/* =========================================================================
   Spatial Data Archival — design system
   Elegant, professional, light color scheme.
   ========================================================================= */
:root {
  --bg: #f6faf9;
  --surface: #ffffff;
  --surface-2: #eef5f3;
  --border: #d8e6e2;
  --border-strong: #c2d8d2;

  --text: #16302c;
  --text-soft: #4d635e;
  --text-faint: #7a908b;

  --primary: #0f766e;
  --primary-strong: #0b5d57;
  --primary-soft: #e1f3ef;
  --accent: #f59e0b;
  --accent-soft: #fef3da;
  --green: #10b981;
  --green-soft: #def5ec;
  --sky: #0e7490;

  --link: #0d6e74;
  --link-hover: #0b4a45;

  --code-bg: #f1f6f4;
  --code-border: #dde9e5;
  --inline-code-bg: rgba(15, 118, 110, 0.09);
  --inline-code-fg: #0b5d57;

  --radius: 14px;
  --radius-sm: 9px;
  --radius-lg: 22px;

  --shadow-sm: 0 1px 2px rgba(16, 48, 44, 0.06);
  --shadow: 0 6px 22px rgba(16, 48, 44, 0.08);
  --shadow-lg: 0 18px 48px rgba(16, 48, 44, 0.14);

  --header-h: 64px;
  --maxw: 1500px;
  --content-maxw: 1500px;

  --font-sans: "Inter", system-ui, -apple-system, "Segoe UI", Roboto, Helvetica,
    Arial, "Apple Color Emoji", "Segoe UI Emoji", sans-serif;
  --font-mono: "JetBrains Mono", "SFMono-Regular", ui-monospace, Menlo, Consolas,
    "Liberation Mono", monospace;
}

*,
*::before,
*::after {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
  scroll-padding-top: calc(var(--header-h) + 16px);
  -webkit-text-size-adjust: 100%;
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  * { animation-duration: 0.01ms !important; transition-duration: 0.01ms !important; }
}

body {
  margin: 0;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  background: var(--bg);
  color: var(--text);
  font-family: var(--font-sans);
  font-size: clamp(16px, 0.95rem + 0.15vw, 18px);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

.skip-link {
  position: absolute;
  left: -9999px;
  top: 0;
  background: var(--primary);
  color: #fff;
  padding: 10px 16px;
  border-radius: 0 0 var(--radius-sm) 0;
  z-index: 200;
}
.skip-link:focus { left: 0; }

/* ---- Shared containers -------------------------------------------------- */
.container {
  width: 100%;
  max-width: var(--maxw);
  margin-inline: auto;
  padding-inline: clamp(18px, 4vw, 48px);
}
main { flex: 1 0 auto; }

a {
  color: var(--link);
  text-decoration: none;
  transition: color 0.18s ease;
}
a:hover { color: var(--link-hover); }

:focus-visible {
  outline: 3px solid var(--accent);
  outline-offset: 2px;
  border-radius: 3px;
}

img,
svg { max-width: 100%; }

/* =========================================================================
   Header
   ========================================================================= */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  height: var(--header-h);
  display: flex;
  align-items: center;
  background: rgba(255, 255, 255, 0.86);
  backdrop-filter: saturate(150%) blur(10px);
  -webkit-backdrop-filter: saturate(150%) blur(10px);
  border-bottom: 1px solid var(--border);
}
.site-header .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
}
.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-weight: 750;
  letter-spacing: -0.01em;
  color: var(--text);
  font-size: 1.02rem;
}
.brand:hover { color: var(--primary-strong); }
.brand svg { width: 34px; height: 34px; flex: none; }
.brand .brand-text { white-space: nowrap; }
.brand .brand-sub { color: var(--text-faint); font-weight: 600; }

.primary-nav { display: flex; align-items: center; }
.primary-nav ul {
  display: flex;
  align-items: center;
  gap: 4px;
  list-style: none;
  margin: 0;
  padding: 0;
}
.primary-nav a {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 9px 14px;
  border-radius: 999px;
  color: var(--text-soft);
  font-weight: 600;
  font-size: 0.95rem;
  border: 1px solid transparent;
  transition: background 0.18s ease, color 0.18s ease, border-color 0.18s ease,
    transform 0.18s ease;
}
.primary-nav a .icon { width: 19px; height: 19px; color: var(--primary); }
.primary-nav a:hover {
  background: var(--primary-soft);
  color: var(--primary-strong);
  transform: translateY(-1px);
}
.primary-nav a[aria-current="page"] {
  background: var(--primary);
  color: #fff;
  border-color: var(--primary-strong);
}
.primary-nav a[aria-current="page"] .icon { color: #fff; }

