* {
            margin: 0;
            padding: 0;
            box-sizing: border-box;
        }

        body {
            background: #141414;
            font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
            color: white;
            overflow-x: hidden;
        }

        /* Header estilo Netflix */
        .header {
            background: linear-gradient(180deg, rgba(0,0,0,0.8) 0%, rgba(0,0,0,0.4) 100%);
            padding: 2rem 0;
            text-align: center;
            position: relative;
            min-height: 40vh;
            display: flex;
            flex-direction: column;
            justify-content: center;
            background-image: 
                radial-gradient(circle at 20% 50%, rgba(255, 107, 107, 0.1) 0%, transparent 50%),
                radial-gradient(circle at 80% 20%, rgba(0, 212, 255, 0.1) 0%, transparent 50%),
                radial-gradient(circle at 40% 80%, rgba(78, 205, 196, 0.1) 0%, transparent 50%);
        }

        .logo-container {
            margin-bottom: 2rem;
        }

        .logo-link {
            display: inline-block;
            transition: all 0.3s ease;
            text-decoration: none;
            cursor: pointer;
            position: relative;
        }

        .logo-link:hover {
            transform: scale(1.05);
            filter: brightness(1.1);
        }

        .company-logo {
            height: 80px;
            width: auto;
            max-width: 300px;
            object-fit: contain;
            filter: drop-shadow(0 4px 8px rgba(0, 0, 0, 0.3));
            transition: all 0.3s ease;
        }

        .header h1 {
            font-size: 4rem;
            font-weight: 900;
            background: linear-gradient(45deg, #ff6b6b, #00d4ff, #4ecdc4);
            -webkit-background-clip: text;
            -webkit-text-fill-color: transparent;
            margin-bottom: 1rem;
            text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.3);
            letter-spacing: -1px;
        }

        .header h2 {
            font-size: 1.8rem;
            color: #fff;
            margin-bottom: 1rem;
            font-weight: 400;
            opacity: 0.9;
        }

        .header p {
            font-size: 1.1rem;
            color: #b3b3b3;
            max-width: 700px;
            margin: 0 auto 2rem;
            line-height: 1.5;
        }

        /* Enlace al índice */
        .index-container {
            display: flex;
            justify-content: center;
            margin: 2rem 0 1rem 0;
            padding: 0 2rem;
        }

        .index-btn {
            display: inline-flex;
            align-items: center;
            gap: 0.8rem;
            padding: 0.8rem 1.5rem;
            background: linear-gradient(45deg, #4ecdc4, #44a08d);
            color: white;
            text-decoration: none;
            border-radius: 25px;
            font-weight: bold;
            font-size: 1rem;
            transition: all 0.3s ease;
            box-shadow: 0 8px 25px rgba(78, 205, 196, 0.3);
            border: 2px solid rgba(255, 255, 255, 0.1);
        }

        .index-btn:hover {
            transform: translateY(-2px);
            box-shadow: 0 12px 35px rgba(78, 205, 196, 0.5);
            background: linear-gradient(45deg, #5fd4cb, #4fa897);
        }

        .index-icon {
            width: 20px;
            height: 20px;
            fill: currentColor;
        }

        /* SECCIÓN MEJORADA: Controles por Unidad organizados por Fases */
        .controls-section {
            background: rgba(0, 0, 0, 0.6);
            backdrop-filter: blur(20px);
            padding: 2rem;
            margin: 1rem 0;
            border-top: 1px solid rgba(255, 255, 255, 0.1);
            border-bottom: 1px solid rgba(255, 255, 255, 0.1);
        }

        .controls-header {
            text-align: center;
            margin-bottom: 3rem;
        }

        .controls-title {
            font-size: 2rem;
            font-weight: 700;
            background: linear-gradient(45deg, #ff6b6b, #ffc107, #4ecdc4);
            -webkit-background-clip: text;
            -webkit-text-fill-color: transparent;
            margin-bottom: 0.5rem;
        }

        .controls-subtitle {
            color: #b3b3b3;
            font-size: 1rem;
            opacity: 0.9;
        }

        /* Fases organizadas */
        .phase-container {
            margin-bottom: 3rem;
        }

        .phase-header {
            text-align: center;
            margin-bottom: 1.5rem;
        }

        .phase-title {
            font-size: 1.4rem;
            font-weight: 600;
            margin-bottom: 0.5rem;
            display: flex;
            align-items: center;
            justify-content: center;
            gap: 0.8rem;
        }

        .phase-1 .phase-title {
            color: #ff6b6b;
        }

        .phase-2 .phase-title {
            color: #4ecdc4;
        }

        .phase-3 .phase-title {
            color: #00d4ff;
        }

        .phase-deadline {
            color: #b3b3b3;
            font-size: 0.9rem;
            opacity: 0.8;
        }

        .controls-grid {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
            gap: 1rem;
            max-width: 1200px;
            margin: 0 auto;
        }

        .control-btn {
            display: flex;
            align-items: center;
            justify-content: center;
            gap: 0.8rem;
            padding: 1rem 1.5rem;
            background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
            color: white;
            text-decoration: none;
            border-radius: 15px;
            font-weight: 600;
            font-size: 0.95rem;
            transition: all 0.3s ease;
            box-shadow: 0 4px 15px rgba(102, 126, 234, 0.3);
            border: 1px solid rgba(255, 255, 255, 0.1);
            position: relative;
            overflow: hidden;
        }

        .control-btn::before {
            content: '';
            position: absolute;
            top: 0;
            left: -100%;
            width: 100%;
            height: 100%;
            background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.2), transparent);
            transition: left 0.5s ease;
        }

        .control-btn:hover::before {
            left: 100%;
        }

        .control-btn:hover {
            transform: translateY(-3px);
            box-shadow: 0 8px 25px rgba(102, 126, 234, 0.5);
            background: linear-gradient(135deg, #7c8ff0 0%, #8a5eb8 100%);
        }

        /* Colores específicos para fase 1 */
        .phase-1 .control-btn:nth-child(4n+1) {
            background: linear-gradient(135deg, #ff6b6b 0%, #ff8e53 100%);
            box-shadow: 0 4px 15px rgba(255, 107, 107, 0.3);
        }

