/* ================================
   PLATAFORMA DE GESTIÓN ACADÉMICA
   SEMINARIO ESDRAS
   Sistema de Estilos Principal
   Versión 2026 - Diseño Moderno
   ================================ */

:root {
    /* Paleta de Colores Basada en Azul - Círculo Cromático 2026 */
    --primary-color: #2563eb;        /* Azul primario vibrante */
    --primary-dark: #1e40af;         /* Azul oscuro */
    --primary-light: #60a5fa;        /* Azul cielo */
    --secondary-color: #7c3aed;      /* Violeta (complementario) */
    --accent-color: #06b6d4;         /* Cyan (análogo) */
    --success-color: #10b981;        /* Verde esmeralda */
    --danger-color: #ef4444;         /* Rojo coral */
    --warning-color: #f59e0b;        /* Ámbar */
    --info-color: #0ea5e9;           /* Azul cielo brillante */

    /* Gradientes Modernos Basados en Azul */
    --gradient-primary: linear-gradient(135deg, #2563eb 0%, #1e40af 100%);
    --gradient-secondary: linear-gradient(135deg, #7c3aed 0%, #2563eb 100%);
    --gradient-cyan: linear-gradient(135deg, #06b6d4 0%, #0891b2 100%);
    --gradient-violet: linear-gradient(135deg, #7c3aed 0%, #6366f1 100%);
    --gradient-success: linear-gradient(135deg, #10b981 0%, #059669 100%);
    --gradient-royal: linear-gradient(135deg, #2563eb 0%, #7c3aed 100%);

    /* Escala de Grises Moderna */
    --text-primary: #1a1a2e;
    --text-secondary: #64748b;
    --text-tertiary: #94a3b8;
    --bg-primary: #ffffff;
    --bg-secondary: #f8fafc;
    --bg-tertiary: #f1f5f9;
    --bg-dark: #0f172a;
    --border-color: #e2e8f0;
    --border-light: #f1f5f9;

    /* Sombras 2026 - Más suaves y naturales */
    --shadow-xs: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.06);
    --shadow-md: 0 4px 16px rgba(0, 0, 0, 0.08);
    --shadow-lg: 0 8px 32px rgba(0, 0, 0, 0.1);
    --shadow-xl: 0 16px 48px rgba(0, 0, 0, 0.12);
    --shadow-2xl: 0 24px 64px rgba(0, 0, 0, 0.15);

    /* Sombras de Color */
    --shadow-primary: 0 8px 32px rgba(37, 99, 235, 0.25);
    --shadow-secondary: 0 8px 32px rgba(124, 58, 237, 0.25);
    --shadow-success: 0 8px 32px rgba(16, 185, 129, 0.25);
    --shadow-cyan: 0 8px 32px rgba(6, 182, 212, 0.25);

    /* Glassmorphism */
    --glass-bg: rgba(255, 255, 255, 0.85);
    --glass-border: rgba(255, 255, 255, 0.18);

    /* Espaciado Sistema 8pt */
    --spacing-xs: 0.5rem;    /* 8px */
    --spacing-sm: 0.75rem;   /* 12px */
    --spacing-md: 1rem;      /* 16px */
    --spacing-lg: 1.5rem;    /* 24px */
    --spacing-xl: 2rem;      /* 32px */
    --spacing-2xl: 3rem;     /* 48px */
    --spacing-3xl: 4rem;     /* 64px */

    /* Tipografía Moderna 2026 */
    --font-primary: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Roboto', 'Oxygen', 'Ubuntu', sans-serif;
    --font-display: 'Playfair Display', Georgia, serif;
    --font-mono: 'SF Mono', 'Monaco', 'Cascadia Code', 'Courier New', monospace;

    --font-size-xs: 0.75rem;   /* 12px */
    --font-size-sm: 0.875rem;  /* 14px */
    --font-size-base: 1rem;    /* 16px */
    --font-size-lg: 1.125rem;  /* 18px */
    --font-size-xl: 1.25rem;   /* 20px */
    --font-size-2xl: 1.5rem;   /* 24px */
    --font-size-3xl: 1.875rem; /* 30px */
    --font-size-4xl: 2.25rem;  /* 36px */

    --font-weight-normal: 400;
    --font-weight-medium: 500;
    --font-weight-semibold: 600;
    --font-weight-bold: 700;

    --line-height-tight: 1.25;
    --line-height-normal: 1.5;
    --line-height-relaxed: 1.75;

    /* Radios Modernos */
    --radius-sm: 6px;
    --radius-md: 10px;
    --radius-lg: 16px;
    --radius-xl: 20px;
    --radius-2xl: 24px;
    --radius-full: 9999px;

