Refactor code structure for improved readability and maintainability

deploy.sh

@@ -56,6 +56,25 @@ echo "   📁 Destino: $REMOTE_PATH"
 echo "   🔑 SSH Key: $PEM_PATH"
 echo ""
 
+echo ""
+echo "----------------------------------------"
+echo "Dónde compilar las imágenes Docker"
+echo "----------------------------------------"
+echo ""
+echo "¿Compilar imágenes en esta máquina y enviar al servidor?"
+echo "  - local: Compilar aquí y transferir vía SSH (recomendado)"
+echo "  - remote: El servidor compila (más lento)"
+echo ""
+read -p "¿Compilar localmente? [Y/n]: " BUILD_LOCAL_CHOICE
+BUILD_LOCAL_CHOICE=${BUILD_LOCAL_CHOICE:-Y}
+if [[ "$BUILD_LOCAL_CHOICE" =~ ^[Yy]$ ]]; then
+    BUILD_LOCAL="true"
+    echo "✅ Compilación local - imágenes se streamearan via SSH"
+else
+    BUILD_LOCAL="false"
+    echo "✅ El servidor compilará las imágenes"
+fi
+
 # Preguntar si continuar
 read -p "¿Desea continuar con el despliegue? [y/N]: " CONFIRM
 if [[ ! "$CONFIRM" =~ ^[Yy]$ ]]; then
@@ -357,24 +376,7 @@ else
     echo "✅ Configuración: HTTP (sin SSL)"
 fi
 
-echo ""
+
-echo "----------------------------------------"
-echo "Dónde compilar las imágenes Docker"
-echo "----------------------------------------"
-echo ""
-echo "¿Compilar imágenes en esta máquina y enviar al servidor?"
-echo "  - local: Compilar aquí y transferir vía SSH (recomendado - CPU i7 >> t3a.large)"
-echo "  - remote: El servidor compila (más lento en t3a.large 2vCPU/8GB)"
-echo ""
-read -p "¿Compilar localmente? [Y/n]: " BUILD_LOCAL_CHOICE
-BUILD_LOCAL_CHOICE=${BUILD_LOCAL_CHOICE:-Y}
-if [[ "$BUILD_LOCAL_CHOICE" =~ ^[Yy]$ ]]; then
-    BUILD_LOCAL="true"
-    echo "✅ Compilación local - imágenes se streamearan via SSH"
-else
-    BUILD_LOCAL="false"
-    echo "✅ El servidor compilará las imágenes"
-fi
 
 echo ""
 echo "========================================"

services/lms-service/src/handlers.rs

@@ -1231,12 +1231,56 @@ pub async fn get_user_enrollments(
         user_id,
         org_ctx.id
     );
-    let enrollments =
+    let enrollments = sqlx::query_as::<_, Enrollment>(
-        sqlx::query_as::<_, Enrollment>("SELECT * FROM enrollments WHERE user_id = $1")
+        r#"
-            .bind(user_id)
+        SELECT
-            .fetch_all(&pool)
+            e.id,
-            .await
+            e.user_id,
-            .map_err(|_| StatusCode::INTERNAL_SERVER_ERROR)?;
+            e.organization_id,
+            e.course_id,
+            e.external_id,
+            CASE
+                WHEN totals.total_lessons > 0
+                    THEN ((COALESCE(graded.graded_done, 0) + COALESCE(ungraded.ungraded_done, 0))::float4 / totals.total_lessons::float4) * 100.0
+                ELSE 0.0::float4
+            END AS progress,
+            e.enrolled_at
+        FROM enrollments e
+        JOIN LATERAL (
+            SELECT COUNT(*)::int AS total_lessons
+            FROM lessons l
+            JOIN modules m ON m.id = l.module_id
+            WHERE m.course_id = e.course_id
+              AND l.organization_id = e.organization_id
+        ) totals ON TRUE
+        LEFT JOIN LATERAL (
+            SELECT COUNT(DISTINCT ug.lesson_id)::int AS graded_done
+            FROM user_grades ug
+            JOIN lessons l ON l.id = ug.lesson_id
+            WHERE ug.user_id = e.user_id
+              AND ug.course_id = e.course_id
+              AND l.is_graded = true
+        ) graded ON TRUE
+        LEFT JOIN LATERAL (
+            SELECT COUNT(DISTINCT li.lesson_id)::int AS ungraded_done
+            FROM lesson_interactions li
+            JOIN lessons l ON l.id = li.lesson_id
+            JOIN modules m ON m.id = l.module_id
+            WHERE li.user_id = e.user_id
+              AND li.event_type = 'complete'
+              AND l.is_graded = false
+              AND m.course_id = e.course_id
+        ) ungraded ON TRUE
+        WHERE e.user_id = $1
+          AND e.organization_id = $2
+        ORDER BY e.enrolled_at DESC
+        "#,
+    )
+    .bind(user_id)
+    .bind(org_ctx.id)
+    .fetch_all(&pool)
+    .await
+    .map_err(|_| StatusCode::INTERNAL_SERVER_ERROR)?;
 