        .phase-1 .control-btn:nth-child(4n+1):hover {
            background: linear-gradient(135deg, #ff7979 0%, #ffa368 100%);
            box-shadow: 0 8px 25px rgba(255, 107, 107, 0.5);
        }

        .phase-1 .control-btn:nth-child(4n+2) {
            background: linear-gradient(135deg, #ffc107 0%, #ff8f00 100%);
            box-shadow: 0 4px 15px rgba(255, 193, 7, 0.3);
        }

        .phase-1 .control-btn:nth-child(4n+2):hover {
            background: linear-gradient(135deg, #ffcd38 0%, #ffa000 100%);
            box-shadow: 0 8px 25px rgba(255, 193, 7, 0.5);
        }

        .phase-1 .control-btn:nth-child(4n+3) {
            background: linear-gradient(135deg, #ff9800 0%, #f57c00 100%);
            box-shadow: 0 4px 15px rgba(255, 152, 0, 0.3);
        }

        .phase-1 .control-btn:nth-child(4n+3):hover {
            background: linear-gradient(135deg, #ffb74d 0%, #ff8f00 100%);
            box-shadow: 0 8px 25px rgba(255, 152, 0, 0.5);
        }

        .phase-1 .control-btn:nth-child(4n+4) {
            background: linear-gradient(135deg, #e91e63 0%, #ad1457 100%);
            box-shadow: 0 4px 15px rgba(233, 30, 99, 0.3);
        }

        .phase-1 .control-btn:nth-child(4n+4):hover {
            background: linear-gradient(135deg, #f06292 0%, #c2185b 100%);
            box-shadow: 0 8px 25px rgba(233, 30, 99, 0.5);
        }

        /* Colores específicos para fase 2 */
        .phase-2 .control-btn:nth-child(4n+1) {
            background: linear-gradient(135deg, #4ecdc4 0%, #44a08d 100%);
            box-shadow: 0 4px 15px rgba(78, 205, 196, 0.3);
        }

        .phase-2 .control-btn:nth-child(4n+1):hover {
            background: linear-gradient(135deg, #5fd4cb 0%, #4fa897 100%);
            box-shadow: 0 8px 25px rgba(78, 205, 196, 0.5);
        }

        .phase-2 .control-btn:nth-child(4n+2) {
            background: linear-gradient(135deg, #26a69a 0%, #00695c 100%);
            box-shadow: 0 4px 15px rgba(38, 166, 154, 0.3);
        }

        .phase-2 .control-btn:nth-child(4n+2):hover {
            background: linear-gradient(135deg, #4db6ac 0%, #00796b 100%);
            box-shadow: 0 8px 25px rgba(38, 166, 154, 0.5);
        }

        .phase-2 .control-btn:nth-child(4n+3) {
            background: linear-gradient(135deg, #009688 0%, #004d40 100%);
            box-shadow: 0 4px 15px rgba(0, 150, 136, 0.3);
        }

        .phase-2 .control-btn:nth-child(4n+3):hover {
            background: linear-gradient(135deg, #26a69a 0%, #00695c 100%);
            box-shadow: 0 8px 25px rgba(0, 150, 136, 0.5);
        }

        .phase-2 .control-btn:nth-child(4n+4) {
            background: linear-gradient(135deg, #00bcd4 0%, #006064 100%);
            box-shadow: 0 4px 15px rgba(0, 188, 212, 0.3);
        }

        .phase-2 .control-btn:nth-child(4n+4):hover {
            background: linear-gradient(135deg, #26c6da 0%, #00838f 100%);
            box-shadow: 0 8px 25px rgba(0, 188, 212, 0.5);
        }

        /* Colores específicos para fase 3 */
        .phase-3 .control-btn:nth-child(4n+1) {
            background: linear-gradient(135deg, #00d4ff 0%, #0099cc 100%);
            box-shadow: 0 4px 15px rgba(0, 212, 255, 0.3);
        }

        .phase-3 .control-btn:nth-child(4n+1):hover {
            background: linear-gradient(135deg, #1ae1ff 0%, #00a8d4 100%);
            box-shadow: 0 8px 25px rgba(0, 212, 255, 0.5);
        }

        .phase-3 .control-btn:nth-child(4n+2) {
            background: linear-gradient(135deg, #2196f3 0%, #0d47a1 100%);
            box-shadow: 0 4px 15px rgba(33, 150, 243, 0.3);
        }

        .phase-3 .control-btn:nth-child(4n+2):hover {
            background: linear-gradient(135deg, #42a5f5 0%, #1565c0 100%);
            box-shadow: 0 8px 25px rgba(33, 150, 243, 0.5);
        }

        .phase-3 .control-btn:nth-child(4n+3) {
            background: linear-gradient(135deg, #3f51b5 0%, #1a237e 100%);
            box-shadow: 0 4px 15px rgba(63, 81, 181, 0.3);
        }

        .phase-3 .control-btn:nth-child(4n+3):hover {
            background: linear-gradient(135deg, #5c6bc0 0%, #283593 100%);
            box-shadow: 0 8px 25px rgba(63, 81, 181, 0.5);
        }

        .phase-3 .control-btn:nth-child(4n+4) {
            background: linear-gradient(135deg, #673ab7 0%, #311b92 100%);
            box-shadow: 0 4px 15px rgba(103, 58, 183, 0.3);
        }

        .phase-3 .control-btn:nth-child(4n+4):hover {
            background: linear-gradient(135deg, #9575cd 0%, #4527a0 100%);
            box-shadow: 0 8px 25px rgba(103, 58, 183, 0.5);
        }

        .control-icon {
            width: 22px;
            height: 22px;
            fill: currentColor;
        }

        /* Barra de búsqueda estilo Netflix */
        .search-container {
            display: flex;
            justify-content: center;
            margin: 1rem 0 2rem 0;
            padding: 0 2rem;
        }

        .search-box {
            position: relative;
            max-width: 500px;
            width: 100%;
        }

