@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700;800&display=swap');

:root {
  /* Color Palette */
  --bg-primary: #ffffff; /* White */
  --bg-secondary: #f3f4f6; /* Light Gray */
  --text-primary: #000000; /* Black */
  --text-secondary: #4b5563; /* Gray */
  
  --primary-color: #ff246a; /* Logo Pink */
  --primary-hover: #e01555; /* Darker Logo Pink */
  --secondary-color: #F40009; /* Coca-Cola Red */
  --accent-color: #00d100; /* Logo Parrot Green */
  
  --border-color: #e2e8f0;
  
  /* Layout */
  --container-width: 1280px;
  --spacing-sm: 0.5rem;
  --spacing-md: 1rem;
  --spacing-lg: 2rem;
  --spacing-xl: 4rem;

  /* Shadows */
  --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
  --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
  --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1), 0 4px 6px -4px rgb(0 0 0 / 0.1);
  --shadow-xl: 0 20px 25px -5px rgb(0 0 0 / 0.1), 0 8px 10px -6px rgb(0 0 0 / 0.1);
  
  /* Glassmorphism */
  --glass-bg: rgba(255, 255, 255, 0.7);
  --glass-border: rgba(255, 255, 255, 0.5);
}

/* Dark Mode Theme */
[data-theme="dark"] {
  --bg-primary: #000000; /* Black */
  --bg-secondary: #1f2937; /* Dark Gray */
  --text-primary: #ffffff; /* White */
  --text-secondary: #d1d5db; /* Light Gray */
  
  --border-color: #374151;
  
  --glass-bg: rgba(15, 23, 42, 0.7);
  --glass-border: rgba(255, 255, 255, 0.1);
}

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

html {
  scroll-behavior: smooth;
  font-family: 'Inter', sans-serif;
}

body {
  background-color: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.6;
  transition: background-color 0.3s ease, color 0.3s ease;
  overflow-x: hidden;
}

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

ul {
  list-style: none;
}

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

/* Utility Classes */
.container {
  max-width: var(--container-width);
  margin: 0 auto;
  padding: 0 var(--spacing-lg);
}

.section {
  padding: var(--spacing-xl) 0;
}

/* Typography */
h1, h2, h3, h4, h5, h6 {
  font-weight: 700;
  line-height: 1.2;
  margin-bottom: var(--spacing-md);
}

h1 {
  font-size: clamp(2.5rem, 5vw, 4rem);
  letter-spacing: -0.02em;
}

h2 {
  font-size: clamp(2rem, 4vw, 3rem);
  letter-spacing: -0.01em;
}

h3 {
  font-size: clamp(1.5rem, 3vw, 2rem);
}

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

.text-gradient {
  background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.75rem 1.5rem;
  border-radius: 9999px;
  font-weight: 600;
  font-size: 1rem;
  transition: all 0.3s ease;
  cursor: pointer;
  border: none;
  gap: 0.5rem;
}

.btn-primary {
  background-color: var(--primary-color);
  color: #fff;
  box-shadow: 0 4px 14px 0 rgba(59, 130, 246, 0.39);
}

.btn-primary:hover {
  background-color: var(--primary-hover);
  transform: translateY(-2px);
  box-shadow: 0 6px 20px rgba(59, 130, 246, 0.23);
}

.btn-outline {
  background-color: transparent;
  border: 1px solid var(--border-color);
  color: var(--text-primary);
}

.btn-outline:hover {
  border-color: var(--primary-color);
  color: var(--primary-color);
}

/* Glassmorphism */
.glass {
  background: var(--glass-bg);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border: 1px solid var(--glass-border);
}

/* Header & Navigation */
header {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  z-index: 1000;
  transition: all 0.3s ease;
  padding: var(--spacing-md) 0;
  background: rgba(255, 255, 255, 0.85);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid rgba(0, 0, 0, 0.05);
}

[data-theme="dark"] header {
  background: rgba(0, 0, 0, 0.85);
  border-bottom: 1px solid rgba(255, 255, 255, 0.05);
}

header.scrolled {
  padding: 0.5rem 0;
  box-shadow: var(--shadow-md);
  border-bottom-color: var(--border-color);
}