     Ok(Json(enrollments))
 }
@@ -1687,7 +1731,30 @@ pub async fn get_student_progress_stats(
 
     // 2. Lecciones completadas
     let completed_lessons: i64 = sqlx::query_scalar(
-        "SELECT COUNT(*) FROM user_grades WHERE user_id = $1 AND course_id = $2 AND organization_id = $3",
+        r#"
+        SELECT COUNT(*)
+        FROM lessons l
+        JOIN modules m ON m.id = l.module_id
+        WHERE m.course_id = $2
+          AND l.organization_id = $3
+          AND (
+              (l.is_graded = true AND EXISTS (
+                  SELECT 1
+                  FROM user_grades ug
+                  WHERE ug.user_id = $1
+                    AND ug.course_id = $2
+                    AND ug.lesson_id = l.id
+              ))
+              OR
+              (l.is_graded = false AND EXISTS (
+                  SELECT 1
+                  FROM lesson_interactions li
+                  WHERE li.user_id = $1
+                    AND li.lesson_id = l.id
+                    AND li.event_type = 'complete'
+              ))
+          )
+        "#,
     )
     .bind(user_id)
     .bind(course_id)

services/lms-service/src/handlers_certificates.rs

@@ -6,7 +6,7 @@ use axum::{
 use common::auth::Claims;
 use serde::{Deserialize, Serialize};
 use sha2::{Sha256, Digest};
-use sqlx::PgPool;
+use sqlx::{PgPool, Row};
 use uuid::Uuid;
 
 // Macro para usar json!() sin importar serde_json
@@ -80,7 +80,7 @@ pub async fn get_certificate(
     })?;
 
     if let Some(org_config) = org_certificates_enabled {
-        if !org_config.certificates_enabled {
+        if !org_config.get::<bool, _>("certificates_enabled") {
             return Err((
                 StatusCode::NOT_IMPLEMENTED,
                 Json(json!({
@@ -120,13 +120,13 @@ pub async fn get_certificate(
 
     if let Some(cert) = existing_cert {
         // Obtener título del curso y nombre del estudiante
-        let course_info = sqlx::query!(
+        let course_info = sqlx::query(
-            "SELECT title FROM courses WHERE id = $1",
+            "SELECT title FROM courses WHERE id = $1"
-            course_id
         )
+        .bind(course_id)
         .fetch_optional(&pool)
         .await
-        .map_err(|e| {
+        .map_err(|e: sqlx::Error| {
             tracing::error!("Error al obtener info del curso: {}", e);
             (
                 StatusCode::INTERNAL_SERVER_ERROR,
@@ -134,13 +134,13 @@ pub async fn get_certificate(
             )
         })?;
 
-        let user_info = sqlx::query!(
+        let user_info = sqlx::query(
-            "SELECT full_name FROM users WHERE id = $1",
+            "SELECT full_name FROM users WHERE id = $1"
-            user_id
         )
+        .bind(user_id)
         .fetch_optional(&pool)
         .await
-        .map_err(|e| {
+        .map_err(|e: sqlx::Error| {
             tracing::error!("Error al obtener info del usuario: {}", e);
             (
                 StatusCode::INTERNAL_SERVER_ERROR,
@@ -152,8 +152,8 @@ pub async fn get_certificate(
             id: cert.id,
             user_id: cert.user_id,
             course_id: cert.course_id,
-            course_title: course_info.map(|c| c.title).unwrap_or_default(),
+            course_title: course_info.map(|c| c.get::<String, _>("title")).unwrap_or_default(),
-            student_name: user_info.map(|u| u.full_name).unwrap_or_default(),
+            student_name: user_info.map(|u| u.get::<String, _>("full_name")).unwrap_or_default(),
             certificate_html: cert.certificate_html,
             issued_at: cert.issued_at.to_string(),
             verification_code: cert.verification_code,
@@ -194,15 +194,15 @@ pub async fn issue_certificate(
     let force_reissue = payload.and_then(|p| p.force_reissue).unwrap_or(false);
 