        .search-input {
            width: 100%;
            padding: 15px 20px 15px 50px;
            border: none;
            border-radius: 30px;
            background: rgba(255, 255, 255, 0.1);
            color: white;
            backdrop-filter: blur(10px);
            border: 2px solid rgba(255, 255, 255, 0.2);
            font-size: 16px;
            transition: all 0.3s ease;
        }

        .search-input:focus {
            outline: none;
            border-color: #ff6b6b;
            background: rgba(255, 255, 255, 0.15);
            box-shadow: 0 0 20px rgba(255, 107, 107, 0.3);
        }

        .search-input::placeholder {
            color: rgba(255, 255, 255, 0.6);
        }

        .search-icon {
            position: absolute;
            left: 18px;
            top: 50%;
            transform: translateY(-50%);
            font-size: 18px;
            color: rgba(255, 255, 255, 0.6);
        }

        /* Stats Bar estilo Netflix */
        .stats-container {
            background: rgba(0, 0, 0, 0.7);
            backdrop-filter: blur(20px);
            padding: 1.5rem 2rem;
            margin: 0;
            border-top: 1px solid rgba(255, 255, 255, 0.1);
            border-bottom: 1px solid rgba(255, 255, 255, 0.1);
        }

        .stats-grid {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
            gap: 2rem;
            max-width: 1200px;
            margin: 0 auto;
            text-align: center;
        }

        .stat-item {
            display: flex;
            flex-direction: column;
            align-items: center;
            gap: 0.5rem;
        }

        .stat-number {
            font-size: 2.5rem;
            font-weight: 900;
            background: linear-gradient(45deg, #ff6b6b, #00d4ff);
            -webkit-background-clip: text;
            -webkit-text-fill-color: transparent;
        }

        .stat-label {
            color: #b3b3b3;
            font-size: 0.9rem;
            text-transform: uppercase;
            letter-spacing: 1px;
        }

        /* NUEVO: SISTEMA DE PESTAÑAS/SLIDES */
        .tabs-container {
            background: rgba(0, 0, 0, 0.8);
            backdrop-filter: blur(20px);
            padding: 2rem 0 0 0;
            margin: 2rem 0 0 0;
            border-top: 1px solid rgba(255, 255, 255, 0.1);
        }

        .tabs-header {
            display: flex;
            justify-content: center;
            margin-bottom: 2rem;
            padding: 0 2rem;
            gap: 1rem;
            overflow-x: auto;
            scrollbar-width: none;
            -ms-overflow-style: none;
        }

        .tabs-header::-webkit-scrollbar {
            display: none;
        }

        .tab-button {
            flex: 0 0 auto;
            padding: 1rem 2rem;
            background: rgba(255, 255, 255, 0.1);
            border: 2px solid rgba(255, 255, 255, 0.2);
            border-radius: 25px;
            color: rgba(255, 255, 255, 0.7);
            font-weight: 600;
            font-size: 1rem;
            cursor: pointer;
            transition: all 0.3s ease;
            display: flex;
            align-items: center;
            gap: 0.8rem;
            min-width: 200px;
            justify-content: center;
            white-space: nowrap;
        }

        .tab-button.active {
            background: linear-gradient(45deg, #ff6b6b, #00d4ff);
            border-color: rgba(255, 255, 255, 0.5);
            color: white;
            transform: translateY(-2px);
            box-shadow: 0 8px 25px rgba(255, 107, 107, 0.3);
        }

        .tab-button:hover:not(.active) {
            background: rgba(255, 255, 255, 0.15);
            border-color: rgba(255, 255, 255, 0.4);
            color: rgba(255, 255, 255, 0.9);
            transform: translateY(-1px);
        }

        .tab-button.phase-1.active {
            background: linear-gradient(45deg, #ff6b6b, #ff8e53);
            box-shadow: 0 8px 25px rgba(255, 107, 107, 0.4);
        }

        .tab-button.phase-2.active {
            background: linear-gradient(45deg, #4ecdc4, #44a08d);
            box-shadow: 0 8px 25px rgba(78, 205, 196, 0.4);
        }

        .tab-button.phase-3.active {
            background: linear-gradient(45deg, #00d4ff, #0099cc);
            box-shadow: 0 8px 25px rgba(0, 212, 255, 0.4);
        }

        .tab-button.phase-4.active {
            background: linear-gradient(45deg, #8e44ad, #9b59b6);
            box-shadow: 0 8px 25px rgba(142, 68, 173, 0.4);
        }

        .tab-icon {
            width: 20px;
            height: 20px;
            fill: currentColor;
        }

        .tabs-content {
            min-height: 600px;
            position: relative;
            overflow: hidden;
        }

        .tab-panel {
            position: absolute;
            top: 0;
            left: 0;
            width: 100%;
            opacity: 0;
            transform: translateX(100px);
            transition: all 0.4s ease;
            pointer-events: none;
        }

        .tab-panel.active {
            opacity: 1;
            transform: translateX(0);
            pointer-events: all;
            position: relative;
        }

        /* Contenedor principal para videos */
        .main-videos-container {
            padding: 0 0 3rem 0;
            background: #141414;
        }

        /* Sección de módulos estilo Netflix */
        .module-section {
            margin-bottom: 4rem;
            padding: 0 2rem;
        }

        .module-header {
            display: flex;
            flex-direction: column;
            margin-bottom: 2rem;
            gap: 1rem;
        }

        .module-title-row {
            display: flex;
            align-items: center;
            gap: 1rem;
        }

        .module-title {
            font-size: 1.8rem;
            font-weight: 700;
            color: white;
            margin: 0;
        }

        .module-count {
            background: linear-gradient(45deg, #ff6b6b, #ff8e53);
            color: white;
            padding: 0.3rem 0.8rem;
            border-radius: 20px;
            font-size: 0.9rem;
            font-weight: 600;
        }

        /* Contador de tiempo descendente */
        .countdown-container {
            display: flex;
            align-items: center;
            justify-content: center;
            gap: 1rem;
            background: rgba(0, 0, 0, 0.5);
            padding: 0.8rem 1.5rem;
            border-radius: 25px;
            border: 1px solid rgba(255, 255, 255, 0.1);
            backdrop-filter: blur(10px);
            max-width: fit-content;
            margin: 0 auto;
        }

