:root {
  --vb-ink-9: #0B1220;
  --vb-ink-6: #2A3550;
  --vb-snow-0: #F7FAFF;
  --vb-glass-1: rgba(255,255,255,0.62);
  --vb-aurora-1: #6EE7FF;
  --vb-aurora-2: #A78BFA;
  --vb-mint-3: #34D399;
  --vb-amber-4: #FBBF24;
  --vb-line-2: rgba(11,18,32,0.12);
  --spacing-xs: 0.5rem;
  --spacing-sm: 1rem;
  --spacing-md: 1.5rem;
  --spacing-lg: 2.5rem;
  --spacing-xl: 4rem;
}

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

html {
  font-size: 16px;
  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: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
  line-height: 1.7;
  color: var(--vb-ink-9);
  background: linear-gradient(135deg, var(--vb-snow-0) 0%, #E0EFFF 100%);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

main {
  flex: 1 0 auto;
  padding-block: var(--spacing-lg);
}

.skip-link {
  position: absolute;
  top: -100px;
  left: var(--spacing-sm);
  background-color: var(--vb-aurora-1);
  color: var(--vb-ink-9);
  padding: var(--spacing-xs) var(--spacing-sm);
  text-decoration: none;
  border-radius: 4px;
  font-weight: 600;
  z-index: 9999;
}

.skip-link:focus {
  top: var(--spacing-sm);
}

h1, h2, h3, h4 {
  font-weight: 700;
  line-height: 1.3;
  margin-bottom: var(--spacing-sm);
}

h1 {
  font-size: 2.25rem;
  color: var(--vb-ink-9);
  background: linear-gradient(120deg, var(--vb-aurora-1), var(--vb-aurora-2));
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
}

h2 {
  font-size: 1.875rem;
  color: var(--vb-ink-6);
  border-left: 4px solid var(--vb-mint-3);
  padding-left: var(--spacing-sm);
}

h3 {
  font-size: 1.5rem;
  color: var(--vb-ink-6);
}

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

a {
  color: var(--vb-aurora-2);
  text-decoration: underline;
  transition: color 0.25s ease, text-decoration-color 0.25s ease;
}

a:hover {
  color: var(--vb-aurora-1);
  text-decoration-color: var(--vb-mint-3);
}

a:focus-visible {
  outline: 3px solid var(--vb-amber-4);
  outline-offset: 3px;
  border-radius: 2px;
}

.site-header {
  background: var(--vb-glass-1);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--vb-line-2);
  position: sticky;
  top: 0;
  z-index: 1000;
  box-shadow: 0 2px 8px rgba(11, 18, 32, 0.08);
}

.header-container {
  max-width: 1200px;
  margin-inline: auto;
  padding: var(--spacing-sm) var(--spacing-md);
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: var(--spacing-sm);
}

.site-branding .site-name {
  font-size: 1.5rem;
  font-weight: 800;
  color: var(--vb-ink-9);
  letter-spacing: -0.02em;
}

.main-nav ul {
  list-style: none;
  display: flex;
  gap: var(--spacing-md);
  flex-wrap: wrap;
}

.main-nav a {
  text-decoration: none;
  color: var(--vb-ink-6);
  font-weight: 600;
  padding: var(--spacing-xs) var(--spacing-sm);
  border-radius: 6px;
  transition: background-color 0.3s ease, color 0.3s ease, transform 0.2s ease;
}

.main-nav a:hover {
  background-color: rgba(110, 231, 255, 0.2);
  color: var(--vb-ink-9);
  transform: translateY(-2px);
}

.main-nav a[aria-current="page"] {
  background-color: var(--vb-aurora-1);
  color: var(--vb-ink-9);
}

.breadcrumb {
  max-width: 1200px;
  margin-inline: auto;
  padding: var(--spacing-sm) var(--spacing-md);
}

.breadcrumb ol {
  list-style: none;
  display: flex;
  gap: var(--spacing-xs);
  flex-wrap: wrap;
  font-size: 0.875rem;
}

.breadcrumb li:not(:last-child)::after {
  content: '/';
  margin-left: var(--spacing-xs);
  color: var(--vb-ink-6);
}

.breadcrumb a {
  color: var(--vb-aurora-2);
  text-decoration: none;
  transition: color 0.2s ease;
}

.breadcrumb a:hover {
  color: var(--vb-aurora-1);
  text-decoration: underline;
}

