/* ===== VARIABLES CSS ===== */
:root {
  /* Colores principales */
  --primary-color: #FF6B35;
  --secondary-color: #2C3E50;
  --accent-color: #F39C12;
  --success-color: #27AE60;
  --warning-color: #F39C12;
  --error-color: #E74C3C;
  --info-color: #3498DB;
  
  /* Colores neutros */
  --white: #FFFFFF;
  --light-gray: #ECF0F1;
  --medium-gray: #BDC3C7;
  --dark-gray: #34495E;
  --black: #2C3E50;
  
  /* Gradientes */
  --primary-gradient: linear-gradient(135deg, #FF6B35 0%, #F39C12 100%);
  --secondary-gradient: linear-gradient(135deg, #2C3E50 0%, #34495E 100%);
  --hero-gradient: linear-gradient(135deg, rgba(255, 107, 53, 0.9) 0%, rgba(243, 156, 18, 0.9) 100%);
  
  /* Tipografía */
  --font-primary: 'Poppins', sans-serif;
  --font-secondary: 'Open Sans', sans-serif;
  
  /* Tamaños de fuente */
  --fs-xs: 0.75rem;
  --fs-sm: 0.875rem;
  --fs-base: 1rem;
  --fs-lg: 1.125rem;
  --fs-xl: 1.25rem;
  --fs-2xl: 1.5rem;
  --fs-3xl: 1.875rem;
  --fs-4xl: 2.25rem;
  --fs-5xl: 3rem;
  --fs-6xl: 3.75rem;
  
  /* 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;
  --spacing-4xl: 6rem;
  
  /* Bordes */
  --border-radius-sm: 0.375rem;
  --border-radius-md: 0.5rem;
  --border-radius-lg: 0.75rem;
  --border-radius-xl: 1rem;
  --border-radius-full: 9999px;
  
  /* Sombras */
  --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);
  
  /* Transiciones */
  --transition-fast: 0.15s ease-in-out;
  --transition-normal: 0.3s ease-in-out;
  --transition-slow: 0.5s ease-in-out;
  
  /* Contenedor máximo */
  --container-max-width: 1200px;
}

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

html {
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-secondary);
  font-size: var(--fs-base);
  line-height: 1.6;
  color: var(--dark-gray);
  background-color: var(--white);
  overflow-x: hidden;
}

/* ===== TIPOGRAFÍA ===== */
h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-primary);
  font-weight: 600;
  line-height: 1.2;
  margin-bottom: var(--spacing-md);
  color: var(--secondary-color);
}

h1 { font-size: var(--fs-5xl); }
h2 { font-size: var(--fs-4xl); }
h3 { font-size: var(--fs-3xl); }
h4 { font-size: var(--fs-2xl); }
h5 { font-size: var(--fs-xl); }
h6 { font-size: var(--fs-lg); }

p {
  margin-bottom: var(--spacing-md);
  line-height: 1.7;
}

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

a:hover {
  color: var(--accent-color);
}

/* ===== UTILIDADES ===== */
.container {
  max-width: var(--container-max-width);
  margin: 0 auto;
  padding: 0 var(--spacing-md);
}

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

.highlight {
  background: var(--primary-gradient);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

/* ===== BOTONES ===== */
.btn {
  display: inline-flex;
  align-items: center;
  gap: var(--spacing-sm);
  padding: var(--spacing-md) var(--spacing-xl);
  font-family: var(--font-primary);
  font-weight: 500;
  font-size: var(--fs-base);
  border: none;
  border-radius: var(--border-radius-md);
  cursor: pointer;
  text-decoration: none;
  transition: var(--transition-normal);
  position: relative;
  overflow: hidden;
}

.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: var(--transition-slow);
}

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

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

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

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

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

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

.btn-outline:hover {
  background: var(--primary-color);
  color: var(--white);
  transform: translateY(-2px);
}

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

.btn-danger:hover {
  background: #C0392B;
  transform: translateY(-2px);
}

.btn-small {
  padding: var(--spacing-sm) var(--spacing-md);
  font-size: var(--fs-sm);
}

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

.btn-icon {
  width: 40px;
  height: 40px;
  padding: 0;
  border-radius: var(--border-radius-full);
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--light-gray);
  color: var(--dark-gray);
  border: none;
  cursor: pointer;
  transition: var(--transition-fast);
}

.btn-icon:hover {
  background: var(--primary-color);
  color: var(--white);
  transform: scale(1.1);
}

