@import url('https://fonts.googleapis.com/css2?family=Instrument+Serif:ital@0;1&family=JetBrains+Mono:wght@400;500;600&family=Plus+Jakarta+Sans:wght@400;500;600;700&display=swap');

:root {
  --bg-app: #FAFAFA;
  --bg-sidebar: #FFFFFF;
  --bg-main: #FFFFFF;
  --bg-card: #F9F9F8;
  --border-color: #EAEAEA;
  --border-darker: #D8D8D8;
  
  --text-primary: #111111;
  --text-secondary: #444444;
  --text-muted: #737373;
  --text-link: #0066CC;
  
  /* GitBook Pastel Callouts */
  --callout-info-bg: #E1F3FE;
  --callout-info-border: #38BDF8;
  --callout-info-text: #1F6C9F;
  
  --callout-tip-bg: #EDF3EC;
  --callout-tip-border: #4ADE80;
  --callout-tip-text: #346538;
  
  --callout-warn-bg: #FBF3DB;
  --callout-warn-border: #FACC15;
  --callout-warn-text: #956400;
  
  --font-serif: 'Instrument Serif', Georgia, serif;
  --font-sans: 'Plus Jakarta Sans', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  --font-mono: 'JetBrains Mono', 'SF Mono', monospace;
  
  --sidebar-width: 280px;
  --toc-width: 220px;
}

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

body {
  font-family: var(--font-sans);
  background-color: var(--bg-app);
  color: var(--text-secondary);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

/* Header */
header.gitbook-header {
  height: 60px;
  background: var(--bg-sidebar);
  border-bottom: 1px solid var(--border-color);
  position: sticky;
  top: 0;
  z-index: 100;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 1.5rem;
}

.header-left {
  display: flex;
  align-items: center;
  gap: 1rem;
}

.brand {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  font-weight: 700;
  font-size: 1.1rem;
  color: var(--text-primary);
  text-decoration: none;
}

.version-badge {
  background: #EAEAEA;
  color: var(--text-secondary);
  font-family: var(--font-mono);
  font-size: 0.725rem;
  padding: 0.15rem 0.45rem;
  border-radius: 4px;
  font-weight: 600;
}

.header-right {
  display: flex;
  align-items: center;
  gap: 1.25rem;
}

.header-right a {
  color: var(--text-muted);
  text-decoration: none;
  font-size: 0.9rem;
  font-weight: 500;
  transition: color 0.15s ease;
}

.header-right a:hover {
  color: var(--text-primary);
}

.btn-gitbook-primary {
  background: var(--text-primary);
  color: #FFFFFF;
  padding: 0.45rem 0.9rem;
  border-radius: 6px;
  font-size: 0.85rem;
  font-weight: 600;
  text-decoration: none;
  transition: background 0.15s ease;
}

.btn-gitbook-primary:hover {
  background: #333333;
}

/* GitBook Layout */
.gitbook-container {
  display: flex;
  min-height: calc(100vh - 60px);
}

/* Left Sidebar Navigation */
aside.gitbook-sidebar {
  width: var(--sidebar-width);
  background: var(--bg-sidebar);
  border-right: 1px solid var(--border-color);
  padding: 1.5rem 1rem;
  position: sticky;
  top: 60px;
  height: calc(100vh - 60px);
  overflow-y: auto;
  flex-shrink: 0;
}

.sidebar-search {
  margin-bottom: 1.5rem;
  position: relative;
}

.sidebar-search input {
  width: 100%;
  padding: 0.5rem 0.75rem 0.5rem 2rem;
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: 6px;
  font-size: 0.85rem;
  color: var(--text-primary);
  outline: none;
}

.sidebar-search svg {
  position: absolute;
  left: 0.6rem;
  top: 50%;
  transform: translateY(-50%);
  width: 14px;
  height: 14px;
  stroke: var(--text-muted);
}

.nav-group {
  margin-bottom: 1.5rem;
}

.nav-group-title {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--text-muted);
  margin-bottom: 0.6rem;
  padding-left: 0.6rem;
  font-weight: 600;
}

.nav-item {
  display: block;
  padding: 0.45rem 0.6rem;
  color: var(--text-secondary);
  text-decoration: none;
  font-size: 0.875rem;
  border-radius: 6px;
  transition: background 0.15s ease, color 0.15s ease;
  margin-bottom: 0.1rem;
}

.nav-item:hover {
  background: #F4F4F4;
  color: var(--text-primary);
}

.nav-item.active {
  background: #EAEAEA;
  color: var(--text-primary);
  font-weight: 600;
}

/* Main Content Area */
main.gitbook-content {
  flex: 1;
  background: var(--bg-main);
  padding: 3rem 4rem;
  max-width: 860px;
}

.breadcrumb {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 0.85rem;
  color: var(--text-muted);
  margin-bottom: 1.5rem;
}

.breadcrumb span {
  color: var(--text-primary);
  font-weight: 500;
}

.page-header h1 {
  font-family: var(--font-serif);
  font-size: 3rem;
  font-weight: 400;
  letter-spacing: -0.02em;
  color: var(--text-primary);
  margin-bottom: 0.75rem;
  line-height: 1.1;
}