.nav-toggle {
  display: none;
  align-items: center;
  justify-content: center;
  width: 42px;
  height: 42px;
  border-radius: 10px;
  border: 1px solid var(--border-strong);
  background: var(--surface);
  color: var(--primary-strong);
  cursor: pointer;
}
.nav-toggle .icon { width: 22px; height: 22px; }
.nav-toggle .icon-close { display: none; }
.nav-toggle[aria-expanded="true"] .icon-open { display: none; }
.nav-toggle[aria-expanded="true"] .icon-close { display: block; }

@media (max-width: 860px) {
  .nav-toggle { display: inline-flex; }
  .primary-nav {
    position: absolute;
    top: var(--header-h);
    left: 0;
    right: 0;
    background: var(--surface);
    border-bottom: 1px solid var(--border);
    box-shadow: var(--shadow);
    padding: 12px clamp(18px, 4vw, 48px);
    display: none;
  }
  .primary-nav.open { display: block; }
  .primary-nav ul { flex-direction: column; align-items: stretch; gap: 6px; }
  .primary-nav a { justify-content: flex-start; padding: 12px 14px; }
}

@media (max-width: 560px) {
  .brand { font-size: 0.95rem; min-width: 0; flex: 0 1 auto; overflow: hidden; }
  .brand .brand-text {
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
  }
  .brand .brand-sub { display: none; }
}

/* =========================================================================
   Footer (pinned to bottom even on empty pages via body flex)
   ========================================================================= */
.site-footer {
  flex-shrink: 0;
  margin-top: 64px;
  background: #0c2b28;
  color: #cfe6e0;
  border-top: 4px solid var(--primary);
}
.site-footer .container {
  display: grid;
  gap: 28px;
  padding-block: 44px;
  grid-template-columns: 1.4fr 1fr;
}
.footer-brand { display: flex; flex-direction: column; gap: 12px; max-width: 46ch; }
.footer-brand .brand { color: #fff; }
.footer-brand .brand .brand-sub { color: #8fc7bd; }
.footer-brand p { margin: 0; color: #9fc4bc; font-size: 0.95rem; }
.footer-nav h2 {
  font-size: 0.78rem;
  text-transform: uppercase;
  letter-spacing: 0.09em;
  color: #7fb8ae;
  margin: 0 0 12px;
}
.footer-nav ul { list-style: none; margin: 0; padding: 0; display: grid; gap: 9px; }
.footer-nav a {
  color: #d6ece6;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-weight: 500;
}
.footer-nav a .icon { width: 17px; height: 17px; color: var(--accent); }
.footer-nav a:hover { color: #fff; }
.footer-bottom {
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  padding-block: 18px;
  font-size: 0.86rem;
  color: #87b4ac;
}
@media (max-width: 720px) {
  .site-footer .container { grid-template-columns: 1fr; }
}

/* =========================================================================
   Homepage
   ========================================================================= */
.hero {
  position: relative;
  text-align: center;
  padding-block: clamp(48px, 7vw, 96px);
  background:
    radial-gradient(120% 120% at 50% -10%, var(--primary-soft) 0%, transparent 60%),
    radial-gradient(80% 80% at 110% 20%, var(--accent-soft) 0%, transparent 55%);
}
.hero-logo {
  display: block;
  width: clamp(96px, 14vw, 156px);
  height: auto;
  margin-inline: auto;
  filter: drop-shadow(0 12px 26px rgba(15, 118, 110, 0.22));
  transition: transform 0.4s ease;
}
.hero-logo:hover { transform: translateY(-4px) rotate(-2deg) scale(1.03); }
.hero h1 {
  margin: 22px auto 8px;
  font-size: clamp(2rem, 1.4rem + 3vw, 3.4rem);
  line-height: 1.08;
  letter-spacing: -0.02em;
  max-width: 18ch;
  background: linear-gradient(100deg, var(--primary-strong), var(--green) 55%, var(--accent));
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}
.hero .lede {
  font-size: clamp(1.05rem, 1rem + 0.4vw, 1.3rem);
  color: var(--text-soft);
  max-width: 60ch;
  margin: 0 auto;
}
.hero-tagline {
  display: inline-block;
  margin-bottom: 6px;
  padding: 6px 14px;
  border-radius: 999px;
  background: var(--surface);
  border: 1px solid var(--border);
  box-shadow: var(--shadow-sm);
  color: var(--primary-strong);
  font-weight: 600;
  font-size: 0.82rem;
  letter-spacing: 0.04em;
  text-transform: uppercase;
}