/* ===== HEADER Y NAVEGACIÓN ===== */
.header {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  background: rgba(255, 255, 255, 0.95);
  backdrop-filter: blur(10px);
  box-shadow: var(--shadow-sm);
  z-index: 1000;
  transition: var(--transition-normal);
}

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

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

.nav-brand .brand-link {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
  font-family: var(--font-primary);
  font-size: var(--fs-2xl);
  font-weight: 700;
  color: var(--secondary-color);
  text-decoration: none;
}

.nav-brand i {
  color: var(--primary-color);
  font-size: var(--fs-3xl);
}

.nav-menu {
  display: flex;
}

.nav-list {
  display: flex;
  list-style: none;
  gap: var(--spacing-xl);
  margin: 0;
  padding: 0;
}

.nav-link {
  display: flex;
  align-items: center;
  gap: var(--spacing-xs);
  padding: var(--spacing-sm) var(--spacing-md);
  font-family: var(--font-primary);
  font-weight: 500;
  color: var(--dark-gray);
  text-decoration: none;
  border-radius: var(--border-radius-md);
  transition: var(--transition-fast);
  position: relative;
}

.nav-link::after {
  content: '';
  position: absolute;
  bottom: -2px;
  left: 50%;
  width: 0;
  height: 2px;
  background: var(--primary-gradient);
  transition: var(--transition-normal);
  transform: translateX(-50%);
}

.nav-link:hover,
.nav-link.active {
  color: var(--primary-color);
  background: rgba(255, 107, 53, 0.1);
}

.nav-link:hover::after,
.nav-link.active::after {
  width: 80%;
}

.nav-toggle {
  display: none;
  flex-direction: column;
  cursor: pointer;
  gap: 4px;
}

.nav-toggle .bar {
  width: 25px;
  height: 3px;
  background: var(--secondary-color);
  border-radius: var(--border-radius-sm);
  transition: var(--transition-fast);
}

/* ===== MAIN CONTENT ===== */
.main-content {
  margin-top: 80px;
  min-height: calc(100vh - 80px);
}

/* ===== HERO SECTION ===== */
.hero {
  position: relative;
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
}

.hero-background {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: linear-gradient(135deg, #FF6B35 0%, #F39C12 50%, #E74C3C 100%);
  z-index: -2;
}

.hero-background::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: url('data:image/svg+xml,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 100 100"><defs><pattern id="grid" width="10" height="10" patternUnits="userSpaceOnUse"><path d="M 10 0 L 0 0 0 10" fill="none" stroke="rgba(255,255,255,0.1)" stroke-width="0.5"/></pattern></defs><rect width="100" height="100" fill="url(%23grid)"/></svg>');
  animation: float 20s ease-in-out infinite;
}

.hero-overlay {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: rgba(44, 62, 80, 0.3);
  z-index: -1;
}

.hero-content {
  text-align: center;
  color: var(--white);
  max-width: 800px;
  z-index: 1;
}

.hero-title {
  font-size: var(--fs-6xl);
  font-weight: 700;
  margin-bottom: var(--spacing-lg);
  text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.3);
  animation: fadeInUp 1s ease-out;
}

.hero-description {
  font-size: var(--fs-xl);
  margin-bottom: var(--spacing-2xl);
  opacity: 0.95;
  animation: fadeInUp 1s ease-out 0.2s both;
}

.hero-buttons {
  display: flex;
  gap: var(--spacing-lg);
  justify-content: center;
  flex-wrap: wrap;
  animation: fadeInUp 1s ease-out 0.4s both;
}

/* ===== PAGE HERO ===== */
.page-hero {
  background: var(--secondary-gradient);
  color: var(--white);
  padding: var(--spacing-4xl) 0 var(--spacing-3xl);
  text-align: center;
  position: relative;
  overflow: hidden;
}

.page-hero::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: url('data:image/svg+xml,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 100 100"><circle cx="50" cy="50" r="2" fill="rgba(255,255,255,0.1)"/></svg>');
  animation: float 15s ease-in-out infinite;
}

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

.page-title {
  font-size: var(--fs-5xl);
  margin-bottom: var(--spacing-md);
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--spacing-md);
}

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

.page-description {
  font-size: var(--fs-lg);
  opacity: 0.9;
  max-width: 600px;
  margin: 0 auto;
}

/* ===== SECCIONES ===== */
section {
  padding: var(--spacing-4xl) 0;
}

.section-header {
  text-align: center;
  margin-bottom: var(--spacing-3xl);
}

.section-title {
  font-size: var(--fs-4xl);
  margin-bottom: var(--spacing-md);
  position: relative;
}