        .countdown-info {
            display: flex;
            flex-direction: column;
            align-items: center;
            gap: 0.3rem;
        }

        .countdown-phase {
            font-size: 0.8rem;
            font-weight: 600;
            opacity: 0.8;
        }

        .countdown-deadline {
            font-size: 0.75rem;
            opacity: 0.7;
        }

        .countdown-timer {
            display: flex;
            align-items: center;
            gap: 0.5rem;
            font-size: 0.9rem;
            font-weight: 600;
            color: #ffc107;
        }

        .countdown-days {
            background: linear-gradient(45deg, #ff6b6b, #ffc107);
            -webkit-background-clip: text;
            -webkit-text-fill-color: transparent;
            font-weight: 900;
            font-size: 1.1rem;
        }

        /* Colores específicos para fases en countdown */
        .phase-1-countdown .countdown-phase,
        .phase-1-countdown .countdown-timer {
            color: #ff6b6b;
        }

        .phase-2-countdown .countdown-phase,
        .phase-2-countdown .countdown-timer {
            color: #4ecdc4;
        }

        .phase-3-countdown .countdown-phase,
        .phase-3-countdown .countdown-timer {
            color: #00d4ff;
        }

        /* Scroll horizontal de videos estilo Netflix */
        .videos-scroll {
            position: relative;
            overflow: hidden;
        }

        .videos-row {
            display: flex;
            gap: 1rem;
            overflow-x: auto;
            scroll-behavior: smooth;
            padding: 1rem 0;
            scrollbar-width: none; /* Firefox */
            -ms-overflow-style: none; /* IE/Edge */
        }

        .videos-row::-webkit-scrollbar {
            display: none; /* Chrome/Safari */
        }

        /* Botones de navegación */
        .nav-btn {
            position: absolute;
            top: 50%;
            transform: translateY(-50%);
            background: rgba(0, 0, 0, 0.8);
            border: none;
            color: white;
            padding: 1rem;
            border-radius: 50%;
            cursor: pointer;
            z-index: 100;
            transition: all 0.3s ease;
            font-size: 1.2rem;
            width: 50px;
            height: 50px;
            display: flex;
            align-items: center;
            justify-content: center;
        }

        .nav-btn:hover {
            background: rgba(255, 255, 255, 0.2);
            transform: translateY(-50%) scale(1.1);
        }

        .nav-btn.prev {
            left: 10px;
        }

        .nav-btn.next {
            right: 10px;
        }

        /* TARJETAS DE VIDEO MEJORADAS PARA MÓVILES */
        .video-card {
            flex: 0 0 300px;
            background: #222;
            border-radius: 8px;
            overflow: hidden;
            transition: all 0.3s ease;
            cursor: pointer;
            position: relative;
            height: 480px;
            min-height: 480px;
        }

        .video-card:hover {
            transform: scale(1.05);
            z-index: 50;
            box-shadow: 0 20px 40px rgba(0, 0, 0, 0.5);
        }

        .video-card.pending {
            opacity: 0.7;
        }

        .video-thumbnail {
            position: relative;
            width: 100%;
            height: 200px;
            overflow: hidden;
            background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
        }

        .video-thumbnail img {
            width: 100%;
            height: 100%;
            object-fit: cover;
            transition: transform 0.3s ease;
        }

        .video-card:hover .video-thumbnail img {
            transform: scale(1.1);
        }

        .video-number {
            position: absolute;
            top: 10px;
            left: 10px;
            background: rgba(0, 0, 0, 0.8);
            color: white;
            padding: 0.3rem 0.8rem;
            border-radius: 15px;
            font-weight: bold;
            font-size: 0.8rem;
            backdrop-filter: blur(10px);
        }

        .play-overlay {
            position: absolute;
            top: 50%;
            left: 50%;
            transform: translate(-50%, -50%);
            background: rgba(255, 107, 107, 0.9);
            border-radius: 50%;
            width: 60px;
            height: 60px;
            display: flex;
            align-items: center;
            justify-content: center;
            opacity: 0;
            transition: opacity 0.3s ease;
            cursor: pointer;
        }

        .video-card:hover .play-overlay {
            opacity: 1;
        }

        .play-icon {
            width: 0;
            height: 0;
            border-left: 20px solid white;
            border-top: 12px solid transparent;
            border-bottom: 12px solid transparent;
            margin-left: 4px;
        }

        .pending-overlay {
            position: absolute;
            top: 50%;
            left: 50%;
            transform: translate(-50%, -50%);
            background: rgba(255, 193, 7, 0.9);
            color: white;
            padding: 0.5rem 1rem;
            border-radius: 20px;
            font-weight: bold;
            font-size: 0.8rem;
        }

        .video-content {
            padding: 1.5rem;
            height: 280px;
            display: flex;
            flex-direction: column;
            justify-content: space-between;
        }

        .video-title {
            font-size: 1rem;
            font-weight: 600;
            color: white;
            margin-bottom: 0.8rem;
            line-height: 1.3;
            flex-grow: 1;
            display: -webkit-box;
            -webkit-line-clamp: 3;
            -webkit-box-orient: vertical;
            overflow: hidden;
        }

        .video-duration {
            background: rgba(78, 205, 196, 0.2);
            color: #4ecdc4;
            padding: 0.3rem 0.6rem;
            border-radius: 12px;
            font-size: 0.8rem;
            font-weight: 500;
            margin-bottom: 1rem;
            align-self: flex-start;
        }

        .video-actions {
            display: flex;
            flex-direction: column;
            gap: 0.8rem;
            margin-top: auto;
        }

        .action-buttons {
            display: flex;
            gap: 0.6rem;
        }

        .action-btn {
            flex: 1;
            padding: 0.6rem 0.4rem;
            border: none;
            border-radius: 8px;
            font-size: 0.8rem;
            font-weight: 600;
            cursor: pointer;
            transition: all 0.3s ease;
            text-decoration: none;
            display: flex;
            align-items: center;
            justify-content: center;
            gap: 0.3rem;
            min-height: 40px;
        }