     // Verificar si la organización tiene certificados habilitados
-    let org_certificates_enabled = sqlx::query!(
+    let org_certificates_enabled = sqlx::query(
         "SELECT certificates_enabled FROM organizations WHERE id = (
             SELECT organization_id FROM courses WHERE id = $1
-        )",
+        )"
-        course_id
     )
+    .bind(course_id)
     .fetch_optional(&pool)
     .await
-    .map_err(|e| {
+    .map_err(|e: sqlx::Error| {
         tracing::error!("Error al verificar configuración de certificados: {}", e);
         (
             StatusCode::INTERNAL_SERVER_ERROR,
@@ -211,7 +211,7 @@ pub async fn issue_certificate(
     })?;
 
     if let Some(org_config) = org_certificates_enabled {
-        if !org_config.certificates_enabled {
+        if !org_config.get::<bool, _>("certificates_enabled") {
             return Err((
                 StatusCode::NOT_IMPLEMENTED,
                 Json(json!({
@@ -223,14 +223,14 @@ pub async fn issue_certificate(
     }
 
     // Verificar si ya existe
-    let existing = sqlx::query!(
+    let existing = sqlx::query(
-        "SELECT id FROM issued_certificates WHERE user_id = $1 AND course_id = $2",
+        "SELECT id FROM issued_certificates WHERE user_id = $1 AND course_id = $2"
-        user_id,
-        course_id
     )
+    .bind(user_id)
+    .bind(course_id)
     .fetch_optional(&pool)
     .await
-    .map_err(|e| {
+    .map_err(|e: sqlx::Error| {
         tracing::error!("Error al verificar certificado existente: {}", e);
         (
             StatusCode::INTERNAL_SERVER_ERROR,
@@ -274,7 +274,7 @@ pub async fn verify_certificate(
     Path(code): Path<String>,
     State(pool): State<PgPool>,
 ) -> Result<Json<CertificateVerificationResponse>, StatusCode> {
-    let cert = sqlx::query!(
+    let cert = sqlx::query(
         r#"
         SELECT 
             ic.id,
@@ -290,29 +290,29 @@ pub async fn verify_certificate(
         JOIN courses c ON c.id = ic.course_id
         JOIN users u ON u.id = ic.user_id
         WHERE ic.verification_code = $1
-        "#,
+        "#
-        code
     )
+    .bind(code)
     .fetch_optional(&pool)
     .await
-    .map_err(|e| {
+    .map_err(|e: sqlx::Error| {
         tracing::error!("Error al verificar certificado: {}", e);
         StatusCode::INTERNAL_SERVER_ERROR
     })?;
 
     match cert {
-        Some(cert) => Ok(Json(CertificateVerificationResponse {
+        Some(row) => Ok(Json(CertificateVerificationResponse {
             valid: true,
             certificate: Some(CertificateResponse {
-                id: cert.id,
+                id: row.get("id"),
-                user_id: cert.user_id,
+                user_id: row.get("user_id"),
-                course_id: cert.course_id,
+                course_id: row.get("course_id"),
-                course_title: cert.course_title,
+                course_title: row.get("course_title"),
-                student_name: cert.student_name,
+                student_name: row.get("student_name"),
-                certificate_html: cert.certificate_html,
+                certificate_html: row.get("certificate_html"),
-                issued_at: cert.issued_at.to_string(),
+                issued_at: row.get::<chrono::DateTime<chrono::Utc>, _>("issued_at").to_string(),
-                verification_code: cert.verification_code,
+                verification_code: row.get("verification_code"),
-                metadata: cert.metadata,
+                metadata: row.get("metadata"),
             }),
             message: "Certificado válido".to_string(),
         })),
@@ -337,18 +337,18 @@ async fn check_course_completion(
     pool: &PgPool,
 ) -> Result<CourseCompletion, (StatusCode, Json<serde_json::Value>)> {
     // Obtener todas las lecciones graduables del curso
-    let gradable_lessons = sqlx::query!(
+    let gradable_lessons = sqlx::query(
         r#"
         SELECT l.id, l.is_graded, l.passing_percentage
         FROM lessons l
         JOIN modules m ON m.id = l.module_id
         WHERE m.course_id = $1 AND l.is_graded = true
-        "#,
+        "#
-        course_id
     )
+    .bind(course_id)
     .fetch_all(pool)
     .await
-    .map_err(|e| {
+    .map_err(|e: sqlx::Error| {
         tracing::error!("Error al obtener lecciones graduables: {}", e);
         (
             StatusCode::INTERNAL_SERVER_ERROR,
@@ -358,14 +358,14 @@ async fn check_course_completion(
 
     if gradable_lessons.is_empty() {
         // Si no hay lecciones graduables, considerar completado si está inscrito
-        let enrolled = sqlx::query!(
+        let enrolled = sqlx::query(
-            "SELECT id FROM enrollments WHERE user_id = $1 AND course_id = $2",
+            "SELECT id FROM enrollments WHERE user_id = $1 AND course_id = $2"
-            user_id,
-            course_id
         )
+        .bind(user_id)
+        .bind(course_id)
         .fetch_optional(pool)
         .await
-        .map_err(|e| {
+        .map_err(|e: sqlx::Error| {
             tracing::error!("Error al verificar inscripción: {}", e);
             (
                 StatusCode::INTERNAL_SERVER_ERROR,
@@ -384,20 +384,21 @@ async fn check_course_completion(
     let mut passed_lessons = 0.0;
 
     for lesson in gradable_lessons {
-        let passing_pct = lesson.passing_percentage.unwrap_or(60.0);
+        let passing_pct = lesson.get::<Option<i32>, _>("passing_percentage").unwrap_or(60) as f64;
+        let lesson_id: Uuid = lesson.get("id");
 