.section-title::after {
  content: '';
  position: absolute;
  bottom: -10px;
  left: 50%;
  width: 60px;
  height: 4px;
  background: var(--primary-gradient);
  border-radius: var(--border-radius-full);
  transform: translateX(-50%);
}

.section-description {
  font-size: var(--fs-lg);
  color: var(--medium-gray);
  max-width: 600px;
  margin: 0 auto;
}

/* ===== SERVICIOS ===== */
.services {
  background: var(--light-gray);
}

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

.service-card {
  background: var(--white);
  padding: var(--spacing-2xl);
  border-radius: var(--border-radius-lg);
  box-shadow: var(--shadow-md);
  text-align: center;
  transition: var(--transition-normal);
  position: relative;
  overflow: hidden;
}

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

.service-card:hover {
  transform: translateY(-10px);
  box-shadow: var(--shadow-xl);
}

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

.service-icon {
  width: 80px;
  height: 80px;
  margin: 0 auto var(--spacing-lg);
  background: var(--primary-gradient);
  border-radius: var(--border-radius-full);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: var(--fs-3xl);
  color: var(--white);
  box-shadow: var(--shadow-md);
}

.service-title {
  font-size: var(--fs-2xl);
  margin-bottom: var(--spacing-md);
  color: var(--secondary-color);
}

.service-description {
  color: var(--dark-gray);
  margin-bottom: var(--spacing-lg);
  line-height: 1.6;
}

.service-link {
  display: inline-flex;
  align-items: center;
  gap: var(--spacing-sm);
  color: var(--primary-color);
  font-weight: 600;
  text-decoration: none;
  transition: var(--transition-fast);
}

.service-link:hover {
  color: var(--accent-color);
  transform: translateX(5px);
}

/* ===== ESTADÍSTICAS ===== */
.stats {
  background: var(--secondary-gradient);
  color: var(--white);
}

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

.stat-item {
  text-align: center;
  padding: var(--spacing-xl);
}

.stat-number {
  font-size: var(--fs-5xl);
  font-weight: 700;
  color: var(--primary-color);
  margin-bottom: var(--spacing-sm);
  font-family: var(--font-primary);
}

.stat-label {
  font-size: var(--fs-lg);
  opacity: 0.9;
}

/* ===== CALCULADORA IMC ===== */
.bmi-calculator {
  background: var(--light-gray);
}

.bmi-content {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--spacing-3xl);
  align-items: center;
}

.bmi-form {
  background: var(--white);
  padding: var(--spacing-2xl);
  border-radius: var(--border-radius-lg);
  box-shadow: var(--shadow-md);
}

.bmi-result {
  background: var(--white);
  padding: var(--spacing-2xl);
  border-radius: var(--border-radius-lg);
  box-shadow: var(--shadow-md);
  text-align: center;
}

.bmi-value {
  display: flex;
  align-items: baseline;
  justify-content: center;
  gap: var(--spacing-sm);
  margin-bottom: var(--spacing-md);
}

.bmi-number {
  font-size: var(--fs-6xl);
  font-weight: 700;
  color: var(--primary-color);
  font-family: var(--font-primary);
}

.bmi-unit {
  font-size: var(--fs-lg);
  color: var(--medium-gray);
}

.bmi-category {
  font-size: var(--fs-2xl);
  font-weight: 600;
  margin-bottom: var(--spacing-sm);
}

.bmi-description {
  color: var(--dark-gray);
}

/* ===== TESTIMONIOS ===== */
.testimonials-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: var(--spacing-xl);
}

.testimonial-card {
  background: var(--white);
  padding: var(--spacing-2xl);
  border-radius: var(--border-radius-lg);
  box-shadow: var(--shadow-md);
  transition: var(--transition-normal);
}

.testimonial-card:hover {
  transform: translateY(-5px);
  box-shadow: var(--shadow-lg);
}

.testimonial-stars {
  display: flex;
  gap: var(--spacing-xs);
  margin-bottom: var(--spacing-md);
  color: var(--accent-color);
}

.testimonial-text {
  font-style: italic;
  margin-bottom: var(--spacing-lg);
  color: var(--dark-gray);
  line-height: 1.6;
}

.testimonial-author {
  display: flex;
  align-items: center;
  gap: var(--spacing-md);
}

.author-avatar {
  width: 50px;
  height: 50px;
  background: var(--primary-gradient);
  border-radius: var(--border-radius-full);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--white);
  font-size: var(--fs-lg);
}