        .btn-watch {
            background: linear-gradient(45deg, #ff6b6b, #ff8e53);
            color: white;
        }

        .btn-watch:hover {
            transform: translateY(-2px);
            box-shadow: 0 5px 15px rgba(255, 107, 107, 0.4);
        }

        .btn-transcript {
            background: linear-gradient(45deg, #00d4ff, #0099cc);
            color: white;
        }

        .btn-transcript:hover {
            transform: translateY(-2px);
            box-shadow: 0 5px 15px rgba(0, 212, 255, 0.4);
        }

        .btn-quiz {
            background: linear-gradient(45deg, #4ecdc4, #44a08d);
            color: white;
        }

        .btn-quiz:hover {
            transform: translateY(-2px);
            box-shadow: 0 5px 15px rgba(78, 205, 196, 0.4);
        }

        .btn-pending {
            background: #555;
            color: #999;
            cursor: default;
        }

        .progress-checkbox {
            display: flex;
            align-items: center;
            gap: 0.5rem;
            padding: 0.6rem 0.8rem;
            background: rgba(255, 255, 255, 0.1);
            border-radius: 15px;
            font-size: 0.8rem;
            cursor: pointer;
            transition: all 0.3s ease;
            min-height: 40px;
        }

        .progress-checkbox:hover {
            background: rgba(255, 255, 255, 0.15);
        }

        .progress-checkbox.completed {
            background: linear-gradient(45deg, #4ecdc4, #44a08d);
        }

        .progress-checkbox input[type="checkbox"] {
            appearance: none;
            width: 16px;
            height: 16px;
            border: 2px solid white;
            border-radius: 3px;
            background: transparent;
            cursor: pointer;
            position: relative;
            flex-shrink: 0;
        }

        .progress-checkbox input[type="checkbox"]:checked {
            background: white;
        }

        .progress-checkbox input[type="checkbox"]:checked::after {
            content: '✓';
            position: absolute;
            top: -3px;
            left: 1px;
            color: #4ecdc4;
            font-weight: bold;
            font-size: 12px;
        }

        /* NUEVA SECCIÓN: FASE 4 - INFORMACIÓN ESTRATÉGICA */
        .strategic-section {
            padding: 3rem 2rem;
            background: linear-gradient(135deg, #2c1810 0%, #8e44ad 100%);
            color: white;
        }

        .strategic-header {
            text-align: center;
            margin-bottom: 4rem;
        }

        .strategic-title {
            font-size: 3rem;
            font-weight: 900;
            background: linear-gradient(45deg, #ffd700, #ff6b6b, #00d4ff);
            -webkit-background-clip: text;
            -webkit-text-fill-color: transparent;
            margin-bottom: 1rem;
        }

        .strategic-subtitle {
            font-size: 1.2rem;
            color: rgba(255, 255, 255, 0.8);
            max-width: 800px;
            margin: 0 auto;
        }

        .strategic-grid {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
            gap: 2rem;
            max-width: 1400px;
            margin: 0 auto;
        }

        .strategic-card {
            background: rgba(0, 0, 0, 0.4);
            border-radius: 20px;
            padding: 2rem;
            backdrop-filter: blur(10px);
            border: 1px solid rgba(255, 255, 255, 0.1);
            transition: all 0.3s ease;
            cursor: pointer;
        }

        .strategic-card:hover {
            transform: translateY(-10px);
            box-shadow: 0 20px 40px rgba(0, 0, 0, 0.3);
            border-color: rgba(255, 255, 255, 0.3);
        }

        .card-icon {
            width: 60px;
            height: 60px;
            margin-bottom: 1.5rem;
            background: linear-gradient(45deg, #ff6b6b, #00d4ff);
            border-radius: 15px;
            display: flex;
            align-items: center;
            justify-content: center;
            font-size: 2rem;
        }

        .card-title {
            font-size: 1.5rem;
            font-weight: 700;
            margin-bottom: 1rem;
            color: white;
        }

        .card-description {
            color: rgba(255, 255, 255, 0.8);
            line-height: 1.6;
            margin-bottom: 1.5rem;
        }

        .card-features {
            list-style: none;
            padding: 0;
        }

        .card-features li {
            padding: 0.5rem 0;
            border-bottom: 1px solid rgba(255, 255, 255, 0.1);
            display: flex;
            align-items: center;
            gap: 0.5rem;
        }

        .card-features li:last-child {
            border-bottom: none;
        }

        .feature-icon {
            color: #4ecdc4;
            font-weight: bold;
        }

        .strategic-cta {
            text-align: center;
            margin-top: 4rem;
            padding: 3rem;
            background: rgba(0, 0, 0, 0.3);
            border-radius: 20px;
            border: 1px solid rgba(255, 255, 255, 0.1);
        }

        .cta-title {
            font-size: 2rem;
            font-weight: 700;
            margin-bottom: 1rem;
            color: white;
        }

        .cta-description {
            font-size: 1.1rem;
            color: rgba(255, 255, 255, 0.8);
            margin-bottom: 2rem;
            max-width: 600px;
            margin-left: auto;
            margin-right: auto;
        }

        .cta-buttons {
            display: flex;
            gap: 1rem;
            justify-content: center;
            flex-wrap: wrap;
        }

        .cta-btn {
            padding: 1rem 2rem;
            background: linear-gradient(45deg, #ff6b6b, #ff8e53);
            color: white;
            text-decoration: none;
            border-radius: 25px;
            font-weight: bold;
            transition: all 0.3s ease;
            display: flex;
            align-items: center;
            gap: 0.5rem;
        }

        .cta-btn:hover {
            transform: translateY(-2px);
            box-shadow: 0 10px 30px rgba(255, 107, 107, 0.4);
        }

        .cta-btn.secondary {
            background: linear-gradient(45deg, #4ecdc4, #44a08d);
        }

        .cta-btn.secondary:hover {
            box-shadow: 0 10px 30px rgba(78, 205, 196, 0.4);
        }

        /* Documentación */
        .documentation-section {
            text-align: center;
            padding: 3rem 2rem;
            background: rgba(0, 0, 0, 0.5);
            margin-top: 3rem;
        }

