:root {
  --color-bg: #0F0F14;
  --color-surface: #181824;
  --color-surface-hover: #1F1F2E;
  --color-border: rgba(255, 255, 255, 0.08);
  --color-text-primary: #FFFFFF;
  --color-text-secondary: #A1A1AA;
  --color-text-muted: #71717A;
  --color-brand: #F59E0B;
  --color-brand-light: #FCD34D;
  --color-accent: #8B5CF6;
  --color-accent-light: #C4B5FD;
  --color-success: #10B981;
  --color-error: #EF4444;
  --color-warning: #F59E0B;
  --font-heading: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --font-body: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 16px;
  --radius-xl: 24px;
  --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.3);
  --shadow-md: 0 4px 16px rgba(0, 0, 0, 0.4);
  --shadow-lg: 0 8px 32px rgba(0, 0, 0, 0.5);
  --transition-fast: 150ms ease;
  --transition-normal: 250ms ease;
}

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

html {
  font-size: 16px;
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-body);
  background-color: var(--color-bg);
  color: var(--color-text-primary);
  line-height: 1.6;
  min-height: 100vh;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

.container {
  max-width: 900px;
  margin: 0 auto;
  padding: 2rem 1.5rem;
}

@media (min-width: 768px) {
  .container {
    padding: 3rem 2rem;
  }
}

/* Header */
.site-header {
  text-align: center;
  margin-bottom: 3rem;
  padding-bottom: 2rem;
  border-bottom: 1px solid var(--color-border);
}

.logo {
  font-family: var(--font-heading);
  font-size: 2.5rem;
  font-weight: 900;
  background: linear-gradient(135deg, var(--color-brand) 0%, var(--color-accent) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  margin-bottom: 0.5rem;
  letter-spacing: -0.02em;
}

@media (min-width: 768px) {
  .logo {
    font-size: 3rem;
  }
}

.subtitle {
  font-size: 1.125rem;
  color: var(--color-text-secondary);
  margin-bottom: 1rem;
}

.update-date {
  font-size: 0.875rem;
  color: var(--color-text-muted);
}

/* Navigation */
.nav-links {
  display: flex;
  flex-direction: column;
  gap: 1rem;
  margin-top: 2rem;
}

@media (min-width: 480px) {
  .nav-links {
    flex-direction: row;
    justify-content: center;
  }
}

.nav-link {
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 1rem 1.5rem;
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  color: var(--color-text-primary);
  text-decoration: none;
  font-weight: 600;
  font-size: 1rem;
  transition: all var(--transition-normal);
  flex: 1;
  max-width: 300px;
}

.nav-link:hover,
.nav-link:focus {
  background: var(--color-surface-hover);
  border-color: var(--color-brand);
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

.nav-link:active {
  transform: translateY(0);
}

/* Main content */
.main-content {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: 2rem;
  margin-bottom: 2rem;
}

@media (min-width: 768px) {
  .main-content {
    padding: 3rem;
  }
}

.page-title {
  font-family: var(--font-heading);
  font-size: 2rem;
  font-weight: 800;
  margin-bottom: 1.5rem;
  color: var(--color-text-primary);
}

@media (min-width: 768px) {
  .page-title {
    font-size: 2.5rem;
  }
}

/* Sections */
.section {
  margin-bottom: 2rem;
  padding-bottom: 2rem;
  border-bottom: 1px solid var(--color-border);
}

.section:last-child {
  border-bottom: none;
  margin-bottom: 0;
  padding-bottom: 0;
}

.section-title {
  font-family: var(--font-heading);
  font-size: 1.5rem;
  font-weight: 700;
  margin-bottom: 1rem;
  color: var(--color-brand);
}

@media (min-width: 768px) {
  .section-title {
    font-size: 1.75rem;
  }
}

.section-content {
  color: var(--color-text-secondary);
  line-height: 1.8;
}

.section-content p {
  margin-bottom: 1rem;
}

.section-content p:last-child {
  margin-bottom: 0;
}

.section-content ul,
.section-content ol {
  margin: 1rem 0;
  padding-left: 1.5rem;
}

.section-content li {
  margin-bottom: 0.5rem;
}

.section-content strong {
  color: var(--color-text-primary);
  font-weight: 600;
}

.section-content a {
  color: var(--color-brand-light);
  text-decoration: none;
  transition: color var(--transition-fast);
}

.section-content a:hover,
.section-content a:focus {
  color: var(--color-brand);
  text-decoration: underline;
}

/* Placeholder styling */
.placeholder {
  background: rgba(245, 158, 11, 0.1);
  border: 1px dashed var(--color-brand);
  border-radius: var(--radius-sm);
  padding: 0.25rem 0.5rem;
  color: var(--color-brand-light);
  font-weight: 600;
  font-size: 0.9em;
}

/* Footer */
.site-footer {
  text-align: center;
  padding-top: 2rem;
  border-top: 1px solid var(--color-border);
  color: var(--color-text-muted);
  font-size: 0.875rem;
}

.site-footer a {
  color: var(--color-brand-light);
  text-decoration: none;
}

.site-footer a:hover {
  text-decoration: underline;
}

/* Back link */
.back-link {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  margin-bottom: 1.5rem;
  color: var(--color-text-secondary);
  text-decoration: none;
  font-size: 0.9375rem;
  transition: color var(--transition-fast);
}

.back-link:hover,
.back-link:focus {
  color: var(--color-brand-light);
}

.back-link::before {
  content: "←";
  font-size: 1.2em;
}

/* Accessibility */
:focus-visible {
  outline: 2px solid var(--color-brand);
  outline-offset: 2px;
}

/* Print styles */
@media print {
  body {
    background: white;
    color: black;
  }

  .site-header,
  .site-footer,
  .back-link,
  .nav-links {
    display: none;
  }

  .main-content {
    background: white;
    border: none;
    padding: 0;
  }

  .section-title {
    color: black;
  }

  .section-content {
    color: black;
  }

  a {
    color: black;
    text-decoration: underline;
  }
}