.author-name {
  font-weight: 600;
  color: var(--secondary-color);
  margin-bottom: var(--spacing-xs);
}

.author-role {
  color: var(--medium-gray);
  font-size: var(--fs-sm);
}

/* ===== CALL TO ACTION ===== */
.cta {
  background: var(--primary-gradient);
  color: var(--white);
  text-align: center;
  position: relative;
  overflow: hidden;
}

.cta::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: url('data:image/svg+xml,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 100 100"><polygon points="0,0 100,0 80,100 0,100" fill="rgba(255,255,255,0.05)"/></svg>');
  animation: float 25s ease-in-out infinite;
}

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

.cta-title {
  font-size: var(--fs-4xl);
  margin-bottom: var(--spacing-md);
  text-shadow: 1px 1px 2px rgba(0, 0, 0, 0.2);
}

.cta-description {
  font-size: var(--fs-lg);
  margin-bottom: var(--spacing-2xl);
  opacity: 0.95;
  max-width: 600px;
  margin-left: auto;
  margin-right: auto;
}

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

/* ===== FORMULARIOS ===== */
.form-group {
  margin-bottom: var(--spacing-lg);
}

.form-group label {
  display: block;
  margin-bottom: var(--spacing-sm);
  font-weight: 600;
  color: var(--secondary-color);
}

.form-group input,
.form-group select,
.form-group textarea {
  width: 100%;
  padding: var(--spacing-md);
  border: 2px solid var(--light-gray);
  border-radius: var(--border-radius-md);
  font-size: var(--fs-base);
  font-family: var(--font-secondary);
  transition: var(--transition-fast);
  background: var(--white);
}

.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus {
  outline: none;
  border-color: var(--primary-color);
  box-shadow: 0 0 0 3px rgba(255, 107, 53, 0.1);
}

.form-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: var(--spacing-lg);
}

.form-actions {
  display: flex;
  gap: var(--spacing-md);
  justify-content: center;
  flex-wrap: wrap;
  margin-top: var(--spacing-2xl);
}

/* ===== ALERTAS ===== */
.alert {
  padding: var(--spacing-md) var(--spacing-lg);
  border-radius: var(--border-radius-md);
  margin-bottom: var(--spacing-lg);
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
  font-weight: 500;
}

.alert-success {
  background: rgba(39, 174, 96, 0.1);
  color: var(--success-color);
  border: 1px solid rgba(39, 174, 96, 0.2);
}

.alert-error {
  background: rgba(231, 76, 60, 0.1);
  color: var(--error-color);
  border: 1px solid rgba(231, 76, 60, 0.2);
}

.alert-warning {
  background: rgba(243, 156, 18, 0.1);
  color: var(--warning-color);
  border: 1px solid rgba(243, 156, 18, 0.2);
}

.alert-info {
  background: rgba(52, 152, 219, 0.1);
  color: var(--info-color);
  border: 1px solid rgba(52, 152, 219, 0.2);
}

/* ===== TABS ===== */
.routine-tabs {
  background: var(--light-gray);
  padding: var(--spacing-lg) 0;
}

.tabs-nav {
  display: flex;
  justify-content: center;
  gap: var(--spacing-md);
  flex-wrap: wrap;
}

.tab-btn {
  padding: var(--spacing-md) var(--spacing-xl);
  background: var(--white);
  border: 2px solid var(--light-gray);
  border-radius: var(--border-radius-md);
  font-family: var(--font-primary);
  font-weight: 500;
  color: var(--dark-gray);
  cursor: pointer;
  transition: var(--transition-fast);
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
}

.tab-btn:hover,
.tab-btn.active {
  background: var(--primary-color);
  color: var(--white);
  border-color: var(--primary-color);
  transform: translateY(-2px);
}

.tab-content {
  display: none;
  padding: var(--spacing-3xl) 0;
}

.tab-content.active {
  display: block;
}

/* ===== RUTINAS ===== */
.routine-creator {
  max-width: 1000px;
  margin: 0 auto;
}

.creator-header {
  text-align: center;
  margin-bottom: var(--spacing-3xl);
}

.creator-title {
  font-size: var(--fs-3xl);
  margin-bottom: var(--spacing-md);
}

.creator-description {
  font-size: var(--fs-lg);
  color: var(--medium-gray);
}

.form-section {
  margin-bottom: var(--spacing-3xl);
  padding: var(--spacing-2xl);
  background: var(--white);
  border-radius: var(--border-radius-lg);
  box-shadow: var(--shadow-md);
}

