/* ==========================================
   🎨 CURSO INTERACTIVO DE FÍSICA - ULTRA MODERNO
   ========================================== */

/* 🎯 VARIABLES CSS AVANZADAS */
:root {
  /* 🌈 Paleta de colores vibrantes */
  --primary: #667eea;
  --primary-dark: #5a67d8;
  --primary-light: #a5b4fc;
  --secondary: #f093fb;
  --secondary-dark: #c471ed;
  --accent: #4facfe;
  --accent-dark: #43a7f5;
  --success: #10d9c4;
  --warning: #fbbf24;
  --danger: #f87171;
  --info: #60a5fa;
  
  /* 🎨 Gradientes espectaculares */
  --gradient-primary: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  --gradient-secondary: linear-gradient(135deg, #f093fb 0%, #f5576c 100%);
  --gradient-accent: linear-gradient(135deg, #4facfe 0%, #00f2fe 100%);
  --gradient-success: linear-gradient(135deg, #a8edea 0%, #fed6e3 100%);
  --gradient-warm: linear-gradient(135deg, #ff9a9e 0%, #fecfef 50%, #fecfef 100%);
  --gradient-cool: linear-gradient(135deg, #a8edea 0%, #fed6e3 100%);
  --gradient-dark: linear-gradient(135deg, #232526 0%, #414345 100%);
  --gradient-cosmic: linear-gradient(45deg, #667eea, #764ba2, #f093fb, #f5576c);
  
  /* 🌙 Modo claro */
  --bg-primary: #ffffff;
  --bg-secondary: #f8fafc;
  --bg-tertiary: #f1f5f9;
  --bg-glass: rgba(255, 255, 255, 0.15);
  --bg-glass-dark: rgba(0, 0, 0, 0.15);
  --bg-overlay: rgba(0, 0, 0, 0.5);
  
  /* 📝 Colores de texto */
  --text-primary: #1a202c;
  --text-secondary: #4a5568;
  --text-muted: #718096;
  --text-inverse: #ffffff;
  --text-accent: var(--primary);
  
  /* 🔲 Bordes y sombras */
  --border-color: #e2e8f0;
  --border-radius: 16px;
  --border-radius-sm: 8px;
  --border-radius-lg: 24px;
  --border-radius-xl: 32px;
  
  /* ✨ Sombras modernas */
  --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);
  --shadow-2xl: 0 25px 50px -12px rgba(0, 0, 0, 0.25);
  --shadow-glow: 0 0 30px rgba(102, 126, 234, 0.3);
  --shadow-glow-pink: 0 0 30px rgba(240, 147, 251, 0.3);
  --shadow-inner: inset 0 2px 4px 0 rgba(0, 0, 0, 0.06);
  
  /* 📏 Espaciado */
  --spacing-xs: 0.25rem;
  --spacing-sm: 0.5rem;
  --spacing-md: 1rem;
  --spacing-lg: 1.5rem;
  --spacing-xl: 2rem;
  --spacing-2xl: 3rem;
  --spacing-3xl: 4rem;
  
  /* 🔤 Tipografía moderna */
  --font-family: 'Inter', system-ui, -apple-system, sans-serif;
  --font-display: 'Space Grotesk', system-ui, 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;
  --font-size-5xl: 3rem;
  --font-size-6xl: 3.75rem;
  
  /* 📐 Dimensiones */
  --sidebar-width: 320px;
  --header-height: 120px;
  
  /* ⚡ Transiciones suaves */
  --transition-fast: 0.15s cubic-bezier(0.4, 0, 0.2, 1);
  --transition-normal: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  --transition-slow: 0.5s cubic-bezier(0.4, 0, 0.2, 1);
  --transition-bounce: 0.6s cubic-bezier(0.68, -0.55, 0.265, 1.55);
}

/* 🌙 TEMA OSCURO */
[data-theme="dark"] {
  --bg-primary: #0f172a;
  --bg-secondary: #1e293b;
  --bg-tertiary: #334155;
  --bg-glass: rgba(0, 0, 0, 0.25);
  --bg-glass-dark: rgba(255, 255, 255, 0.1);
  --bg-overlay: rgba(0, 0, 0, 0.7);
  
  --text-primary: #f1f5f9;
  --text-secondary: #cbd5e1;
  --text-muted: #64748b;
  
  --border-color: #475569;
  
  --shadow-glow: 0 0 40px rgba(102, 126, 234, 0.4);
  --shadow-glow-pink: 0 0 40px rgba(240, 147, 251, 0.4);
}

/* 🔄 RESET Y BASE */
*, *::before, *::after {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

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

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

/* 🎭 BACKGROUND ANIMADO */
.animated-background {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  z-index: -1;
  overflow: hidden;
  pointer-events: none;
}

.bg-shapes {
  position: relative;
  width: 100%;
  height: 100%;
}

.shape {
  position: absolute;
  border-radius: 50%;
  background: var(--gradient-primary);
  opacity: 0.1;
  animation: float 20s infinite linear;
}

.shape-1 {
  width: 80px;
  height: 80px;
  top: 20%;
  left: 10%;
  animation-delay: 0s;
  background: var(--gradient-accent);
}

.shape-2 {
  width: 120px;
  height: 120px;
  top: 60%;
  right: 15%;
  animation-delay: -5s;
  background: var(--gradient-secondary);
}

.shape-3 {
  width: 60px;
  height: 60px;
  bottom: 30%;
  left: 20%;
  animation-delay: -10s;
  background: var(--gradient-warm);
}

.shape-4 {
  width: 100px;
  height: 100px;
  top: 40%;
  left: 50%;
  animation-delay: -15s;
  background: var(--gradient-cool);
}

.shape-5 {
  width: 140px;
  height: 140px;
  bottom: 20%;
  right: 30%;
  animation-delay: -20s;
  background: var(--gradient-success);
}

@keyframes float {
  0%, 100% { transform: translateY(0px) rotate(0deg); }
  33% { transform: translateY(-30px) rotate(120deg); }
  66% { transform: translateY(20px) rotate(240deg); }
}

