/* ==========================================
   VARIABLES CSS Y CONFIGURACIÓN GLOBAL
   ========================================== */

:root {
  /* Colores principales */
  --primary-color: #3b82f6;
  --primary-dark: #2563eb;
  --secondary-color: #10b981;
  --accent-color: #8b5cf6;
  
  /* Colores de fondo */
  --bg-primary: #ffffff;
  --bg-secondary: #f8fafc;
  --bg-tertiary: #f1f5f9;
  --bg-overlay: rgba(0, 0, 0, 0.5);
  
  /* Colores de texto */
  --text-primary: #1e293b;
  --text-secondary: #64748b;
  --text-muted: #94a3b8;
  --text-inverse: #ffffff;
  
  /* Bordes y sombras */
  --border-color: #e2e8f0;
  --border-radius: 12px;
  --border-radius-sm: 8px;
  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
  --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);
  
  /* Espaciado */
  --spacing-xs: 0.25rem;
  --spacing-sm: 0.5rem;
  --spacing-md: 1rem;
  --spacing-lg: 1.5rem;
  --spacing-xl: 2rem;
  --spacing-2xl: 3rem;
  
  /* Tipografía */
  --font-family: 'Inter', system-ui, -apple-system, sans-serif;
  --font-mono: 'JetBrains Mono', 'Fira Code', monospace;
  --font-size-xs: 0.75rem;
  --font-size-sm: 0.875rem;
  --font-size-base: 1rem;
  --font-size-lg: 1.125rem;
  --font-size-xl: 1.25rem;
  --font-size-2xl: 1.5rem;
  --font-size-3xl: 1.875rem;
  --font-size-4xl: 2.25rem;
  
  /* Dimensiones */
  --sidebar-width: 280px;
  --header-height: 80px;
  --footer-height: auto;
  
  /* Transiciones */
  --transition-fast: 0.15s ease;
  --transition-normal: 0.3s ease;
  --transition-slow: 0.5s ease;
}

/* Tema oscuro */
[data-theme="dark"] {
  --bg-primary: #0f172a;
  --bg-secondary: #1e293b;
  --bg-tertiary: #334155;
  --bg-overlay: rgba(0, 0, 0, 0.7);
  
  --text-primary: #f1f5f9;
  --text-secondary: #cbd5e1;
  --text-muted: #64748b;
  
  --border-color: #334155;
}

/* Reset y estilos base */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

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

body {
  font-family: var(--font-family);
  font-size: var(--font-size-base);
  line-height: 1.6;
  color: var(--text-primary);
  background-color: var(--bg-primary);
  transition: background-color var(--transition-normal), color var(--transition-normal);
  overflow-x: hidden;
}

/* ==========================================
   LOADER
   ========================================== */

.loader {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100vh;
  background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 9999;
  transition: opacity var(--transition-slow), visibility var(--transition-slow);
}

.loader.hidden {
  opacity: 0;
  visibility: hidden;
}

.loader-content {
  text-align: center;
  color: white;
}

.loader-content i {
  font-size: 4rem;
  margin-bottom: var(--spacing-lg);
  animation: pulse 2s infinite;
}

.loader-text {
  font-size: var(--font-size-lg);
  font-weight: 500;
}

/* ==========================================
   SIDEBAR
   ========================================== */

.sidebar {
  position: fixed;
  top: 0;
  left: 0;
  width: var(--sidebar-width);
  height: 100vh;
  background-color: var(--bg-secondary);
  border-right: 1px solid var(--border-color);
  transform: translateX(0);
  transition: transform var(--transition-normal);
  z-index: 1000;
  display: flex;
  flex-direction: column;
}

.sidebar.collapsed {
  transform: translateX(-100%);
}

.sidebar-header {
  padding: var(--spacing-lg);
  border-bottom: 1px solid var(--border-color);
  display: flex;
  align-items: center;
  justify-content: space-between;
  min-height: var(--header-height);
}

.logo {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
  font-weight: 700;
  font-size: var(--font-size-lg);
  color: var(--primary-color);
}