.section-title {
  font-size: var(--fs-2xl);
  margin-bottom: var(--spacing-lg);
  color: var(--secondary-color);
  border-bottom: 2px solid var(--light-gray);
  padding-bottom: var(--spacing-sm);
}

.exercise-selector {
  margin-top: var(--spacing-lg);
}

.selector-filters {
  display: flex;
  gap: var(--spacing-md);
  margin-bottom: var(--spacing-lg);
  flex-wrap: wrap;
}

.filter-select,
.filter-input {
  padding: var(--spacing-sm) var(--spacing-md);
  border: 2px solid var(--light-gray);
  border-radius: var(--border-radius-md);
  font-size: var(--fs-base);
  background: var(--white);
  transition: var(--transition-fast);
}

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

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

.exercise-card {
  background: var(--white);
  border: 2px solid var(--light-gray);
  border-radius: var(--border-radius-lg);
  padding: var(--spacing-lg);
  transition: var(--transition-normal);
  position: relative;
}

.exercise-card:hover {
  border-color: var(--primary-color);
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

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

.exercise-name {
  font-size: var(--fs-lg);
  font-weight: 600;
  color: var(--secondary-color);
  margin: 0;
}

.exercise-category {
  display: flex;
  align-items: center;
  gap: var(--spacing-xs);
  font-size: var(--fs-sm);
  font-weight: 500;
  padding: var(--spacing-xs) var(--spacing-sm);
  background: rgba(255, 107, 53, 0.1);
  border-radius: var(--border-radius-sm);
}

.exercise-description {
  color: var(--dark-gray);
  margin-bottom: var(--spacing-md);
  font-size: var(--fs-sm);
  line-height: 1.5;
}

.exercise-meta {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: var(--spacing-md);
  font-size: var(--fs-sm);
}

.exercise-duration,
.exercise-difficulty {
  display: flex;
  align-items: center;
  gap: var(--spacing-xs);
}

.add-exercise-btn {
  width: 100%;
  justify-content: center;
}

.selected-exercises {
  min-height: 200px;
  border: 2px dashed var(--light-gray);
  border-radius: var(--border-radius-lg);
  padding: var(--spacing-lg);
}

.empty-state {
  text-align: center;
  color: var(--medium-gray);
  padding: var(--spacing-2xl);
}

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

/* ===== BIBLIOTECA DE EJERCICIOS ===== */
.exercise-library {
  max-width: 1200px;
  margin: 0 auto;
}

.library-header {
  text-align: center;
  margin-bottom: var(--spacing-2xl);
}

.library-title {
  font-size: var(--fs-3xl);
  margin-bottom: var(--spacing-md);
}

.library-description {
  font-size: var(--fs-lg);
  color: var(--medium-gray);
}

.library-filters {
  display: flex;
  gap: var(--spacing-md);
  margin-bottom: var(--spacing-2xl);
  flex-wrap: wrap;
  justify-content: center;
}

.library-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(350px, 1fr));
  gap: var(--spacing-lg);
}

.library-exercise-card {
  background: var(--white);
  border-radius: var(--border-radius-lg);
  padding: var(--spacing-xl);
  box-shadow: var(--shadow-md);
  transition: var(--transition-normal);
}

.library-exercise-card:hover {
  transform: translateY(-5px);
  box-shadow: var(--shadow-lg);
}

.library-exercise-header {
  display: flex;
  align-items: flex-start;
  gap: var(--spacing-md);
  margin-bottom: var(--spacing-md);
}

.exercise-icon {
  width: 60px;
  height: 60px;
  background: var(--primary-gradient);
  border-radius: var(--border-radius-lg);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--white);
  font-size: var(--fs-2xl);
  flex-shrink: 0;
}

.exercise-info {
  flex: 1;
}

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

.tag {
  padding: var(--spacing-xs) var(--spacing-sm);
  border-radius: var(--border-radius-sm);
  font-size: var(--fs-xs);
  font-weight: 500;
  color: var(--white);
}

.tag-category {
  background: var(--info-color);
}

.tag-difficulty {
  background: var(--warning-color);
}

.exercise-stats {
  display: flex;
  gap: var(--spacing-lg);
  margin-top: var(--spacing-md);
}

.stat {
  display: flex;
  align-items: center;
  gap: var(--spacing-xs);
  color: var(--medium-gray);
  font-size: var(--fs-sm);
}