/* 🎭 LOADER ESPECTACULAR */
.loader {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100vh;
  background: var(--gradient-cosmic);
  background-size: 400% 400%;
  animation: gradientShift 4s ease infinite;
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 10000;
  transition: opacity var(--transition-slow), visibility var(--transition-slow);
}

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

.loader-container {
  position: relative;
  text-align: center;
  color: white;
}

.loader-content {
  position: relative;
  z-index: 2;
}

.loader-icon {
  position: relative;
  display: inline-block;
  margin-bottom: var(--spacing-xl);
}

.loader-icon i {
  font-size: 4rem;
  animation: pulse 2s infinite, rotate 3s linear infinite;
  color: white;
  filter: drop-shadow(0 0 20px rgba(255, 255, 255, 0.5));
}

.loader-orbit {
  position: absolute;
  border: 2px solid rgba(255, 255, 255, 0.3);
  border-radius: 50%;
  animation: orbit 2s linear infinite;
}

.orbit-1 {
  width: 80px;
  height: 80px;
  top: 50%;
  left: 50%;
  margin: -40px 0 0 -40px;
  border-top-color: white;
  animation-duration: 1s;
}

.orbit-2 {
  width: 100px;
  height: 100px;
  top: 50%;
  left: 50%;
  margin: -50px 0 0 -50px;
  border-right-color: white;
  animation-duration: 1.5s;
  animation-direction: reverse;
}

.orbit-3 {
  width: 120px;
  height: 120px;
  top: 50%;
  left: 50%;
  margin: -60px 0 0 -60px;
  border-bottom-color: white;
  animation-duration: 2s;
}

.loader-text h3 {
  font-family: var(--font-display);
  font-size: var(--font-size-2xl);
  font-weight: 700;
  margin-bottom: var(--spacing-sm);
  text-shadow: 0 2px 10px rgba(0, 0, 0, 0.3);
}

.loader-text p {
  font-size: var(--font-size-lg);
  opacity: 0.9;
  margin-bottom: var(--spacing-lg);
}

.loader-progress {
  width: 200px;
  height: 4px;
  background: rgba(255, 255, 255, 0.2);
  border-radius: 2px;
  overflow: hidden;
  margin: 0 auto;
}

.loader-progress-bar {
  height: 100%;
  background: linear-gradient(90deg, transparent, white, transparent);
  animation: progress 2s linear infinite;
}

.loader-particles {
  position: absolute;
  top: 50%;
  left: 50%;
  width: 200px;
  height: 200px;
  margin: -100px 0 0 -100px;
}

.loader-particles span {
  position: absolute;
  width: 4px;
  height: 4px;
  background: white;
  border-radius: 50%;
  animation: particle 3s linear infinite;
}

.loader-particles span:nth-child(1) { animation-delay: 0s; }
.loader-particles span:nth-child(2) { animation-delay: 0.3s; }
.loader-particles span:nth-child(3) { animation-delay: 0.6s; }
.loader-particles span:nth-child(4) { animation-delay: 0.9s; }
.loader-particles span:nth-child(5) { animation-delay: 1.2s; }
.loader-particles span:nth-child(6) { animation-delay: 1.5s; }
.loader-particles span:nth-child(7) { animation-delay: 1.8s; }
.loader-particles span:nth-child(8) { animation-delay: 2.1s; }
.loader-particles span:nth-child(9) { animation-delay: 2.4s; }
.loader-particles span:nth-child(10) { animation-delay: 2.7s; }

@keyframes gradientShift {
  0% { background-position: 0% 50%; }
  50% { background-position: 100% 50%; }
  100% { background-position: 0% 50%; }
}

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

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

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

@keyframes progress {
  0% { transform: translateX(-100%); }
  100% { transform: translateX(200px); }
}

@keyframes particle {
  0% {
    transform: translate(0, 100px) rotate(0deg);
    opacity: 1;
  }
  100% {
    transform: translate(0, -100px) rotate(360deg);
    opacity: 0;
  }
}

/* 📱 SIDEBAR ULTRA MODERNO */
.sidebar {
  position: fixed;
  top: 0;
  left: 0;
  width: var(--sidebar-width);
  height: 100vh;
  background: rgba(255, 255, 255, 0.95);
  backdrop-filter: blur(20px);
  border-right: 1px solid var(--border-color);
  transform: translateX(0);
  transition: transform var(--transition-normal);
  z-index: 1000;
  display: flex;
  flex-direction: column;
  box-shadow: var(--shadow-2xl);
}

[data-theme="dark"] .sidebar {
  background: rgba(15, 23, 42, 0.95);
}

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

.sidebar-header {
  padding: var(--spacing-xl);
  border-bottom: 1px solid var(--border-color);
  display: flex;
  align-items: center;
  justify-content: space-between;
  background: var(--gradient-primary);
  color: white;
  position: relative;
  overflow: hidden;
}

.sidebar-header::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: url("data:image/svg+xml,%3Csvg width='40' height='40' viewBox='0 0 40 40' xmlns='http://www.w3.org/2000/svg'%3E%3Cg fill='%23ffffff' fill-opacity='0.1'%3E%3Ccircle cx='20' cy='20' r='2'/%3E%3C/g%3E%3C/svg%3E") repeat;
  pointer-events: none;
}

.logo {
  display: flex;
  align-items: center;
  gap: var(--spacing-md);
  position: relative;
  z-index: 1;
}

.logo-icon {
  width: 48px;
  height: 48px;
  background: rgba(255, 255, 255, 0.2);
  border-radius: var(--border-radius);
  display: flex;
  align-items: center;
  justify-content: center;
  backdrop-filter: blur(10px);
  border: 1px solid rgba(255, 255, 255, 0.3);
}

.logo-icon i {
  font-size: var(--font-size-xl);
  animation: logoSpin 6s ease-in-out infinite;
}

