/* === Reset & Base === */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

:root {
  --color-bg: #ffffff;
  --color-bg-secondary: #f8f9fb;
  --color-text: #1a1a2e;
  --color-text-secondary: #555;
  --color-accent: #4f46e5;
  --color-accent-light: #eef2ff;
  --color-border: #e2e8f0;
  --color-code-bg: #f4f5f7;
  --color-code-text: #1f2937;
  --color-success: #16a34a;
  --color-warning: #f59e0b;
  --color-danger: #dc2626;
  --max-width: 1100px;
  --header-height: 64px;
  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --font-mono: "SF Mono", "Fira Code", "Fira Mono", "Roboto Mono", Consolas, monospace;
}

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

body {
  font-family: var(--font-sans);
  color: var(--color-text);
  background: var(--color-bg);
  line-height: 1.7;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

a { color: var(--color-accent); text-decoration: none; }
a:hover { text-decoration: underline; }

.container { max-width: var(--max-width); margin: 0 auto; padding: 0 2.5rem; }

@media (max-width: 768px) {
  .container { padding: 0 1.25rem; }
}

/* === Header === */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(255, 255, 255, 0.92);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--color-border);
  height: var(--header-height);
}

.site-header .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 100%;
}

.logo {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-weight: 700;
  font-size: 1.25rem;
  color: var(--color-text);
  text-decoration: none;
}

.logo:hover { text-decoration: none; }

.logo-icon {
  font-size: 1.65rem;
  font-weight: 800;
  font-style: italic;
  color: var(--color-accent);
  font-family: var(--font-mono);
  transform: scaleX(1.3);
  display: inline-block;
  line-height: 1;
}
.logo-text small { font-weight: 400; font-size: 0.75rem; color: var(--color-text-secondary); margin-left: 0.25rem; }

/* === Navigation === */
.main-nav ul {
  display: flex;
  list-style: none;
  gap: 0.15rem;
  align-items: center;
}

.main-nav a {
  display: inline-flex;
  align-items: center;
  padding: 0.3rem 0.6rem;
  border-radius: 4px;
  font-size: 0.9rem;
  font-weight: 500;
  color: var(--color-text-secondary);
  line-height: 1;
  transition: color 0.15s;
  position: relative;
}

.main-nav a::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0.6rem;
  right: 0.6rem;
  height: 2px;
  background: var(--color-accent);
  border-radius: 1px;
  transform: scaleX(0);
  transform-origin: center;
  transition: transform 0.2s ease;
}

.main-nav a:hover {
  color: var(--color-text);
  text-decoration: none;
}

.main-nav a:hover::after {
  transform: scaleX(1);
}

.main-nav a.active {
  color: var(--color-accent);
  text-decoration: none;
  font-weight: 600;
}

.main-nav a.active::after {
  transform: scaleX(1);
  background: var(--color-accent);
}

.external-icon { font-size: 0.7rem; opacity: 0.5; margin-left: 0.2rem; }

.nav-toggle { display: none; }
.nav-toggle-label { display: none; flex-direction: column; gap: 4px; cursor: pointer; padding: 0.5rem; }
.nav-toggle-label span { display: block; width: 20px; height: 2px; background: var(--color-text); border-radius: 1px; }

@media (max-width: 768px) {
  .nav-toggle-label { display: flex; }
  .main-nav ul {
    display: none;
    flex-direction: column;
    position: absolute;
    top: var(--header-height);
    left: 0;
    right: 0;
    background: var(--color-bg);
    border-bottom: 1px solid var(--color-border);
    padding: 0.5rem;
    gap: 0;
  }
  .nav-toggle:checked ~ ul { display: flex; }
  .main-nav a { padding: 0.6rem 0.85rem; }
}

/* === Content === */
.content { flex: 1; padding: 3rem 0; }

.content h1 { font-size: 2.25rem; font-weight: 800; line-height: 1.2; margin-bottom: 0.5rem; }
.content h2 { font-size: 1.6rem; font-weight: 700; margin-top: 2.5rem; margin-bottom: 0.75rem; padding-bottom: 0.4rem; border-bottom: 1px solid var(--color-border); }
.content h3 { font-size: 1.25rem; font-weight: 600; margin-top: 2rem; margin-bottom: 0.5rem; }
.content h4 { font-size: 1.1rem; font-weight: 600; margin-top: 1.5rem; margin-bottom: 0.5rem; }

/* Discreet heading anchor links — always visible, placed before heading text */
.heading-anchor {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  margin-left: 0.45rem;
  padding: 0.1rem 0.35rem;
  color: #b0b8c4;
  text-decoration: none !important;
  font-size: 0.75em;
  font-family: var(--font-mono);
  border-radius: 3px;
  background: transparent;
  vertical-align: 0.05em;
  opacity: 0;
  transition: opacity 0.15s, background 0.15s, color 0.15s;
  user-select: none;
}

.content h2:hover .heading-anchor,
.content h3:hover .heading-anchor,
.content h4:hover .heading-anchor {
  opacity: 1;
}

