/* Import Poppins font */
@import url('https://fonts.googleapis.com/css2?family=Poppins:wght@300;400;500;600;700&display=swap');

/* ===== CSS VARIABLES ===== */
:root {
  /* Colors - Light Theme */
  --color-primary: #2563EB;      /* Bright blue */
  --color-secondary: #7C3AED;     /* Vibrant purple */
  --color-accent: #2564eb;        /* Amber */
  --color-bg-light: #FFFFFF;      /* Pure white background */
  --color-bg-gray: #F9FAFB;       /* Very light gray */
  --color-bg-card: #FFFFFF;       /* Card background */
  --color-text-primary: #111827;  /* Dark gray text */
  --color-text-secondary: #6B7280; /* Medium gray text */
  --color-border: #E5E7EB;        /* Light gray border */
  
  /* Spacing */
  --spacing-xs: 0.5rem;
  --spacing-sm: 1rem;
  --spacing-md: 1.5rem;
  --spacing-lg: 2rem;
  --spacing-xl: 3rem;
  --spacing-2xl: 4rem;
  --spacing-3xl: 6rem;
  
  /* Typography */
  --font-family: 'Poppins', sans-serif;
  --font-size-sm: 0.875rem;
  --font-size-base: 1rem;
  --font-size-lg: 1.125rem;
  --font-size-xl: 1.5rem;
  --font-size-2xl: 2rem;
  --font-size-3xl: 3rem;
  --font-size-4xl: 4rem;
  
  /* Effects */
  --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.1);
  --shadow-md: 0 4px 16px rgba(0, 0, 0, 0.2);
  --shadow-lg: 0 8px 32px rgba(0, 0, 0, 0.3);
  --border-radius: 12px;
}

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

html {
  scroll-behavior: smooth;
}

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

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

h1 {
  font-size: var(--font-size-4xl);
  font-weight: 700;
}

h2 {
  font-size: var(--font-size-3xl);
  font-weight: 700;
}

h3 {
  font-size: var(--font-size-2xl);
}

h4 {
  font-size: var(--font-size-xl);
}

p {
  margin-bottom: var(--spacing-md);
  color: var(--color-text-secondary);
}

strong {
  color: var(--color-text-primary);
}

ul li {
  color: var(--color-text-secondary);
}

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

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

a:focus-visible {
  outline: 2px solid var(--color-accent);
  outline-offset: 4px;
  border-radius: 2px;
}

/* ===== LAYOUT ===== */
.container {
  max-width: 1280px;
  margin: 0 auto;
  padding: 0 var(--spacing-lg);
}

section {
  padding: var(--spacing-3xl) 0;
  position: relative;
}

/* ===== NAVIGATION ===== */
.nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  background: rgba(255, 255, 255, 0.95);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--color-border);
  z-index: 1000;
  padding: var(--spacing-md) 0;
}

.nav-container {
  max-width: 1280px;
  margin: 0 auto;
  padding: 0 var(--spacing-lg);
  display: flex;
  justify-content: space-between;
  align-items: center;
  position: relative;
  z-index: 100;
}

.nav-brand {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
  color: var(--color-text-primary);
  z-index: 102;
  font-weight: 600;
}

.nav-brand a {
  color: var(--color-text-primary);
  text-decoration: none;
  transition: var(--transition);
}

.nav-brand a:hover {
  color: var(--color-primary);
}

.nav-logo {
  height: 40px;
  width: auto;
}

.nav-menu {
  display: flex;
  gap: var(--spacing-lg);
}

/* Hamburger menu */
.hamburger {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: var(--spacing-sm);
  z-index: 1002;
  position: relative;
}

.hamburger span {
  display: block;
  width: 25px;
  height: 3px;
  background: var(--color-text-primary);
  transition: all 0.3s ease;
  border-radius: 2px;
}

.hamburger.active span:nth-child(1) {
  transform: rotate(45deg) translate(7px, 7px);
}

.hamburger.active span:nth-child(2) {
  opacity: 0;
}

.hamburger.active span:nth-child(3) {
  transform: rotate(-45deg) translate(7px, -7px);
}

/* Menu backdrop overlay */
.menu-backdrop {
  display: none;
  position: fixed;
  top: 0;
  left: 0;
  width: 100vw;
  height: 100vh;
  background: rgba(0, 0, 0, 0.5);
  z-index: 999;
  opacity: 0;
  transition: opacity 0.3s ease;
}

