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

:root {
  /* Colors - Dark Theme - WCAG Compliant */
  --primary-dark: #1a1a2e;
  --primary-blue: #4a9eff; /* Lighter for dark mode contrast */
  --accent-blue: #0a3555;
  --light-blue: #e3f2fd;
  --text-primary: #ffffff;
  --text-secondary: #c9d1d9; /* Lighter for better contrast */
  --text-light: #8b949e; /* Lighter for better contrast */
  --background-primary: #0d1117;
  --background-secondary: #161b22;
  --border-color: #30363d;
  --shadow-light: 0 2px 10px rgba(0, 0, 0, 0.3);
  --shadow-medium: 0 4px 20px rgba(0, 0, 0, 0.4);
  --shadow-heavy: 0 8px 30px rgba(0, 0, 0, 0.5);

  /* Typography */
  --font-family: "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto,
    sans-serif;
  --font-size-xs: 0.75rem;
  --font-size-sm: 0.875rem;
  --font-size-base: 1rem;
  --font-size-lg: 1.125rem;
  --font-size-xl: 1.25rem;
  --font-size-2xl: 1.5rem;
  --font-size-3xl: 1.875rem;
  --font-size-4xl: 2.25rem;
  --font-size-5xl: 3rem;

  /* Spacing */
  --space-xs: 0.5rem;
  --space-sm: 0.75rem;
  --space-md: 1rem;
  --space-lg: 1.5rem;
  --space-xl: 2rem;
  --space-2xl: 3rem;
  --space-3xl: 4rem;
  --space-4xl: 6rem;

  /* Layout */
  --container-max-width: 1200px;
  --section-padding: var(--space-4xl) var(--space-xl);
  --border-radius: 12px;
  --border-radius-sm: 8px;
  --border-radius-lg: 16px;

  /* Transitions */
  --transition-fast: 0.2s ease;
  --transition-medium: 0.3s ease;
  --transition-slow: 0.5s ease;
}

/* Navigation styles for dark theme */
nav-header {
  background-color: rgba(13, 17, 23, 0.98) !important;
  border-bottom: 1px solid var(--border-color);
}

nav-header .nav-link:hover,
nav-header .nav-link.active {
  background-color: rgba(74, 158, 255, 0.15);
}

nav-header .mobile-menu-btn:hover {
  background-color: rgba(74, 158, 255, 0.15);
}

/* Base styles */
html {
  scroll-behavior: smooth;
  font-size: 16px;
}

body {
  font-family: var(--font-family);
  line-height: 1.6;
  color: var(--text-primary);
  background-color: var(--background-primary);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

/* Container utility */
.container {
  max-width: var(--container-max-width);
  margin: 0 auto;
  padding: 0 var(--space-xl);
}

/* Section utility */
.section {
  padding: var(--section-padding);
}

/* Button styles */
.btn {
  display: inline-flex;
  align-items: center;
  gap: var(--space-sm);
  padding: var(--space-sm) var(--space-lg);
  border: none;
  border-radius: var(--border-radius-sm);
  font-family: inherit;
  font-size: var(--font-size-base);
  font-weight: 500;
  text-decoration: none;
  cursor: pointer;
  transition: all var(--transition-medium);
  white-space: nowrap;
}

.btn-primary {
  background-color: var(--primary-blue);
  color: white;
}

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

.btn-secondary {
  background-color: transparent;
  color: var(--primary-blue);
  border: 2px solid var(--primary-blue);
}

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

.btn-lg {
  padding: var(--space-md) var(--space-xl);
  font-size: var(--font-size-lg);
}

/* Card styles */
.card {
  background-color: var(--background-primary);
  border-radius: var(--border-radius);
  padding: var(--space-xl);
  box-shadow: var(--shadow-light);
  transition: all var(--transition-medium);
  border: 1px solid var(--border-color);
}

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

/* Grid utilities */
.grid {
  display: grid;
  gap: var(--space-xl);
}

/* Flex utilities */
.flex {
  display: flex;
}

.flex-col {
  flex-direction: column;
}

.items-center {
  align-items: center;
}

.justify-center {
  justify-content: center;
}

.justify-between {
  justify-content: space-between;
}

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

.animate-fade-in-up {
  animation: fadeInUp 0.6s ease-out forwards;
}

/* Focus styles for accessibility */
*:focus {
  outline: 3px solid var(--primary-blue); /* Thicker outline */
  outline-offset: 3px;
  border-radius: 2px;
}

/* Button focus styles */
.btn:focus {
  outline: 3px solid var(--primary-blue);
  outline-offset: 2px;
}

/* Link focus styles */
a:focus {
  outline: 3px solid var(--primary-blue);
  outline-offset: 2px;
  text-decoration: underline;
}

/* High contrast mode support */
@media (prefers-contrast: high) {
  :root {
    --text-primary: #ffffff;
    --text-secondary: #ffffff;
    --primary-blue: #66b3ff;
    --background-primary: #000000;
    --border-color: #ffffff;
  }
}

/* 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;
    scroll-behavior: auto !important;
  }
}

/* Selection styles */
::selection {
  background-color: rgba(74, 158, 255, 0.3);
  color: var(--text-primary);
}

/* Scrollbar styles */
::-webkit-scrollbar {
  width: 8px;
}

::-webkit-scrollbar-track {
  background: var(--background-secondary);
}

::-webkit-scrollbar-thumb {
  background: var(--border-color);
  border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
  background: var(--text-light);
}