/* ============================================
   SISTEMA DE DISEÑO - VARIABLES CSS
   ============================================ */
:root {
    /* Colores Principales */
    --primary-gradient: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    --secondary-gradient: linear-gradient(135deg, #f093fb 0%, #f5576c 100%);
    --success-gradient: linear-gradient(135deg, #4facfe 0%, #00f2fe 100%);
    --expert-gradient: linear-gradient(135deg, #fa709a 0%, #fee140 100%);

    /* Colores de Fondo */
    --bg-dark: #0f0f23;
    --bg-card: rgba(255, 255, 255, 0.05);
    --bg-card-hover: rgba(255, 255, 255, 0.08);
    --bg-glass: rgba(255, 255, 255, 0.1);

    /* Colores de Texto */
    --text-primary: #ffffff;
    --text-secondary: #a0aec0;
    --text-muted: #718096;

    /* Colores por Nivel */
    --level-beginner: #4facfe;
    --level-intermediate: #667eea;
    --level-advanced: #f093fb;
    --level-expert: #fee140;

    /* Sombras */
    --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.1);
    --shadow-md: 0 4px 16px rgba(0, 0, 0, 0.2);
    --shadow-lg: 0 8px 32px rgba(0, 0, 0, 0.3);
    --shadow-glow: 0 0 20px rgba(102, 126, 234, 0.3);

    /* Espaciado */
    --spacing-xs: 0.5rem;
    --spacing-sm: 1rem;
    --spacing-md: 1.5rem;
    --spacing-lg: 2rem;
    --spacing-xl: 3rem;

    /* Bordes */
    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 16px;
    --radius-xl: 24px;

    /* Transiciones */
    --transition-fast: 0.2s ease;
    --transition-normal: 0.3s ease;
    --transition-slow: 0.5s ease;
}

/* ============================================
   RESET Y BASE
   ============================================ */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    background: var(--bg-dark);
    color: var(--text-primary);
    line-height: 1.6;
    overflow-x: hidden;
}

/* Fondo animado con gradiente */
body::before {
    content: '';
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background:
        radial-gradient(circle at 20% 50%, rgba(102, 126, 234, 0.1) 0%, transparent 50%),
        radial-gradient(circle at 80% 80%, rgba(240, 147, 251, 0.1) 0%, transparent 50%),
        radial-gradient(circle at 40% 20%, rgba(79, 172, 254, 0.1) 0%, transparent 50%);
    z-index: -1;
    animation: gradientShift 15s ease infinite;
}

@keyframes gradientShift {

    0%,
    100% {
        opacity: 1;
    }

    50% {
        opacity: 0.8;
    }
}

/* ============================================
   TIPOGRAFÍA
   ============================================ */
@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700;800&family=Fira+Code:wght@400;500;600&display=swap');

h1,
h2,
h3,
h4,
h5,
h6 {
    font-weight: 700;
    line-height: 1.2;
    margin-bottom: var(--spacing-sm);
}

h1 {
    font-size: 3.5rem;
}

h2 {
    font-size: 2.5rem;
}

h3 {
    font-size: 2rem;
}

h4 {
    font-size: 1.5rem;
}

h5 {
    font-size: 1.25rem;
}

h6 {
    font-size: 1rem;
}

code,
pre {
    font-family: 'Fira Code', monospace;
}

/* ============================================
   HEADER Y NAVEGACIÓN
   ============================================ */
.header {
    position: sticky;
    top: 0;
    z-index: 1000;
    background: rgba(15, 15, 35, 0.8);
    backdrop-filter: blur(20px);
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
    padding: var(--spacing-sm) 0;
}

.nav-container {
    max-width: 1400px;
    margin: 0 auto;
    padding: 0 var(--spacing-lg);
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    font-size: 1.5rem;
    font-weight: 800;
    background: var(--primary-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.logo-icon {
    font-size: 2rem;
}

.nav-links {
    display: flex;
    gap: var(--spacing-md);
    list-style: none;
}