.heading-anchor:hover {
  background: var(--color-accent-light);
  color: var(--color-accent);
}

.content p { margin-bottom: 1.25rem; }
.content ul, .content ol { margin-bottom: 1.25rem; padding-left: 1.5rem; }
.content li { margin-bottom: 0.35rem; }

.content strong { font-weight: 600; }

.content table {
  width: 100%;
  border-collapse: collapse;
  margin-bottom: 1.5rem;
  font-size: 0.9rem;
}

@media (max-width: 768px) {
  .content table {
    display: block;
    overflow-x: auto;
  }
}

.content th {
  text-align: left;
  padding: 0.6rem 0.8rem;
  background: var(--color-bg-secondary);
  font-weight: 600;
  border-bottom: 2px solid var(--color-border);
}

.content td {
  padding: 0.55rem 0.8rem;
  border-bottom: 1px solid var(--color-border);
}

.content tr:hover td { background: var(--color-bg-secondary); }

/* Inline code */
.content p code, .content li code, .content td code {
  background: var(--color-accent-light);
  color: var(--color-accent);
  padding: 0.15em 0.4em;
  border-radius: 4px;
  font-size: 0.88em;
  font-family: var(--font-mono);
}

/* Code blocks */
.highlight, pre.highlight {
  background: var(--color-code-bg) !important;
  border-radius: 4px;
  margin: 1rem 0;
  overflow-x: auto;
}

.highlight code, pre.highlight code {
  color: var(--color-code-text) !important;
  background: none !important;
  padding: 0 !important;
  font-size: 0.84rem;
  line-height: 1.5;
}

.highlight { padding: 0.6rem; }

/* Copy button */
.code-block-wrapper {
  position: relative;
  margin: 1rem 0;
}

.code-block-wrapper .highlight {
  margin: 0;
}

.code-copy-btn {
  position: absolute;
  top: 0.4rem;
  right: 0.4rem;
  display: flex;
  align-items: center;
  justify-content: center;
  width: 26px;
  height: 26px;
  padding: 0;
  background: rgba(0,0,0,0.04);
  border: 1px solid rgba(0,0,0,0.08);
  border-radius: 4px;
  color: rgba(0,0,0,0.35);
  cursor: pointer;
  opacity: 0;
  transition: opacity 0.15s, color 0.15s, background 0.15s;
}

.code-block-wrapper:hover .code-copy-btn {
  opacity: 1;
}

/* Always visible on touch devices where :hover doesn't work */
@media (hover: none) {
  .code-copy-btn {
    opacity: 1;
  }
}

.code-copy-btn:hover {
  color: rgba(0,0,0,0.7);
  background: rgba(0,0,0,0.07);
}

.code-copy-btn.copied {
  color: #059669;
  border-color: rgba(5,150,105,0.3);
}

/* Cypher keyword highlighting */
.highlight .cy-kw   { color: #7c3aed; font-weight: 600; }
.highlight .cy-fn   { color: #2563eb; }
.highlight .cy-label { color: #d97706; }
.highlight .cy-rel  { color: #0d9488; font-weight: 600; }
.highlight .cy-str  { color: #059669; }
.highlight .cy-num  { color: #d97706; }
.highlight .cy-cmt  { color: #52525b; font-style: italic; }

/* Rouge syntax highlighting (light theme) */
.highlight .c, .highlight .c1, .highlight .cm, .highlight .cp { color: #52525b; font-style: italic; }
.highlight .err { color: #dc2626; }
.highlight .k, .highlight .kd, .highlight .kn, .highlight .kp, .highlight .kr { color: #7c3aed; }
.highlight .kt { color: #d97706; }
.highlight .m, .highlight .mf, .highlight .mh, .highlight .mi { color: #d97706; }
.highlight .s, .highlight .s1, .highlight .s2, .highlight .sc, .highlight .se, .highlight .sh, .highlight .si, .highlight .sx { color: #059669; }
.highlight .n, .highlight .nn, .highlight .py { color: #1f2937; }
.highlight .na, .highlight .nc, .highlight .nd, .highlight .ne, .highlight .nf { color: #2563eb; }
.highlight .nl, .highlight .nv, .highlight .vc, .highlight .vg, .highlight .vi { color: #dc2626; }
.highlight .o { color: #0d9488; }
.highlight .p { color: #6b7280; }
.highlight .ow { color: #7c3aed; }
.highlight .e { color: #dc2626; }
.highlight .gu, .highlight .gd { color: #dc2626; }
.highlight .gi { color: #059669; }

/* === Hero (home page) === */
.hero {
  text-align: center;
  padding: 3rem 0 2rem;
}

.hero h1 {
  font-size: 3rem;
  font-weight: 800;
  margin-bottom: 1rem;
  background: linear-gradient(135deg, var(--color-accent), #7c3aed);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero .tagline {
  font-size: 1.2rem;
  color: var(--color-text-secondary);
  max-width: 600px;
  margin: 0 auto 2rem;
}

.hero-actions {
  display: flex;
  gap: 1rem;
  justify-content: center;
  flex-wrap: wrap;
  margin-bottom: 2rem;
}

