/* ===== Shared Design System & Layout Tokens ===== */
:root {
  --font-mono: 'Space Mono', monospace;
  
  --color-gray-50: oklch(98.5% 0.002 247.839);
  --color-gray-100: oklch(96.7% 0.003 264.542);
  --color-gray-200: oklch(92.8% 0.006 264.531);
  --color-gray-400: oklch(70.7% 0.022 261.325);
  --color-gray-500: oklch(55.1% 0.027 264.364);
  --color-gray-600: oklch(44.6% 0.03 256.802);
  --color-gray-700: oklch(37.3% 0.034 259.733);
  --color-gray-800: oklch(27.8% 0.033 256.848);
  --color-gray-900: oklch(21% 0.034 264.665);
  
  --color-white: #fff;
  --color-blue-500: oklch(62.3% 0.214 259.815);
  --color-purple-500: oklch(62% 0.2 300);
  
  --radius-xl: 0.75rem;
  --radius-2xl: 1rem;
  --radius-full: 9999px;
  
  --tw-ease: cubic-bezier(0.4, 0, 0.2, 1);
  --tw-duration: 0.15s;
}

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

body {
  font-family: var(--font-mono);
  background-color: var(--color-white);
  color: var(--color-gray-900);
  -webkit-font-smoothing: antialiased;
  overflow-x: clip;
  line-height: 1.6;
}

.container {
  width: 100%;
  max-width: 64rem;
  margin-inline: auto;
  padding-inline: 1.5rem;
}

/* Header */
.header {
  position: sticky;
  top: 0;
  z-index: 100;
  background-color: transparent;
  border-bottom: 1px solid transparent;
  padding-block: 1.5rem;
  transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

.header.scrolled {
  background-color: rgba(255, 255, 255, 0.85);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--color-gray-100);
  padding-block: 0.875rem;
  box-shadow: 0 4px 30px rgba(0, 0, 0, 0.02);
}

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

.logo {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-weight: 700;
  font-size: 1.125rem;
  text-decoration: none;
  color: var(--color-gray-900);
}

.logo-svg {
  width: 2rem;
  height: 2rem;
  flex-shrink: 0;
  transition: transform 0.2s ease;
}

.logo:hover .logo-svg {
  transform: scale(1.1) rotate(5deg);
}

.nav-btn-back {
  font-size: 0.875rem;
  font-weight: 700;
  color: var(--color-gray-900);
  text-decoration: none;
  border: 1px solid var(--color-gray-200);
  padding: 0.5rem 1.25rem;
  border-radius: var(--radius-full);
  transition: all 0.2s ease;
  background: var(--color-gray-50);
}

.nav-btn-back:hover {
  background: var(--color-white);
  border-color: var(--color-gray-900);
  transform: translateY(-1px);
}

/* Breadcrumb Navigation */
.breadcrumb {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 0.8125rem;
  color: var(--color-gray-500);
  margin-bottom: 1.5rem;
}

.breadcrumb a {
  color: var(--color-blue-500);
  text-decoration: none;
  transition: color var(--tw-duration) var(--tw-ease);
}

.breadcrumb a:hover {
  color: var(--color-gray-900);
}

.breadcrumb span {
  color: var(--color-gray-400);
}

/* Page Hero */
.page-hero {
  padding-block: 4rem 2rem;
  text-align: center;
  position: relative;
}

.page-hero::before {
  content: '';
  position: absolute;
  width: 20rem;
  height: 20rem;
  background: radial-gradient(circle, rgba(99, 102, 241, 0.08) 0%, transparent 70%);
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  z-index: -1;
  pointer-events: none;
}

.page-title {
  font-size: 2.25rem;
  font-weight: 800;
  letter-spacing: -0.04em;
  margin-bottom: 0.75rem;
  background: linear-gradient(135deg, var(--color-blue-500), var(--color-purple-500));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.page-subtitle {
  font-size: 0.95rem;
  color: var(--color-gray-500);
  max-width: 38rem;
  margin-inline: auto;
}

/* Content Layout */
.content-wrapper {
  padding-block: 2rem 6rem;
  max-width: 48rem;
  margin-inline: auto;
}

.doc-section {
  background: var(--color-white);
  border: 1px solid var(--color-gray-200);
  border-radius: var(--radius-2xl);
  padding: 2.25rem;
  margin-bottom: 2rem;
  box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.02), 0 2px 4px -1px rgba(0, 0, 0, 0.01);
  transition: border-color 0.2s ease, box-shadow 0.2s ease;
}

