:root {
  /* Material 3 Deep Green Palette - Light Mode */
  --md-sys-color-primary: #1e8e3e;
  --md-sys-color-on-primary: #ffffff;
  --md-sys-color-primary-container: #81c995;
  --md-sys-color-on-primary-container: #00210a;
  
  --md-sys-color-secondary: #006b5b;
  --md-sys-color-on-secondary: #ffffff;
  --md-sys-color-secondary-container: #79f8dd;
  --md-sys-color-on-secondary-container: #00201a;
  
  --md-sys-color-surface: #fbfdf9;
  --md-sys-color-on-surface: #1a1c1a;
  --md-sys-color-surface-variant: #dde5db;
  --md-sys-color-on-surface-variant: #414941;
  --md-sys-color-outline: #717971;
  --md-sys-color-surface-container-low: #f5f8f3;
  --md-sys-color-surface-container: #eff2ec;

  /* Typography */
  --font-family: 'Roboto', 'Inter', system-ui, -apple-system, sans-serif;
  
  /* Layout */
  --max-width: 1200px;
  --spacing-base: 8px;
  --border-radius-md: 12px;
  --border-radius-lg: 24px;
}

@media (prefers-color-scheme: dark) {
  :root {
    /* Material 3 Deep Green Palette - Dark Mode */
    --md-sys-color-primary: #81c995;
    --md-sys-color-on-primary: #003915;
    --md-sys-color-primary-container: #005322;
    --md-sys-color-on-primary-container: #a2e7b3;
    
    --md-sys-color-surface: #121412;
    --md-sys-color-on-surface: #e1e3de;
    --md-sys-color-surface-variant: #414941;
    --md-sys-color-on-surface-variant: #c1c9be;
    --md-sys-color-outline: #8b938a;
    --md-sys-color-surface-container-low: #1a1c1a;
    --md-sys-color-surface-container: #1e201e;
  }
}

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

body {
  font-family: var(--font-family);
  background-color: var(--md-sys-color-surface);
  color: var(--md-sys-color-on-surface);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  transition: background-color 0.3s ease, color 0.3s ease;
}

/* Material Typography */
h1, h2, h3, h4 {
  font-weight: 500;
  line-height: 1.2;
  margin-bottom: 16px;
  color: var(--md-sys-color-on-surface);
}

h1 { font-size: clamp(2.5rem, 5vw, 3.5rem); letter-spacing: -0.02em; }
h2 { font-size: clamp(1.75rem, 3vw, 2.25rem); }
h3 { font-size: 1.5rem; }

p {
  margin-bottom: 16px;
  color: var(--md-sys-color-on-surface-variant);
}

a {
  color: var(--md-sys-color-primary);
  text-decoration: none;
  font-weight: 500;
  transition: color 0.2s ease;
}

a:hover {
  text-decoration: underline;
  color: var(--md-sys-color-primary-container);
}

/* Base Layout Objects */
.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 24px;
}

/* UI Elements */
.header-glass {
  position: sticky;
  top: 0;
  z-index: 100;
  background-color: color-mix(in srgb, var(--md-sys-color-surface) 80%, transparent);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--md-sys-color-outline);
  padding: 16px 0;
}

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

.nav-title {
  font-size: 1.25rem;
  font-weight: 600;
  color: var(--md-sys-color-primary);
}

.nav-links a {
  margin-left: 24px;
  color: var(--md-sys-color-on-surface);
}

.hero {
  padding: 120px 0 80px;
  text-align: center;
}

.hero-subtitle {
  font-size: 1.25rem;
  color: var(--md-sys-color-secondary);
  font-weight: 500;
  margin-bottom: 32px;
}

/* Cards (Material 3 State Layers & Elevation) */
.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: 24px;
  margin: 48px 0;
}

.card {
  background-color: var(--md-sys-color-surface-container);
  border-radius: var(--border-radius-lg);
  padding: 24px;
  border: 1px solid transparent;
  transition: all 0.3s cubic-bezier(0.2, 0, 0, 1);
  position: relative;
  overflow: hidden;
}

.card::before {
  content: "";
  position: absolute;
  top: 0; left: 0; right: 0; bottom: 0;
  background-color: var(--md-sys-color-on-surface);
  opacity: 0;
  transition: opacity 0.2s ease;
  pointer-events: none;
}

.card:hover {
  transform: translateY(-4px);
  box-shadow: 0 12px 24px -8px rgba(0,0,0,0.15);
  border-color: var(--md-sys-color-outline);
}

.card:hover::before {
  opacity: 0.04; /* State layer */
}

.card-title {
  color: var(--md-sys-color-primary);
  margin-bottom: 8px;
}

.tag {
  display: inline-block;
  padding: 4px 12px;
  border-radius: 100px;
  font-size: 0.875rem;
  font-weight: 500;
  background-color: var(--md-sys-color-secondary-container);
  color: var(--md-sys-color-on-secondary-container);
  margin-bottom: 16px;
}

/* Material Footer */
.footer {
  margin-top: 80px;
  padding: 40px 0;
  background-color: var(--md-sys-color-surface-container-low);
  text-align: center;
  border-top: 1px solid var(--md-sys-color-outline);
}

.footer-links {
  display: flex;
  justify-content: center;
  gap: 24px;
  margin-bottom: 16px;
  flex-wrap: wrap;
}

/* Document Article (For Privacy/Terms) */
.document-article {
  max-width: 800px;
  margin: 64px auto;
  background-color: var(--md-sys-color-surface-container);
  padding: 48px;
  border-radius: var(--border-radius-lg);
  box-shadow: 0 4px 12px rgba(0,0,0,0.05);
}

.document-article h1 { font-size: 2.25rem; margin-bottom: 8px;}
.document-article .last-updated { color: var(--md-sys-color-primary); font-weight: 500; margin-bottom: 48px; border-bottom: 1px solid var(--md-sys-color-outline); padding-bottom: 16px;}
.document-article h2 { margin-top: 40px; font-size: 1.5rem; }
.document-article p { margin-bottom: 24px; line-height: 1.8; }
.document-article ul { margin-bottom: 24px; padding-left: 24px; color: var(--md-sys-color-on-surface-variant); }

@media (max-width: 768px) {
  .document-article {
    padding: 32px 24px;
    margin: 32px 16px;
    border-radius: var(--border-radius-md);
  }
}