.logo i {
  font-size: var(--font-size-2xl);
}

.sidebar-toggle {
  background: none;
  border: none;
  color: var(--text-secondary);
  font-size: var(--font-size-lg);
  cursor: pointer;
  padding: var(--spacing-sm);
  border-radius: var(--border-radius-sm);
  transition: background-color var(--transition-fast);
}

.sidebar-toggle:hover {
  background-color: var(--bg-tertiary);
}

.sidebar-content {
  flex: 1;
  overflow-y: auto;
  padding: var(--spacing-md) 0;
}

.sidebar-menu {
  padding: 0 var(--spacing-md);
}

.menu-section {
  margin-bottom: var(--spacing-xl);
}

.menu-section-title {
  font-size: var(--font-size-sm);
  font-weight: 600;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  padding: var(--spacing-sm) var(--spacing-md);
  margin-bottom: var(--spacing-sm);
}

.menu-item {
  display: block;
  width: 100%;
  padding: var(--spacing-sm) var(--spacing-md);
  color: var(--text-secondary);
  text-decoration: none;
  border-radius: var(--border-radius-sm);
  transition: all var(--transition-fast);
  cursor: pointer;
  border: none;
  background: none;
  text-align: left;
  font-size: var(--font-size-sm);
  line-height: 1.5;
}

.menu-item:hover {
  background-color: var(--bg-tertiary);
  color: var(--text-primary);
  transform: translateX(4px);
}

.menu-item.active {
  background-color: var(--primary-color);
  color: var(--text-inverse);
}

.menu-item i {
  width: 16px;
  margin-right: var(--spacing-sm);
}

.sidebar-footer {
  padding: var(--spacing-lg);
  border-top: 1px solid var(--border-color);
}

.theme-toggle {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
  width: 100%;
  padding: var(--spacing-sm) var(--spacing-md);
  background: none;
  border: 1px solid var(--border-color);
  border-radius: var(--border-radius-sm);
  color: var(--text-secondary);
  cursor: pointer;
  transition: all var(--transition-fast);
  font-size: var(--font-size-sm);
}

.theme-toggle:hover {
  background-color: var(--bg-tertiary);
  border-color: var(--primary-color);
}

/* ==========================================
   OVERLAY
   ========================================== */

.sidebar-overlay {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100vh;
  background-color: var(--bg-overlay);
  z-index: 999;
  opacity: 0;
  visibility: hidden;
  transition: all var(--transition-normal);
}

.sidebar-overlay.active {
  opacity: 1;
  visibility: visible;
}

/* ==========================================
   CONTENIDO PRINCIPAL
   ========================================== */

.main-content {
  margin-left: var(--sidebar-width);
  min-height: 100vh;
  transition: margin-left var(--transition-normal);
  display: flex;
  flex-direction: column;
}

.main-content.sidebar-collapsed {
  margin-left: 0;
}

/* ==========================================
   HEADER
   ========================================== */

.header {
  background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
  color: white;
  padding: var(--spacing-2xl) var(--spacing-xl);
  position: relative;
  overflow: hidden;
}

.header::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: url("data:image/svg+xml,%3Csvg width='60' height='60' viewBox='0 0 60 60' xmlns='http://www.w3.org/2000/svg'%3E%3Cg fill='none' fill-rule='evenodd'%3E%3Cg fill='%23ffffff' fill-opacity='0.1'%3E%3Ccircle cx='30' cy='30' r='4'/%3E%3C/g%3E%3C/g%3E%3C/svg%3E") repeat;
  pointer-events: none;
}

.header-content {
  position: relative;
  z-index: 1;
  display: flex;
  align-items: center;
  justify-content: space-between;
  max-width: 1200px;
  margin: 0 auto;
}

.mobile-menu-toggle {
  display: none;
  background: none;
  border: none;
  color: white;
  font-size: var(--font-size-xl);
  cursor: pointer;
  padding: var(--spacing-sm);
  border-radius: var(--border-radius-sm);
  transition: background-color var(--transition-fast);
}