.doc-section:hover {
  border-color: var(--color-gray-300);
  box-shadow: 0 10px 15px -3px rgba(0, 0, 0, 0.03);
}

.section-header {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  margin-bottom: 1.25rem;
}

.section-num {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 2.25rem;
  height: 2.25rem;
  background-color: var(--color-gray-50);
  border: 1px solid var(--color-gray-200);
  border-radius: var(--radius-xl);
  font-size: 0.875rem;
  font-weight: 700;
  color: var(--color-blue-500);
}

.section-title {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--color-gray-900);
  letter-spacing: -0.025em;
}

.doc-section p {
  color: var(--color-gray-600);
  font-size: 0.9375rem;
  margin-bottom: 1rem;
  line-height: 1.7;
}

.doc-section p strong {
  color: var(--color-gray-900);
}

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

.doc-section ul, .doc-section ol {
  list-style-type: none;
  padding: 0;
  margin: 1rem 0;
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

.doc-section li {
  position: relative;
  padding-left: 1.5rem;
  font-size: 0.9375rem;
  color: var(--color-gray-600);
}

.doc-section li::before {
  content: "→";
  position: absolute;
  left: 0;
  color: var(--color-blue-500);
  font-weight: 700;
}

/* Hub Grid Layout */
.hub-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1.5rem;
  margin-block: 2rem;
}

.hub-card {
  background: var(--color-white);
  border: 1px solid var(--color-gray-200);
  border-radius: var(--radius-2xl);
  padding: 1.75rem;
  text-decoration: none;
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
  box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.01);
  transition: all 0.2s cubic-bezier(0.16, 1, 0.3, 1);
}

.hub-card:hover {
  border-color: var(--color-blue-500);
  transform: translateY(-2px);
  box-shadow: 0 12px 20px -8px rgba(37, 99, 235, 0.08);
}

.hub-card-title {
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--color-gray-900);
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.hub-card-desc {
  font-size: 0.8125rem;
  color: var(--color-gray-500);
  line-height: 1.6;
}

.hub-card-btn {
  font-size: 0.8125rem;
  font-weight: 700;
  color: var(--color-blue-500);
  margin-top: auto;
  display: flex;
  align-items: center;
  gap: 0.25rem;
}

/* CTA Card */
.cta-card {
  background: linear-gradient(135deg, rgba(37, 99, 235, 0.03) 0%, rgba(99, 102, 241, 0.03) 100%);
  border: 1px dashed var(--color-blue-500);
  border-radius: var(--radius-2xl);
  padding: 2.25rem;
  text-align: center;
  margin-bottom: 2rem;
}

.cta-btn {
  display: inline-block;
  background: linear-gradient(135deg, var(--color-blue-500) 0%, var(--color-purple-500) 100%);
  color: var(--color-white);
  font-weight: 700;
  font-size: 0.95rem;
  text-decoration: none;
  padding: 0.85rem 2rem;
  border-radius: var(--radius-full);
  box-shadow: 0 4px 15px rgba(37, 99, 235, 0.2);
  transition: all 0.25s ease;
  margin-top: 1rem;
}

.cta-btn:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 20px rgba(37, 99, 235, 0.35);
}

/* FAQ Details */
.faq-item {
  border-bottom: 1px solid var(--color-gray-100);
  padding-block: 1.25rem;
}

.faq-item:last-child {
  border-bottom: none;
}

.faq-question {
  font-weight: 700;
  font-size: 1rem;
  color: var(--color-gray-900);
  margin-bottom: 0.5rem;
}

.faq-answer {
  font-size: 0.9375rem;
  color: var(--color-gray-600);
  line-height: 1.6;
}

/* Multi-column Footer Styles */
.footer {
  border-top: 1px solid var(--color-gray-100);
  padding-block: 4rem 3rem;
  background-color: var(--color-white);
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr;
  gap: 3rem;
  margin-bottom: 3rem;
}

.footer-col-info {
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.footer-brand {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-weight: 700;
  color: var(--color-gray-900);
  text-decoration: none;
}

.footer-brand-desc {
  font-size: 0.8125rem;
  color: var(--color-gray-500);
  line-height: 1.6;
  max-width: 24rem;
}

.footer-col-title {
  font-size: 0.875rem;
  font-weight: 700;
  color: var(--color-gray-900);
  margin-bottom: 1.25rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.footer-col-links {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

.footer-col-link {
  font-size: 0.8125rem;
  color: var(--color-gray-500);
  text-decoration: none;
  transition: color var(--tw-duration) var(--tw-ease);
}