.page-description {
  font-size: 1.15rem;
  color: var(--text-muted);
  margin-bottom: 2.5rem;
  line-height: 1.5;
}

/* Callout Box */
.callout {
  border-left: 4px solid;
  padding: 1rem 1.25rem;
  border-radius: 0 8px 8px 0;
  margin: 1.5rem 0;
  font-size: 0.925rem;
}

.callout-info {
  background: var(--callout-info-bg);
  border-color: var(--callout-info-border);
  color: var(--callout-info-text);
}

.callout-tip {
  background: var(--callout-tip-bg);
  border-color: var(--callout-tip-border);
  color: var(--callout-tip-text);
}

.callout-warning {
  background: var(--callout-warn-bg);
  border-color: var(--callout-warn-border);
  color: var(--callout-warn-text);
}

.callout-title {
  font-weight: 700;
  margin-bottom: 0.25rem;
}

/* Code Blocks & Copy */
.code-block-wrapper {
  position: relative;
  margin: 1.5rem 0;
}

pre {
  background: #18181B;
  color: #FAFAFA;
  padding: 1.25rem;
  border-radius: 8px;
  font-family: var(--font-mono);
  font-size: 0.85rem;
  overflow-x: auto;
  line-height: 1.5;
}

.copy-btn {
  position: absolute;
  top: 0.6rem;
  right: 0.6rem;
  background: rgba(255, 255, 255, 0.15);
  color: #FFFFFF;
  border: none;
  padding: 0.25rem 0.5rem;
  border-radius: 4px;
  font-size: 0.75rem;
  font-family: var(--font-mono);
  cursor: pointer;
  transition: background 0.15s ease;
}

.copy-btn:hover {
  background: rgba(255, 255, 255, 0.3);
}

/* Content Headings */
article section {
  margin-bottom: 3.5rem;
}

article h2 {
  font-size: 1.75rem;
  font-weight: 700;
  color: var(--text-primary);
  margin-top: 2rem;
  margin-bottom: 1rem;
  letter-spacing: -0.01em;
  border-bottom: 1px solid var(--border-color);
  padding-bottom: 0.5rem;
}

article h3 {
  font-size: 1.25rem;
  font-weight: 600;
  color: var(--text-primary);
  margin-top: 1.5rem;
  margin-bottom: 0.75rem;
}

article p {
  margin-bottom: 1.25rem;
  font-size: 0.95rem;
  line-height: 1.65;
}

/* Feature Grid inside GitBook */
.grid-cards {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 1rem;
  margin: 1.5rem 0;
}

.card-item {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: 8px;
  padding: 1.25rem;
}

.card-item h4 {
  font-size: 1rem;
  color: var(--text-primary);
  margin-bottom: 0.4rem;
}

.card-item p {
  font-size: 0.875rem;
  color: var(--text-muted);
  margin-bottom: 0;
}

/* Table */
table.gitbook-table {
  width: 100%;
  border-collapse: collapse;
  margin: 1.5rem 0;
  background: var(--bg-sidebar);
  border: 1px solid var(--border-color);
  border-radius: 8px;
  overflow: hidden;
}

table.gitbook-table th, table.gitbook-table td {
  padding: 0.75rem 1rem;
  text-align: left;
  font-size: 0.875rem;
}

table.gitbook-table th {
  background: #F4F4F4;
  color: var(--text-primary);
  font-weight: 600;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  text-transform: uppercase;
}

table.gitbook-table tr:not(:last-child) td {
  border-bottom: 1px solid var(--border-color);
}

kbd {
  font-family: var(--font-mono);
  font-size: 0.8rem;
  background: #F4F4F4;
  border: 1px solid var(--border-darker);
  border-radius: 4px;
  padding: 0.15rem 0.4rem;
  color: var(--text-primary);
}

/* Right TOC */
aside.gitbook-toc {
  width: var(--toc-width);
  background: var(--bg-sidebar);
  border-left: 1px solid var(--border-color);
  padding: 2rem 1rem;
  position: sticky;
  top: 60px;
  height: calc(100vh - 60px);
  overflow-y: auto;
  flex-shrink: 0;
}

.toc-title {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--text-muted);
  margin-bottom: 0.75rem;
  font-weight: 600;
}

.toc-link {
  display: block;
  font-size: 0.825rem;
  color: var(--text-muted);
  text-decoration: none;
  padding: 0.3rem 0;
  border-left: 2px solid transparent;
  padding-left: 0.75rem;
  margin-left: -0.75rem;
  transition: color 0.15s ease, border-color 0.15s ease;
}

.toc-link:hover, .toc-link.active {
  color: var(--text-primary);
  border-left-color: var(--text-primary);
  font-weight: 500;
}

/* GitBook Footer */
footer.gitbook-footer {
  margin-top: 4rem;
  padding-top: 2rem;
  border-top: 1px solid var(--border-color);
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 0.85rem;
  color: var(--text-muted);
}

.footer-territory {
  font-style: italic;
  font-size: 0.8rem;
  color: var(--text-muted);
}