-        let best_score = sqlx::query!(
+        let best_score = sqlx::query(
             r#"
             SELECT MAX(score_percentage) as max_score
             FROM grades
             WHERE user_id = $1 AND lesson_id = $2
-            "#,
+            "#
-            user_id,
-            lesson.id
         )
+        .bind(user_id)
+        .bind(lesson_id)
         .fetch_optional(pool)
         .await
-        .map_err(|e| {
+        .map_err(|e: sqlx::Error| {
             tracing::error!("Error al obtener calificaciones: {}", e);
             (
                 StatusCode::INTERNAL_SERVER_ERROR,
@@ -405,8 +406,8 @@ async fn check_course_completion(
             )
         })?;
 
-        if let Some(score) = best_score {
+        if let Some(row) = best_score {
-            if score.max_score.unwrap_or(0.0) >= passing_pct {
+            if row.get::<Option<f64>, _>("max_score").unwrap_or(0.0) >= passing_pct {
                 passed_lessons += 1.0;
             }
         }
@@ -427,17 +428,17 @@ async fn issue_certificate_internal(
     _certificate_template_override: Option<&str>,
 ) -> Result<Json<CertificateResponse>, (StatusCode, Json<serde_json::Value>)> {
     // Obtener datos necesarios
-    let course_data = sqlx::query!(
+    let course_row = sqlx::query(
         r#"
         SELECT title, certificate_template, organization_id
         FROM courses
         WHERE id = $1
-        "#,
+        "#
-        course_id
     )
+    .bind(course_id)
     .fetch_optional(pool)
     .await
-    .map_err(|e| {
+    .map_err(|e: sqlx::Error| {
         tracing::error!("Error al obtener datos del curso: {}", e);
         (
             StatusCode::INTERNAL_SERVER_ERROR,
@@ -445,37 +446,38 @@ async fn issue_certificate_internal(
         )
     })?;
 
-    let course_data = course_data.ok_or((
+    let course_row = course_row.ok_or((
         StatusCode::NOT_FOUND,
         Json(json!({"error": "Curso no encontrado"})),
     ))?;
 
-    let user_name = sqlx::query!(
+    let user_name = sqlx::query(
-        "SELECT full_name FROM users WHERE id = $1",
+        "SELECT full_name FROM users WHERE id = $1"
-        user_id
     )
+    .bind(user_id)
     .fetch_one(pool)
     .await
-    .map_err(|e| {
+    .map_err(|e: sqlx::Error| {
         tracing::error!("Error al obtener nombre del usuario: {}", e);
         (
             StatusCode::INTERNAL_SERVER_ERROR,
             Json(json!({"error": "Error interno del servidor"})),
         )
     })?
-    .full_name;
+    .get::<String, _>("full_name");
 
-    let org_data = sqlx::query!(
+    let organization_id: Uuid = course_row.get("organization_id");
+    let org_data = sqlx::query(
         r#"
         SELECT name, certificate_template
         FROM organizations
         WHERE id = $1
-        "#,
+        "#
-        course_data.organization_id
     )
+    .bind(organization_id)
     .fetch_optional(pool)
     .await
-    .map_err(|e| {
+    .map_err(|e: sqlx::Error| {
         tracing::error!("Error al obtener datos de la organización: {}", e);
         (
             StatusCode::INTERNAL_SERVER_ERROR,
@@ -484,16 +486,19 @@ async fn issue_certificate_internal(
     })?;
 
     // Determinar template a usar (curso > organización > default)
-    let template = course_data
+    let course_title = course_row.get::<String, _>("title");
-        .certificate_template
+    let template = course_row
-        .or_else(|| org_data.and_then(|o| o.certificate_template))
+        .get::<Option<String>, _>("certificate_template")
+        .or_else(|| org_data.as_ref().and_then(|o| o.get::<Option<String>, _>("certificate_template")))
         .unwrap_or_else(|| get_default_certificate_template());
 