.nav-links a {
    color: var(--text-secondary);
    text-decoration: none;
    font-weight: 500;
    transition: color var(--transition-fast);
    position: relative;
}

.nav-links a::after {
    content: '';
    position: absolute;
    bottom: -4px;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--primary-gradient);
    transition: width var(--transition-normal);
}

.nav-links a:hover {
    color: var(--text-primary);
}

.nav-links a:hover::after {
    width: 100%;
}

/* ============================================
   CONTENEDOR PRINCIPAL
   ============================================ */
.container {
    max-width: 1400px;
    margin: 0 auto;
    padding: 0 var(--spacing-lg);
}

/* ============================================
   SECCIÓN HERO
   ============================================ */
.hero {
    padding: var(--spacing-xl) 0;
    text-align: center;
}

.hero h1 {
    background: linear-gradient(135deg, #ffffff 0%, #667eea 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    margin-bottom: var(--spacing-md);
    animation: fadeInUp 0.8s ease;
}

.hero-subtitle {
    font-size: 1.25rem;
    color: var(--text-secondary);
    max-width: 700px;
    margin: 0 auto var(--spacing-lg);
    animation: fadeInUp 0.8s ease 0.2s backwards;
}

.hero-stats {
    display: flex;
    justify-content: center;
    gap: var(--spacing-xl);
    flex-wrap: wrap;
    animation: fadeInUp 0.8s ease 0.4s backwards;
}

.stat-item {
    text-align: center;
}

.stat-number {
    font-size: 2.5rem;
    font-weight: 800;
    background: var(--primary-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    display: block;
}

.stat-label {
    color: var(--text-muted);
    font-size: 0.9rem;
    text-transform: uppercase;
    letter-spacing: 1px;
}

/* ============================================
   SECCIÓN DE NIVELES
   ============================================ */
.levels-section {
    padding: var(--spacing-xl) 0;
}

.section-title {
    text-align: center;
    margin-bottom: var(--spacing-xl);
    font-size: 2.5rem;
}

.levels-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: var(--spacing-lg);
    margin-bottom: var(--spacing-xl);
}

.level-card {
    background: var(--bg-card);
    border: 1px solid rgba(255, 255, 255, 0.1);
    border-radius: var(--radius-lg);
    padding: var(--spacing-lg);
    cursor: pointer;
    transition: all var(--transition-normal);
    position: relative;
    overflow: hidden;
}

.level-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 4px;
    background: var(--primary-gradient);
    transform: scaleX(0);
    transform-origin: left;
    transition: transform var(--transition-normal);
}

.level-card:hover::before {
    transform: scaleX(1);
}

.level-card:hover {
    background: var(--bg-card-hover);
    transform: translateY(-8px);
    box-shadow: var(--shadow-lg);
}

.level-card.beginner::before {
    background: linear-gradient(90deg, var(--level-beginner), #00f2fe);
}

.level-card.intermediate::before {
    background: linear-gradient(90deg, var(--level-intermediate), #764ba2);
}

.level-card.advanced::before {
    background: linear-gradient(90deg, var(--level-advanced), #f5576c);
}

.level-card.expert::before {
    background: linear-gradient(90deg, var(--level-expert), #fa709a);
}

.level-header {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    margin-bottom: var(--spacing-md);
}

.level-icon {
    font-size: 2.5rem;
}

.level-info h3 {
    margin-bottom: 0.25rem;
}

.level-lessons {
    font-size: 0.9rem;
    color: var(--text-muted);
}

.level-description {
    color: var(--text-secondary);
    margin-bottom: var(--spacing-md);
    line-height: 1.6;
}

.level-progress {
    margin-bottom: var(--spacing-sm);
}

.progress-bar {
    width: 100%;
    height: 8px;
    background: rgba(255, 255, 255, 0.1);
    border-radius: 10px;
    overflow: hidden;
}

.progress-fill {
    height: 100%;
    background: var(--primary-gradient);
    border-radius: 10px;
    transition: width var(--transition-slow);
}