    /* Transiciones Suaves 2026 */
    --transition-fast: 150ms cubic-bezier(0.4, 0, 0.2, 1);
    --transition-base: 250ms cubic-bezier(0.4, 0, 0.2, 1);
    --transition-slow: 350ms cubic-bezier(0.4, 0, 0.2, 1);
    --transition-bounce: 500ms cubic-bezier(0.34, 1.56, 0.64, 1);

    /* Z-index Scale */
    --z-dropdown: 1000;
    --z-sticky: 1020;
    --z-fixed: 1030;
    --z-modal-backdrop: 1040;
    --z-modal: 1050;
    --z-tooltip: 1070;
}

/* ================================
   RESET Y ESTILOS BASE
   ================================ */

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

html {
    font-size: 16px;
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-primary);
    color: var(--text-primary);
    background: var(--bg-secondary);
    line-height: var(--line-height-normal);
    overflow-x: hidden;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    text-rendering: optimizeLegibility;
}

a {
    color: var(--primary-color);
    text-decoration: none;
    transition: color var(--transition-fast);
}

a:hover {
    color: var(--primary-dark);
}

img {
    max-width: 100%;
    height: auto;
    display: block;
}

button {
    cursor: pointer;
    border: none;
    outline: none;
    font-family: inherit;
}

input, textarea, select {
    font-family: inherit;
    font-size: inherit;
}

/* ================================
   UTILIDADES
   ================================ */

.container {
    max-width: 1400px;
    margin: 0 auto;
    padding: 0 var(--spacing-md);
}

.container-fluid {
    width: 100%;
    padding: 0 var(--spacing-md);
}

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

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

.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-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); }

/* ================================
   HEADER PRINCIPAL - 2026
   ================================ */

.header {
    background: var(--gradient-secondary);
    color: white;
    padding: var(--spacing-md) 0;
    box-shadow: var(--shadow-lg);
    position: sticky;
    top: 0;
    z-index: var(--z-sticky);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
}

.header-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.header-logo {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
}

.header-logo h1 {
    font-size: var(--font-size-xl);
    font-weight: 600;
}

.header-logo-icon {
    width: 50px;
    height: 50px;
    background: var(--glass-bg);
    backdrop-filter: blur(10px);
    border-radius: var(--radius-lg);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
    box-shadow: var(--shadow-md);
    transition: transform var(--transition-base);
}

.header-logo-icon:hover {
    transform: scale(1.05) rotate(-5deg);
}

.header-user {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
}

.user-avatar {
    width: 45px;
    height: 45px;
    border-radius: var(--radius-full);
    background: var(--gradient-warm);
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: var(--font-weight-semibold);
    font-size: var(--font-size-lg);
    box-shadow: var(--shadow-md);
    border: 2px solid rgba(255, 255, 255, 0.3);
    transition: transform var(--transition-base);
    cursor: pointer;
}

.user-avatar:hover {
    transform: scale(1.1);
    box-shadow: var(--shadow-lg);
}

.user-info h3 {
    font-size: var(--font-size-base);
    font-weight: 600;
}

.user-info p {
    font-size: var(--font-size-sm);
    opacity: 0.9;
}

.btn-logout {
    background: rgba(255,255,255,0.2);
    color: white;
    padding: var(--spacing-xs) var(--spacing-md);
    border-radius: var(--radius-md);
    font-size: var(--font-size-sm);
    transition: background var(--transition-base);
    margin-left: var(--spacing-md);
}

.btn-logout:hover {
    background: rgba(255,255,255,0.3);
}

/* ================================
   SIDEBAR NAVIGATION - 2026
   ================================ */

.layout {
    display: flex;
    min-height: calc(100vh - 80px);
}

.sidebar {
    width: 280px;
    background: var(--bg-primary);
    box-shadow: var(--shadow-md);
    padding: var(--spacing-xl) 0;
    position: sticky;
    top: 80px;
    height: calc(100vh - 80px);
    overflow-y: auto;
    border-right: 1px solid var(--border-light);
}

.sidebar::-webkit-scrollbar {
    width: 6px;
}

.sidebar::-webkit-scrollbar-track {
    background: var(--bg-secondary);
}

.sidebar::-webkit-scrollbar-thumb {
    background: var(--border-color);
    border-radius: var(--radius-full);
}

.sidebar::-webkit-scrollbar-thumb:hover {
    background: var(--text-secondary);
}