+    let _org_name = org_data.as_ref().map(|o| o.get::<String, _>("name")).unwrap_or_else(|| "OpenCCB".to_string());
+
     // Reemplazar variables en el template
     let now = chrono::Utc::now();
     let certificate_html = template
         .replace("{{student_name}}", &user_name)
-        .replace("{{course_title}}", &course_data.title)
+        .replace("{{course_title}}", &course_title)
         .replace("{{date}}", &now.format("%d/%m/%Y").to_string())
         .replace("{{score}}", "Aprobado")
         .replace("{{verification_code}}", "VER-PLACEHOLDER");
@@ -524,10 +529,9 @@ async fn issue_certificate_internal(
     let metadata = serde_json::json!({
         "completion_date": now.to_rfc3339(),
         "final_score": course_completion.progress,
-        "organization_id": course_data.organization_id.to_string(),
+        "organization_id": organization_id.to_string(),
     });
 
-    use sqlx::Row;
     let issued_cert = sqlx::query(
         r#"
         INSERT INTO issued_certificates 
@@ -536,12 +540,12 @@ async fn issue_certificate_internal(
         RETURNING id, issued_at
         "#
     )
-    .bind(user_id)
+    .bind(user_id.clone())
-    .bind(course_id)
+    .bind(course_id.clone())
-    .bind(certificate_html)
+    .bind(certificate_html.clone())
-    .bind(certificate_hash)
+    .bind(certificate_hash.clone())
-    .bind(verification_code)
+    .bind(verification_code.clone())
-    .bind(metadata)
+    .bind(metadata.clone())
     .fetch_one(pool)
     .await
     .map_err(|e: sqlx::Error| {
@@ -563,7 +567,7 @@ async fn issue_certificate_internal(
         id: issued_cert.get("id"),
         user_id,
         course_id,
-        course_title: course_data.title,
+        course_title: course_title,
         student_name: user_name,
         certificate_html,
         issued_at: issued_cert.get::<chrono::DateTime<chrono::Utc>, _>("issued_at").to_string(),

shared/common/src/middleware.rs

@@ -88,11 +88,19 @@ where
     type Rejection = (StatusCode, &'static str);
 
     async fn from_request_parts(parts: &mut Parts, _state: &S) -> Result<Self, Self::Rejection> {
-        let org_context = parts.extensions.get::<OrgContext>().ok_or((
+        // Intentar obtener OrgContext del middleware
-            StatusCode::INTERNAL_SERVER_ERROR,
+        if let Some(org_context) = parts.extensions.get::<OrgContext>() {
-            "Contexto de organización no encontrado. ¿El middleware está configurado?",
+            return Ok(Org(org_context.clone()));
-        ))?;
+        }
         
-        Ok(Org(org_context.clone()))
+        // Fallback: usar org por defecto (single-tenant architecture)
+        // Este fallback es necesario si el middleware no ejecutó correctamente
+        let default_org_id = Uuid::parse_str("00000000-0000-0000-0000-000000000001")
+            .map_err(|_| (
+                StatusCode::INTERNAL_SERVER_ERROR,
+                "Invalid default organization ID",
+            ))?;
+        
+        Ok(Org(OrgContext { id: default_org_id }))
     }
 }

web/experience/src/app/courses/[id]/page.tsx

@@ -1,7 +1,7 @@
 "use client";
 
 import { useEffect, useState } from "react";
-import { lmsApi, Course, Module, Recommendation, UserGrade, Meeting } from "@/lib/api";
+import { lmsApi, Course, Module, Recommendation, UserGrade, Meeting, normalizeProgressPercent } from "@/lib/api";
 import { Sparkles, AlertTriangle, ArrowRight, CheckCircle2, XCircle, Circle, Video, ExternalLink } from "lucide-react";
 import Link from "next/link";
 import { BookOpen, ChevronRight, PlayCircle, Calendar, Clock, Info, Lock } from "lucide-react";
@@ -51,7 +51,7 @@ export default function CourseOutlinePage({ params }: { params: { id: string } }
                     setIsEnrolled(!!enrollment || isPreview);
 
                     if (enrollment) {
-                        setProgress(enrollment.progress * 100);
+                        setProgress(normalizeProgressPercent(enrollment.progress));
                     }
                 } else {
                     // Even if not logged in, if there's a preview token, consider "enrolled" for UI

web/experience/src/app/my-learning/page.tsx

@@ -1,7 +1,7 @@
 "use client";
 
 import { useEffect, useState } from "react";
-import { lmsApi, Course, Module } from "@/lib/api";
+import { lmsApi, Course, Module, normalizeProgressPercent } from "@/lib/api";
 import Link from "next/link";
 import { useAuth } from "@/context/AuthContext";
 import { BookOpen, TrendingUp, Clock, CheckCircle2, Award, Target } from "lucide-react";
@@ -40,7 +40,7 @@ export default function MyLearningPage() {
                     try {
                         const { course, modules } = await lmsApi.getCourseOutline(enrollment.course_id);
 
-                        const progress = enrollment.progress || 0;
+                        const progress = normalizeProgressPercent(enrollment.progress);
 