.logo-text {
  display: flex;
  flex-direction: column;
}

.logo-title {
  font-family: var(--font-display);
  font-size: var(--font-size-xl);
  font-weight: 700;
  line-height: 1;
}

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

.sidebar-toggle {
  background: rgba(255, 255, 255, 0.2);
  border: 1px solid rgba(255, 255, 255, 0.3);
  color: white;
  width: 40px;
  height: 40px;
  border-radius: var(--border-radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: all var(--transition-fast);
  backdrop-filter: blur(10px);
  position: relative;
  z-index: 1;
}

.sidebar-toggle:hover {
  background: rgba(255, 255, 255, 0.3);
  transform: scale(1.05);
}

.sidebar-content {
  flex: 1;
  overflow-y: auto;
  padding: var(--spacing-lg) 0;
  scrollbar-width: thin;
  scrollbar-color: var(--primary) transparent;
}

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

.sidebar-content::-webkit-scrollbar-track {
  background: transparent;
}

.sidebar-content::-webkit-scrollbar-thumb {
  background: var(--primary);
  border-radius: 3px;
}

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

.menu-section-title {
  font-family: var(--font-display);
  font-size: var(--font-size-sm);
  font-weight: 700;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.1em;
  padding: var(--spacing-md) var(--spacing-lg);
  margin: var(--spacing-lg) 0 var(--spacing-sm);
  background: var(--bg-tertiary);
  border-radius: var(--border-radius);
  border-left: 4px solid var(--primary);
  position: relative;
  overflow: hidden;
}

.menu-section-title::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: linear-gradient(45deg, transparent 30%, rgba(255, 255, 255, 0.1) 50%, transparent 70%);
  transform: translateX(-100%);
  animation: shine 3s infinite;
}

.menu-list {
  list-style: none;
  margin-bottom: var(--spacing-xl);
}

.menu-item {
  display: flex;
  align-items: center;
  gap: var(--spacing-md);
  padding: var(--spacing-md) var(--spacing-lg);
  color: var(--text-secondary);
  text-decoration: none;
  border-radius: var(--border-radius);
  transition: all var(--transition-fast);
  cursor: pointer;
  border: none;
  background: none;
  text-align: left;
  font-size: var(--font-size-sm);
  line-height: 1.5;
  margin-bottom: var(--spacing-xs);
  position: relative;
  overflow: hidden;
}

.menu-item::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 0;
  height: 100%;
  background: var(--gradient-primary);
  transition: width var(--transition-fast);
  z-index: -1;
}

.menu-item:hover {
  color: white;
  transform: translateX(8px);
  box-shadow: var(--shadow-lg);
}

.menu-item:hover::before {
  width: 100%;
}

.menu-item.active {
  background: var(--gradient-primary);
  color: white;
  box-shadow: var(--shadow-glow);
  transform: translateX(4px);
}

.menu-item i {
  width: 20px;
  text-align: center;
  font-size: var(--font-size-base);
}

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

.theme-controls {
  margin-bottom: var(--spacing-md);
}

.theme-toggle {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
  width: 100%;
  padding: var(--spacing-md) var(--spacing-lg);
  background: var(--bg-primary);
  border: 1px solid var(--border-color);
  border-radius: var(--border-radius);
  color: var(--text-secondary);
  cursor: pointer;
  transition: all var(--transition-fast);
  font-size: var(--font-size-sm);
  position: relative;
  overflow: hidden;
}

.theme-toggle::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: var(--gradient-accent);
  opacity: 0;
  transition: opacity var(--transition-fast);
  z-index: -1;
}

.theme-toggle:hover {
  color: white;
  border-color: var(--accent);
  transform: scale(1.02);
}

.theme-toggle:hover::before {
  opacity: 1;
}

.sidebar-credits {
  text-align: center;
  font-size: var(--font-size-xs);
  color: var(--text-muted);
}

.sidebar-credits strong {
  color: var(--primary);
  font-weight: 600;
}

/* 🌊 OVERLAY */
.sidebar-overlay {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100vh;
  background: var(--bg-overlay);
  z-index: 999;
  opacity: 0;
  visibility: hidden;
  transition: all var(--transition-normal);
  backdrop-filter: blur(4px);
}

.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;
  position: relative;
}

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

/* 🌟 HEADER ESPECTACULAR */
.header {
  background: var(--gradient-cosmic);
  background-size: 400% 400%;
  animation: gradientShift 8s ease infinite;
  color: white;
  padding: var(--spacing-3xl) var(--spacing-xl);
  position: relative;
  overflow: hidden;
  min-height: var(--header-height);
}

.header-background {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  pointer-events: none;
}

.header-particles {
  position: absolute;
  width: 100%;
  height: 100%;
  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='2'/%3E%3C/g%3E%3C/g%3E%3C/svg%3E") repeat;
  animation: particleMove 20s linear infinite;
}

.header-glow {
  position: absolute;
  top: 50%;
  left: 50%;
  width: 300px;
  height: 300px;
  background: radial-gradient(circle, rgba(255, 255, 255, 0.1) 0%, transparent 70%);
  transform: translate(-50%, -50%);
  animation: glow 4s ease-in-out infinite alternate;
}

.header-content {
  position: relative;
  z-index: 1;
  display: flex;
  align-items: center;
  justify-content: space-between;
  max-width: 1400px;
  margin: 0 auto;
}

.mobile-menu-toggle {
  display: none;
  background: rgba(255, 255, 255, 0.2);
  border: 1px solid rgba(255, 255, 255, 0.3);
  color: white;
  width: 48px;
  height: 48px;
  border-radius: var(--border-radius);
  cursor: pointer;
  transition: all var(--transition-fast);
  backdrop-filter: blur(10px);
}

.mobile-menu-toggle:hover {
  background: rgba(255, 255, 255, 0.3);
  transform: scale(1.05);
}

