta | null;
+}): Record<string, unknown> {
+  const payload: Record<string, unknown> = {
     contentType: input.contentType,
   };
 
@@ -92,6 +233,44 @@ export function buildLessonDescriptionMeta(input: {
   const materialUrl = (input.materialUrl ?? "").trim();
   if (materialUrl) payload.materialUrl = materialUrl;
 
+  const lectureContent = (input.lectureContent ?? "").trim();
+  if (lectureContent) payload.lectureContent = lectureContent;
+
+  const activity = input.activity;
+  if (activity && activity.questions.length > 0) {
+    payload.activity = {
+      instructions: activity.instructions.trim(),
+      passingScorePercent: Math.max(0, Math.min(100, Math.round(activity.passingScorePercent))),
+      questions: activity.questions.map((question, qIndex) => {
+        const questionId = question.id.trim() || `q-${qIndex + 1}`;
+        const prompt = question.prompt.trim();
+        const explanation = question.explanation.trim();
+        const kind: LessonQuestionKind = question.kind === "TRUE_FALSE" ? "TRUE_FALSE" : "MULTIPLE_CHOICE";
+        const options = question.options
+          .map((option, optionIndex) => {
+            const optionId = option.id.trim() || `opt-${optionIndex + 1}`;
+            const optionText = option.text.trim();
+            if (!optionText) return null;
+            return {
+              id: optionId,
+              text: optionText,
+              isCorrect: Boolean(option.isCorrect),
+            };
+          })
+          .filter((option): option is LessonQuestionOption => option !== null);
+        const hasCorrect = options.some((option) => option.isCorrect);
+        const normalizedOptions = hasCorrect ? options : options.map((option, optionIndex) => ({ ...option, isCorrect: optionIndex === 0 }));
+        return {
+          id: questionId,
+          kind,
+          prompt,
+          explanation,
+          options: normalizedOptions,
+        };
+      }),
+    };
+  }
+
   return payload;
 }
 
diff --git a/lib/courses/lessonMarkdown.ts b/lib/courses/lessonMarkdown.ts
new file mode 100644
index 0000000..54c9c59
--- /dev/null
+++ b/lib/courses/lessonMarkdown.ts
@@ -0,0 +1,126 @@
+function escapeHtml(value: string): string {
+  return value
+    .replaceAll("&", "&amp;")
+    .replaceAll("<", "&lt;")
+    .replaceAll(">", "&gt;")
+    .replaceAll('"', "&quot;")
+    .replaceAll("'", "&#39;");
+}
+
+function escapeAttribute(value: string): string {
+  return value.replaceAll("&", "&amp;").replaceAll('"', "&quot;");
+}
+
+function normalizeHttpUrl(rawUrl: string): string | null {
+  try {
+    const parsed = new URL(rawUrl);
+    if (parsed.protocol !== "http:" && parsed.protocol !== "https:") return null;
+    return parsed.toString();
+  } catch {
+    return null;
+  }
+}
+
+function renderInline(markdown: string): string {
+  let rendered = escapeHtml(markdown);
+
+  rendered = rendered.replace(/`([^`]+)`/g, (_match, value: string) => `<code>${value}</code>`);
+  rendered = rendered.replace(/\*\*([^*]+)\*\*/g, (_match, value: string) => `<strong>${value}</strong>`);
+  rendered = rendered.replace(/\*([^*]+)\*/g, (_match, value: string) => `<em>${value}</em>`);
+  rendered = rendered.replace(/\[([^\]]+)\]\(([^)\s]+)\)/g, (_match, label: string, url: string) => {
+    const safeUrl = normalizeHttpUrl(url);
+    if (!safeUrl) return label;
+    return `<a href="${escapeAttribute(safeUrl)}" target="_blank" rel="noopener noreferrer">${label}</a>`;
+  });
+
+  return rendered;
+}
+
+export function markdownToSafeHtml(markdown: string): string {
+  const source = markdown.replace(/\r\n/g, "\n").trim();
+  if (!source) return "<p>Sin contenido.</p>";
+
+  const lines = source.split("\n");
+  const output: string[] = [];
+  let listMode: "ol" | "ul" | null = null;
+
+  const closeList = () => {
+    if (!listMode) return;
+    output.push(listMode === "ol" ? "</ol>" : "</ul>");
+    listMode = null;
+  };
+
+  for (const rawLine of lines) {
+    const line = rawLine.trim();
+
+    if (!line) {
+      closeList();
+      continue;
+    }
+
+    const h3 = line.match(/^###\s+(.+)$/);
+    if (h3) {
+      closeList();
+      output.push(`<h3>${renderInline(h3[1])}</h3>`);
+      continue;
+    }
+
+    const h2 = line.match(/^##\s+(.+)$/);
+    if (h2) {
+      closeList();
+      output.push(`<h2>${renderInline(h2[1])}</h2>`);
+      continue;
+    }
+
+    const h1 = line.match(/^#\s+(.+)$/);
+    if (h1) {
+      closeList();
+      output.push(`<h1>${renderInline(h1[1])}</h1>`);
+      continue;
+    }
+
+    const ordered = line.match(/^\d+\.\s+(.+)$/);
+    if (ordered) {
+      if (listMode !== "ol") {
+        closeList();
+        output.push("<ol>");
+        listMode = "ol";
+      }
+      output.push(`<li>${renderInline(ordered[1])}</li>`);
+      continue;
+    }
+
+    const unordered = line.match(/^[-*]\s+(.+)$/);
+    if (unordered) {
+      if (listMode !== "ul") {
+        closeList();
+        output.push("<ul>");
+        listMode = "ul";
+      }
+      output.push(`<li>${renderInline(unordered[1])}</li>`);
+      continue;
+    }
+
+    const quote = line.match(/^>\s+(.+)$/);
+    if (quote) {
+      closeList();
+      output.push(`<blockquote>${renderInline(quote[1])}</blockquote>`);
+      continue;
+    }
+
+    closeList();
+    output.push(`<p>${renderInline(line)}</p>`);
+  }
+
+  closeList();
+  return output.join("\n");
+}
+
+export function markdownToPlainText(markdown: string): string {
+  return markdown
+    .replace(/\r\n/g, "\n")
+    .replace(/\[([^\]]+)\]\(([^)]+)\)/g, "$1")
+    .replace(/[`*_>#-]/g, "")
+    .replace(/\n{2,}/g, "\n")
+    .trim();
+}