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

.logo {
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

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

.logo-icon {
  color: var(--primary-color);
}

.nav-links {
  display: flex;
  gap: 2rem;
  align-items: center;
}

.nav-link {
  font-weight: 500;
  color: var(--text-secondary);
  transition: all 0.3s ease;
  position: relative;
  padding: 0.5rem 1rem;
  border-radius: 9999px;
}

.nav-link:hover {
  color: var(--primary-color);
  background: rgba(255, 36, 106, 0.08);
}

.mobile-menu-btn {
  display: none;
  background: none;
  border: none;
  color: var(--text-primary);
  font-size: 1.5rem;
  cursor: pointer;
}

.theme-toggle {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
  border-radius: 50%;
  background-color: var(--bg-secondary);
  border: 1px solid var(--border-color);
  color: var(--text-primary);
  font-size: 1.25rem;
  cursor: pointer;
  transition: all 0.3s ease;
}

.theme-toggle:hover {
  background-color: var(--primary-color);
  color: #ffffff;
  border-color: var(--primary-color);
  transform: rotate(15deg) scale(1.05);
  box-shadow: 0 4px 10px rgba(255, 36, 106, 0.3);
}

.floating-toggle {
  position: fixed;
  bottom: 2rem;
  left: 2rem;
  z-index: 9999;
  width: 50px;
  height: 50px;
  background-color: var(--bg-primary);
  box-shadow: var(--shadow-lg);
  font-size: 1.5rem;
}

@media (max-width: 768px) {
  .floating-toggle {
    bottom: 1rem;
    left: 1rem;
    width: 45px;
    height: 45px;
    font-size: 1.25rem;
  }
}

/* Animations */
@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(20px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.animate-fade-in-up {
  animation: fadeInUp 0.8s ease-out forwards;
}

.delay-100 { animation-delay: 100ms; }
.delay-200 { animation-delay: 200ms; }
.delay-300 { animation-delay: 300ms; }

/* Animated Gradient Background */
.animated-gradient-bg {
  background: linear-gradient(-45deg, var(--primary-color), var(--secondary-color), var(--accent-color), var(--primary-hover));
  background-size: 400% 400%;
  animation: gradient 15s ease infinite;
}

@keyframes gradient {
  0% { background-position: 0% 50%; }
  50% { background-position: 100% 50%; }
  100% { background-position: 0% 50%; }
}

/* Responsive & Mobile Optimization */
@media (max-width: 992px) {
  .nav-links {
    display: none; /* Hide on mobile by default, toggled via JS */
  }
  
  .mobile-menu-btn {
    display: block;
  }
  
  .nav-links.active {
    display: flex;
    flex-direction: column;
    position: absolute;
    top: 100%;
    left: 0;
    width: 100%;
    background-color: var(--bg-primary);
    padding: var(--spacing-lg);
    box-shadow: var(--shadow-md);
    border-top: 1px solid var(--border-color);
    max-height: calc(100vh - 70px);
    overflow-y: auto;
    z-index: 1000;
  }

  .nav-links .nav-link {
    padding: 0.75rem 0;
    border-bottom: 1px solid var(--border-color);
    width: 100%;
  }

  .nav-actions {
    gap: 0.5rem;
  }
}

@media (max-width: 768px) {
  .container {
    padding-left: 1.25rem;
    padding-right: 1.25rem;
  }

  h1 {
    font-size: clamp(2rem, 8vw, 2.75rem);
  }

  h2 {
    font-size: clamp(1.6rem, 6vw, 2.2rem);
  }

  .btn-lg {
    padding: 0.75rem 1.5rem;
    font-size: 1rem;
    width: 100%;
    justify-content: center;
  }

  .anniversary-top-bar {
    font-size: 0.82rem !important;
    padding: 0.45rem 0.75rem !important;
    text-align: center;
  }

  .anniversary-top-bar a {
    font-size: 0.78rem !important;
    padding: 0.2rem 0.65rem !important;
  }
}

@media (max-width: 480px) {
  .anniversary-top-bar {
    flex-direction: column !important;
    gap: 0.35rem !important;
    font-size: 0.78rem !important;
    padding: 0.5rem 0.5rem !important;
  }

  .logo-img {
    max-height: 34px;
  }

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