/* ===== RUTINAS GUARDADAS ===== */
.saved-routines {
  max-width: 1200px;
  margin: 0 auto;
}

.saved-header {
  text-align: center;
  margin-bottom: var(--spacing-2xl);
}

.saved-title {
  font-size: var(--fs-3xl);
  margin-bottom: var(--spacing-md);
}

.saved-description {
  font-size: var(--fs-lg);
  color: var(--medium-gray);
}

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

.routine-card {
  background: var(--white);
  border-radius: var(--border-radius-lg);
  padding: var(--spacing-xl);
  box-shadow: var(--shadow-md);
  transition: var(--transition-normal);
  border: 2px solid transparent;
}

.routine-card:hover {
  transform: translateY(-5px);
  box-shadow: var(--shadow-lg);
  border-color: var(--primary-color);
}

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

.routine-name {
  font-size: var(--fs-xl);
  font-weight: 600;
  color: var(--secondary-color);
  margin: 0;
  flex: 1;
}

.routine-actions {
  display: flex;
  gap: var(--spacing-sm);
}

.routine-description {
  color: var(--dark-gray);
  margin-bottom: var(--spacing-md);
  font-size: var(--fs-sm);
  line-height: 1.5;
}

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

.meta-item {
  display: flex;
  align-items: center;
  gap: var(--spacing-xs);
  color: var(--medium-gray);
  font-size: var(--fs-sm);
}

.routine-actions-bottom {
  text-align: center;
}

/* ===== MODALES ===== */
.modal {
  display: none;
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: rgba(0, 0, 0, 0.5);
  z-index: 2000;
  backdrop-filter: blur(5px);
}

.modal.active {
  display: flex;
  align-items: center;
  justify-content: center;
  animation: fadeIn 0.3s ease-out;
}

.modal-content {
  background: var(--white);
  border-radius: var(--border-radius-lg);
  box-shadow: var(--shadow-xl);
  max-width: 90vw;
  max-height: 90vh;
  overflow-y: auto;
  animation: slideInUp 0.3s ease-out;
}

.modal-small {
  max-width: 500px;
}

.modal-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: var(--spacing-xl);
  border-bottom: 1px solid var(--light-gray);
}

.modal-title {
  font-size: var(--fs-2xl);
  margin: 0;
  color: var(--secondary-color);
}

.modal-close {
  background: none;
  border: none;
  font-size: var(--fs-xl);
  color: var(--medium-gray);
  cursor: pointer;
  padding: var(--spacing-sm);
  border-radius: var(--border-radius-sm);
  transition: var(--transition-fast);
}

.modal-close:hover {
  background: var(--light-gray);
  color: var(--dark-gray);
}

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

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

/* ===== FOOTER ===== */
.footer {
  background: var(--secondary-gradient);
  color: var(--white);
  padding: var(--spacing-4xl) 0 var(--spacing-lg);
}

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

.footer-section h3,
.footer-section h4 {
  color: var(--white);
  margin-bottom: var(--spacing-lg);
}

.footer-title {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
  font-size: var(--fs-2xl);
  margin-bottom: var(--spacing-md);
}

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

.footer-description {
  line-height: 1.6;
  opacity: 0.9;
  margin-bottom: var(--spacing-lg);
}

.social-links {
  display: flex;
  gap: var(--spacing-md);
}

.social-link {
  width: 40px;
  height: 40px;
  background: rgba(255, 255, 255, 0.1);
  border-radius: var(--border-radius-full);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--white);
  text-decoration: none;
  transition: var(--transition-fast);
}

.social-link:hover {
  background: var(--primary-color);
  transform: translateY(-2px);
}

.footer-subtitle {
  font-size: var(--fs-lg);
  margin-bottom: var(--spacing-md);
  color: var(--primary-color);
}

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

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

.footer-links a {
  color: rgba(255, 255, 255, 0.8);
  text-decoration: none;
  transition: var(--transition-fast);
}

.footer-links a:hover {
  color: var(--primary-color);
  padding-left: var(--spacing-sm);
}

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

.contact-item {
  display: flex;
  align-items: flex-start;
  gap: var(--spacing-sm);
}

.contact-item i {
  color: var(--primary-color);
  margin-top: 2px;
  flex-shrink: 0;
}

.footer-bottom {
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  padding-top: var(--spacing-lg);
}

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

.footer-bottom-links {
  display: flex;
  gap: var(--spacing-lg);
}

.footer-bottom-links a {
  color: rgba(255, 255, 255, 0.7);
  text-decoration: none;
  font-size: var(--fs-sm);
  transition: var(--transition-fast);
}