.nav-menu {
    list-style: none;
}

.nav-item {
    margin-bottom: var(--spacing-xs);
}

.nav-link {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
    padding: var(--spacing-md) var(--spacing-xl);
    color: var(--text-primary);
    transition: all var(--transition-base);
    border-left: 3px solid transparent;
    margin: var(--spacing-xs) var(--spacing-md);
    border-radius: 0 var(--radius-lg) var(--radius-lg) 0;
    position: relative;
    overflow: hidden;
}

.nav-link::before {
    content: '';
    position: absolute;
    left: 0;
    top: 0;
    height: 100%;
    width: 3px;
    background: var(--gradient-secondary);
    transform: scaleY(0);
    transition: transform var(--transition-base);
}

.nav-link:hover {
    background: linear-gradient(90deg, var(--bg-secondary) 0%, transparent 100%);
    color: var(--primary-color);
    transform: translateX(4px);
}

.nav-link:hover::before {
    transform: scaleY(1);
}

.nav-link.active {
    background: linear-gradient(90deg, rgba(74, 144, 226, 0.1) 0%, transparent 100%);
    color: var(--primary-color);
    font-weight: var(--font-weight-semibold);
}

.nav-link.active::before {
    transform: scaleY(1);
}

.nav-icon {
    font-size: 1.4rem;
    width: 28px;
    text-align: center;
    transition: transform var(--transition-base);
}

.nav-link:hover .nav-icon {
    transform: scale(1.15);
}

.nav-link.active .nav-icon {
    transform: scale(1.1);
}

/* ================================
   MAIN CONTENT
   ================================ */

.main-content {
    flex: 1;
    padding: var(--spacing-lg);
    background: var(--bg-secondary);
}

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

.page-title {
    font-family: var(--font-display);
    font-size: var(--font-size-3xl);
    color: var(--text-primary);
    margin-bottom: var(--spacing-xs);
    font-weight: var(--font-weight-bold);
}

.page-subtitle {
    color: var(--text-secondary);
    font-size: var(--font-size-base);
}

/* ================================
   CARDS - 2026 Modern Design
   ================================ */

.card {
    background: var(--bg-primary);
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-sm);
    padding: var(--spacing-xl);
    margin-bottom: var(--spacing-lg);
    transition: all var(--transition-base);
    border: 1px solid var(--border-light);
    position: relative;
    overflow: hidden;
}

.card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 3px;
    background: var(--gradient-secondary);
    transform: scaleX(0);
    transition: transform var(--transition-base);
}

.card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
    border-color: var(--primary-light);
}

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

.card-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: var(--spacing-md);
    padding-bottom: var(--spacing-sm);
    border-bottom: 2px solid var(--bg-tertiary);
}

.card-title {
    font-size: var(--font-size-lg);
    font-weight: 600;
    color: var(--text-primary);
}

.card-body {
    color: var(--text-primary);
}

.card-footer {
    margin-top: var(--spacing-md);
    padding-top: var(--spacing-md);
    border-top: 1px solid var(--border-color);
}

/* ================================
   GRID SYSTEM
   ================================ */

.grid {
    display: grid;
    gap: var(--spacing-md);
}

.grid-2 {
    grid-template-columns: repeat(2, 1fr);
}

.grid-3 {
    grid-template-columns: repeat(3, 1fr);
}

.grid-4 {
    grid-template-columns: repeat(4, 1fr);
}

/* ================================
   KPI CARDS - 2026 Design
   ================================ */

.kpi-card {
    background: var(--gradient-secondary);
    color: white;
    padding: var(--spacing-xl);
    border-radius: var(--radius-2xl);
    box-shadow: var(--shadow-secondary);
    position: relative;
    overflow: hidden;
    transition: all var(--transition-base);
    border: 1px solid rgba(255, 255, 255, 0.1);
}

.kpi-card:hover {
    transform: translateY(-8px) scale(1.02);
    box-shadow: var(--shadow-2xl);
}

.kpi-card::before {
    content: '';
    position: absolute;
    top: -50%;
    right: -10%;
    width: 180px;
    height: 180px;
    background: rgba(255,255,255,0.08);
    border-radius: var(--radius-full);
    transition: all var(--transition-slow);
}

.kpi-card:hover::before {
    transform: scale(1.2) rotate(45deg);
    background: rgba(255,255,255,0.12);
}

.kpi-icon {
    font-size: 2.5rem;
    margin-bottom: var(--spacing-sm);
    opacity: 0.9;
}

.kpi-value {
    font-size: var(--font-size-2xl);
    font-weight: 700;
    margin-bottom: var(--spacing-xs);
}

.kpi-label {
    font-size: var(--font-size-sm);
    opacity: 0.95;
    font-weight: 500;
}

/* ================================
   BOTONES - 2026 Modern Style
   ================================ */