.header-text {
  flex: 1;
  text-align: center;
  max-width: 800px;
}

.header-title {
  font-family: var(--font-display);
  font-size: var(--font-size-5xl);
  font-weight: 800;
  margin-bottom: var(--spacing-lg);
  text-shadow: 0 4px 20px rgba(0, 0, 0, 0.3);
  line-height: 1.1;
}

.title-icon {
  display: inline-block;
  animation: bounce 2s infinite;
  margin-right: var(--spacing-sm);
}

.title-main {
  display: block;
  background: linear-gradient(45deg, #ffffff, #f0f9ff, #dbeafe);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.title-sub {
  display: block;
  font-size: var(--font-size-3xl);
  opacity: 0.9;
  font-weight: 600;
}

.header-subtitle {
  font-size: var(--font-size-lg);
  opacity: 0.9;
  font-weight: 400;
  line-height: 1.6;
  max-width: 600px;
  margin: 0 auto;
}

.header-actions {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-md);
  align-items: center;
}

/* 🔘 BOTONES MODERNOS */
.btn {
  display: inline-flex;
  align-items: center;
  gap: var(--spacing-sm);
  padding: var(--spacing-md) var(--spacing-xl);
  border: none;
  border-radius: var(--border-radius);
  font-family: var(--font-family);
  font-size: var(--font-size-sm);
  font-weight: 600;
  text-decoration: none;
  cursor: pointer;
  transition: all var(--transition-fast);
  white-space: nowrap;
  position: relative;
  overflow: hidden;
  backdrop-filter: blur(10px);
}

.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 var(--transition-normal);
}

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

.btn-large {
  padding: var(--spacing-lg) var(--spacing-2xl);
  font-size: var(--font-size-base);
}

.btn-primary {
  background: rgba(255, 255, 255, 0.2);
  color: white;
  border: 1px solid rgba(255, 255, 255, 0.3);
}

.btn-primary:hover {
  background: rgba(255, 255, 255, 0.3);
  transform: translateY(-2px);
  box-shadow: 0 10px 25px rgba(0, 0, 0, 0.2);
}

.btn-secondary {
  background: rgba(255, 255, 255, 0.1);
  color: white;
  border: 1px solid rgba(255, 255, 255, 0.2);
}

.btn-secondary:hover {
  background: rgba(255, 255, 255, 0.2);
  transform: translateY(-2px);
}

.btn-glass {
  background: var(--bg-glass);
  color: white;
  border: 1px solid rgba(255, 255, 255, 0.2);
  backdrop-filter: blur(20px);
}

.btn-glass:hover {
  background: rgba(255, 255, 255, 0.2);
  transform: translateY(-2px);
}

.btn-glow {
  box-shadow: var(--shadow-glow);
}

.btn-glow:hover {
  box-shadow: var(--shadow-glow), 0 10px 25px rgba(0, 0, 0, 0.2);
}

/* 📖 ÁREA DE CONTENIDO */
.content-area {
  flex: 1;
  padding: var(--spacing-2xl);
  position: relative;
}

/* 🏠 PÁGINA DE BIENVENIDA */
.welcome-container {
  max-width: 1200px;
  margin: 0 auto;
}

.welcome-hero {
  text-align: center;
  padding: var(--spacing-3xl) var(--spacing-xl);
  background: rgba(255, 255, 255, 0.8);
  backdrop-filter: blur(20px);
  border-radius: var(--border-radius-xl);
  border: 1px solid var(--border-color);
  box-shadow: var(--shadow-2xl);
  margin-bottom: var(--spacing-3xl);
  position: relative;
  overflow: hidden;
}

[data-theme="dark"] .welcome-hero {
  background: rgba(15, 23, 42, 0.8);
}

.welcome-hero::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: var(--gradient-primary);
  opacity: 0.05;
  z-index: -1;
}

.hero-content {
  position: relative;
  z-index: 1;
}

.hero-icon {
  width: 80px;
  height: 80px;
  background: var(--gradient-primary);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  margin: 0 auto var(--spacing-xl);
  box-shadow: var(--shadow-glow);
  animation: float 3s ease-in-out infinite;
}

.hero-icon i {
  font-size: var(--font-size-3xl);
  color: white;
}

.hero-title {
  font-family: var(--font-display);
  font-size: var(--font-size-4xl);
  font-weight: 800;
  color: var(--text-primary);
  margin-bottom: var(--spacing-lg);
  line-height: 1.2;
}

.hero-description {
  font-size: var(--font-size-lg);
  color: var(--text-secondary);
  line-height: 1.6;
  max-width: 600px;
  margin: 0 auto var(--spacing-2xl);
}

.hero-actions {
  display: flex;
  gap: var(--spacing-lg);
  justify-content: center;
  flex-wrap: wrap;
}

/* 📊 ESTADÍSTICAS */
.stats-section {
  margin-bottom: var(--spacing-3xl);
}

.course-stats {
  background: rgba(255, 255, 255, 0.9);
  backdrop-filter: blur(20px);
  border-radius: var(--border-radius-lg);
  padding: var(--spacing-2xl);
  border: 1px solid var(--border-color);
  box-shadow: var(--shadow-xl);
}

[data-theme="dark"] .course-stats {
  background: rgba(15, 23, 42, 0.9);
}

.stats-title {
  font-family: var(--font-display);
  font-size: var(--font-size-2xl);
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: var(--spacing-xl);
  text-align: center;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--spacing-md);
}

.stats-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: var(--spacing-lg);
}

.stats-card {
  text-align: center;
  padding: var(--spacing-xl);
  background: var(--gradient-primary);
  border-radius: var(--border-radius);
  color: white;
  box-shadow: var(--shadow-lg);
  transition: transform var(--transition-fast);
  position: relative;
  overflow: hidden;
}

.stats-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: linear-gradient(45deg, transparent 30%, rgba(255, 255, 255, 0.1) 50%, transparent 70%);
  transform: translateX(-100%);
  animation: shine 3s infinite;
}

