/* 
   EESV2026 Modern Design System 
   Based on Scientific/Academic aesthetic with a premium feel.
   Primary Color: Orange/Gold (#c67816) modernized to a richer amber.
*/

:root {
  --primary-color: #d9822b; /* Vibrant Amber */
  --primary-dark: #b06218;
  --secondary-color: #2c3e50; /* Deep Blue Grey */
  --accent-color: #f1c40f; /* Highlight */
  --text-dark: #333333;
  --text-light: #7f8c8d;
  --bg-light: #f9f9f9;
  --white: #ffffff;
  --border-color: #e0e0e0;
  
  --font-heading: 'Roboto', sans-serif;
  --font-body: 'Open Sans', sans-serif;

  --spacing-xs: 0.5rem;
  --spacing-sm: 1rem;
  --spacing-md: 2rem;
  --spacing-lg: 4rem;
  
  --shadow-sm: 0 2px 4px rgba(0,0,0,0.05);
  --shadow-md: 0 4px 6px rgba(0,0,0,0.1);
  --shadow-lg: 0 10px 15px rgba(0,0,0,0.1);
}

/* Reset & Base */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

body {
  font-family: var(--font-body);
  line-height: 1.6;
  color: var(--text-dark);
  background-color: var(--bg-light);
}

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

a {
  color: var(--primary-color);
  text-decoration: none;
  transition: color 0.3s ease;
}

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

/* Typography */
h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-heading);
  color: var(--secondary-color);
  line-height: 1.25;
  margin-bottom: var(--spacing-sm);
  font-weight: 700;
}

h1 { font-size: 3rem; }
h2 { font-size: 2.25rem; border-bottom: 3px solid var(--primary-color); display: inline-block; padding-bottom: 0.5rem; margin-bottom: var(--spacing-md); }
h3 { font-size: 1.5rem; }

p {
  margin-bottom: var(--spacing-sm);
}

/* Utilities */
.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 var(--spacing-sm);
}

.text-center { text-align: center; }
.text-justify { text-align: justify; }
.mt-1 { margin-top: var(--spacing-sm); }
.mt-2 { margin-top: var(--spacing-md); }
.mb-2 { margin-bottom: var(--spacing-md); }

.btn {
  display: inline-block;
  padding: 12px 24px;
  background-color: var(--primary-color);
  color: var(--white);
  border-radius: 4px;
  font-weight: 600;
  transition: all 0.3s ease;
  border: none;
  cursor: pointer;
}

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

/* Header & Nav */
header {
  background-color: var(--white);
  box-shadow: var(--shadow-sm);
  position: sticky;
  top: 0;
  z-index: 1000;
}

.navbar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: var(--spacing-sm) 0;
}

.nav-links {
  display: flex;
  list-style: none;
  gap: var(--spacing-md);
}

.nav-links a {
  color: var(--secondary-color);
  font-weight: 500;
  font-size: 1rem;
  padding: 0.5rem 0;
  position: relative;
}

.nav-links a::after {
  content: '';
  position: absolute;
  width: 0;
  height: 2px;
  bottom: 0;
  left: 0;
  background-color: var(--primary-color);
  transition: width 0.3s ease;
}

.nav-links a:hover::after,
.nav-links a.active::after {
  width: 100%;
}

.mobile-menu-btn {
  display: none;
  font-size: 1.5rem;
  cursor: pointer;
}

/* Hero Section */
.hero {
  background: linear-gradient(rgba(44, 62, 80, 0.8), rgba(44, 62, 80, 0.8)), url('../images/hero-bg.jpg');
  background-size: cover;
  background-position: center;
  color: var(--white);
  padding: 120px 0;
  text-align: center;
}

.hero h1 {
  color: var(--white);
  margin-bottom: var(--spacing-sm);
  text-shadow: 2px 2px 4px rgba(0,0,0,0.5);
}

.hero-subtitle {
  font-size: 1.5rem;
  font-weight: 300;
  margin-bottom: var(--spacing-md);
  max-width: 800px;
  margin-left: auto;
  margin-right: auto;
}

/* Cards (for key info, speakers) */
.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: var(--spacing-md);
  margin-top: var(--spacing-md);
}

.card {
  background: var(--white);
  border-radius: 8px;
  padding: var(--spacing-md);
  box-shadow: var(--shadow-sm);
  transition: transform 0.3s ease, box-shadow 0.3s ease;
}

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

.card h3 {
  color: var(--primary-color);
  font-size: 1.25rem;
  margin-bottom: var(--spacing-xs);
}

/* Footer */
footer {
  background-color: var(--secondary-color);
  color: var(--white);
  padding: var(--spacing-lg) 0;
  margin-top: var(--spacing-lg);
}

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

.footer-logos {
  display: flex;
  flex-wrap: wrap;
  gap: var(--spacing-sm);
  align-items: center;
}

.footer-logos img {
  height: 40px;
  width: auto;
  opacity: 0.8;
  transition: opacity 0.3s;
}

.footer-logos img:hover {
  opacity: 1;
}

.footer-links a {
  color: #bdc3c7;
  display: block;
  margin-bottom: 0.5rem;
}

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

/* Responsive */
@media (max-width: 768px) {
  .nav-links {
    display: none; /* Mobile menu implementation needed if using JS, for now simple stack */
    flex-direction: column;
    position: absolute;
    top: 70px;
    left: 0;
    right: 0;
    background: var(--white);
    padding: var(--spacing-md);
    box-shadow: var(--shadow-lg);
  }
  
  .nav-links.active {
    display: flex;
  }
  
  .mobile-menu-btn {
    display: block;
  }
  
  h1 { font-size: 2.2rem; }
  h2 { font-size: 1.75rem; }
}

/* Specific Section Styles */
.logos-container {
    background: white;
    padding: var(--spacing-md);
    border-radius: 8px;
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 20px;
    align-items: center;
}

.logos-container img {
    max-height: 60px;
    width: auto;
    filter: grayscale(10%);
    transition: all 0.3s;
}

.logos-container img:hover {
    filter: grayscale(0%);
    transform: scale(1.05);
}