.btn {
    padding: var(--spacing-sm) var(--spacing-xl);
    border-radius: var(--radius-lg);
    font-size: var(--font-size-base);
    font-weight: var(--font-weight-semibold);
    transition: all var(--transition-base);
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-xs);
    cursor: pointer;
    border: none;
    position: relative;
    overflow: hidden;
    letter-spacing: 0.3px;
}

.btn::before {
    content: '';
    position: absolute;
    top: 50%;
    left: 50%;
    width: 0;
    height: 0;
    border-radius: var(--radius-full);
    background: rgba(255, 255, 255, 0.2);
    transform: translate(-50%, -50%);
    transition: width 0.6s, height 0.6s;
}

.btn:hover::before {
    width: 300px;
    height: 300px;
}

.btn-primary {
    background: var(--gradient-secondary);
    color: white;
    box-shadow: var(--shadow-primary);
}

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

.btn-secondary {
    background: var(--secondary-color);
    color: white;
}

.btn-secondary:hover {
    background: #3a7bc8;
}

.btn-success {
    background: var(--success-color);
    color: white;
}

.btn-success:hover {
    background: #229954;
}

.btn-danger {
    background: var(--danger-color);
    color: white;
}

.btn-danger:hover {
    background: #c0392b;
}

.btn-outline {
    background: transparent;
    border: 2px solid var(--primary-color);
    color: var(--primary-color);
}

.btn-outline:hover {
    background: var(--primary-color);
    color: white;
}

.btn-lg {
    padding: var(--spacing-md) var(--spacing-xl);
    font-size: var(--font-size-lg);
}

.btn-sm {
    padding: var(--spacing-xs) var(--spacing-sm);
    font-size: var(--font-size-sm);
}

.btn-block {
    display: flex;
    width: 100%;
    justify-content: center;
}

/* ================================
   FORMULARIOS
   ================================ */

.form-group {
    margin-bottom: var(--spacing-md);
}

.form-label {
    display: block;
    margin-bottom: var(--spacing-xs);
    font-weight: 500;
    color: var(--text-primary);
}

.form-control {
    width: 100%;
    padding: var(--spacing-sm);
    border: 2px solid var(--border-color);
    border-radius: var(--radius-md);
    font-size: var(--font-size-base);
    transition: border-color var(--transition-base);
    background: var(--bg-primary);
}

.form-control:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(26, 77, 124, 0.1);
}

.form-select {
    appearance: none;
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' viewBox='0 0 12 12'%3E%3Cpath fill='%232c3e50' d='M6 9L1 4h10z'/%3E%3C/svg%3E");
    background-repeat: no-repeat;
    background-position: right var(--spacing-sm) center;
    padding-right: var(--spacing-xl);
}

textarea.form-control {
    resize: vertical;
    min-height: 100px;
}

/* ================================
   TABLAS
   ================================ */

.table-responsive {
    overflow-x: auto;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-sm);
}

.table {
    width: 100%;
    border-collapse: collapse;
    background: var(--bg-primary);
}

.table thead {
    background: var(--bg-tertiary);
}

.table th {
    padding: var(--spacing-md);
    text-align: left;
    font-weight: 600;
    color: var(--text-primary);
    border-bottom: 2px solid var(--border-color);
}

.table td {
    padding: var(--spacing-md);
    border-bottom: 1px solid var(--border-color);
}

.table tbody tr {
    transition: background var(--transition-fast);
}

.table tbody tr:hover {
    background: var(--bg-secondary);
}

/* ================================
   BADGES Y ESTADOS
   ================================ */

.badge {
    display: inline-block;
    padding: 0.25rem 0.75rem;
    border-radius: var(--radius-full);
    font-size: var(--font-size-sm);
    font-weight: 600;
}

.badge-success {
    background: #d5f4e6;
    color: var(--success-color);
}

.badge-danger {
    background: #fadbd8;
    color: var(--danger-color);
}

.badge-warning {
    background: #fef5e7;
    color: var(--warning-color);
}

.badge-info {
    background: #d6eaf8;
    color: var(--info-color);
}

/* ================================
   MODAL - 2026 Enhanced
   ================================ */

.modal {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0,0,0,0.6);
    z-index: var(--z-modal);
    align-items: center;
    justify-content: center;
    backdrop-filter: blur(8px);
    padding: var(--spacing-lg);
}

.modal.active {
    display: flex;
    animation: fadeIn 0.3s ease;
}

.modal-content {
    background: var(--bg-primary);
    border-radius: var(--radius-2xl);
    max-width: 900px;
    width: 100%;
    max-height: 90vh;
    overflow-y: auto;
    box-shadow: var(--shadow-2xl);
    animation: modalSlideIn 0.4s cubic-bezier(0.34, 1.56, 0.64, 1);
    border: 1px solid var(--border-light);
}