.mobile-menu-toggle:hover {
  background-color: rgba(255, 255, 255, 0.1);
}

.header-text {
  flex: 1;
  text-align: center;
}

.header-title {
  font-size: var(--font-size-4xl);
  font-weight: 700;
  margin-bottom: var(--spacing-sm);
  text-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
}

.header-subtitle {
  font-size: var(--font-size-lg);
  opacity: 0.9;
  font-weight: 400;
}

.header-actions {
  display: flex;
  gap: var(--spacing-md);
}

/* ==========================================
   BOTONES
   ========================================== */

.btn {
  display: inline-flex;
  align-items: center;
  gap: var(--spacing-sm);
  padding: var(--spacing-sm) var(--spacing-lg);
  border: none;
  border-radius: var(--border-radius-sm);
  font-size: var(--font-size-sm);
  font-weight: 500;
  text-decoration: none;
  cursor: pointer;
  transition: all var(--transition-fast);
  white-space: nowrap;
}

.btn-primary {
  background-color: var(--text-inverse);
  color: var(--primary-color);
}

.btn-primary:hover {
  background-color: rgba(255, 255, 255, 0.9);
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

.btn-secondary {
  background-color: var(--bg-secondary);
  color: var(--text-primary);
  border: 1px solid var(--border-color);
}

.btn-secondary:hover {
  background-color: var(--bg-tertiary);
  border-color: var(--primary-color);
}

/* ==========================================
   ÁREA DE CONTENIDO
   ========================================== */

.content-area {
  flex: 1;
  padding: var(--spacing-2xl);
  max-width: 1200px;
  margin: 0 auto;
  width: 100%;
}

.content-section {
  background-color: var(--bg-primary);
  border-radius: var(--border-radius);
  padding: var(--spacing-2xl);
  box-shadow: var(--shadow-sm);
  border: 1px solid var(--border-color);
  animation: fadeInUp 0.6s ease-out;
}

.content-title {
  font-size: var(--font-size-3xl);
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: var(--spacing-lg);
  display: flex;
  align-items: center;
  gap: var(--spacing-md);
}

.content-title i {
  color: var(--primary-color);
}

.content-subtitle {
  font-size: var(--font-size-xl);
  font-weight: 600;
  color: var(--text-primary);
  margin: var(--spacing-xl) 0 var(--spacing-md);
}

.content-text {
  color: var(--text-secondary);
  line-height: 1.7;
  margin-bottom: var(--spacing-lg);
}

/* ==========================================
   CÓDIGO Y RESALTADO DE SINTAXIS
   ========================================== */

.code-block {
  background-color: var(--bg-tertiary);
  border: 1px solid var(--border-color);
  border-radius: var(--border-radius-sm);
  padding: var(--spacing-lg);
  margin: var(--spacing-lg) 0;
  overflow-x: auto;
  font-family: var(--font-mono);
  font-size: var(--font-size-sm);
}

.code-inline {
  background-color: var(--bg-tertiary);
  padding: 2px 6px;
  border-radius: 4px;
  font-family: var(--font-mono);
  font-size: 0.9em;
  color: var(--accent-color);
}

/* ==========================================
   LISTAS Y ELEMENTOS
   ========================================== */

.content-list {
  list-style: none;
  padding-left: 0;
}

.content-list li {
  padding: var(--spacing-sm) 0;
  padding-left: var(--spacing-xl);
  position: relative;
  color: var(--text-secondary);
}

.content-list li::before {
  content: '→';
  position: absolute;
  left: 0;
  color: var(--primary-color);
  font-weight: bold;
}

/* ==========================================
   TARJETAS
   ========================================== */

.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: var(--spacing-lg);
  margin: var(--spacing-xl) 0;
}

.card {
  background-color: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--border-radius);
  padding: var(--spacing-xl);
  transition: all var(--transition-normal);
  cursor: pointer;
}

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

.card-title {
  font-size: var(--font-size-lg);
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: var(--spacing-sm);
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
}

.card-description {
  color: var(--text-secondary);
  line-height: 1.6;
}

/* ==========================================
   FOOTER
   ========================================== */

.footer {
  background-color: var(--bg-secondary);
  border-top: 1px solid var(--border-color);
  padding: var(--spacing-2xl) var(--spacing-xl);
  margin-top: auto;
}