.progress-text {
    font-size: 0.85rem;
    color: var(--text-muted);
    text-align: right;
    margin-top: 0.25rem;
}

/* ============================================
   SECCIÓN DE LECCIONES
   ============================================ */
.lessons-section {
    padding: var(--spacing-xl) 0;
}

.lessons-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: var(--spacing-lg);
    flex-wrap: wrap;
    gap: var(--spacing-md);
}

.filter-buttons {
    display: flex;
    gap: var(--spacing-sm);
    flex-wrap: wrap;
}

.filter-btn {
    padding: 0.5rem 1.25rem;
    border: 1px solid rgba(255, 255, 255, 0.2);
    background: transparent;
    color: var(--text-secondary);
    border-radius: var(--radius-md);
    cursor: pointer;
    font-weight: 500;
    transition: all var(--transition-fast);
}

.filter-btn:hover {
    background: var(--bg-glass);
    color: var(--text-primary);
}

.filter-btn.active {
    background: var(--primary-gradient);
    color: white;
    border-color: transparent;
}

.lessons-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
    gap: var(--spacing-md);
}

.lesson-card {
    background: var(--bg-card);
    border: 1px solid rgba(255, 255, 255, 0.1);
    border-radius: var(--radius-md);
    padding: var(--spacing-md);
    cursor: pointer;
    transition: all var(--transition-normal);
    display: flex;
    flex-direction: column;
}

.lesson-card:hover {
    background: var(--bg-card-hover);
    transform: translateX(8px);
    border-color: rgba(102, 126, 234, 0.5);
}

.lesson-header {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    margin-bottom: var(--spacing-sm);
}

.lesson-number {
    font-size: 0.85rem;
    color: var(--text-muted);
    font-weight: 600;
}

.lesson-badge {
    padding: 0.25rem 0.75rem;
    border-radius: var(--radius-sm);
    font-size: 0.75rem;
    font-weight: 600;
    text-transform: uppercase;
}

.lesson-badge.beginner {
    background: rgba(79, 172, 254, 0.2);
    color: var(--level-beginner);
}

.lesson-badge.intermediate {
    background: rgba(102, 126, 234, 0.2);
    color: var(--level-intermediate);
}

.lesson-badge.advanced {
    background: rgba(240, 147, 251, 0.2);
    color: var(--level-advanced);
}

.lesson-badge.expert {
    background: rgba(254, 225, 64, 0.2);
    color: var(--level-expert);
}

.lesson-title {
    font-size: 1.1rem;
    margin-bottom: var(--spacing-xs);
    color: var(--text-primary);
}

.lesson-description {
    color: var(--text-secondary);
    font-size: 0.9rem;
    margin-bottom: var(--spacing-sm);
    flex-grow: 1;
}

.lesson-footer {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding-top: var(--spacing-sm);
    border-top: 1px solid rgba(255, 255, 255, 0.05);
}

.lesson-duration {
    font-size: 0.85rem;
    color: var(--text-muted);
    display: flex;
    align-items: center;
    gap: 0.25rem;
}

.lesson-status {
    font-size: 0.85rem;
    font-weight: 600;
}

.lesson-status.completed {
    color: #48bb78;
}

.lesson-status.in-progress {
    color: #f6ad55;
}

.lesson-status.locked {
    color: var(--text-muted);
}

/* ============================================
   VISOR DE LECCIÓN
   ============================================ */
.lesson-viewer {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.9);
    z-index: 2000;
    overflow-y: auto;
    animation: fadeIn 0.3s ease;
}

.lesson-viewer.active {
    display: block;
}

.lesson-content {
    max-width: 900px;
    margin: var(--spacing-xl) auto;
    padding: var(--spacing-xl);
    background: var(--bg-dark);
    border-radius: var(--radius-lg);
    border: 1px solid rgba(255, 255, 255, 0.1);
    position: relative;
}

