/* ==========================================================================
   SHEAC Website Stylesheet
   Brand Colors:
   - Deep Forest Green: #1B5E20
   - Leaf Green: #4CAF50
   - Biodiversity Gold: #F4B942
   - Background: #F7F8F3
   - Text: #263238
   ========================================================================== */

:root {
  --primary: #1B5E20;
  --primary-dark: #0f3d13;
  --secondary: #4CAF50;
  --accent: #F4B942;
  --earth: #795548;
  --bg-main: #F7F8F3;
  --bg-card: #FFFFFF;
  --text-main: #263238;
  --text-muted: #546E7A;
  --border-color: #E0E0E0;
  --font-heading: 'Poppins', 'Montserrat', sans-serif;
  --font-body: 'Inter', 'Open Sans', 'Mukta', sans-serif;
  --transition: all 0.3s ease;
  --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.06);
  --shadow-md: 0 4px 16px rgba(0, 0, 0, 0.1);
  --radius: 8px;
}

* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

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

body {
  font-family: var(--font-body);
  background-color: var(--bg-main);
  color: var(--text-main);
  line-height: 1.6;
  display: flex;
  flex-direction: column;
  min-height: 100vh;
}

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

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

ul {
  list-style: none;
}

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

.section-title {
  text-align: center;
  margin-bottom: 2.5rem;
}

.section-title h2 {
  font-size: 2.25rem;
  position: relative;
  display: inline-block;
  padding-bottom: 0.5rem;
}

.section-title h2::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 50%;
  transform: translateX(-50%);
  width: 60px;
  height: 4px;
  background-color: var(--accent);
  border-radius: 2px;
}

.section-title p {
  color: var(--text-muted);
  margin-top: 0.5rem;
  font-size: 1.1rem;
}

/* Layout Containers */
.container {
  width: 90%;
  max-width: 1200px;
  margin: 0 auto;
}

section {
  padding: 4.5rem 0;
}

/* Header & Navigation */
header {
  position: sticky;
  top: 0;
  background-color: var(--primary);
  color: #fff;
  z-index: 1000;
  box-shadow: var(--shadow-md);
}

.nav-container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0.8rem 0;
}

.brand-logo {
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.brand-logo img {
  height: 100px;
  width: auto;
}

.brand-text .title {
  font-size: 1.3rem;
  font-weight: 700;
  color: #fff;
  letter-spacing: 0.5px;
}

.brand-text .sub-title {
  font-size: 0.75rem;
  color: var(--accent);
  display: block;
}

.nav-menu {
  display: flex;
  align-items: center;
  gap: 1.25rem;
}

.nav-link {
  color: #fff;
  font-weight: 500;
  font-size: 0.95rem;
  padding: 0.4rem 0;
  position: relative;
}

.nav-link:hover, .nav-link.active {
  color: var(--accent);
}

.nav-link.active::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 100%;
  height: 2px;
  background-color: var(--accent);
}

.hamburger {
  display: none;
  cursor: pointer;
  background: none;
  border: none;
  color: #fff;
  font-size: 1.8rem;
}

/* Hero Section with GROUP.png Background */
.hero {
  position: relative;
  background: linear-gradient(rgba(27, 94, 32, 0.8), rgba(0, 0, 0, 0.75)), url('../images/GROUP.png') center/cover no-repeat;
  color: #fff;
  padding: 8rem 1rem;
  text-align: center;
}

.hero-content {
  max-width: 850px;
  margin: 0 auto;
}

.hero-tagline {
  font-size: 1.25rem;
  color: var(--accent);
  text-transform: uppercase;
  letter-spacing: 2px;
  font-weight: 600;
  margin-bottom: 1rem;
}

.hero h1 {
  font-size: 2.75rem;
  color: #fff;
  margin-bottom: 1.25rem;
}

.hero p {
  font-size: 1.15rem;
  margin-bottom: 2rem;
  opacity: 0.95;
}

/* Buttons */
.hero-buttons {
  display: flex;
  justify-content: center;
  gap: 1rem;
  flex-wrap: wrap;
}