.btn {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  padding: 0.7rem 1.5rem;
  border-radius: 8px;
  font-weight: 600;
  font-size: 0.95rem;
  transition: transform 0.15s, box-shadow 0.15s;
}

.btn:hover { transform: translateY(-1px); text-decoration: none; }

.btn-primary {
  background: var(--color-accent);
  color: #fff;
  box-shadow: 0 2px 8px rgba(79, 70, 229, 0.3);
}

.btn-primary:hover { box-shadow: 0 4px 16px rgba(79, 70, 229, 0.4); }

.btn-secondary {
  background: var(--color-bg-secondary);
  color: var(--color-text);
  border: 1px solid var(--color-border);
}

.btn-secondary:hover { border-color: var(--color-accent); }

/* === Feature Cards === */
.feature-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 1.25rem;
  margin: 2rem 0;
}

.feature-card {
  background: var(--color-bg-secondary);
  border: 1px solid var(--color-border);
  border-radius: 6px;
  padding: 1rem 1.15rem;
  transition: box-shadow 0.2s, border-color 0.2s;
}

.feature-card:hover {
  border-color: var(--color-accent);
  box-shadow: 0 4px 12px rgba(79, 70, 229, 0.08);
}

.feature-card h3 {
  margin-top: 0;
  margin-bottom: 0.5rem;
  font-size: 1.1rem;
}

.feature-card p {
  color: var(--color-text-secondary);
  font-size: 0.92rem;
  margin-bottom: 0;
}

/* === Callout === */
.callout {
  border-left: 3px solid var(--color-accent);
  background: var(--color-accent-light);
  padding: 0.6rem 0.85rem;
  border-radius: 0 4px 4px 0;
  margin: 1.25rem 0;
}

.callout p { margin-bottom: 0; }
.callout p + p { margin-top: 0.5rem; }

/* === Breadcrumb === */
.breadcrumb {
  font-size: 0.85rem;
  color: var(--color-text-secondary);
  margin-bottom: 1rem;
}

.breadcrumb a { color: var(--color-text-secondary); }
.breadcrumb a:hover { color: var(--color-accent); }
.breadcrumb span { margin: 0 0.4rem; }

/* === Status badges === */
.badge {
  display: inline-block;
  padding: 0.15em 0.5em;
  border-radius: 4px;
  font-size: 0.8rem;
  font-weight: 600;
  vertical-align: middle;
}

.badge-success { background: #dcfce7; color: var(--color-success); }
.badge-warning { background: #fef3c7; color: var(--color-warning); }
.badge-danger { background: #fee2e2; color: var(--color-danger); }

/* === Footer === */
.site-footer {
  border-top: 1px solid var(--color-border);
  padding: 2rem 0;
  text-align: center;
  font-size: 0.85rem;
  color: var(--color-text-secondary);
}

.site-footer a { color: var(--color-text-secondary); }
.site-footer a:hover { color: var(--color-accent); }

/* === Scrollbar === */
.highlight::-webkit-scrollbar { height: 6px; }
.highlight::-webkit-scrollbar-track { background: transparent; }
.highlight::-webkit-scrollbar-thumb { background: rgba(0,0,0,0.15); border-radius: 3px; }

/* === Page TOC (sticky sidebar) === */
.page-toc {
  position: fixed;
  top: var(--header-height);
  right: 0;
  z-index: 50;
  width: 195px;
  max-height: calc(100vh - var(--header-height));
  overflow-y: auto;
  padding: 2rem 1.25rem 2rem 1.5rem;
  opacity: 0;
  animation: page-toc-fade-in 0.3s 0.15s forwards;
}

@keyframes page-toc-fade-in {
  to { opacity: 1; }
}

.page-toc::-webkit-scrollbar { width: 4px; }
.page-toc::-webkit-scrollbar-track { background: transparent; }
.page-toc::-webkit-scrollbar-thumb { background: rgba(0,0,0,0.1); border-radius: 2px; }

.page-toc__title {
  font-size: 0.7rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--color-text-secondary);
  margin-bottom: 0.65rem;
  padding-bottom: 0.4rem;
  border-bottom: 1px solid var(--color-border);
}

.page-toc__list {
  list-style: none;
  padding: 0;
  margin: 0;
}

.page-toc__list li {
  margin-bottom: 2px;
}

.page-toc__list a {
  display: block;
  padding: 0.2rem 0 0.2rem 0.75rem;
  font-size: 0.78rem;
  line-height: 1.4;
  color: var(--color-text-secondary);
  border-left: 2px solid transparent;
  text-decoration: none;
  transition: color 0.15s, border-color 0.15s;
  word-break: break-word;
}

.page-toc__list a:hover {
  color: var(--color-text);
  text-decoration: none;
}

.page-toc__list li.active a {
  color: var(--color-accent);
  border-left-color: var(--color-accent);
  background: var(--color-accent-light);
}

.page-toc__list .level-h3 a {
  padding-left: 1.35rem;
  font-size: 0.74rem;
}

@media (max-width: 1180px) {
  .page-toc { display: none; }
}