.menu-backdrop.active {
  display: block;
  opacity: 1;
}

.nav a {
  color: var(--color-text-secondary);
  font-weight: 500;
  padding: var(--spacing-xs) var(--spacing-md);
  border-radius: 6px;
  transition: var(--transition);
}

.nav a:hover {
  color: var(--color-primary);
  background: var(--color-bg-gray);
}

.nav a.active {
  color: var(--color-primary);
  background: var(--color-bg-gray);
  font-weight: 600;
}

/* ===== HEADER / HERO ===== */
.hero {
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  text-align: center;
  position: relative;
  background: linear-gradient(135deg, #F0F9FF 0%, #FFF 100%);
  padding-top: 80px;
}

.hero::after {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background-image: url('/public/banner.png');
  background-size: cover;
  background-position: center;
  background-repeat: no-repeat;
  opacity: 0.3;
  pointer-events: none;
  z-index: 0;
}

.hero-content {
  position: relative;
  z-index: 1;
  animation: fadeInUp 1s ease-out;
}

.logo {
  width: 200px;
  height: auto;
  margin-bottom: var(--spacing-xl);
  animation: float 3s ease-in-out infinite;
}

.hero h1 {
  margin-bottom: var(--spacing-md);
  color: var(--color-text-primary);
}

.hero .subtitle {
  font-size: var(--font-size-xl);
  color: var(--color-text-secondary);
  font-weight: 300;
  max-width: 800px;
  margin: 0 auto var(--spacing-xl);
}

.hero-intro {
  font-size: var(--font-size-lg);
  color: var(--color-text-secondary);
  font-weight: 400;
  margin-bottom: var(--spacing-md);
}

.hero-title {
  font-size: var(--font-size-3xl);
  font-weight: 700;
  color: var(--color-text-primary);
  margin-bottom: var(--spacing-lg);
  max-width: 900px;
  margin-left: auto;
  margin-right: auto;
}

.hero-subtitle {
  font-size: var(--font-size-xl);
  color: var(--color-primary);
  font-weight: 400;
  margin-bottom: var(--spacing-lg);
}

.hero-location {
  font-size: var(--font-size-lg);
  color: var(--color-text-secondary);
  font-weight: 500;
}

/* ===== CARDS ===== */
.card {
  background: var(--color-bg-card);
  border-radius: var(--border-radius);
  padding: var(--spacing-xl);
  border: 1px solid var(--color-border);
  transition: var(--transition);
  position: relative;
  overflow: hidden;
  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.05);
}

.card:hover {
  transform: translateY(-2px);
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
  border-color: var(--color-primary);
}

/* ===== CAROUSEL ===== */
.carousel {
  position: relative;
  max-width: 900px;
  margin: var(--spacing-2xl) auto;
}

.carousel-container {
  position: relative;
  overflow: hidden;
  border-radius: var(--border-radius);
  background: var(--color-bg-card);
  padding: var(--spacing-lg);
}

.carousel-track {
  display: flex;
  transition: transform 0.5s cubic-bezier(0.4, 0, 0.2, 1);
}

.carousel-slide {
  min-width: 100%;
  padding: var(--spacing-xl);
  text-align: center;
}

.carousel-slide img {
  max-width: 100%;
  height: auto;
  border-radius: var(--border-radius);
}

.carousel-controls {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-top: var(--spacing-lg);
}

.carousel-btn {
  background: var(--color-secondary);
  color: white;
  border: none;
  padding: var(--spacing-sm) var(--spacing-lg);
  border-radius: var(--border-radius);
  cursor: pointer;
  font-family: var(--font-family);
  font-weight: 500;
  transition: var(--transition);
  font-size: var(--font-size-base);
}

.carousel-btn:hover:not(:disabled) {
  background: var(--color-accent);
  transform: scale(1.05);
}

.carousel-btn:disabled {
  opacity: 0.5;
  cursor: not-allowed;
}

.carousel-btn:focus-visible {
  outline: 2px solid var(--color-accent);
  outline-offset: 2px;
}