.modal-content::-webkit-scrollbar {
    width: 8px;
}

.modal-content::-webkit-scrollbar-track {
    background: var(--bg-secondary);
}

.modal-content::-webkit-scrollbar-thumb {
    background: var(--border-color);
    border-radius: var(--radius-full);
}

@keyframes modalSlideIn {
    from {
        opacity: 0;
        transform: translateY(-50px) scale(0.95);
    }
    to {
        opacity: 1;
        transform: translateY(0) scale(1);
    }
}

.modal-header {
    padding: var(--spacing-lg);
    border-bottom: 2px solid var(--border-color);
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.modal-title {
    font-size: var(--font-size-xl);
    font-weight: 600;
}

.modal-close {
    background: none;
    font-size: 1.5rem;
    color: var(--text-secondary);
    width: 32px;
    height: 32px;
    border-radius: var(--radius-full);
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all var(--transition-base);
}

.modal-close:hover {
    background: var(--bg-secondary);
    color: var(--text-primary);
}

.modal-body {
    padding: var(--spacing-lg);
}

.modal-footer {
    padding: var(--spacing-lg);
    border-top: 1px solid var(--border-color);
    display: flex;
    justify-content: flex-end;
    gap: var(--spacing-sm);
}

/* ================================
   ALERTS
   ================================ */

.alert {
    padding: var(--spacing-md);
    border-radius: var(--radius-md);
    margin-bottom: var(--spacing-md);
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
}

.alert-icon {
    font-size: 1.5rem;
}

.alert-success {
    background: #d5f4e6;
    color: var(--success-color);
    border-left: 4px solid var(--success-color);
}

.alert-danger {
    background: #fadbd8;
    color: var(--danger-color);
    border-left: 4px solid var(--danger-color);
}

.alert-warning {
    background: #fef5e7;
    color: var(--warning-color);
    border-left: 4px solid var(--warning-color);
}

.alert-info {
    background: #d6eaf8;
    color: var(--info-color);
    border-left: 4px solid var(--info-color);
}

/* ================================
   COURSE CARDS - 2026 Design
   ================================ */

.course-card {
    background: var(--bg-primary);
    border-radius: var(--radius-2xl);
    overflow: hidden;
    box-shadow: var(--shadow-md);
    transition: all var(--transition-base);
    cursor: pointer;
    border: 1px solid var(--border-light);
    position: relative;
}

.course-card::after {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: linear-gradient(180deg, transparent 0%, rgba(0,0,0,0.03) 100%);
    opacity: 0;
    transition: opacity var(--transition-base);
}

.course-card:hover {
    transform: translateY(-8px) scale(1.02);
    box-shadow: var(--shadow-xl);
    border-color: var(--primary-color);
}

.course-card:hover::after {
    opacity: 1;
}

.course-card-image {
    width: 100%;
    height: 180px;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 4rem;
    color: white;
}

.course-card-body {
    padding: var(--spacing-md);
}

.course-card-title {
    font-size: var(--font-size-lg);
    font-weight: 600;
    margin-bottom: var(--spacing-xs);
    color: var(--text-primary);
}

.course-card-meta {
    color: var(--text-secondary);
    font-size: var(--font-size-sm);
    margin-bottom: var(--spacing-sm);
}

.course-card-actions {
    display: flex;
    gap: var(--spacing-xs);
    margin-top: var(--spacing-md);
}

/* ================================
   TABS
   ================================ */

.tabs {
    border-bottom: 2px solid var(--border-color);
    margin-bottom: var(--spacing-lg);
    display: flex;
    gap: var(--spacing-sm);
}

.tab {
    padding: var(--spacing-sm) var(--spacing-lg);
    background: none;
    color: var(--text-secondary);
    border-bottom: 3px solid transparent;
    margin-bottom: -2px;
    transition: all var(--transition-base);
    font-weight: 500;
}

.tab:hover {
    color: var(--primary-color);
}

.tab.active {
    color: var(--primary-color);
    border-bottom-color: var(--primary-color);
}

.tab-content {
    display: none;
}

.tab-content.active {
    display: block;
    animation: fadeIn 0.3s ease;
}

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

/* ================================
   ACCORDION
   ================================ */

.accordion-item {
    background: var(--bg-primary);
    border-radius: var(--radius-md);
    margin-bottom: var(--spacing-sm);
    overflow: hidden;
    box-shadow: var(--shadow-sm);
}