.section-block { padding-block: clamp(36px, 5vw, 64px); }
.section-intro { max-width: 70ch; margin: 0 auto 40px; text-align: center; }
.section-intro h2 { font-size: clamp(1.5rem, 1.2rem + 1vw, 2.1rem); margin: 0 0 12px; }
.section-intro p { color: var(--text-soft); margin: 0; }

.cta-grid {
  display: grid;
  gap: 22px;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  margin-top: 38px;
}
.cta-card {
  display: flex;
  flex-direction: column;
  gap: 14px;
  padding: 26px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow-sm);
  text-align: left;
  color: var(--text);
  transition: transform 0.2s ease, box-shadow 0.2s ease, border-color 0.2s ease;
}
.cta-card:hover {
  transform: translateY(-5px);
  box-shadow: var(--shadow-lg);
  border-color: var(--border-strong);
  color: var(--text);
}
.cta-ico {
  width: 56px;
  height: 56px;
  border-radius: 16px;
  display: grid;
  place-items: center;
  color: #fff;
  box-shadow: var(--shadow);
}
.cta-ico .icon { width: 30px; height: 30px; }
.cta-ico.c1 { background: linear-gradient(135deg, #14b8a6, #0f766e); }
.cta-ico.c2 { background: linear-gradient(135deg, #34d399, #059669); }
.cta-ico.c3 { background: linear-gradient(135deg, #fbbf24, #f97316); }
.cta-card h3 { margin: 0; font-size: 1.18rem; color: var(--primary-strong); }
.cta-card p { margin: 0; color: var(--text-soft); font-size: 0.97rem; }
.cta-more {
  margin-top: auto;
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-weight: 650;
  color: var(--primary);
}
.cta-card:hover .cta-more { gap: 11px; }
.cta-more .icon { width: 18px; height: 18px; transition: transform 0.2s ease; }

.home-prose {
  max-width: 100%;
}
.home-prose p { color: var(--text-soft); }
.home-prose a { font-weight: 600; }

/* =========================================================================
   Content pages
   ========================================================================= */
.page-wrap { padding-block: 30px 64px; }
.content-shell {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-sm);
  padding: clamp(22px, 3.5vw, 52px);
}

/* Breadcrumbs */
.breadcrumbs { margin-bottom: 20px; font-size: 0.9rem; }
.breadcrumbs ol {
  list-style: none;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 6px;
  margin: 0;
  padding: 0;
  color: var(--text-faint);
}
.breadcrumbs li { display: inline-flex; align-items: center; gap: 6px; }
.breadcrumbs li:not(:last-child)::after {
  content: "›";
  color: var(--border-strong);
  margin-left: 6px;
}
.breadcrumbs a { color: var(--text-soft); font-weight: 500; }
.breadcrumbs a:hover { color: var(--primary); }
.breadcrumbs [aria-current="page"] { color: var(--primary-strong); font-weight: 650; }

/* Prose typography */
.prose { max-width: 100%; }
.prose > :first-child { margin-top: 0; }
.prose h1 {
  font-size: clamp(1.8rem, 1.4rem + 2vw, 2.7rem);
  line-height: 1.12;
  letter-spacing: -0.02em;
  margin: 0 0 0.6em;
  background: linear-gradient(100deg, var(--primary-strong), var(--green) 60%, var(--accent));
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}
.prose h2 {
  font-size: clamp(1.35rem, 1.15rem + 0.9vw, 1.8rem);
  margin: 2em 0 0.6em;
  padding-bottom: 0.3em;
  color: var(--primary-strong);
  border-bottom: 2px solid var(--primary-soft);
  letter-spacing: -0.01em;
}
.prose h3 {
  font-size: clamp(1.12rem, 1.02rem + 0.5vw, 1.4rem);
  margin: 1.6em 0 0.5em;
  color: var(--text);
}
.prose h4 { font-size: 1.08rem; margin: 1.4em 0 0.4em; color: var(--primary-strong); }
.prose p { margin: 0 0 1.15em; }
.prose ul,
.prose ol { margin: 0 0 1.15em; padding-left: 1.4em; }
.prose li { margin: 0.35em 0; }
.prose li::marker { color: var(--primary); }
.prose strong { color: var(--text); font-weight: 700; }
.prose blockquote {
  margin: 1.4em 0;
  padding: 0.6em 1.2em;
  border-left: 4px solid var(--primary);
  background: var(--surface-2);
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  color: var(--text-soft);
}
.prose hr { border: none; border-top: 1px solid var(--border); margin: 2.2em 0; }