.stats-card:hover {
  transform: translateY(-4px);
}

.stats-card span {
  display: block;
  font-size: var(--font-size-3xl);
  font-weight: 800;
  margin-bottom: var(--spacing-sm);
}

.stats-card small {
  font-size: var(--font-size-sm);
  opacity: 0.9;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

/* 🌟 DESTACADOS */
.highlights-section {
  margin-bottom: var(--spacing-3xl);
}

.section-title {
  font-family: var(--font-display);
  font-size: var(--font-size-2xl);
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: var(--spacing-xl);
  text-align: center;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--spacing-md);
}

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

.highlight-card {
  background: rgba(255, 255, 255, 0.9);
  backdrop-filter: blur(20px);
  border-radius: var(--border-radius-lg);
  padding: var(--spacing-xl);
  border: 1px solid var(--border-color);
  box-shadow: var(--shadow-lg);
  transition: all var(--transition-fast);
  cursor: pointer;
  position: relative;
  overflow: hidden;
}

[data-theme="dark"] .highlight-card {
  background: rgba(15, 23, 42, 0.9);
}

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

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

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

.card-icon {
  width: 60px;
  height: 60px;
  background: var(--gradient-primary);
  border-radius: var(--border-radius);
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: var(--spacing-lg);
  box-shadow: var(--shadow-md);
}

.highlight-icon {
  font-size: var(--font-size-xl);
  color: white;
}

.card-content h4 {
  font-family: var(--font-display);
  font-size: var(--font-size-lg);
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: var(--spacing-sm);
}

.card-content p {
  color: var(--text-secondary);
  line-height: 1.6;
  font-size: var(--font-size-sm);
}

.card-arrow {
  margin-top: var(--spacing-lg);
  color: var(--primary);
  opacity: 0;
  transform: translateX(-10px);
  transition: all var(--transition-fast);
}

.highlight-card:hover .card-arrow {
  opacity: 1;
  transform: translateX(0);
}

/* 🎯 CARACTERÍSTICAS */
.features-section {
  margin-bottom: var(--spacing-3xl);
}

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

.feature-card {
  background: rgba(255, 255, 255, 0.9);
  backdrop-filter: blur(20px);
  border-radius: var(--border-radius-lg);
  padding: var(--spacing-2xl);
  border: 1px solid var(--border-color);
  box-shadow: var(--shadow-lg);
  text-align: center;
  transition: all var(--transition-fast);
  position: relative;
  overflow: hidden;
}

[data-theme="dark"] .feature-card {
  background: rgba(15, 23, 42, 0.9);
}

.feature-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: var(--gradient-primary);
  opacity: 0;
  transition: opacity var(--transition-fast);
  z-index: -1;
}

.feature-card:hover {
  transform: translateY(-8px);
  color: white;
  box-shadow: var(--shadow-2xl);
}

.feature-card:hover::before {
  opacity: 1;
}

.feature-icon {
  width: 80px;
  height: 80px;
  background: var(--gradient-primary);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  margin: 0 auto var(--spacing-lg);
  box-shadow: var(--shadow-lg);
  transition: all var(--transition-fast);
}

.feature-card:hover .feature-icon {
  background: rgba(255, 255, 255, 0.2);
  transform: scale(1.1);
}

.feature-icon i {
  font-size: var(--font-size-2xl);
  color: white;
}

.feature-card h4 {
  font-family: var(--font-display);
  font-size: var(--font-size-lg);
  font-weight: 600;
  margin-bottom: var(--spacing-md);
  color: var(--text-primary);
  transition: color var(--transition-fast);
}

.feature-card:hover h4 {
  color: white;
}

.feature-card p {
  color: var(--text-secondary);
  line-height: 1.6;
  transition: color var(--transition-fast);
}

.feature-card:hover p {
  color: rgba(255, 255, 255, 0.9);
}

/* 🦶 FOOTER MODERNO */
.footer {
  background: var(--bg-secondary);
  border-top: 1px solid var(--border-color);
  padding: var(--spacing-3xl) var(--spacing-xl) var(--spacing-xl);
  margin-top: auto;
  position: relative;
}

.footer::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 4px;
  background: var(--gradient-primary);
}

.footer-content {
  max-width: 1200px;
  margin: 0 auto;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: var(--spacing-2xl);
}

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

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

.instructor-card {
  background: rgba(255, 255, 255, 0.8);
  backdrop-filter: blur(10px);
  border-radius: var(--border-radius);
  padding: var(--spacing-lg);
  border: 1px solid var(--border-color);
  transition: all var(--transition-fast);
}

[data-theme="dark"] .instructor-card {
  background: rgba(15, 23, 42, 0.8);
}

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

.instructor-avatar {
  width: 60px;
  height: 60px;
  background: var(--gradient-primary);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: var(--spacing-md);
  box-shadow: var(--shadow-md);
}

.instructor-avatar i {
  font-size: var(--font-size-xl);
  color: white;
}

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

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

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

.contact-link {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
  color: var(--text-secondary);
  text-decoration: none;
  padding: var(--spacing-sm) var(--spacing-md);
  border-radius: var(--border-radius-sm);
  transition: all var(--transition-fast);
  border: 1px solid transparent;
}

.contact-link:hover {
  color: var(--primary);
  background: var(--bg-primary);
  border-color: var(--primary);
  transform: translateX(4px);
}

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

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

.footer-link {
  color: var(--text-secondary);
  text-decoration: none;
  padding: var(--spacing-xs) var(--spacing-sm);
  border-radius: var(--border-radius-sm);
  transition: all var(--transition-fast);
  display: inline-block;
}

.footer-link:hover {
  color: var(--primary);
  background: var(--bg-primary);
  transform: translateX(4px);
}

.course-info {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-md);
}

.info-item {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
  padding: var(--spacing-sm);
  background: var(--bg-primary);
  border-radius: var(--border-radius-sm);
  border: 1px solid var(--border-color);
  transition: all var(--transition-fast);
}