.footer-content {
  max-width: 1200px;
  margin: 0 auto;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: var(--spacing-2xl);
}

.footer-section {
  color: var(--text-secondary);
}

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

.instructor-name {
  font-size: var(--font-size-xl);
  font-weight: 700;
  color: var(--primary-color);
  margin-bottom: var(--spacing-sm);
}

.instructor-description {
  color: var(--text-secondary);
  line-height: 1.6;
}

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

.contact-link {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
  color: var(--text-secondary);
  text-decoration: none;
  transition: color var(--transition-fast);
}

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

.footer-links {
  list-style: none;
  padding: 0;
}

.footer-links li {
  margin-bottom: var(--spacing-sm);
}

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

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

.footer-bottom {
  margin-top: var(--spacing-2xl);
  padding-top: var(--spacing-xl);
  border-top: 1px solid var(--border-color);
  text-align: center;
  color: var(--text-muted);
  max-width: 1200px;
  margin-left: auto;
  margin-right: auto;
}

.footer-bottom strong {
  color: var(--primary-color);
  font-weight: 600;
}

/* ==========================================
   ANIMACIONES
   ========================================== */

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

@keyframes pulse {
  0%, 100% {
    transform: scale(1);
  }
  50% {
    transform: scale(1.1);
  }
}

@keyframes slideInLeft {
  from {
    transform: translateX(-100%);
  }
  to {
    transform: translateX(0);
  }
}

/* ==========================================
   RESPONSIVE DESIGN
   ========================================== */

/* Tablets */
@media (max-width: 1024px) {
  .header-title {
    font-size: var(--font-size-3xl);
  }
  
  .content-area {
    padding: var(--spacing-xl);
  }
  
  .header {
    padding: var(--spacing-xl);
  }
}

/* Móviles */
@media (max-width: 768px) {
  :root {
    --sidebar-width: 280px;
  }
  
  .sidebar {
    transform: translateX(-100%);
    z-index: 1001;
  }
  
  .sidebar.open {
    transform: translateX(0);
  }
  
  .main-content {
    margin-left: 0;
  }
  
  .mobile-menu-toggle {
    display: block;
  }
  
  .header-content {
    flex-direction: column;
    text-align: center;
    gap: var(--spacing-lg);
  }
  
  .header-text {
    order: 1;
  }
  
  .mobile-menu-toggle {
    position: absolute;
    top: var(--spacing-lg);
    left: var(--spacing-lg);
  }
  
  .header-actions {
    order: 2;
  }
  
  .header-title {
    font-size: var(--font-size-2xl);
  }
  
  .header-subtitle {
    font-size: var(--font-size-base);
  }
  
  .content-area {
    padding: var(--spacing-lg);
  }
  
  .content-section {
    padding: var(--spacing-lg);
  }
  
  .card-grid {
    grid-template-columns: 1fr;
  }
  
  .footer-content {
    grid-template-columns: 1fr;
    gap: var(--spacing-xl);
  }
  
  .contact-links {
    flex-direction: row;
    flex-wrap: wrap;
  }
}

/* Móviles pequeños */
@media (max-width: 480px) {
  .header {
    padding: var(--spacing-lg) var(--spacing-md);
  }
  
  .content-area {
    padding: var(--spacing-md);
  }
  
  .content-section {
    padding: var(--spacing-md);
  }
  
  .footer {
    padding: var(--spacing-xl) var(--spacing-md);
  }
  
  .header-title {
    font-size: var(--font-size-xl);
  }
  
  .content-title {
    font-size: var(--font-size-2xl);
  }
}

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

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

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

.text-secondary {
  color: var(--text-secondary);
}

.hidden {
  display: none;
}

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

/* Mejoras de accesibilidad */
@media (prefers-reduced-motion: reduce) {
  * {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
}

/* Focus visible para navegación por teclado */
.menu-item:focus-visible,
.btn:focus-visible,
.theme-toggle:focus-visible,
.sidebar-toggle:focus-visible {
  outline: 2px solid var(--primary-color);
  outline-offset: 2px;
}