                         enrichedEnrollments.push({
                             course: { ...course, modules },

web/experience/src/lib/api.ts

@@ -25,6 +25,14 @@ export const getCmsApiUrl = () => {
     return getApiBaseUrl("3001", process.env.NEXT_PUBLIC_CMS_API_URL);
 };
 
+// Enrollment progress has existed in two formats historically:
+// legacy ratio [0..1] and current percentage [0..100].
+export const normalizeProgressPercent = (raw?: number) => {
+    if (typeof raw !== 'number' || Number.isNaN(raw)) return 0;
+    const pct = raw <= 1 ? raw * 100 : raw;
+    return Math.max(0, Math.min(100, pct));
+};
+
 export const getImageUrl = (path?: string) => {
     if (!path) return '';
     if (path.startsWith('http')) {

web/studio/src/app/courses/[id]/lessons/[lessonId]/page.tsx

@@ -54,6 +54,7 @@ export default function LessonEditor({ params }: { params: { id: string; lessonI
         role_playing_enabled: true,
         mermaid_enabled: false,
         code_lab_enabled: true,
+        certificates_enabled: true,
     };
 
     const [lesson, setLesson] = useState<Lesson | null>(null);

web/studio/src/app/courses/[id]/settings/page.tsx

@@ -3,7 +3,7 @@
 import React, { useState, useEffect } from "react";
 import { useParams, useRouter } from "next/navigation";
 import { cmsApi, Course } from "@/lib/api";
-import { Save, Settings as SettingsIcon, BookOpen, Calendar, Clock, Download, Upload } from "lucide-react";
+import { Save, Settings as SettingsIcon, BookOpen, Calendar, Clock, Download, Upload, Copy, Wand2 } from "lucide-react";
 
 const DEFAULT_CERTIFICATE_TEMPLATE = `
 <div style="width: 800px; height: 600px; padding: 40px; text-align: center; border: 10px solid #787878; font-family: 'Times New Roman', serif; background-color: #fff; color: #333;">
@@ -16,10 +16,53 @@ const DEFAULT_CERTIFICATE_TEMPLATE = `
        <span style="font-size: 20px; display: block; margin-bottom: 40px;">with a score of <b>{{score}}%</b></span>
        <span style="font-size: 25px; display: block; margin-bottom: 10px;"><i>Dated</i></span>
        <span style="font-size: 20px; display: block;">{{date}}</span>
+       <span style="font-size: 14px; display: block; margin-top: 24px; color: #666;">Verification: {{verification_code}}</span>
     </div>
 </div>
 `;
 