.info-item:hover {
  transform: scale(1.02);
  box-shadow: var(--shadow-sm);
}

.info-item i {
  color: var(--primary);
  width: 20px;
  text-align: center;
}

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

.footer-bottom-content {
  color: var(--text-muted);
}

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

.footer-tagline {
  margin-top: var(--spacing-sm);
  font-size: var(--font-size-sm);
  opacity: 0.8;
}

/* 📖 CONTENIDO DE LECCIONES */
.lesson-header {
  background: rgba(255, 255, 255, 0.9);
  backdrop-filter: blur(20px);
  padding: var(--spacing-2xl);
  margin-bottom: var(--spacing-xl);
  border-radius: var(--border-radius-lg);
  box-shadow: var(--shadow-xl);
  border: 1px solid var(--border-color);
  position: relative;
  overflow: hidden;
}

[data-theme="dark"] .lesson-header {
  background: rgba(15, 23, 42, 0.9);
}

.lesson-header::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 6px;
  height: 100%;
  background: var(--gradient-primary);
}

.lesson-header h2 {
  font-family: var(--font-display);
  font-size: var(--font-size-3xl);
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: var(--spacing-md);
  display: flex;
  align-items: center;
  gap: var(--spacing-md);
}

.lesson-header h2 i {
  color: var(--primary);
}

.lesson-meta {
  display: flex;
  flex-wrap: wrap;
  gap: var(--spacing-lg);
  margin-bottom: var(--spacing-lg);
}

.lesson-meta span {
  display: flex;
  align-items: center;
  gap: var(--spacing-xs);
  font-size: var(--font-size-sm);
  color: var(--text-muted);
  background: var(--bg-tertiary);
  padding: var(--spacing-xs) var(--spacing-sm);
  border-radius: var(--border-radius-sm);
}

.badge-sim {
  background: var(--gradient-accent) !important;
  color: white !important;
  font-weight: 600;
  animation: pulse 2s infinite;
}

.lesson-desc {
  color: var(--text-secondary);
  font-size: var(--font-size-base);
  line-height: 1.6;
}

.lesson-content {
  background: rgba(255, 255, 255, 0.9);
  backdrop-filter: blur(20px);
  padding: var(--spacing-2xl);
  border-radius: var(--border-radius-lg);
  box-shadow: var(--shadow-lg);
  border: 1px solid var(--border-color);
  line-height: 1.7;
}

[data-theme="dark"] .lesson-content {
  background: rgba(15, 23, 42, 0.9);
}

.lesson-content h1,
.lesson-content h2,
.lesson-content h3,
.lesson-content h4,
.lesson-content h5,
.lesson-content h6 {
  font-family: var(--font-display);
  color: var(--text-primary);
  margin: var(--spacing-xl) 0 var(--spacing-md);
  font-weight: 600;
}

.lesson-content h1 { font-size: var(--font-size-3xl); }
.lesson-content h2 { font-size: var(--font-size-2xl); }
.lesson-content h3 { font-size: var(--font-size-xl); }
.lesson-content h4 { font-size: var(--font-size-lg); }

.lesson-content p {
  margin-bottom: var(--spacing-lg);
  color: var(--text-secondary);
}

.lesson-content ul,
.lesson-content ol {
  margin: var(--spacing-lg) 0;
  padding-left: var(--spacing-xl);
}

.lesson-content li {
  margin-bottom: var(--spacing-sm);
  color: var(--text-secondary);
}

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

.lesson-content pre {
  background: var(--bg-tertiary);
  border: 1px solid var(--border-color);
  border-radius: var(--border-radius);
  padding: var(--spacing-lg);
  margin: var(--spacing-lg) 0;
  overflow-x: auto;
  font-family: var(--font-mono);
  font-size: var(--font-size-sm);
  line-height: 1.5;
}

.lesson-content blockquote {
  border-left: 4px solid var(--primary);
  background: var(--bg-tertiary);
  padding: var(--spacing-lg);
  margin: var(--spacing-lg) 0;
  border-radius: 0 var(--border-radius-sm) var(--border-radius-sm) 0;
  color: var(--text-secondary);
  font-style: italic;
}

/* ❌ MENSAJES DE ERROR */
.error-message {
  background: rgba(248, 113, 113, 0.1);
  border: 1px solid var(--danger);
  border-radius: var(--border-radius);
  padding: var(--spacing-xl);
  margin: var(--spacing-xl) 0;
  text-align: center;
}

.error-message h3 {
  color: var(--danger);
  font-family: var(--font-display);
  font-size: var(--font-size-lg);
  margin-bottom: var(--spacing-md);
}

.error-message p {
  color: var(--text-secondary);
  margin-bottom: var(--spacing-sm);
}

.error-message code {
  background: rgba(248, 113, 113, 0.2);
  color: var(--danger);
}

/* ✨ ANIMACIONES AVANZADAS */
@keyframes logoSpin {
  0%, 100% { transform: rotate(0deg) scale(1); }
  50% { transform: rotate(180deg) scale(1.1); }
}

@keyframes bounce {
  0%, 20%, 53%, 80%, 100% { transform: translateY(0); }
  40%, 43% { transform: translateY(-10px); }
  70% { transform: translateY(-5px); }
  90% { transform: translateY(-2px); }
}

@keyframes shine {
  0% { transform: translateX(-100%); }
  100% { transform: translateX(100%); }
}

@keyframes particleMove {
  0% { transform: translateX(0) translateY(0); }
  100% { transform: translateX(-60px) translateY(-60px); }
}

@keyframes glow {
  0% { opacity: 0.1; transform: translate(-50%, -50%) scale(1); }
  100% { opacity: 0.2; transform: translate(-50%, -50%) scale(1.2); }
}

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

@keyframes slideInLeft {
  from {
    transform: translateX(-100%);
    opacity: 0;
  }
  to {
    transform: translateX(0);
    opacity: 1;
  }
}

@keyframes zoomIn {
  from {
    transform: scale(0.8);
    opacity: 0;
  }
  to {
    transform: scale(1);
    opacity: 1;
  }
}