        .documentation-btn {
            display: inline-flex;
            align-items: center;
            gap: 1rem;
            padding: 1rem 2rem;
            background: linear-gradient(45deg, #ff6b6b, #ff8e53);
            color: white;
            text-decoration: none;
            border-radius: 30px;
            font-weight: bold;
            font-size: 1.1rem;
            transition: all 0.3s ease;
            box-shadow: 0 10px 30px rgba(255, 107, 107, 0.3);
            margin: 0 1rem 1rem 0;
        }

        .documentation-btn:hover {
            transform: translateY(-3px);
            box-shadow: 0 15px 40px rgba(255, 107, 107, 0.5);
        }

        .final-exam-btn {
            display: inline-flex;
            align-items: center;
            gap: 1rem;
            padding: 1rem 2rem;
            background: linear-gradient(45deg, #8e44ad, #9b59b6);
            color: white;
            text-decoration: none;
            border-radius: 30px;
            font-weight: bold;
            font-size: 1.1rem;
            transition: all 0.3s ease;
            box-shadow: 0 10px 30px rgba(142, 68, 173, 0.3);
            margin: 0 1rem 1rem 0;
            position: relative;
            overflow: hidden;
        }

        .final-exam-btn::before {
            content: '';
            position: absolute;
            top: -50%;
            left: -50%;
            width: 200%;
            height: 200%;
            background: linear-gradient(45deg, transparent, rgba(255, 255, 255, 0.1), transparent);
            transform: rotate(45deg);
            transition: all 0.6s ease;
            opacity: 0;
        }

        .final-exam-btn:hover::before {
            opacity: 1;
            transform: rotate(45deg) translate(50%, 50%);
        }

        .final-exam-btn:hover {
            transform: translateY(-3px);
            box-shadow: 0 15px 40px rgba(142, 68, 173, 0.5);
            background: linear-gradient(45deg, #9c56c7, #a569db);
        }

        .checklist-btn {
            display: inline-flex;
            align-items: center;
            gap: 1rem;
            padding: 1rem 2rem;
            background: linear-gradient(45deg, #27ae60, #2ecc71);
            color: white;
            text-decoration: none;
            border-radius: 30px;
            font-weight: bold;
            font-size: 1.1rem;
            transition: all 0.3s ease;
            box-shadow: 0 10px 30px rgba(39, 174, 96, 0.3);
            margin: 0 1rem 1rem 0;
            position: relative;
            overflow: hidden;
        }

        .checklist-btn::before {
            content: '';
            position: absolute;
            top: -50%;
            left: -50%;
            width: 200%;
            height: 200%;
            background: linear-gradient(45deg, transparent, rgba(255, 255, 255, 0.1), transparent);
            transform: rotate(45deg);
            transition: all 0.6s ease;
            opacity: 0;
        }

        .checklist-btn:hover::before {
            opacity: 1;
            transform: rotate(45deg) translate(50%, 50%);
        }

        .checklist-btn:hover {
            transform: translateY(-3px);
            box-shadow: 0 15px 40px rgba(39, 174, 96, 0.5);
            background: linear-gradient(45deg, #2ecc71, #58d68d);
        }

        /* Footer */
        .footer {
            background: #000;
            text-align: center;
            padding: 2rem;
            border-top: 1px solid rgba(255, 255, 255, 0.1);
        }

        .footer p {
            color: #666;
            margin-bottom: 0.5rem;
        }

        .footer a {
            color: #00d4ff;
            text-decoration: none;
            transition: color 0.3s ease;
        }

        .footer a:hover {
            color: white;
        }

        /* Responsive */
        @media (max-width: 768px) {
            .header h1 {
                font-size: 2.5rem;
            }

            .controls-grid {
                grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
                gap: 0.8rem;
            }

            .control-btn {
                padding: 0.8rem 1rem;
                font-size: 0.9rem;
            }

            .video-card {
                flex: 0 0 280px;
                height: 460px;
            }

            .video-content {
                padding: 1.2rem;
                height: 260px;
            }

            .videos-row {
                gap: 0.8rem;
            }

            .module-section {
                padding: 0 1rem;
            }

            .search-container {
                padding: 0 1rem;
            }

            .index-container {
                padding: 0 1rem;
            }

            .controls-section {
                padding: 1.5rem 1rem;
            }

            .countdown-container {
                flex-direction: column;
                gap: 0.5rem;
                padding: 0.6rem 1rem;
            }

            .countdown-timer {
                font-size: 0.8rem;
            }

            .tabs-header {
                padding: 0 1rem;
                gap: 0.5rem;
            }

            .tab-button {
                min-width: 150px;
                padding: 0.8rem 1.5rem;
                font-size: 0.9rem;
            }

            .strategic-grid {
                grid-template-columns: 1fr;
                gap: 1.5rem;
            }

            .strategic-card {
                padding: 1.5rem;
            }

            .strategic-title {
                font-size: 2rem;
            }

            .cta-buttons {
                flex-direction: column;
                align-items: center;
            }
        }

        @media (max-width: 480px) {
            .header h1 {
                font-size: 2rem;
            }

            .controls-grid {
                grid-template-columns: 1fr;
            }

            .video-card {
                flex: 0 0 260px;
                height: 440px;
            }

            .video-content {
                padding: 1rem;
                height: 240px;
            }

            .action-buttons {
                flex-direction: column;
                gap: 0.4rem;
            }

            .action-btn {
                padding: 0.5rem;
                font-size: 0.75rem;
                min-height: 36px;
            }

            .progress-checkbox {
                padding: 0.5rem;
                font-size: 0.75rem;
                min-height: 36px;
            }

            .documentation-btn,
            .final-exam-btn,
            .checklist-btn {
                display: block;
                margin: 0.5rem auto;
                width: 90%;
                font-size: 1rem;
                padding: 0.8rem 1.5rem;
            }

            .countdown-container {
                padding: 0.5rem 0.8rem;
                margin: 0;
            }