.lesson-close {
    position: absolute;
    top: var(--spacing-md);
    right: var(--spacing-md);
    background: rgba(255, 255, 255, 0.1);
    border: none;
    color: var(--text-primary);
    width: 40px;
    height: 40px;
    border-radius: 50%;
    cursor: pointer;
    font-size: 1.5rem;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all var(--transition-fast);
}

.lesson-close:hover {
    background: rgba(255, 255, 255, 0.2);
    transform: rotate(90deg);
}

.lesson-content h2 {
    margin-bottom: var(--spacing-md);
    background: var(--primary-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.lesson-content h3 {
    margin-top: var(--spacing-lg);
    margin-bottom: var(--spacing-sm);
    color: var(--text-primary);
}

.lesson-content p {
    color: var(--text-secondary);
    margin-bottom: var(--spacing-md);
    line-height: 1.8;
}

.lesson-content ul,
.lesson-content ol {
    color: var(--text-secondary);
    margin-bottom: var(--spacing-md);
    padding-left: var(--spacing-lg);
}

.lesson-content li {
    margin-bottom: var(--spacing-xs);
    line-height: 1.6;
}

.code-block {
    background: rgba(0, 0, 0, 0.5);
    border: 1px solid rgba(255, 255, 255, 0.1);
    border-radius: var(--radius-md);
    padding: var(--spacing-md);
    margin: var(--spacing-md) 0;
    position: relative;
    overflow-x: auto;
}

.code-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: var(--spacing-sm);
    padding-bottom: var(--spacing-xs);
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
}

.code-language {
    font-size: 0.85rem;
    color: var(--text-muted);
    font-weight: 600;
    text-transform: uppercase;
}

.copy-btn {
    background: rgba(102, 126, 234, 0.2);
    border: 1px solid rgba(102, 126, 234, 0.3);
    color: var(--level-intermediate);
    padding: 0.25rem 0.75rem;
    border-radius: var(--radius-sm);
    cursor: pointer;
    font-size: 0.85rem;
    transition: all var(--transition-fast);
}

.copy-btn:hover {
    background: rgba(102, 126, 234, 0.3);
}

.code-block pre {
    margin: 0;
    color: #e2e8f0;
    font-size: 0.95rem;
    line-height: 1.6;
}

.code-block code {
    color: inherit;
}

.info-box {
    background: rgba(79, 172, 254, 0.1);
    border-left: 4px solid var(--level-beginner);
    padding: var(--spacing-md);
    border-radius: var(--radius-sm);
    margin: var(--spacing-md) 0;
}

.info-box.warning {
    background: rgba(246, 173, 85, 0.1);
    border-left-color: #f6ad55;
}

.info-box.success {
    background: rgba(72, 187, 120, 0.1);
    border-left-color: #48bb78;
}

.lesson-navigation {
    display: flex;
    justify-content: space-between;
    margin-top: var(--spacing-xl);
    padding-top: var(--spacing-lg);
    border-top: 1px solid rgba(255, 255, 255, 0.1);
}

.nav-btn {
    padding: 0.75rem 1.5rem;
    background: var(--primary-gradient);
    border: none;
    color: white;
    border-radius: var(--radius-md);
    cursor: pointer;
    font-weight: 600;
    transition: all var(--transition-fast);
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.nav-btn:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-glow);
}

.nav-btn:disabled {
    opacity: 0.5;
    cursor: not-allowed;
}

.nav-btn:disabled:hover {
    transform: none;
    box-shadow: none;
}

/* ============================================
   FOOTER
   ============================================ */
.footer {
    background: rgba(255, 255, 255, 0.02);
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    padding: var(--spacing-xl) 0;
    margin-top: var(--spacing-xl);
}

.footer-content {
    max-width: 1400px;
    margin: 0 auto;
    padding: 0 var(--spacing-lg);
    text-align: center;
}

.footer-content p {
    color: var(--text-muted);
    margin-bottom: var(--spacing-sm);
}

.footer-links {
    display: flex;
    justify-content: center;
    gap: var(--spacing-lg);
    margin-top: var(--spacing-md);
}