.accordion-header {
    padding: var(--spacing-md);
    cursor: pointer;
    display: flex;
    justify-content: space-between;
    align-items: center;
    transition: background var(--transition-base);
    font-weight: 600;
    color: var(--text-primary);
}

.accordion-header:hover {
    background: var(--bg-secondary);
}

.accordion-icon {
    transition: transform var(--transition-base);
}

.accordion-item.active .accordion-icon {
    transform: rotate(180deg);
}

.accordion-body {
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.3s ease;
}

.accordion-item.active .accordion-body {
    max-height: 1000px;
    padding: var(--spacing-md);
    border-top: 1px solid var(--border-color);
}

/* ================================
   PROGRESS BAR
   ================================ */

.progress {
    height: 8px;
    background: var(--bg-tertiary);
    border-radius: var(--radius-full);
    overflow: hidden;
}

.progress-bar {
    height: 100%;
    background: linear-gradient(90deg, var(--primary-color), var(--secondary-color));
    transition: width 0.5s ease;
}

/* ================================
   RESPONSIVE - TABLET
   ================================ */

@media (max-width: 1024px) {
    .grid-4 {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .sidebar {
        width: 240px;
    }
}

/* ================================
   RESPONSIVE - MOBILE
   ================================ */

@media (max-width: 768px) {
    :root {
        font-size: 14px;
    }
    
    .header-content {
        flex-wrap: wrap;
        padding: 0.5rem 1rem;
    }
    
    .header-logo h1 {
        font-size: 1.1rem;
    }
    
    .header-logo p {
        display: none;
    }
    
    .header-logo-icon {
        width: 40px;
        height: 40px;
        font-size: 1.25rem;
    }
    
    .user-info {
        display: none;
    }
    
    .user-avatar {
        width: 35px;
        height: 35px;
        font-size: 0.9rem;
    }
    
    .btn-logout {
        padding: 0.4rem 0.8rem;
        font-size: 0.75rem;
        margin-left: 0.5rem;
    }
    
    .layout {
        flex-direction: column;
    }
    
    .sidebar {
        display: none;
    }
    
    .main-content {
        padding: var(--spacing-sm);
        padding-bottom: 80px;
    }
    
    .page-title {
        font-size: 1.5rem;
    }
    
    .page-subtitle {
        font-size: 0.875rem;
    }
    
    .grid-2,
    .grid-3,
    .grid-4 {
        grid-template-columns: 1fr;
        gap: var(--spacing-sm);
    }
    
    .kpi-card {
        padding: var(--spacing-md);
    }
    
    .kpi-value {
        font-size: 1.5rem;
    }
    
    .kpi-label {
        font-size: 0.8rem;
    }
    
    .card {
        padding: var(--spacing-md);
        margin-bottom: var(--spacing-sm);
    }
    
    .card-header {
        flex-direction: column;
        align-items: flex-start;
        gap: var(--spacing-sm);
    }
    
    .card-title {
        font-size: 1rem;
    }
    
    .table-responsive {
        font-size: var(--font-size-sm);
        overflow-x: auto;
    }
    
    .table {
        min-width: 600px;
    }
    
    .table th,
    .table td {
        padding: var(--spacing-xs);
        font-size: 0.8rem;
    }
    
    .btn {
        width: 100%;
        justify-content: center;
        padding: var(--spacing-sm) var(--spacing-md);
        font-size: 0.875rem;
    }
    
    .btn-sm {
        padding: 0.4rem 0.6rem;
        font-size: 0.75rem;
        width: auto;
    }
    
    .modal-content {
        width: 95%;
        max-width: 95%;
        max-height: 90vh;
        margin: 1rem;
    }
    
    .modal-header {
        padding: var(--spacing-md);
    }
    
    .modal-body {
        padding: var(--spacing-md);
    }
    
    .modal-footer {
        padding: var(--spacing-md);
        flex-direction: column;
        gap: var(--spacing-sm);
    }
    
    .modal-footer .btn {
        width: 100%;
    }
    
    .course-card-actions {
        flex-direction: column;
        gap: var(--spacing-xs);
    }
    
    .course-card-actions .btn {
        width: 100%;
    }
    
    .tabs {
        overflow-x: auto;
        -webkit-overflow-scrolling: touch;
        scrollbar-width: none;
        -ms-overflow-style: none;
    }
    
    .tabs::-webkit-scrollbar {
        display: none;
    }
    
    .tab {
        padding: var(--spacing-sm) var(--spacing-md);
        font-size: 0.875rem;
        white-space: nowrap;
    }
    