            .countdown-info {
                gap: 0.2rem;
            }

            .countdown-phase {
                font-size: 0.7rem;
            }

            .countdown-deadline {
                font-size: 0.65rem;
            }

            .countdown-timer {
                font-size: 0.75rem;
            }

            .countdown-days {
                font-size: 0.9rem;
            }

            .tab-button {
                min-width: 120px;
                padding: 0.6rem 1rem;
                font-size: 0.8rem;
            }

            .strategic-title {
                font-size: 1.8rem;
            }

            .card-title {
                font-size: 1.2rem;
            }

            .cta-title {
                font-size: 1.5rem;
            }
        }

        /* Animaciones */
        @keyframes slideIn {
            from {
                opacity: 0;
                transform: translateY(20px);
            }
            to {
                opacity: 1;
                transform: translateY(0);
            }
        }

        .module-section,
        .controls-section {
            animation: slideIn 0.6s ease-out;
        }

        /* Loading */
        .loading {
            text-align: center;
            padding: 3rem;
            color: #666;
            font-size: 1.2rem;
        }

        .spinner {
            border: 3px solid rgba(255, 255, 255, 0.1);
            border-top: 3px solid #ff6b6b;
            border-radius: 50%;
            width: 40px;
            height: 40px;
            animation: spin 1s linear infinite;
            margin: 0 auto 1rem;
        }

        @keyframes spin {
            0% { transform: rotate(0deg); }
            100% { transform: rotate(360deg); }
        }

        /* Iconos SVG pequeños */
        .icon {
            width: 14px;
            height: 14px;
            fill: currentColor;
        }

        /* Animación para contadores */
        @keyframes pulse {
            0% { transform: scale(1); }
            50% { transform: scale(1.05); }
            100% { transform: scale(1); }
        }

        .countdown-days {
            animation: pulse 2s infinite;
        }

/* Estilos del sistema de administración */
        .admin-access-btn {
            position: fixed;
            bottom: 20px;
            right: 20px;
            width: 60px;
            height: 60px;
            background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
            border-radius: 50%;
            display: flex;
            align-items: center;
            justify-content: center;
            cursor: pointer;
            box-shadow: 0 4px 20px rgba(102, 126, 234, 0.4);
            transition: all 0.3s ease;
            z-index: 9999;
            border: 2px solid rgba(255, 255, 255, 0.2);
        }

        .admin-access-btn:hover {
            transform: scale(1.1) rotate(90deg);
            box-shadow: 0 6px 30px rgba(102, 126, 234, 0.6);
        }

        .admin-access-btn svg {
            width: 30px;
            height: 30px;
        }

        .admin-modal {
            display: none;
            position: fixed;
            top: 0;
            left: 0;
            width: 100%;
            height: 100%;
            background: rgba(0, 0, 0, 0.95);
            z-index: 10000;
            overflow-y: auto;
            animation: fadeIn 0.3s ease;
        }

        .admin-modal.active {
            display: block;
        }

        @keyframes fadeIn {
            from { opacity: 0; }
            to { opacity: 1; }
        }

        .admin-container {
            max-width: 1200px;
            margin: 2rem auto;
            padding: 2rem;
            background: rgba(20, 20, 20, 0.95);
            border-radius: 20px;
            border: 2px solid rgba(255, 255, 255, 0.1);
        }

        .admin-header {
            display: flex;
            justify-content: space-between;
            align-items: center;
            margin-bottom: 2rem;
            padding-bottom: 1rem;
            border-bottom: 2px solid rgba(255, 255, 255, 0.1);
        }

        .admin-title {
            font-size: 2rem;
            background: linear-gradient(45deg, #667eea, #764ba2);
            -webkit-background-clip: text;
            -webkit-text-fill-color: transparent;
        }

        .admin-close {
            background: #ff6b6b;
            border: none;
            color: white;
            width: 40px;
            height: 40px;
            border-radius: 50%;
            cursor: pointer;
            font-size: 1.5rem;
            transition: all 0.3s ease;
        }

        .admin-close:hover {
            transform: scale(1.1);
            background: #ff5252;
        }

        .admin-tabs {
            display: flex;
            gap: 1rem;
            margin-bottom: 2rem;
            flex-wrap: wrap;
        }

        .admin-tab {
            padding: 0.8rem 1.5rem;
            background: rgba(255, 255, 255, 0.1);
            border: 2px solid transparent;
            border-radius: 10px;
            cursor: pointer;
            transition: all 0.3s ease;
            font-weight: 600;
            color: white;
        }

        .admin-tab.active {
            background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
            border-color: rgba(255, 255, 255, 0.3);
        }

        .admin-tab:hover {
            border-color: rgba(255, 255, 255, 0.5);
        }

        .admin-panel {
            display: none;
        }

        .admin-panel.active {
            display: block;
        }

        .video-form {
            background: rgba(255, 255, 255, 0.05);
            padding: 2rem;
            border-radius: 15px;
            margin-bottom: 2rem;
        }

        .form-group {
            margin-bottom: 1.5rem;
        }

        .form-group label {
            display: block;
            margin-bottom: 0.5rem;
            color: #4ecdc4;
            font-weight: 600;
        }

        .form-group input,
        .form-group select {
            width: 100%;
            padding: 0.8rem;
            background: rgba(255, 255, 255, 0.1);
            border: 2px solid rgba(255, 255, 255, 0.2);
            border-radius: 8px;
            color: white;
            font-size: 1rem;
        }

        .form-group input:focus,
        .form-group select:focus {
            outline: none;
            border-color: #4ecdc4;
        }

        .form-actions {
            display: flex;
            gap: 1rem;
            flex-wrap: wrap;
        }

        .btn {
            padding: 0.8rem 1.5rem;
            border: none;
            border-radius: 8px;
            cursor: pointer;
            font-weight: 600;
            transition: all 0.3s ease;
            font-size: 1rem;
        }

        .btn-primary {
            background: linear-gradient(135deg, #4ecdc4, #44a08d);
            color: white;
        }

        .btn-primary:hover {
            transform: translateY(-2px);
            box-shadow: 0 4px 15px rgba(78, 205, 196, 0.4);
        }

        .btn-secondary {
            background: rgba(255, 255, 255, 0.1);
            color: white;
        }