.footer-links a {
    color: var(--text-secondary);
    text-decoration: none;
    transition: color var(--transition-fast);
}

.footer-links a:hover {
    color: var(--text-primary);
}

/* ============================================
   EJERCICIOS INTERACTIVOS
   ============================================ */
.exercise-editor {
    background: rgba(0, 0, 0, 0.5);
    border: 1px solid rgba(255, 255, 255, 0.1);
    border-radius: var(--radius-md);
    padding: var(--spacing-md);
    margin: var(--spacing-md) 0;
}

.exercise-textarea {
    width: 100%;
    min-height: 200px;
    background: rgba(0, 0, 0, 0.3);
    border: 1px solid rgba(255, 255, 255, 0.2);
    border-radius: var(--radius-sm);
    padding: var(--spacing-md);
    color: var(--text-primary);
    font-family: 'Fira Code', monospace;
    font-size: 0.95rem;
    line-height: 1.6;
    resize: vertical;
}

.exercise-textarea:focus {
    outline: none;
    border-color: rgba(102, 126, 234, 0.5);
    box-shadow: 0 0 0 3px rgba(102, 126, 234, 0.1);
}

.exercise-actions {
    display: flex;
    gap: var(--spacing-sm);
    margin-top: var(--spacing-sm);
}

.btn-primary {
    padding: 0.75rem 1.5rem;
    background: var(--primary-gradient);
    border: none;
    color: white;
    border-radius: var(--radius-md);
    cursor: pointer;
    font-weight: 600;
    transition: all var(--transition-fast);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-glow);
}

.btn-secondary {
    padding: 0.75rem 1.5rem;
    background: rgba(255, 255, 255, 0.1);
    border: 1px solid rgba(255, 255, 255, 0.2);
    color: var(--text-primary);
    border-radius: var(--radius-md);
    cursor: pointer;
    font-weight: 600;
    transition: all var(--transition-fast);
}

.btn-secondary:hover {
    background: rgba(255, 255, 255, 0.15);
}

.exercise-result {
    margin-top: var(--spacing-md);
    padding: var(--spacing-md);
    border-radius: var(--radius-md);
    border-left: 4px solid;
    animation: fadeInUp 0.3s ease;
}

.exercise-result.success {
    background: rgba(72, 187, 120, 0.1);
    border-left-color: #48bb78;
    color: #48bb78;
}

.exercise-result.error {
    background: rgba(245, 87, 108, 0.1);
    border-left-color: #f5576c;
    color: #f5576c;
}

.exercise-hint {
    background: rgba(246, 173, 85, 0.1);
    border-left: 4px solid #f6ad55;
    padding: var(--spacing-md);
    border-radius: var(--radius-sm);
    margin-top: var(--spacing-md);
    color: var(--text-secondary);
}

/* ============================================
   EVALUACIONES
   ============================================ */
.evaluation-content {
    max-width: 800px;
}

.evaluation-header {
    text-align: center;
    margin-bottom: var(--spacing-xl);
}

.evaluation-timer {
    font-size: 1.5rem;
    color: var(--level-beginner);
    font-weight: 700;
    margin-top: var(--spacing-sm);
}

.question-card {
    background: rgba(255, 255, 255, 0.05);
    border: 1px solid rgba(255, 255, 255, 0.1);
    border-radius: var(--radius-md);
    padding: var(--spacing-lg);
    margin-bottom: var(--spacing-lg);
}

.question-number {
    font-size: 0.9rem;
    color: var(--text-muted);
    font-weight: 600;
    margin-bottom: var(--spacing-sm);
}

.question-text {
    font-size: 1.1rem;
    color: var(--text-primary);
    margin-bottom: var(--spacing-md);
    line-height: 1.6;
}

.question-options {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-sm);
}

.option-btn {
    width: 100%;
    padding: var(--spacing-md);
    background: rgba(255, 255, 255, 0.05);
    border: 2px solid rgba(255, 255, 255, 0.1);
    border-radius: var(--radius-md);
    color: var(--text-primary);
    text-align: left;
    cursor: pointer;
    transition: all var(--transition-fast);
    font-size: 1rem;
}