    .accordion-header {
        padding: var(--spacing-sm);
        font-size: 0.9rem;
    }
    
    .accordion-body {
        padding: var(--spacing-sm);
    }
    
    .alert {
        padding: var(--spacing-sm);
        font-size: 0.875rem;
    }
    
    .form-control,
    .form-select {
        font-size: 1rem; /* Previene zoom en iOS */
    }
    
    /* Ocultar columnas menos importantes en móvil */
    .table .hide-mobile {
        display: none;
    }
}

/* ================================
   MOBILE BOTTOM NAV
   ================================ */

@media (max-width: 768px) {
    .mobile-bottom-nav {
        position: fixed;
        bottom: 0;
        left: 0;
        right: 0;
        background: var(--bg-primary);
        box-shadow: 0 -2px 10px rgba(0,0,0,0.1);
        display: flex;
        justify-content: space-around;
        padding: var(--spacing-xs) 0;
        z-index: 99;
    }
    
    .mobile-nav-item {
        display: flex;
        flex-direction: column;
        align-items: center;
        gap: 0.25rem;
        color: var(--text-secondary);
        font-size: var(--font-size-sm);
        padding: var(--spacing-xs);
        transition: color var(--transition-base);
    }
    
    .mobile-nav-item.active {
        color: var(--primary-color);
    }
    
    .mobile-nav-icon {
        font-size: 1.5rem;
    }
    
    .main-content {
        padding-bottom: 80px;
    }
}

/* ================================
   LOADING SPINNER - 2026
   ================================ */

.spinner {
    width: 48px;
    height: 48px;
    border: 4px solid var(--bg-tertiary);
    border-top-color: var(--primary-color);
    border-right-color: var(--secondary-color);
    border-radius: var(--radius-full);
    animation: spin 0.8s cubic-bezier(0.68, -0.55, 0.265, 1.55) infinite;
    margin: var(--spacing-xl) auto;
    box-shadow: var(--shadow-md);
}

@keyframes spin {
    to { transform: rotate(360deg); }
}

/* Modern Loading Dots */
.loading-dots {
    display: flex;
    gap: var(--spacing-sm);
    justify-content: center;
    align-items: center;
}

.loading-dots span {
    width: 12px;
    height: 12px;
    border-radius: var(--radius-full);
    background: var(--primary-color);
    animation: bounce 1.4s infinite ease-in-out both;
}

.loading-dots span:nth-child(1) { animation-delay: -0.32s; }
.loading-dots span:nth-child(2) { animation-delay: -0.16s; }

@keyframes bounce {
    0%, 80%, 100% { transform: scale(0); }
    40% { transform: scale(1); }
}

/* ================================
   EMPTY STATE
   ================================ */

.empty-state {
    text-align: center;
    padding: var(--spacing-xl) var(--spacing-lg);
    color: var(--text-secondary);
}

.empty-state-icon {
    font-size: 4rem;
    margin-bottom: var(--spacing-md);
    opacity: 0.5;
}

.empty-state-text {
    font-size: var(--font-size-lg);
    margin-bottom: var(--spacing-sm);
}

/* ================================
   ANIMATIONS - 2026 Enhanced
   ================================ */

.fade-in {
    animation: fadeIn 0.6s cubic-bezier(0.4, 0, 0.2, 1);
}

.slide-up {
    animation: slideUp 0.6s cubic-bezier(0.34, 1.56, 0.64, 1);
}

.scale-in {
    animation: scaleIn 0.5s cubic-bezier(0.34, 1.56, 0.64, 1);
}

.slide-right {
    animation: slideRight 0.6s cubic-bezier(0.4, 0, 0.2, 1);
}

@keyframes slideUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

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

@keyframes scaleIn {
    from {
        opacity: 0;
        transform: scale(0.9);
    }
    to {
        opacity: 1;
        transform: scale(1);
    }
}

@keyframes slideRight {
    from {
        opacity: 0;
        transform: translateX(-30px);
    }
    to {
        opacity: 1;
        transform: translateX(0);
    }
}

/* Stagger Animation Delays */
.card:nth-child(1) { animation-delay: 0.1s; }
.card:nth-child(2) { animation-delay: 0.2s; }
.card:nth-child(3) { animation-delay: 0.3s; }
.card:nth-child(4) { animation-delay: 0.4s; }
.card:nth-child(5) { animation-delay: 0.5s; }
.card:nth-child(6) { animation-delay: 0.6s; }

/* ================================
   PRINT STYLES
   ================================ */

@media print {
    .sidebar,
    .header,
    .btn,
    .mobile-bottom-nav {
        display: none !important;
    }
    