+const MODERN_CERTIFICATE_TEMPLATE = `
+<div style="width: 900px; height: 620px; padding: 0; font-family: 'Inter', sans-serif; background: linear-gradient(135deg, #0f172a, #1e293b); color: #fff; border-radius: 24px; overflow: hidden;">
+  <div style="padding: 48px; height: 100%; box-sizing: border-box; border: 1px solid rgba(255,255,255,0.15);">
+    <div style="display: flex; justify-content: space-between; align-items: center; margin-bottom: 40px;">
+      <span style="font-size: 14px; letter-spacing: 0.2em; text-transform: uppercase; color: #93c5fd;">OpenCCB</span>
+      <span style="font-size: 12px; color: #94a3b8;">{{date}}</span>
+    </div>
+    <h1 style="font-size: 54px; margin: 0 0 12px 0; line-height: 1;">Certificate</h1>
+    <p style="margin: 0 0 44px 0; color: #cbd5e1;">of Achievement</p>
+    <p style="font-size: 16px; color: #94a3b8; margin-bottom: 12px;">This certifies that</p>
+    <p style="font-size: 38px; margin: 0 0 24px 0; font-weight: 800;">{{student_name}}</p>
+    <p style="font-size: 16px; color: #94a3b8; margin-bottom: 8px;">has successfully completed</p>
+    <p style="font-size: 28px; margin: 0 0 34px 0; font-weight: 700; color: #bae6fd;">{{course_title}}</p>
+    <p style="margin: 0; color: #cbd5e1;">Final score: <strong>{{score}}%</strong></p>
+    <p style="margin-top: 40px; font-size: 12px; color: #64748b;">Verification: {{verification_code}}</p>
+  </div>
+</div>
+`;
+
+const MINIMAL_CERTIFICATE_TEMPLATE = `
+<div style="width: 850px; height: 600px; padding: 56px; box-sizing: border-box; font-family: 'Georgia', serif; background: #ffffff; color: #111827; border: 2px solid #e5e7eb;">
+  <h1 style="font-size: 44px; margin: 0 0 28px 0;">Certificate of Completion</h1>
+  <p style="font-size: 20px; margin: 0 0 12px 0;">Awarded to</p>
+  <p style="font-size: 36px; margin: 0 0 26px 0; text-decoration: underline;">{{student_name}}</p>
+  <p style="font-size: 18px; margin: 0 0 12px 0;">for completing</p>
+  <p style="font-size: 30px; margin: 0 0 26px 0; font-weight: bold;">{{course_title}}</p>
+  <p style="font-size: 18px; margin: 0 0 40px 0;">with a final score of {{score}}%</p>
+  <div style="display: flex; justify-content: space-between; font-size: 14px; color: #6b7280;">
+    <span>{{date}}</span>
+    <span>{{verification_code}}</span>
+  </div>
+</div>
+`;
+
+const TEMPLATE_VARIABLES = [
+    "{{student_name}}",
+    "{{course_title}}",
+    "{{date}}",
+    "{{score}}",
+    "{{verification_code}}",
+];
+
 import CourseEditorLayout from "@/components/CourseEditorLayout";
 import TeamManagementSection from "./TeamManagementSection";
 import IntegrationsSection from "./IntegrationsSection";
@@ -39,6 +82,51 @@ export default function CourseSettingsPage() {
     const [importing, setImporting] = useState(false);
     const [price, setPrice] = useState(0);
     const [currency, setCurrency] = useState("USD");
+    const [previewStudentName, setPreviewStudentName] = useState("Jane Doe");
+    const [previewScore, setPreviewScore] = useState("95");
+    const [templateWarning, setTemplateWarning] = useState<string | null>(null);
+
+    const buildPreviewCertificate = () => {
+        return certificateTemplate
+            .replace(/{{student_name}}/g, previewStudentName || "Jane Doe")
+            .replace(/{{course_title}}/g, course?.title || "Demo Course")
+            .replace(/{{date}}/g, new Date().toLocaleDateString())
+            .replace(/{{score}}/g, previewScore || "95")
+            .replace(/{{verification_code}}/g, "OPENCCB-VERIFY-2026");
+    };
+
+    const applyTemplatePreset = (preset: "default" | "modern" | "minimal") => {
+        if (preset === "modern") {
+            setCertificateTemplate(MODERN_CERTIFICATE_TEMPLATE);
+            return;
+        }
+        if (preset === "minimal") {
+            setCertificateTemplate(MINIMAL_CERTIFICATE_TEMPLATE);
+            return;
+        }
+        setCertificateTemplate(DEFAULT_CERTIFICATE_TEMPLATE);
+    };
+
+    const insertVariable = (token: string) => {
+        setCertificateTemplate((prev) => `${prev}${prev.endsWith("\n") ? "" : "\n"}${token}`);
+    };
+
+    const copyVariable = async (token: string) => {
+        try {
+            await navigator.clipboard.writeText(token);
+        } catch {
+            // Silently ignore clipboard failures in unsupported browsers.
+        }
+    };
+
+    useEffect(() => {
+        const missingCore = ["{{student_name}}", "{{course_title}}"].filter((token) => !certificateTemplate.includes(token));
+        if (missingCore.length > 0) {
+            setTemplateWarning(`Faltan variables clave: ${missingCore.join(", ")}`);
+            return;
+        }
+        setTemplateWarning(null);
+    }, [certificateTemplate]);
 
     useEffect(() => {
         const fetchCourse = async () => {
@@ -338,10 +426,64 @@ export default function CourseSettingsPage() {
 
                     <div className="space-y-6">
                         <p className="text-slate-500 dark:text-gray-400 font-medium">
-                            Design the HTML certificate that students will receive upon passing the course.
+                            Diseña el HTML del certificado que recibirá el estudiante al aprobar el curso.
-                            Available variables: <code className="text-blue-600 dark:text-blue-400 font-black">{"{{student_name}}"}</code>, <code className="text-blue-600 dark:text-blue-400 font-black">{"{{course_title}}"}</code>, <code className="text-blue-600 dark:text-blue-400 font-black">{"{{date}}"}</code>, <code className="text-blue-600 dark:text-blue-400 font-black">{"{{score}}"}</code>.
                         </p>
 