.section-container {
  max-width: 1200px;
  margin-inline: auto;
  padding-inline: var(--spacing-md);
}

section {
  margin-bottom: var(--spacing-xl);
}

.hero-section {
  background: linear-gradient(135deg, rgba(110, 231, 255, 0.15), rgba(167, 139, 250, 0.15));
  border-radius: 16px;
  padding: var(--spacing-lg);
  box-shadow: 0 8px 24px rgba(11, 18, 32, 0.1);
  border: 1px solid var(--vb-line-2);
}

.intro-content p:first-of-type::first-letter {
  font-size: 3rem;
  font-weight: 700;
  float: left;
  line-height: 1;
  margin-right: 0.1em;
  color: var(--vb-aurora-2);
}

.rules-section {
  background-color: white;
  border-radius: 12px;
  padding: var(--spacing-lg) var(--spacing-md);
  box-shadow: 0 4px 16px rgba(11, 18, 32, 0.06);
}

.tip-box {
  background: linear-gradient(to right, rgba(52, 211, 153, 0.1), rgba(110, 231, 255, 0.1));
  border-left: 5px solid var(--vb-mint-3);
  padding: var(--spacing-md);
  margin-top: var(--spacing-md);
  border-radius: 8px;
}

.tip-box h3 {
  color: var(--vb-mint-3);
  margin-bottom: var(--spacing-sm);
  font-size: 1.25rem;
}

.tip-box ul {
  list-style-position: inside;
  padding-left: var(--spacing-sm);
}

.tip-box li {
  margin-bottom: var(--spacing-xs);
}

.table-section {
  background: rgba(255, 255, 255, 0.7);
  backdrop-filter: blur(8px);
  border-radius: 12px;
  padding: var(--spacing-lg) var(--spacing-md);
  border: 1px solid var(--vb-line-2);
}

.table-wrapper {
  overflow-x: auto;
  margin-block: var(--spacing-md);
  border-radius: 8px;
  box-shadow: 0 2px 12px rgba(11, 18, 32, 0.08);
}

table {
  width: 100%;
  border-collapse: collapse;
  background-color: white;
  font-size: 0.95rem;
}

caption {
  caption-side: top;
  padding: var(--spacing-sm);
  font-weight: 700;
  font-size: 1.1rem;
  color: var(--vb-ink-9);
  text-align: left;
  background: linear-gradient(90deg, var(--vb-aurora-1), var(--vb-aurora-2));
  color: white;
  border-radius: 8px 8px 0 0;
}

thead {
  background-color: var(--vb-ink-6);
  color: white;
}

th {
  padding: var(--spacing-sm);
  text-align: left;
  font-weight: 600;
  border-bottom: 2px solid var(--vb-line-2);
}

td {
  padding: var(--spacing-sm);
  border-bottom: 1px solid var(--vb-line-2);
}

tbody tr:nth-child(odd) {
  background-color: rgba(110, 231, 255, 0.05);
}

tbody tr:hover {
  background-color: rgba(167, 139, 250, 0.1);
  transition: background-color 0.3s ease;
}

td:nth-child(2), td:nth-child(3) {
  text-align: right;
  font-variant-numeric: tabular-nums;
}

.table-explanation {
  margin-top: var(--spacing-md);
  padding: var(--spacing-md);
  background-color: rgba(251, 191, 36, 0.1);
  border-left: 4px solid var(--vb-amber-4);
  border-radius: 6px;
}

.sources-section {
  background: white;
  padding: var(--spacing-lg) var(--spacing-md);
  border-radius: 12px;
  box-shadow: 0 6px 20px rgba(11, 18, 32, 0.08);
}

.authoritative-links {
  list-style: none;
  margin-top: var(--spacing-md);
}

.authoritative-links li {
  margin-bottom: var(--spacing-sm);
  padding-left: var(--spacing-md);
  position: relative;
}

.authoritative-links li::before {
  content: '→';
  position: absolute;
  left: 0;
  color: var(--vb-mint-3);
  font-weight: 700;
}

.internal-section {
  background: linear-gradient(to bottom right, rgba(167, 139, 250, 0.1), rgba(110, 231, 255, 0.1));
  padding: var(--spacing-lg) var(--spacing-md);
  border-radius: 12px;
  border: 2px dashed var(--vb-aurora-2);
}

.internal-links {
  list-style: none;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: var(--spacing-md);
  margin-top: var(--spacing-md);
}

.internal-links li a {
  display: block;
  padding: var(--spacing-md);
  background-color: white;
  border-radius: 8px;
  text-decoration: none;
  font-weight: 600;
  color: var(--vb-ink-9);
  box-shadow: 0 2px 8px rgba(11, 18, 32, 0.1);
  transition: transform 0.3s ease, box-shadow 0.3s ease, background-color 0.3s ease;
}