    .main-content {
        padding: 0;
    }
    
    .card {
        box-shadow: none;
        border: 1px solid var(--border-color);
        page-break-inside: avoid;
    }
}

/* ================================
   SISTEMA DE MENSAJERÍA
   ================================ */

.messages-container {
    display: flex;
    flex-direction: column;
    height: 500px;
    background: var(--bg-primary);
    border-radius: var(--radius-lg);
    overflow: hidden;
}

.messages-header {
    padding: var(--spacing-md);
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    color: white;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.messages-list {
    flex: 1;
    overflow-y: auto;
    padding: var(--spacing-md);
    background: var(--bg-secondary);
}

.message-item {
    margin-bottom: var(--spacing-md);
    animation: fadeIn 0.3s ease;
}

.message-sent {
    display: flex;
    justify-content: flex-end;
}

.message-received {
    display: flex;
    justify-content: flex-start;
}

.message-bubble {
    max-width: 70%;
    padding: var(--spacing-sm) var(--spacing-md);
    border-radius: var(--radius-lg);
    position: relative;
}

.message-sent .message-bubble {
    background: var(--primary-color);
    color: white;
    border-bottom-right-radius: 4px;
}

.message-received .message-bubble {
    background: white;
    color: var(--text-primary);
    border-bottom-left-radius: 4px;
    box-shadow: var(--shadow-sm);
}

.message-author {
    font-weight: 600;
    font-size: var(--font-size-sm);
    margin-bottom: 0.25rem;
}

.message-sent .message-author {
    color: rgba(255,255,255,0.9);
}

.message-received .message-author {
    color: var(--primary-color);
}

.message-text {
    font-size: var(--font-size-base);
    line-height: 1.5;
    word-wrap: break-word;
}

.message-time {
    font-size: 0.75rem;
    opacity: 0.7;
    margin-top: 0.25rem;
}

.message-input-container {
    padding: var(--spacing-md);
    background: white;
    border-top: 1px solid var(--border-color);
    display: flex;
    gap: var(--spacing-sm);
    align-items: flex-end;
}

.message-input {
    flex: 1;
    resize: none;
    min-height: 40px;
    max-height: 100px;
    border: 2px solid var(--border-color);
    border-radius: var(--radius-md);
    padding: var(--spacing-sm);
    font-family: inherit;
    font-size: var(--font-size-base);
    transition: border-color var(--transition-base);
}

.message-input:focus {
    outline: none;
    border-color: var(--primary-color);
}

.message-send-btn {
    background: var(--primary-color);
    color: white;
    border: none;
    border-radius: var(--radius-md);
    padding: var(--spacing-sm) var(--spacing-md);
    font-size: var(--font-size-base);
    font-weight: 600;
    cursor: pointer;
    transition: all var(--transition-base);
    min-width: 80px;
}

.message-send-btn:hover {
    background: var(--primary-dark);
    transform: translateY(-1px);
}

.message-send-btn:disabled {
    background: var(--bg-tertiary);
    color: var(--text-secondary);
    cursor: not-allowed;
    transform: none;
}

.no-messages {
    text-align: center;
    padding: var(--spacing-xl);
    color: var(--text-secondary);
}

.no-messages-icon {
    font-size: 4rem;
    margin-bottom: var(--spacing-md);
    opacity: 0.3;
}

/* Responsivo - Mensajería */
@media (max-width: 768px) {
    .messages-container {
        height: 400px;
    }
    
    .message-bubble {
        max-width: 85%;
    }
    
    .messages-list {
        padding: var(--spacing-sm);
    }
    
    .message-input-container {
        padding: var(--spacing-sm);
    }
}

/* ================================
   MEJORAS ADICIONALES DE RESPONSIVE
   ================================ */

@media (max-width: 480px) {
    .header-logo h1 {
        font-size: 1rem;
    }
    
    .header-logo-icon {
        width: 35px;
        height: 35px;
        font-size: 1rem;
    }
    
    .kpi-card {
        padding: var(--spacing-sm);
    }
    
    .kpi-icon {
        font-size: 2rem;
    }
    
    .kpi-value {
        font-size: 1.25rem;
    }
    
    .course-card-title {
        font-size: 1rem;
    }
    
    .course-card-image {
        height: 120px;
        font-size: 3rem;
    }
}

/* ================================
   MEJORAS DE ACCESIBILIDAD
   ================================ */

.sr-only {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border-width: 0;
}

*:focus-visible {
    outline: 3px solid var(--primary-color);
    outline-offset: 2px;
}

button:focus-visible,
a:focus-visible {
    outline: 2px solid var(--primary-color);
    outline-offset: 2px;
}