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

/* ===== ANIMACIONES ===== */
@keyframes fadeIn {
  from { opacity: 0; }
  to { opacity: 1; }
}

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

@keyframes slideInUp {
  from {
    opacity: 0;
    transform: translateY(50px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes float {
  0%, 100% { transform: translateY(0px) rotate(0deg); }
  50% { transform: translateY(-20px) rotate(180deg); }
}

/* ===== RESPONSIVE DESIGN ===== */
@media (max-width: 768px) {
  :root {
    --fs-6xl: 2.5rem;
    --fs-5xl: 2rem;
    --fs-4xl: 1.75rem;
    --fs-3xl: 1.5rem;
  }
  
  .nav-menu {
    position: fixed;
    top: 80px;
    left: -100%;
    width: 100%;
    height: calc(100vh - 80px);
    background: var(--white);
    flex-direction: column;
    justify-content: flex-start;
    align-items: center;
    padding-top: var(--spacing-2xl);
    transition: var(--transition-normal);
    box-shadow: var(--shadow-lg);
  }
  
  .nav-menu.active {
    left: 0;
  }
  
  .nav-list {
    flex-direction: column;
    gap: var(--spacing-lg);
    width: 100%;
    text-align: center;
  }
  
  .nav-toggle {
    display: flex;
  }
  
  .nav-toggle.active .bar:nth-child(1) {
    transform: rotate(45deg) translate(5px, 5px);
  }
  
  .nav-toggle.active .bar:nth-child(2) {
    opacity: 0;
  }
  
  .nav-toggle.active .bar:nth-child(3) {
    transform: rotate(-45deg) translate(7px, -6px);
  }
  
  .hero-title {
    font-size: var(--fs-4xl);
  }
  
  .hero-buttons {
    flex-direction: column;
    align-items: center;
  }
  
  .bmi-content {
    grid-template-columns: 1fr;
  }
  
  .services-grid,
  .testimonials-grid,
  .routines-grid {
    grid-template-columns: 1fr;
  }
  
  .stats-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  
  .form-grid {
    grid-template-columns: 1fr;
  }
  
  .tabs-nav {
    flex-direction: column;
    align-items: center;
  }
  
  .tab-btn {
    width: 100%;
    max-width: 300px;
    justify-content: center;
  }
  
  .exercises-grid,
  .library-grid {
    grid-template-columns: 1fr;
  }
  
  .selector-filters,
  .library-filters {
    flex-direction: column;
  }
  
  .footer-bottom-content {
    flex-direction: column;
    text-align: center;
  }
  
  .cta-buttons {
    flex-direction: column;
    align-items: center;
  }
  
  .hero-buttons .btn,
  .cta-buttons .btn {
    width: 100%;
    max-width: 300px;
    justify-content: center;
  }
}

@media (max-width: 480px) {
  .container {
    padding: 0 var(--spacing-sm);
  }
  
  section {
    padding: var(--spacing-2xl) 0;
  }
  
  .page-hero {
    padding: var(--spacing-2xl) 0;
  }
  
  .stats-grid {
    grid-template-columns: 1fr;
  }
  
  .routine-header {
    flex-direction: column;
    gap: var(--spacing-md);
    align-items: flex-start;
  }
  
  .routine-actions {
    align-self: flex-end;
  }
  
  .modal-content {
    margin: var(--spacing-md);
    max-width: calc(100vw - 2rem);
  }
  
  .modal-header,
  .modal-body {
    padding: var(--spacing-md);
  }
}


/* ===== SISTEMA DE AUTENTICACIÓN ===== */

/* Navegación con autenticación */
.navbar {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: var(--spacing-md) 0;
}

.nav-auth {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
}

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

.btn-small {
    padding: var(--spacing-sm) var(--spacing-md);
    font-size: var(--fs-sm);
}

/* Menú de usuario */
.user-menu-container {
    position: relative;
}

.user-menu-btn {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    background: none;
    border: none;
    cursor: pointer;
    padding: var(--spacing-sm) var(--spacing-md);
    border-radius: var(--border-radius-md);
    transition: var(--transition-normal);
    color: var(--dark-gray);
}

.user-menu-btn:hover {
    background: var(--light-gray);
}

.user-avatar {
    width: 32px;
    height: 32px;
    border-radius: var(--border-radius-full);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--white);
    font-size: var(--fs-sm);
    font-weight: 600;
}