.internal-links li a:hover {
  transform: translateY(-4px);
  box-shadow: 0 8px 24px rgba(110, 231, 255, 0.3);
  background-color: var(--vb-aurora-1);
}

.intro-section {
  background: rgba(255, 255, 255, 0.8);
  padding: var(--spacing-lg) var(--spacing-md);
  border-radius: 12px;
  box-shadow: 0 4px 16px rgba(11, 18, 32, 0.07);
}

.accordion-section {
  background-color: white;
  padding: var(--spacing-lg) var(--spacing-md);
  border-radius: 12px;
  box-shadow: 0 4px 16px rgba(11, 18, 32, 0.06);
}

.faq-accordion {
  margin-block: var(--spacing-md);
}

details {
  background-color: rgba(110, 231, 255, 0.08);
  border: 1px solid var(--vb-line-2);
  border-radius: 8px;
  margin-bottom: var(--spacing-sm);
  padding: var(--spacing-sm);
  transition: background-color 0.3s ease, box-shadow 0.3s ease;
}

details:hover {
  background-color: rgba(167, 139, 250, 0.1);
  box-shadow: 0 4px 12px rgba(11, 18, 32, 0.1);
}

details[open] {
  background-color: rgba(52, 211, 153, 0.08);
  border-color: var(--vb-mint-3);
}

summary {
  cursor: pointer;
  font-weight: 700;
  font-size: 1.1rem;
  color: var(--vb-ink-9);
  padding: var(--spacing-sm);
  list-style: none;
  display: flex;
  align-items: center;
  gap: var(--spacing-xs);
  transition: color 0.2s ease;
}

summary::-webkit-details-marker {
  display: none;
}

summary::before {
  content: '▶';
  display: inline-block;
  transition: transform 0.3s ease;
  color: var(--vb-aurora-2);
  font-size: 0.875rem;
}

details[open] summary::before {
  transform: rotate(90deg);
  color: var(--vb-mint-3);
}

summary:hover {
  color: var(--vb-aurora-2);
}

summary:focus-visible {
  outline: 3px solid var(--vb-amber-4);
  outline-offset: 2px;
  border-radius: 4px;
}

details div[itemprop="text"] {
  padding: var(--spacing-md);
  padding-top: var(--spacing-sm);
  color: var(--vb-ink-6);
  line-height: 1.7;
}

.accordion-context {
  margin-top: var(--spacing-lg);
  padding: var(--spacing-md);
  background: linear-gradient(to right, rgba(251, 191, 36, 0.1), rgba(110, 231, 255, 0.1));
  border-radius: 8px;
  border-left: 4px solid var(--vb-amber-4);
}

.who-section, .method-section, .references-section, .cta-section {
  background-color: white;
  padding: var(--spacing-lg) var(--spacing-md);
  border-radius: 12px;
  box-shadow: 0 4px 16px rgba(11, 18, 32, 0.06);
  margin-bottom: var(--spacing-lg);
}

.site-footer {
  background: linear-gradient(to top, var(--vb-ink-9), var(--vb-ink-6));
  color: var(--vb-snow-0);
  padding-block: var(--spacing-lg);
  margin-top: auto;
  flex-shrink: 0;
}

.footer-container {
  max-width: 1200px;
  margin-inline: auto;
  padding-inline: var(--spacing-md);
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--spacing-md);
  text-align: center;
}

.footer-nav ul {
  list-style: none;
  display: flex;
  justify-content: center;
  gap: var(--spacing-md);
  flex-wrap: wrap;
}

.footer-nav a {
  color: var(--vb-snow-0);
  text-decoration: none;
  font-weight: 500;
  transition: color 0.2s ease, text-decoration 0.2s ease;
}

.footer-nav a:hover {
  color: var(--vb-aurora-1);
  text-decoration: underline;
}

.copyright, .disclaimer {
  font-size: 0.875rem;
  color: rgba(247, 250, 255, 0.8);
}

@media (min-width: 768px) {
  .footer-container {
    grid-template-columns: 1fr 2fr 1fr;
    text-align: left;
  }
  .footer-nav ul {
    justify-content: flex-start;
  }
}

@media (max-width: 767px) {
  h1 {
    font-size: 1.75rem;
  }
  h2 {
    font-size: 1.5rem;
  }
  .header-container {
    flex-direction: column;
    align-items: flex-start;
  }
  .main-nav ul {
    flex-direction: column;
    gap: var(--spacing-xs);
  }
  .internal-links {
    grid-template-columns: 1fr;
  }
  table {
    font-size: 0.85rem;
  }
  th, td {
    padding: var(--spacing-xs);
  }
}