/* 📱 RESPONSIVE DESIGN */
@media (max-width: 1200px) {
  :root {
    --sidebar-width: 280px;
    --font-size-5xl: 2.5rem;
    --font-size-4xl: 2rem;
  }
  
  .header-title {
    font-size: var(--font-size-4xl);
  }
  
  .features-grid {
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  }
}

@media (max-width: 1024px) {
  .header {
    padding: var(--spacing-2xl) var(--spacing-lg);
  }
  
  .content-area {
    padding: var(--spacing-xl);
  }
  
  .welcome-hero {
    padding: var(--spacing-2xl) var(--spacing-lg);
  }
  
  .stats-grid {
    grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
  }
}

@media (max-width: 768px) {
  :root {
    --sidebar-width: 280px;
    --font-size-5xl: 2rem;
    --font-size-4xl: 1.75rem;
    --font-size-3xl: 1.5rem;
  }
  
  .sidebar {
    transform: translateX(-100%);
    z-index: 1001;
  }
  
  .sidebar.open {
    transform: translateX(0);
  }
  
  .main-content {
    margin-left: 0;
  }
  
  .mobile-menu-toggle {
    display: flex;
  }
  
  .header-content {
    flex-direction: column;
    text-align: center;
    gap: var(--spacing-xl);
    position: relative;
  }
  
  .mobile-menu-toggle {
    position: absolute;
    top: var(--spacing-lg);
    left: var(--spacing-lg);
  }
  
  .header-text {
    order: 1;
    margin-top: var(--spacing-xl);
  }
  
  .header-actions {
    order: 2;
    flex-direction: row;
    justify-content: center;
  }
  
  .title-main,
  .title-sub {
    display: inline;
  }
  
  .header-title {
    font-size: var(--font-size-3xl);
  }
  
  .header-subtitle {
    font-size: var(--font-size-base);
  }
  
  .content-area {
    padding: var(--spacing-lg);
  }
  
  .welcome-hero {
    padding: var(--spacing-xl) var(--spacing-md);
  }
  
  .hero-title {
    font-size: var(--font-size-2xl);
  }
  
  .hero-actions {
    flex-direction: column;
    align-items: center;
  }
  
  .features-grid {
    grid-template-columns: 1fr;
  }
  
  .physics-highlights {
    grid-template-columns: 1fr;
  }
  
  .footer-content {
    grid-template-columns: 1fr;
    gap: var(--spacing-xl);
  }
  
  .contact-links {
    flex-direction: column;
  }
  
  .lesson-header {
    padding: var(--spacing-lg);
  }
  
  .lesson-header h2 {
    font-size: var(--font-size-xl);
    flex-direction: column;
    align-items: flex-start;
    gap: var(--spacing-sm);
  }
  
  .lesson-content {
    padding: var(--spacing-lg);
  }
  
  .lesson-meta {
    flex-direction: column;
    gap: var(--spacing-sm);
  }
}

@media (max-width: 480px) {
  .header {
    padding: var(--spacing-xl) var(--spacing-md);
  }
  
  .content-area {
    padding: var(--spacing-md);
  }
  
  .welcome-hero {
    padding: var(--spacing-lg) var(--spacing-md);
  }
  
  .footer {
    padding: var(--spacing-xl) var(--spacing-md) var(--spacing-lg);
  }
  
  .hero-title {
    font-size: var(--font-size-xl);
  }
  
  .hero-description {
    font-size: var(--font-size-base);
  }
  
  .btn-large {
    padding: var(--spacing-md) var(--spacing-lg);
    font-size: var(--font-size-sm);
  }
  
  .stats-grid {
    grid-template-columns: 1fr;
  }
  
  .hero-actions {
    gap: var(--spacing-md);
  }
  
  .lesson-header,
  .lesson-content {
    padding: var(--spacing-md);
  }
}

/* 🔍 UTILIDADES */
.text-center { text-align: center; }
.text-left { text-align: left; }
.text-right { text-align: right; }

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

.bg-primary { background: var(--bg-primary); }
.bg-secondary { background: var(--bg-secondary); }
.bg-tertiary { background: var(--bg-tertiary); }

.hidden { display: none !important; }
.visible { display: block !important; }

.mb-0 { margin-bottom: 0 !important; }
.mb-sm { margin-bottom: var(--spacing-sm) !important; }
.mb-md { margin-bottom: var(--spacing-md) !important; }
.mb-lg { margin-bottom: var(--spacing-lg) !important; }
.mb-xl { margin-bottom: var(--spacing-xl) !important; }

.mt-0 { margin-top: 0 !important; }
.mt-sm { margin-top: var(--spacing-sm) !important; }
.mt-md { margin-top: var(--spacing-md) !important; }
.mt-lg { margin-top: var(--spacing-lg) !important; }
.mt-xl { margin-top: var(--spacing-xl) !important; }

/* 🎯 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: 0;
}

/* Focus visible para navegación por teclado */
.menu-item:focus-visible,
.btn:focus-visible,
.theme-toggle:focus-visible,
.sidebar-toggle:focus-visible,
.mobile-menu-toggle:focus-visible {
  outline: 2px solid var(--primary);
  outline-offset: 2px;
  box-shadow: 0 0 0 4px rgba(102, 126, 234, 0.3);
}

/* Respeto por preferencias de movimiento reducido */
@media (prefers-reduced-motion: reduce) {
  * {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
  
  .loader-orbit,
  .loader-particles span,
  .shape {
    animation: none !important;
  }
}

/* Alto contraste */
@media (prefers-contrast: high) {
  :root {
    --border-color: #000000;
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.3);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.3);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.3);
  }
  
  .btn {
    border: 2px solid currentColor;
  }
}



.loader-quote {
  font-family: 'Merriweather', serif;
  font-style: italic;
  font-size: 1em;
  color: #4b5563;
  margin-top: 1em;
  text-align: center;
  max-width: 80%;
  margin-left: auto;
  margin-right: auto;
}


