/* =========================================
   Modern Design System - Nutrición Deportiva Fit
   ========================================= */

:root {
  /* Color Palette - Vibrant & Trustworthy */
  --primary-color: #2563EB;
  /* Royal Blue */
  --primary-dark: #1E40AF;
  --accent-color: #F59E0B;
  /* Amber for energy */
  --text-main: #1F2937;
  --text-light: #4B5563;
  --bg-body: #F9FAFB;
  --bg-card: #FFFFFF;
  --white: #FFFFFF;

  /* Typography */
  --font-main: 'Outfit', sans-serif;

  /* Spacing & Layout */
  --container-width: 1200px;
  --header-height: 80px;
  --radius-md: 12px;
  --radius-lg: 20px;

  /* Effects */
  --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.1);
  --shadow-md: 0 4px 6px rgba(0, 0, 0, 0.05);
  --shadow-lg: 0 10px 15px rgba(0, 0, 0, 0.1);
  --transition-fast: 0.2s ease;
}

/* =========================================
   Reset & Base Styles
   ========================================= */
*,
*::before,
*::after {
  box-sizing: border-box;
}

body {
  margin: 0;
  padding: 0;
  font-family: var(--font-main);
  background-color: var(--bg-body);
  color: var(--text-main);
  line-height: 1.6;
}

h1,
h2,
h3,
h4 {
  margin-top: 0;
  line-height: 1.2;
}

a {
  text-decoration: none;
  color: inherit;
}

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

.container {
  max-width: var(--container-width);
  margin: 0 auto;
  padding: 0 1.5rem;
}

/* =========================================
   Header & Navigation
   ========================================= */
header .logo a {
  display: block;
  line-height: 0;
}

/* Re-using existing structure but improving visual if possible, 
   assuming header loaded via JS matches basic structure */
header nav {
  background: var(--white);
  box-shadow: var(--shadow-sm);
  padding: 1rem 0;
}

/* =========================================
   Hero Section
   ========================================= */
.hero-section {
  position: relative;
  height: 85vh;
  min-height: 500px;
  display: flex;
  align-items: center;
  color: var(--white);
  overflow: hidden;
}

.hero-bg {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  z-index: -1;
  filter: brightness(0.7);
}

.hero-overlay {
  position: absolute;
  inset: 0;
  background: linear-gradient(to right, rgba(0, 0, 0, 0.8), rgba(0, 0, 0, 0.2));
  z-index: 0;
}

.hero-content {
  position: relative;
  z-index: 2;
  max-width: 800px;
}

.hero-content h1 {
  font-size: 3.5rem;
  font-weight: 700;
  margin-bottom: 1rem;
}

.text-gradient {
  color: var(--accent-color);
  /* Optional: gradient text support */
  background: linear-gradient(45deg, #F59E0B, #FBBF24);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  display: inline-block;
}

.hero-subtitle {
  font-size: 1.5rem;
  margin-bottom: 2rem;
  opacity: 0.9;
}

.btn {
  display: inline-block;
  padding: 1rem 2rem;
  border-radius: 50px;
  font-weight: 600;
  transition: transform var(--transition-fast), box-shadow var(--transition-fast);
  cursor: pointer;
}

.btn-primary {
  background-color: var(--primary-color);
  color: var(--white);
  box-shadow: 0 4px 14px rgba(37, 99, 235, 0.4);
}

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

/* =========================================
   Sections & Layouts
   ========================================= */
section {
  padding: 5rem 0;
}

.section-header {
  text-align: center;
  max-width: 700px;
  margin: 0 auto 3rem;
}

.section-header h2 {
  font-size: 2.5rem;
  color: var(--primary-dark);
  margin-bottom: 1rem;
}

.grid-2 {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
  gap: 2rem;
  align-items: center;
}

.grid-3 {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 2rem;
}

/* =========================================
   Cards
   ========================================= */
.card,
.feature-card,
.diet-card {
  background: var(--bg-card);
  padding: 2rem;
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-md);
  transition: transform var(--transition-fast), box-shadow var(--transition-fast);
  border: 1px solid rgba(0, 0, 0, 0.05);
}

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

.icon {
  font-size: 3rem;
  margin-bottom: 1rem;
}

.benefit-card h3,
.feature-card h3 {
  color: var(--primary-color);
  margin-bottom: 0.5rem;
}

/* Diet Cards specific */
.diet-card {
  border-top: 4px solid var(--primary-color);
}

.diet-card.gain {
  border-color: #10B981;
}

/* Emerald */
.diet-card.cut {
  border-color: #EF4444;
}

/* Red */
.diet-card.maintain {
  border-color: #3B82F6;
}

/* Blue */

/* =========================================
   Science Tabs / Grid
   ========================================= */
.tabs-container {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 1.5rem;
}

.tab {
  background: #EFF6FF;
  /* clear blue bg */
  padding: 2rem;
  border-radius: var(--radius-md);
}

.tab h3 {
  color: var(--primary-dark);
  border-bottom: 2px solid var(--primary-color);
  padding-bottom: 0.5rem;
  display: inline-block;
}

/* =========================================
   FAQ
   ========================================= */
details {
  background: var(--white);
  margin-bottom: 1rem;
  padding: 1.5rem;
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-sm);
  cursor: pointer;
}

summary {
  font-weight: 600;
  font-size: 1.1rem;
}

details[open] summary {
  margin-bottom: 1rem;
  color: var(--primary-color);
}

/* =========================================
   CTA & Footer
   ========================================= */
.cta-section {
  background: linear-gradient(135deg, var(--primary-dark), var(--primary-color));
  color: var(--white);
  text-align: center;
  border-radius: var(--radius-lg);
  margin: 3rem auto;
  max-width: var(--container-width);
}

footer {
  background: #111;
  color: #aaa;
  padding: 3rem 0;
  margin-top: auto;
}

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

  .grid-2,
  .grid-3 {
    grid-template-columns: 1fr;
  }
}