.user-name {
    font-weight: 500;
    color: var(--secondary-color);
    max-width: 120px;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}

.user-dropdown {
    position: absolute;
    top: 100%;
    right: 0;
    background: var(--white);
    border-radius: var(--border-radius-lg);
    box-shadow: var(--shadow-lg);
    min-width: 250px;
    opacity: 0;
    visibility: hidden;
    transform: translateY(-10px);
    transition: var(--transition-normal);
    z-index: 1000;
    border: 1px solid var(--light-gray);
}

.user-dropdown.show {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

.user-info {
    padding: var(--spacing-lg);
    border-bottom: 1px solid var(--light-gray);
}

.user-details {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-xs);
}

.user-full-name {
    font-weight: 600;
    color: var(--secondary-color);
}

.user-role {
    font-size: var(--fs-sm);
    color: var(--medium-gray);
}

.dropdown-divider {
    height: 1px;
    background: var(--light-gray);
    margin: var(--spacing-xs) 0;
}

.dropdown-item {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    padding: var(--spacing-md) var(--spacing-lg);
    text-decoration: none;
    color: var(--dark-gray);
    transition: var(--transition-normal);
    font-size: var(--fs-sm);
}

.dropdown-item:hover {
    background: var(--light-gray);
}

.dropdown-item.logout {
    color: var(--error-color);
}

.dropdown-item.logout:hover {
    background: rgba(231, 76, 60, 0.1);
}

/* Notificaciones del sistema */
.system-notification {
    position: fixed;
    top: var(--spacing-lg);
    right: var(--spacing-lg);
    z-index: 1000;
    animation: slideInRight 0.5s ease;
}

.notification {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    padding: var(--spacing-md) var(--spacing-lg);
    border-radius: var(--border-radius-md);
    box-shadow: var(--shadow-lg);
    background: var(--white);
    border-left: 4px solid;
    min-width: 300px;
}

.notification-success {
    border-left-color: var(--success-color);
    color: var(--success-color);
}

.notification-error {
    border-left-color: var(--error-color);
    color: var(--error-color);
}

.notification-warning {
    border-left-color: var(--warning-color);
    color: var(--warning-color);
}

.notification-info {
    border-left-color: var(--info-color);
    color: var(--info-color);
}

.notification-close {
    background: none;
    border: none;
    color: inherit;
    cursor: pointer;
    padding: var(--spacing-xs);
    margin-left: auto;
    border-radius: var(--border-radius-sm);
    transition: var(--transition-normal);
}

.notification-close:hover {
    background: rgba(0, 0, 0, 0.1);
}

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

/* Responsive para autenticación */
@media (max-width: 768px) {
    .navbar {
        flex-wrap: wrap;
    }
    
    .nav-auth {
        order: 3;
        width: 100%;
        justify-content: center;
        margin-top: var(--spacing-md);
    }
    
    .auth-buttons {
        width: 100%;
        justify-content: center;
    }
    
    .user-menu-btn .user-name {
        display: none;
    }
    
    .user-dropdown {
        right: auto;
        left: 50%;
        transform: translateX(-50%) translateY(-10px);
    }
    
    .user-dropdown.show {
        transform: translateX(-50%) translateY(0);
    }
    
    .system-notification {
        top: var(--spacing-sm);
        right: var(--spacing-sm);
        left: var(--spacing-sm);
    }
    
    .notification {
        min-width: auto;
    }
}

/* Estilos para páginas de dashboard */
.dashboard-page .header {
    display: none;
}

.admin-page .header {
    display: none;
}

/* Animaciones adicionales */
.animate-in {
    animation: fadeInUp 0.6s ease forwards;
}

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

/* Estados de carga */
.loading {
    opacity: 0.6;
    pointer-events: none;
}

.loading::after {
    content: '';
    position: absolute;
    top: 50%;
    left: 50%;
    width: 20px;
    height: 20px;
    margin: -10px 0 0 -10px;
    border: 2px solid var(--light-gray);
    border-top-color: var(--primary-color);
    border-radius: 50%;
    animation: spin 1s linear infinite;
}

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

/* 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: 0;
}

/* Focus states mejorados */
.btn:focus,
.form-input:focus,
.user-menu-btn:focus,
.dropdown-item:focus {
    outline: 2px solid var(--primary-color);
    outline-offset: 2px;
}

/* Transiciones suaves para todos los elementos interactivos */
.btn,
.nav-link,
.dropdown-item,
.user-menu-btn,
.notification-close {
    transition: all var(--transition-normal);
}