/* Design Tokens */
:root {
  /* Colors - Light Mode - Blueish-grey theme */
  --color-bg: #F8F9FA;
  --color-text: #1A1F2E;
  --color-text-secondary: #5A6C7D;
  --color-text-tertiary: #8A9BA8;
  --color-border: #D1D9E0;
  --color-border-light: #E8EDF2;
  --color-accent: #6B8FA8; /* Blueish-grey accent */
  --color-accent-hover: #5A7D96;
  --color-neutral-100: #F0F3F6;
  --color-neutral-200: #E1E7ED;
  --color-neutral-300: #C8D1D9;
  --color-neutral-600: #6B7A8A;
  --color-neutral-700: #4A5568;
  
  /* Typography */
  --font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Inter', system-ui, sans-serif;
  --font-size-base: 16px;
  --font-size-sm: 14px;
  --font-size-lg: 18px;
  --font-size-xl: 20px;
  --line-height-base: 1.6;
  --line-height-tight: 1.4;
  --line-height-loose: 1.8;
  
  /* Spacing */
  --spacing-xs: 8px;
  --spacing-sm: 16px;
  --spacing-md: 24px;
  --spacing-lg: 32px;
  --spacing-xl: 56px;
  --spacing-2xl: 80px;
  --spacing-3xl: 120px;
  
  /* Layout */
  --max-width: 1120px;
  --gutter-mobile: 24px;
  --gutter-desktop: 32px;
  
  /* Typography Scale */
  --font-size-h1: clamp(36px, 5vw, 64px);
  --font-size-h2: clamp(28px, 4vw, 40px);
  --font-size-h3: clamp(22px, 3vw, 28px);
  --font-size-h4: clamp(18px, 2.5vw, 24px);
  
  /* Shadows */
  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 6px rgba(0, 0, 0, 0.07);
  --shadow-lg: 0 10px 20px rgba(0, 0, 0, 0.1);
  
  /* Transitions */
  --transition-fast: 150ms ease;
  --transition-base: 250ms ease;
  --transition-slow: 350ms ease;
  
  /* Border Radius */
  --radius-sm: 4px;
  --radius-md: 8px;
  --radius-lg: 12px;
  
  /* Z-index */
  --z-header: 100;
  --z-overlay: 200;
}

/* Dark Mode */
@media (prefers-color-scheme: dark) {
  :root {
    --color-bg: #0F1419;
    --color-text: #E8EDF2;
    --color-text-secondary: #A8B8C8;
    --color-text-tertiary: #7A8A9A;
    --color-border: #2A3440;
    --color-border-light: #1A2328;
    --color-neutral-100: #1A2328;
    --color-neutral-200: #2A3440;
    --color-neutral-300: #3A4450;
    --color-neutral-600: #A8B8C8;
    --color-neutral-700: #D1D9E0;
    --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.3);
    --shadow-md: 0 4px 6px rgba(0, 0, 0, 0.4);
    --shadow-lg: 0 10px 20px rgba(0, 0, 0, 0.5);
  }
}

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

html {
  font-size: var(--font-size-base);
  scroll-behavior: smooth;
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }
  
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
}

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

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

h1 {
  font-size: var(--font-size-h1);
  font-weight: 700;
  margin-bottom: var(--spacing-lg);
}

h2 {
  font-size: var(--font-size-h2);
  margin-bottom: var(--spacing-md);
}

h3 {
  font-size: var(--font-size-h3);
  margin-bottom: var(--spacing-sm);
}

h4 {
  font-size: var(--font-size-h4);
  margin-bottom: var(--spacing-sm);
}

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

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

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

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

/* Utilities */
.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;
}

.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 var(--gutter-mobile);
}

@media (min-width: 768px) {
  .container {
    padding: 0 var(--gutter-desktop);
  }
}

/* Section Spacing */
.section {
  padding: var(--spacing-2xl) 0;
}

@media (min-width: 768px) {
  .section {
    padding: var(--spacing-3xl) 0;
  }
}

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

.section-lg {
  padding: var(--spacing-3xl) 0;
}

@media (min-width: 768px) {
  .section-lg {
    padding: calc(var(--spacing-3xl) * 1.5) 0;
  }
}