        .btn-danger {
            background: #ff6b6b;
            color: white;
        }

        .videos-list {
            background: rgba(255, 255, 255, 0.05);
            padding: 1.5rem;
            border-radius: 15px;
        }

        .video-item {
            background: rgba(255, 255, 255, 0.1);
            padding: 1rem;
            margin-bottom: 1rem;
            border-radius: 8px;
            display: flex;
            justify-content: space-between;
            align-items: center;
            flex-wrap: wrap;
            gap: 1rem;
        }

        .video-info {
            flex: 1;
        }

        .video-code {
            color: #4ecdc4;
            font-weight: bold;
            font-size: 1.1rem;
        }

        .video-url {
            color: #b3b3b3;
            font-size: 0.9rem;
            word-break: break-all;
        }

        .video-actions {
            display: flex;
            gap: 0.5rem;
        }

        .btn-small {
            padding: 0.5rem 1rem;
            font-size: 0.9rem;
        }

        .stats-grid {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
            gap: 1.5rem;
            margin-bottom: 2rem;
        }

        .stat-card {
            background: rgba(255, 255, 255, 0.05);
            padding: 1.5rem;
            border-radius: 15px;
            text-align: center;
        }

        .stat-number {
            font-size: 2.5rem;
            font-weight: bold;
            background: linear-gradient(45deg, #4ecdc4, #44a08d);
            -webkit-background-clip: text;
            -webkit-text-fill-color: transparent;
        }

        .stat-label {
            color: #b3b3b3;
            margin-top: 0.5rem;
        }

        .import-export {
            display: flex;
            gap: 1rem;
            margin-top: 2rem;
            flex-wrap: wrap;
        }

        .file-input-wrapper {
            position: relative;
            overflow: hidden;
            display: inline-block;
        }

        .file-input-wrapper input[type=file] {
            position: absolute;
            left: -9999px;
        }

        .login-screen {
            background: rgba(0, 0, 0, 0.98);
            padding: 3rem;
            border-radius: 20px;
            max-width: 400px;
            margin: 10rem auto;
            text-align: center;
        }

        .login-title {
            font-size: 2rem;
            margin-bottom: 2rem;
            background: linear-gradient(45deg, #667eea, #764ba2);
            -webkit-background-clip: text;
            -webkit-text-fill-color: transparent;
        }

        .login-form input {
            width: 100%;
            padding: 1rem;
            margin-bottom: 1rem;
            background: rgba(255, 255, 255, 0.1);
            border: 2px solid rgba(255, 255, 255, 0.2);
            border-radius: 8px;
            color: white;
            font-size: 1rem;
        }

        .error-message {
            color: #ff6b6b;
            margin-top: 1rem;
            display: none;
        }

        .error-message.show {
            display: block;
        }

        @media (max-width: 768px) {
            .admin-container {
                padding: 1rem;
                margin: 1rem;
            }
            .admin-title {
                font-size: 1.5rem;
            }
            .stats-grid {
                grid-template-columns: 1fr;
            }
        }
    
        /* Botón de Administración en Header */
        .admin-header-btn {
            position: fixed;
            top: 20px;
            right: 20px;
            display: flex;
            align-items: center;
            gap: 8px;
            padding: 12px 20px;
            background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
            border-radius: 30px;
            cursor: pointer;
            box-shadow: 0 4px 20px rgba(102, 126, 234, 0.4);
            transition: all 0.3s ease;
            z-index: 9999;
            border: 2px solid rgba(255, 255, 255, 0.2);
        }
        
        .admin-header-btn:hover {
            transform: translateY(-3px);
            box-shadow: 0 6px 30px rgba(102, 126, 234, 0.6);
            background: linear-gradient(135deg, #7c8ef5 0%, #8658b8 100%);
        }
        
        .admin-header-btn svg {
            width: 24px;
            height: 24px;
            animation: rotate 4s linear infinite;
        }
        
        .admin-header-btn:hover svg {
            animation: rotate 1s linear infinite;
        }
        
        .admin-header-btn span {
            color: white;
            font-weight: 700;
            font-size: 16px;
            letter-spacing: 0.5px;
        }
        
        @keyframes rotate {
            from { transform: rotate(0deg); }
            to { transform: rotate(360deg); }
        }
        
        @media (max-width: 768px) {
            .admin-header-btn {
                padding: 10px 15px;
                top: 15px;
                right: 15px;
            }
            .admin-header-btn svg {
                width: 20px;
                height: 20px;
            }
            .admin-header-btn span {
                font-size: 14px;
            }
        }

/* ===== Material / Textos (Admin) ===== */
.admin-form-grid{
  display:grid;
  grid-template-columns: 1fr 1fr;
  gap: 0.75rem;
}
@media (max-width: 720px){
  .admin-form-grid{ grid-template-columns: 1fr; }
}
.admin-label{
  display:block;
  margin-bottom: 0.35rem;
  color:#b3b3b3;
  font-size:0.85rem;
}
.admin-divider{
  height:1px;
  background: rgba(255,255,255,0.10);
  margin: 1.25rem 0;
}
.admin-alert{
  padding: 0.75rem 0.9rem;
  border-radius: 10px;
  background: rgba(255,255,255,0.06);
  border: 1px solid rgba(255,255,255,0.10);
  color: #fff;
}
.admin-alert.ok{ border-color: rgba(46, 204, 113, 0.35); }
.admin-alert.warn{ border-color: rgba(241, 196, 15, 0.35); }
.admin-alert.error{ border-color: rgba(231, 76, 60, 0.35); }

.material-item{
  display:flex;
  align-items:center;
  justify-content: space-between;
  gap: 0.75rem;
  padding: 0.6rem 0.75rem;
  border-radius: 10px;
  background: rgba(255,255,255,0.04);
  border: 1px solid rgba(255,255,255,0.08);
  margin-bottom: 0.5rem;
}
.material-item a{
  color: #ffffff;
  text-decoration: none;
}
.material-item a:hover{
  text-decoration: underline;
}
.material-meta{
  color:#b3b3b3;
  font-size:0.85rem;
}