.carousel-indicators {
  display: flex;
  gap: var(--spacing-sm);
}

.carousel-indicator {
  width: 12px;
  height: 12px;
  border-radius: 50%;
  background: var(--color-border);
  border: none;
  cursor: pointer;
  transition: var(--transition);
  padding: 0;
}

.carousel-indicator.active {
  background: var(--color-secondary);
  transform: scale(1.2);
}

.carousel-indicator:hover {
  background: var(--color-primary);
}

.carousel-indicator:focus-visible {
  outline: 2px solid var(--color-accent);
  outline-offset: 2px;
}

/* ===== ORGANIZERS GRID ===== */
.organizers-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: var(--spacing-xl);
  margin-top: var(--spacing-2xl);
}

.organizer-card {
  text-align: center;
}

.organizer-photo {
  width: 150px;
  height: 150px;
  border-radius: 50%;
  object-fit: cover;
  margin: 0 auto var(--spacing-md);
  border: 3px solid var(--color-primary);
  transition: var(--transition);
}

.organizer-card:hover .organizer-photo {
  border-color: var(--color-accent);
  transform: scale(1.05);
}

.organizer-name {
  font-size: var(--font-size-lg);
  font-weight: 600;
  margin-bottom: var(--spacing-xs);
  color: var(--color-text-primary);
}

.organizer-role {
  font-size: var(--font-size-sm);
  color: var(--color-text-secondary);
  line-height: 1.5;
}

.role-title {
  display: block;
  font-weight: 500;
  color: var(--color-text-primary);
  margin-bottom: 0.25rem;
}

.role-affiliation {
  display: block;
  color: var(--color-text-secondary);
}

/* ===== DATES SECTION ===== */
.dates-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: var(--spacing-lg);
  margin-top: var(--spacing-xl);
}

.date-item {
  background: var(--color-bg-card);
  padding: var(--spacing-lg);
  border-radius: var(--border-radius);
  border-left: 4px solid var(--color-secondary);
  transition: var(--transition);
}

.date-item:hover {
  border-left-color: var(--color-accent);
  transform: translateX(8px);
}

.date-label {
  font-size: var(--font-size-sm);
  color: var(--color-accent);
  text-transform: uppercase;
  letter-spacing: 1px;
  font-weight: 600;
  margin-bottom: var(--spacing-xs);
}

.date-value {
  font-size: var(--font-size-xl);
  font-weight: 700;
  color: var(--color-text-primary);
}

/* ===== PROGRAM ACTIVITIES ===== */
.program-activities {
  margin-top: var(--spacing-xl);
}

.activity-item {
  display: grid;
  grid-template-columns: 100px 1fr;
  gap: var(--spacing-lg);
  padding: var(--spacing-lg) 0;
  border-bottom: 1px solid var(--color-border);
}

.activity-item:last-child {
  border-bottom: none;
}

.activity-time {
  font-weight: 600;
  color: var(--color-primary);
  font-size: var(--font-size-base);
}

.activity-content h4 {
  margin-bottom: var(--spacing-xs);
  color: var(--color-text-primary);
}

.activity-content p {
  margin-bottom: 0;
  font-size: var(--font-size-sm);
}

/* ===== SIMPLE DATES ===== */
.dates-simple {
  margin-top: var(--spacing-lg);
  display: flex;
  flex-direction: column;
  gap: var(--spacing-sm);
}

.dates-simple div {
  padding: var(--spacing-sm) 0;
  color: var(--color-text-secondary);
  font-size: var(--font-size-base);
}

.dates-simple strong {
  color: var(--color-text-primary);
  margin-right: var(--spacing-xs);
}

/* ===== BUTTONS ===== */
.btn {
  display: inline-block;
  padding: var(--spacing-md) var(--spacing-xl);
  background: var(--color-secondary);
  color: white;
  border-radius: var(--border-radius);
  font-weight: 600;
  font-size: var(--font-size-base);
  text-align: center;
  cursor: pointer;
  transition: var(--transition);
  border: none;
  font-family: var(--font-family);
}

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

.btn:focus-visible {
  outline: 2px solid var(--color-accent);
  outline-offset: 4px;
}

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

@keyframes float {
  0%, 100% {
    transform: translateY(0);
  }
  50% {
    transform: translateY(-10px);
  }
}

.fade-in {
  opacity: 0;
  transform: translateY(20px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}