.btn {
  display: inline-block;
  padding: 0.75rem 1.75rem;
  border-radius: var(--radius);
  font-weight: 600;
  text-align: center;
  cursor: pointer;
  border: 2px solid transparent;
  transition: var(--transition);
}

.btn-primary {
  background-color: var(--secondary);
  color: #fff;
}

.btn-primary:hover {
  background-color: #388E3C;
  transform: translateY(-2px);
}

.btn-accent {
  background-color: var(--accent);
  color: var(--text-main);
}

.btn-accent:hover {
  background-color: #e0a32e;
  transform: translateY(-2px);
}

/* Page Banner (for inner pages) */
.page-banner {
  background: linear-gradient(rgba(27, 94, 32, 0.85), rgba(15, 61, 19, 0.9)), url('../images/GROUP.png') center/cover no-repeat;
  color: #fff;
  padding: 3.5rem 0;
  text-align: center;
}

.page-banner h1 {
  color: #fff;
  font-size: 2.25rem;
  margin-bottom: 0.5rem;
}

.page-banner p {
  color: var(--accent);
  font-size: 1.1rem;
}

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

.grid-2 {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(400px, 1fr));
  gap: 2rem;
}

.card {
  background: var(--bg-card);
  border-radius: var(--radius);
  overflow: hidden;
  box-shadow: var(--shadow-sm);
  transition: var(--transition);
  display: flex;
  flex-direction: column;
  border: 1px solid var(--border-color);
  padding: 1.5rem;
}

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

.card h3 {
  margin-bottom: 0.75rem;
}

.card p {
  color: var(--text-muted);
  font-size: 0.95rem;
  margin-bottom: 1rem;
}

.card-tag {
  display: inline-block;
  padding: 0.25rem 0.75rem;
  background-color: rgba(76, 175, 80, 0.15);
  color: var(--primary);
  border-radius: 20px;
  font-size: 0.8rem;
  font-weight: 600;
  margin-bottom: 0.75rem;
  width: fit-content;
}

/* Lightbox Modal */
.lightbox-modal {
  display: none;
  position: fixed;
  z-index: 2000;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: rgba(0, 0, 0, 0.9);
  justify-content: center;
  align-items: center;
}

.lightbox-modal img {
  max-width: 90%;
  max-height: 80%;
  border-radius: 4px;
}

.lightbox-close {
  position: absolute;
  top: 20px;
  right: 30px;
  color: #fff;
  font-size: 2.5rem;
  cursor: pointer;
}

/* Gallery Grid */
.gallery-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
  gap: 1.25rem;
}

.gallery-item {
  position: relative;
  border-radius: var(--radius);
  overflow: hidden;
  cursor: pointer;
  height: 220px;
  background: #e0e0e0;
}

.gallery-item img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: var(--transition);
}

.gallery-item:hover img {
  transform: scale(1.05);
}

/* Footer */
footer {
  background-color: var(--primary-dark);
  color: #fff;
  padding: 3.5rem 0 2rem 0;
  margin-top: auto;
}

.footer-bottom {
  text-align: center;
  font-size: 0.9rem;
  color: #CFD8DC;
}

/* Mobile Responsiveness */
@media (max-width: 768px) {
  .hamburger {
    display: block;
  }
  .nav-menu {
    position: absolute;
    top: 100%;
    left: 0;
    width: 100%;
    background-color: var(--primary);
    flex-direction: column;
    align-items: flex-start;
    padding: 1rem 2rem;
    display: none;
  }
  .nav-menu.active {
    display: flex;
  }
  .hero h1 {
    font-size: 2rem;
  }
  .grid-2, .grid-3 {
    grid-template-columns: 1fr;
  }
}