/* === Estilo del emoji animado del loader === */
.loader-emoji {
  font-size: 80px;
  text-align: center;
  margin-bottom: 20px;
  animation: bounce 1.8s infinite;
}

/* === Animación suave para rebote del emoji === */
@keyframes bounce {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-10px); }
}

/* ================================================
   🎯 VERSIÓN LIMPIA DEL ENCABEZADO - ESTILO PERSONALIZADO
   Este bloque oculta elementos visuales no esenciales como:
   - Botones de acción "Comenzar Curso" y "Simulaciones"
   - Subtítulo animado del encabezado principal
   Ideal para una presentación más sobria o institucional.
   ================================================= */

/* 🔘 Oculta los botones de acción del encabezado */
.header-actions {
  display: none !important; /* ❌ Botones ocultos completamente */
}

/* 📝 Oculta la descripción con emojis debajo del título principal */
.header-subtitle {
  display: none !important; /* 🚫 Elimina la frase "Aprende física de manera interactiva..." */
}


/* ===========================================
   🧩 OCULTAR BOTÓN DE MENÚ LATERAL
   Este botón aparece en la cabecera del sidebar
   =========================================== */
.sidebar-toggle {
  display: none !important;
}

/* ===========================================
   🚀 AUMENTAR TAMAÑO DE LOGO EN SIDEBAR
   Mejora visual del ícono y texto de "Física Interactiva"
   =========================================== */
.logo {
  display: flex;
  align-items: center;
  gap: var(--spacing-md);
  font-size: 1.4rem; /* ⬅️ Aumenta el tamaño del texto */
  font-weight: 700;
  color: white;
}

.logo i, .logo svg {
  font-size: 2rem; /* ⬅️ Aumenta el tamaño del ícono */
  line-height: 1;
  animation: logoSpin 6s ease-in-out infinite; /* Conserva la animación */
}


/* ===========================================
   🧮 CONTENEDORES INTERACTIVOS PARA GEOGEBRA
   Solución para problemas de interactividad
   =========================================== */

/* Contenedor principal para iframes interactivos */
.iframe-container-interactive {
  position: relative;
  z-index: 9999;
  isolation: isolate;
  background: white;
  padding: 15px;
  border-radius: var(--border-radius);
  margin: var(--spacing-xl) 0;
  box-shadow: var(--shadow-xl);
  border: 1px solid var(--border-color);
  transition: all var(--transition-normal);
}

/* Tema oscuro para el contenedor */
[data-theme="dark"] .iframe-container-interactive {
  background: var(--bg-secondary);
  border-color: var(--border-color);
}

/* Hover effect para el contenedor */
.iframe-container-interactive:hover {
  box-shadow: var(--shadow-2xl);
  transform: translateY(-2px);
}

/* Iframe específico dentro del contenedor */
.iframe-container-interactive iframe {
  border: 0;
  pointer-events: auto;
  position: relative;
  z-index: 1000;
  display: block;
  width: 100%;
  border-radius: var(--border-radius-sm);
  background: white;
}

/* Título opcional para el iframe */
.iframe-container-interactive .iframe-title {
  font-family: var(--font-display);
  font-size: var(--font-size-lg);
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: var(--spacing-md);
  text-align: center;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--spacing-sm);
}

/* Botones de control para iframe */
.iframe-controls {
  display: flex;
  justify-content: center;
  gap: var(--spacing-md);
  margin-top: var(--spacing-md);
  flex-wrap: wrap;
}

.iframe-btn {
  background: var(--gradient-primary);
  color: white;
  border: none;
  padding: var(--spacing-sm) var(--spacing-lg);
  border-radius: var(--border-radius);
  font-size: var(--font-size-sm);
  font-weight: 600;
  cursor: pointer;
  transition: all var(--transition-fast);
  box-shadow: var(--shadow-md);
  display: flex;
  align-items: center;
  gap: var(--spacing-xs);
}

.iframe-btn:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-lg);
  background: var(--gradient-accent);
}

/* Responsive para contenedores interactivos */
@media (max-width: 768px) {
  .iframe-container-interactive {
    padding: var(--spacing-md);
    margin: var(--spacing-lg) 0;
  }
  
  .iframe-container-interactive iframe {
    height: 450px !important;
  }
  
  .iframe-controls {
    flex-direction: column;
    align-items: center;
  }
  
  .iframe-btn {
    width: 200px;
    justify-content: center;
  }
}


/* Transicciones adicionales

@keyframes fadeInUp {
  from { opacity: 0; transform: translateY(30px);}
  to   { opacity: 1; transform: translateY(0);}
}
@keyframes slideInUp {
  from { opacity: 0; transform: translateY(40px);}
  to   { opacity: 1; transform: translateY(0);}
}
@keyframes globeSpin {
  from { transform: rotateY(0deg);}
  to   { transform: rotateY(360deg);}
}
.card, .sistema-ref-card-enhanced {
  transition: box-shadow 0.4s, transform 0.4s;
}
.card:hover, .sistema-ref-card-enhanced:hover {
  box-shadow: 0 20px 50px rgba(245, 158, 11, 0.15);
  transform: translateY(-8px) scale(1.02);
}
.card ul li, .sistema-ref-card-enhanced ul li {
  transition: transform 0.24s, box-shadow 0.24s;
}
.card ul li:hover, .sistema-ref-card-enhanced ul li:hover {
  transform: scale(1.07);
  box-shadow: 0 4px 22px #fbbf2433;
}

.text-primary { color: var(--primary) !important; }
.text-primary-dark { color: var(--primary-dark) !important; }
.text-accent { color: var(--accent) !important; }
.text-warning { color: var(--warning) !important; }
.text-danger { color: var(--danger) !important; }
.text-secondary-dark { color: var(--secondary-dark) !important; }
.bg-warning { background: var(--warning) !important; }
.bg-accent { background: var(--accent) !important; }
/* Agrega las que necesites */