.fade-in.visible {
  opacity: 1;
  transform: translateY(0);
}

/* ===== RESPONSIVE ===== */
@media (max-width: 768px) {
  :root {
    --font-size-4xl: 2.5rem;
    --font-size-3xl: 2rem;
    --font-size-2xl: 1.75rem;
    --font-size-xl: 1.25rem;
    --font-size-lg: 1.125rem;
  }
  
  section {
    padding: var(--spacing-xl) 0;
  }
  
  /* Hero takes full viewport on mobile */
  .hero {
    min-height: 100vh;
    padding-top: 70px;
    display: flex;
    align-items: center;
    justify-content: center;
  }
  
  .hero-content {
    padding: 0 var(--spacing-md);
  }
  
  .nav {
    position: fixed;
    background: rgba(255, 255, 255, 0.98);
    backdrop-filter: blur(10px);
    padding: 2px 0;
  }
  
  .nav-container {
    padding: 2px 8px;
  }
  
  .nav-brand {
    flex: 1;
  }
  
  /* Show hamburger */
  .hamburger {
    display: flex;
  }
  
  /* Hide desktop menu, show mobile slide-in */
  .nav-menu {
    position: fixed;
    top: 0;
    right: -100%;
    height: 100vh;
    width: 280px;
    background: white;
    box-shadow: -4px 0 20px rgba(0, 0, 0, 0.1);
    flex-direction: column;
    padding: var(--spacing-3xl) var(--spacing-xl);
    gap: var(--spacing-md);
    transition: right 0.3s ease;
    z-index: 1001;
    overflow-y: auto;
  }
  
  .nav-menu.active {
    right: 0;
  }
  
  .nav-menu a {
    font-size: var(--font-size-lg);
    padding: var(--spacing-md);
    width: 100%;
    text-align: left;
    border-radius: var(--border-radius);
  }
  
  .nav-menu a:hover,
  .nav-menu a.active {
    background: var(--color-bg-light);
  }
  
  /* Program activities responsive - stack vertically on mobile */
  .activity-item {
    grid-template-columns: 1fr;
    gap: var(--spacing-sm);
    padding: var(--spacing-lg) 0;
  }
  
  .activity-time {
    text-align: left;
    font-size: var(--font-size-sm);
    margin-bottom: var(--spacing-xs);
    font-weight: 600;
  }
  
  .activity-content h4 {
    font-size: var(--font-size-lg);
  }
  
  .logo {
    width: 150px;
  }
  
  .organizers-grid {
    grid-template-columns: 1fr;
  }
  
  .dates-grid {
    grid-template-columns: 1fr;
  }
  
  /* Hero text sizing - larger for mobile readability */
  .hero-title {
    font-size: 2.25rem;
  }
  
  .hero-intro {
    font-size: 1.6rem;
  }
  
  .hero-subtitle {
    font-size: 1.5rem;
  }
  
  .hero-location {
    font-size: 1.25rem;
  }
}

@media (max-width: 480px) {
  :root {
    --font-size-4xl: 2rem;
    --font-size-3xl: 1.5rem;
    --spacing-xl: 2rem;
    --spacing-2xl: 3rem;
  }
  
  .container {
    padding: 0 var(--spacing-md);
  }
  
  .carousel-btn {
    padding: var(--spacing-xs) var(--spacing-md);
    font-size: var(--font-size-sm);
  }
  
  /* Logo sizing on small screens */
  .nav-logo {
    height: 30px;
  }
  
  /* List readability on mobile */
  ul, ol {
    padding-left: var(--spacing-lg);
  }
  
  li {
    margin-bottom: var(--spacing-xs);
  }
  
  /* Hero adjustments for very small screens */
  .hero-title {
    font-size: var(--font-size-xl);
  }
  
  .hero-intro, .hero-subtitle {
    font-size: var(--font-size-base);
  }
  
  /* Activity content */
  .activity-content h4 {
    font-size: var(--font-size-sm);
  }
  
  .activity-content p {
    font-size: var(--font-size-xs);
  }
}

/* ===== ACCESSIBILITY ===== */
.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border-width: 0;
}

/* High contrast mode support */
@media (prefers-contrast: high) {
  :root {
    --color-border: rgba(255, 255, 255, 0.3);
  }
  
  .card {
    border-width: 2px;
  }
}

/* Reduced motion support */
@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
}