.option-btn:hover {
    background: rgba(255, 255, 255, 0.08);
    border-color: rgba(102, 126, 234, 0.5);
}

.option-btn.selected {
    background: rgba(102, 126, 234, 0.2);
    border-color: var(--level-intermediate);
}

.option-btn.correct {
    background: rgba(72, 187, 120, 0.2);
    border-color: #48bb78;
}

.option-btn.incorrect {
    background: rgba(245, 87, 108, 0.2);
    border-color: #f5576c;
}

.evaluation-actions {
    display: flex;
    justify-content: center;
    gap: var(--spacing-md);
    margin-top: var(--spacing-xl);
}

.evaluation-result {
    text-align: center;
    padding: var(--spacing-xl);
}

.result-score {
    font-size: 4rem;
    font-weight: 800;
    background: var(--primary-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    margin-bottom: var(--spacing-md);
}

.result-message {
    font-size: 1.5rem;
    color: var(--text-primary);
    margin-bottom: var(--spacing-sm);
}

.result-details {
    color: var(--text-secondary);
    margin-bottom: var(--spacing-xl);
}

/* ============================================
   CERTIFICADO
   ============================================ */
.certificate-container {
    max-width: 900px;
    margin: var(--spacing-xl) auto;
    padding: var(--spacing-xl);
    position: relative;
}

.certificate {
    background: linear-gradient(135deg, #ffffff 0%, #f8f9fa 100%);
    border: 20px solid transparent;
    border-image: var(--primary-gradient) 1;
    border-radius: var(--radius-lg);
    padding: var(--spacing-xl);
    text-align: center;
    position: relative;
    box-shadow: var(--shadow-lg);
}

.certificate::before {
    content: '';
    position: absolute;
    top: 20px;
    left: 20px;
    right: 20px;
    bottom: 20px;
    border: 2px solid rgba(102, 126, 234, 0.2);
    border-radius: var(--radius-sm);
    pointer-events: none;
}

.certificate-header {
    margin-bottom: var(--spacing-lg);
}

.certificate-logo {
    font-size: 3rem;
    margin-bottom: var(--spacing-sm);
}

.certificate-title {
    font-size: 2.5rem;
    font-weight: 800;
    background: var(--primary-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    margin-bottom: var(--spacing-sm);
}

.certificate-subtitle {
    font-size: 1.2rem;
    color: #4a5568;
    margin-bottom: var(--spacing-xl);
}

.certificate-body {
    margin-bottom: var(--spacing-xl);
}

.certificate-text {
    font-size: 1.1rem;
    color: #2d3748;
    line-height: 1.8;
    margin-bottom: var(--spacing-md);
}

.certificate-name {
    font-size: 2.5rem;
    font-weight: 800;
    color: #1a202c;
    margin: var(--spacing-lg) 0;
    font-family: 'Georgia', serif;
}

.certificate-achievement {
    font-size: 1.1rem;
    color: #4a5568;
    margin-bottom: var(--spacing-xl);
}

.certificate-footer {
    display: flex;
    justify-content: space-around;
    margin-top: var(--spacing-xl);
    padding-top: var(--spacing-lg);
    border-top: 2px solid rgba(102, 126, 234, 0.2);
}

.certificate-signature {
    text-align: center;
}

.signature-line {
    width: 200px;
    height: 2px;
    background: #cbd5e0;
    margin: 0 auto var(--spacing-sm);
}

.signature-name {
    font-weight: 700;
    color: #2d3748;
    margin-bottom: 0.25rem;
}

.signature-title {
    font-size: 0.9rem;
    color: #718096;
}

.certificate-date {
    font-size: 0.9rem;
    color: #718096;
    margin-top: var(--spacing-lg);
}

.certificate-actions {
    display: flex;
    justify-content: center;
    gap: var(--spacing-md);
    margin-top: var(--spacing-xl);
}