.footer-col-link:hover {
  color: var(--color-gray-900);
}

.footer-bottom {
  display: flex;
  justify-content: space-between;
  align-items: center;
  border-top: 1px solid var(--color-gray-100);
  padding-top: 2rem;
  font-size: 0.75rem;
  color: var(--color-gray-400);
}

.footer-links {
  display: flex;
  gap: 1.5rem;
}

.footer-link {
  color: var(--color-gray-500);
  text-decoration: none;
  transition: color var(--tw-duration) var(--tw-ease);
  font-weight: 700;
}

.footer-link:hover {
  color: var(--color-gray-900);
}

/* API Tables */
.api-table-wrapper {
  overflow-x: auto;
  margin-block: 1.5rem;
  border: 1px solid var(--color-gray-200);
  border-radius: var(--radius-xl);
}

.api-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.8125rem;
  text-align: left;
}

.api-table th {
  background: var(--color-gray-50);
  padding: 0.75rem 1rem;
  font-weight: 700;
  color: var(--color-gray-900);
  border-bottom: 1px solid var(--color-gray-200);
}

.api-table td {
  padding: 0.75rem 1rem;
  color: var(--color-gray-600);
  border-bottom: 1px solid var(--color-gray-100);
}

.api-table tr:last-child td {
  border-bottom: none;
}

/* Code Snippets */
.code-block {
  background: var(--color-gray-50);
  border: 1px solid var(--color-gray-200);
  border-radius: var(--radius-xl);
  padding: 1.25rem;
  font-family: monospace;
  font-size: 0.8125rem;
  color: var(--color-gray-800);
  overflow-x: auto;
  margin-block: 1.5rem;
}

@media (max-width: 48rem) {
  .nav-flex, .footer-flex {
    flex-direction: column;
    text-align: center;
    gap: 1rem;
  }
  .page-hero {
    padding-block: 2.5rem 1.5rem;
  }
  .page-title {
    font-size: 1.75rem;
  }
  .content-wrapper {
    padding-block: 1rem 3rem;
  }
  .hub-grid {
    grid-template-columns: 1fr;
  }
  .footer-grid {
    grid-template-columns: 1fr;
    gap: 2rem;
  }
  .footer-bottom {
    flex-direction: column;
    gap: 1rem;
    text-align: center;
  }
}

/* ===== Format Table ===== */
.format-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.85rem;
  margin-top: 0.5rem;
}

.format-table thead {
  background: var(--color-gray-50);
}

.format-table th,
.format-table td {
  padding: 0.625rem 1rem;
  text-align: left;
  border-bottom: 1px solid var(--color-gray-100);
}

.format-table th {
  font-weight: 700;
  color: var(--color-gray-700);
  font-size: 0.8rem;
  text-transform: uppercase;
  letter-spacing: 0.04em;
}

.format-table td {
  color: var(--color-gray-600);
}

.format-table tbody tr:hover {
  background: var(--color-gray-50);
}

/* ===== FAQ Accordion ===== */
.faq-list {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.faq-item {
  border: 1px solid var(--color-gray-100);
  border-radius: var(--radius-xl);
  overflow: hidden;
  transition: border-color 0.2s ease;
}

.faq-item[open] {
  border-color: var(--color-gray-200);
}

.faq-question {
  padding: 0.875rem 1rem;
  font-weight: 700;
  font-size: 0.9rem;
  cursor: pointer;
  list-style: none;
  display: flex;
  justify-content: space-between;
  align-items: center;
  user-select: none;
  color: var(--color-gray-800);
  transition: background 0.15s ease;
}

.faq-question:hover {
  background: var(--color-gray-50);
}

.faq-question::after {
  content: '+';
  font-size: 1.2rem;
  font-weight: 700;
  color: var(--color-gray-400);
  transition: transform 0.2s ease;
}

.faq-item[open] .faq-question::after {
  content: '−';
  transform: rotate(180deg);
}

.faq-question::-webkit-details-marker {
  display: none;
}

.faq-answer {
  padding: 0 1rem 0.875rem;
  font-size: 0.85rem;
  color: var(--color-gray-600);
  line-height: 1.7;
}

/* ===== Content Lists ===== */
.doc-section ul {
  list-style: none;
  padding: 0;
}

.doc-section ul li {
  padding: 0.375rem 0;
  padding-left: 1.25rem;
  position: relative;
  font-size: 0.9rem;
  color: var(--color-gray-600);
}

.doc-section ul li::before {
  content: '→';
  position: absolute;
  left: 0;
  color: var(--color-blue-500);
  font-weight: 700;
}