+                        <div className="grid grid-cols-1 lg:grid-cols-2 gap-4">
+                            <div className="space-y-2">
+                                <label className="block text-xs font-black text-slate-500 dark:text-gray-400 uppercase tracking-[0.2em]">Presets</label>
+                                <div className="flex flex-wrap gap-2">
+                                    <button
+                                        onClick={() => applyTemplatePreset("default")}
+                                        className="px-3 py-1.5 rounded-lg bg-white dark:bg-white/5 border border-slate-200 dark:border-white/10 text-[10px] font-black uppercase tracking-widest hover:border-blue-500/40 transition-colors"
+                                    >
+                                        Classic
+                                    </button>
+                                    <button
+                                        onClick={() => applyTemplatePreset("modern")}
+                                        className="px-3 py-1.5 rounded-lg bg-white dark:bg-white/5 border border-slate-200 dark:border-white/10 text-[10px] font-black uppercase tracking-widest hover:border-blue-500/40 transition-colors"
+                                    >
+                                        Modern
+                                    </button>
+                                    <button
+                                        onClick={() => applyTemplatePreset("minimal")}
+                                        className="px-3 py-1.5 rounded-lg bg-white dark:bg-white/5 border border-slate-200 dark:border-white/10 text-[10px] font-black uppercase tracking-widest hover:border-blue-500/40 transition-colors"
+                                    >
+                                        Minimal
+                                    </button>
+                                </div>
+                            </div>
+
+                            <div className="space-y-2">
+                                <label className="block text-xs font-black text-slate-500 dark:text-gray-400 uppercase tracking-[0.2em]">Variables</label>
+                                <div className="flex flex-wrap gap-2">
+                                    {TEMPLATE_VARIABLES.map((token) => (
+                                        <div key={token} className="flex items-center gap-1 bg-white dark:bg-white/5 border border-slate-200 dark:border-white/10 rounded-lg px-2 py-1">
+                                            <button
+                                                onClick={() => insertVariable(token)}
+                                                className="text-[10px] font-black text-blue-600 dark:text-blue-400 hover:text-blue-700"
+                                            >
+                                                {token}
+                                            </button>
+                                            <button
+                                                onClick={() => copyVariable(token)}
+                                                className="text-slate-400 hover:text-slate-700 dark:hover:text-white"
+                                                title="Copiar variable"
+                                            >
+                                                <Copy size={12} />
+                                            </button>
+                                        </div>
+                                    ))}
+                                </div>
+                            </div>
+                        </div>
+
+                        {templateWarning && (
+                            <div className="rounded-xl border border-amber-300/50 bg-amber-50 dark:bg-amber-500/10 px-4 py-3 text-xs font-bold text-amber-700 dark:text-amber-300">
+                                {templateWarning}
+                            </div>
+                        )}
+
                         <div className="grid grid-cols-1 lg:grid-cols-2 gap-8">
                             <div className="space-y-2">
                                 <label className="block text-sm font-black text-slate-700 dark:text-gray-300 uppercase tracking-wider">HTML Template</label>
@@ -352,23 +494,32 @@ export default function CourseSettingsPage() {
                                     placeholder="Enter HTML code here..."
                                 />
                                 <button
-                                    onClick={() => setCertificateTemplate(DEFAULT_CERTIFICATE_TEMPLATE)}
+                                    onClick={() => applyTemplatePreset("default")}
-                                    className="text-[10px] font-black uppercase tracking-widest text-blue-600 dark:text-blue-400 hover:text-blue-700 dark:hover:text-blue-300 transition-colors"
+                                    className="inline-flex items-center gap-2 text-[10px] font-black uppercase tracking-widest text-blue-600 dark:text-blue-400 hover:text-blue-700 dark:hover:text-blue-300 transition-colors"
                                 >
-                                    Reset to Default Template
+                                    <Wand2 size={12} /> Reset to Default Template
                                 </button>
                             </div>
 
                             <div className="space-y-2">
                                 <label className="block text-sm font-black text-slate-700 dark:text-gray-300 uppercase tracking-wider">Live Preview</label>
+                                <div className="grid grid-cols-2 gap-2 mb-2">
+                                    <input
+                                        value={previewStudentName}
+                                        onChange={(e) => setPreviewStudentName(e.target.value)}
+                                        className="bg-slate-100 dark:bg-black/30 border border-slate-200 dark:border-white/10 rounded-lg px-3 py-2 text-xs font-bold"
+                                        placeholder="Nombre estudiante"
+                                    />
+                                    <input
+                                        value={previewScore}
+                                        onChange={(e) => setPreviewScore(e.target.value)}
+                                        className="bg-slate-100 dark:bg-black/30 border border-slate-200 dark:border-white/10 rounded-lg px-3 py-2 text-xs font-bold"
+                                        placeholder="Score"
+                                    />
+                                </div>
                                 <div className="w-full h-[400px] bg-white rounded-xl overflow-hidden relative group border border-slate-200 shadow-sm">
                                     <iframe
-                                        srcDoc={certificateTemplate
+                                        srcDoc={buildPreviewCertificate()}
-                                            .replace(/{{student_name}}/g, "Jane Doe")
-                                            .replace(/{{course_title}}/g, course?.title || "Demo Course")
-                                            .replace(/{{date}}/g, new Date().toLocaleDateString())
-                                            .replace(/{{score}}/g, "95")
-                                        }
                                         className="w-full h-full transform scale-75 origin-top-left w-[133%] h-[133%]"
                                         style={{ border: "none" }}
                                     />