/* ============================================
   ANIMACIONES
   ============================================ */
@keyframes fadeIn {
    from {
        opacity: 0;
    }

    to {
        opacity: 1;
    }
}

@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }

    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes slideInRight {
    from {
        opacity: 0;
        transform: translateX(-30px);
    }

    to {
        opacity: 1;
        transform: translateX(0);
    }
}

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

    h2 {
        font-size: 2rem;
    }

    h3 {
        font-size: 1.5rem;
    }

    .nav-links {
        display: none;
    }

    .hero-stats {
        gap: var(--spacing-md);
    }

    .stat-number {
        font-size: 2rem;
    }

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

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

    .lesson-content {
        margin: var(--spacing-md);
        padding: var(--spacing-md);
    }

    .filter-buttons {
        width: 100%;
    }

    .filter-btn {
        flex: 1;
        min-width: 100px;
    }
}

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

    .container {
        padding: 0 var(--spacing-sm);
    }

    .hero {
        padding: var(--spacing-lg) 0;
    }

    .code-block {
        font-size: 0.85rem;
    }
}

/* ============================================
   UTILIDADES
   ============================================ */
.hidden {
    display: none !important;
}

.text-center {
    text-align: center;
}

.mb-0 {
    margin-bottom: 0;
}

.mb-1 {
    margin-bottom: var(--spacing-xs);
}

.mb-2 {
    margin-bottom: var(--spacing-sm);
}

.mb-3 {
    margin-bottom: var(--spacing-md);
}

.mb-4 {
    margin-bottom: var(--spacing-lg);
}

.mt-0 {
    margin-top: 0;
}

.mt-1 {
    margin-top: var(--spacing-xs);
}

.mt-2 {
    margin-top: var(--spacing-sm);
}

.mt-3 {
    margin-top: var(--spacing-md);
}

.mt-4 {
    margin-top: var(--spacing-lg);
}
/* ============================================
   MI PROGRESO SECTION
   ============================================ */
.progress-section {
    padding: 4rem 0;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
}

.progress-section .section-title {
    color: white;
}

.progress-section .section-subtitle {
    color: rgba(255, 255, 255, 0.9);
    text-align: center;
    margin-bottom: 2rem;
}

.total-progress-card {
    background: white;
    border-radius: 16px;
    padding: 2rem;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.2);
    margin-bottom: 2rem;
}

.total-progress-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1.5rem;
}

.total-progress-header h3 {
    font-size: 1.5rem;
    color: #1a202c;
    margin: 0;
}

.total-percentage {
    font-size: 2.5rem;
    font-weight: 700;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.total-progress-bar {
    height: 20px;
    background: #e2e8f0;
    border-radius: 10px;
    overflow: hidden;
    margin-bottom: 2rem;
}

.total-progress-fill {
    height: 100%;
    background: linear-gradient(90deg, #667eea 0%, #764ba2 100%);
    transition: width 0.5s ease;
    border-radius: 10px;
}

.progress-stats {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
    gap: 2rem;
    text-align: center;
}

.progress-stats .stat {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.stat-value {
    font-size: 2rem;
    font-weight: 700;
    color: #667eea;
}

.stat-label {
    font-size: 0.9rem;
    color: #718096;
}

.level-progress-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 1.5rem;
}

.level-progress-item {
    background: white;
    padding: 1.5rem;
    border-radius: 12px;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
}

.level-progress-item h4 {
    margin: 0 0 1rem 0;
    color: #1a202c;
    font-size: 1.1rem;
}

.mini-progress-bar {
    height: 8px;
    background: #e2e8f0;
    border-radius: 4px;
    overflow: hidden;
    margin-bottom: 0.5rem;
}

.mini-progress-fill {
    height: 100%;
    background: linear-gradient(90deg, #667eea 0%, #764ba2 100%);
    transition: width 0.5s ease;
    border-radius: 4px;
}

.mini-progress-text {
    font-size: 0.9rem;
    color: #718096;
    font-weight: 600;
}