/* Anchored headings honour the sticky header height */
.prose :is(h1, h2, h3, h4, h5, h6)[id] {
  scroll-margin-top: calc(var(--header-h) + 18px);
}
.heading-anchor {
  margin-left: 0.4em;
  color: var(--border-strong);
  font-weight: 600;
  opacity: 0;
  transition: opacity 0.15s ease, color 0.15s ease;
  text-decoration: none;
}
.prose :is(h2, h3, h4):hover .heading-anchor { opacity: 1; }
.heading-anchor:hover { color: var(--primary); }

/* Links inside prose */
.prose a {
  color: var(--link);
  font-weight: 550;
  text-decoration: underline;
  text-decoration-color: color-mix(in srgb, var(--link) 35%, transparent);
  text-underline-offset: 3px;
  text-decoration-thickness: 1.5px;
  transition: color 0.18s ease, text-decoration-color 0.18s ease;
}
.prose a:hover {
  color: var(--link-hover);
  text-decoration-color: var(--link-hover);
}

/* Inline code — subtle, borderless, blends with text */
.prose :not(pre) > code {
  font-family: var(--font-mono);
  font-size: 0.88em;
  background: var(--inline-code-bg);
  color: var(--inline-code-fg);
  padding: 0.12em 0.4em;
  border-radius: 6px;
  white-space: break-spaces;
}

/* Code blocks */
.code-block {
  position: relative;
  margin: 1.4em 0;
}
.prose pre[class*="language-"] {
  margin: 0;
  background: var(--code-bg);
  border: 1px solid var(--code-border);
  border-radius: var(--radius);
  padding: 18px 18px;
  overflow-x: auto;
  font-size: 0.86rem;
  line-height: 1.6;
  box-shadow: var(--shadow-sm);
}
.prose pre[class*="language-"] code {
  font-family: var(--font-mono);
  background: none;
  color: inherit;
  padding: 0;
  font-size: inherit;
}
.copy-btn {
  position: absolute;
  top: 10px;
  right: 10px;
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 6px 10px;
  font: inherit;
  font-size: 0.78rem;
  font-weight: 600;
  color: var(--primary-strong);
  background: rgba(255, 255, 255, 0.9);
  border: 1px solid var(--code-border);
  border-radius: 8px;
  cursor: pointer;
  opacity: 0;
  transform: translateY(-2px);
  transition: opacity 0.16s ease, transform 0.16s ease, background 0.16s ease;
}
.code-block:hover .copy-btn,
.copy-btn:focus-visible { opacity: 1; transform: none; }
.copy-btn:hover { background: var(--primary-soft); }
.copy-btn .icon { width: 15px; height: 15px; }
.copy-btn.copied { color: #fff; background: var(--green); border-color: var(--green); }

/* Tables */
.table-wrap {
  overflow-x: auto;
  margin: 1.5em 0;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow-sm);
  -webkit-overflow-scrolling: touch;
}
.prose table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.92rem;
  min-width: 520px;
}
.prose th,
.prose td {
  text-align: left;
  padding: 12px 16px;
  border-bottom: 1px solid var(--border);
  vertical-align: top;
}
.prose thead th {
  background: var(--primary-soft);
  color: var(--primary-strong);
  font-weight: 700;
  white-space: nowrap;
}
.prose tbody tr:nth-child(even) { background: var(--surface-2); }
.prose tbody tr:hover { background: var(--green-soft); }
.prose tbody tr:last-child td { border-bottom: none; }

/* Task lists — interactive checkboxes, no leading bullet */
.prose ul.contains-task-list { list-style: none; padding-left: 0.2em; }
.prose ul.contains-task-list ul.contains-task-list { padding-left: 1.4em; }
.prose li.task-list-item { display: block; }
.prose li.task-list-item::marker { content: none; }
.prose li.task-list-item > label {
  display: inline-flex;
  align-items: flex-start;
  gap: 0.55em;
}
.prose li.task-list-item input[type="checkbox"] {
  appearance: none;
  -webkit-appearance: none;
  flex: none;
  width: 1.18em;
  height: 1.18em;
  margin-top: 0.18em;
  border: 2px solid var(--border-strong);
  border-radius: 6px;
  background: var(--surface);
  cursor: pointer;
  display: grid;
  place-content: center;
  transition: background 0.15s ease, border-color 0.15s ease;
}
.prose li.task-list-item input[type="checkbox"]::before {
  content: "";
  width: 0.62em;
  height: 0.62em;
  transform: scale(0);
  transition: transform 0.12s ease;
  box-shadow: inset 1em 1em #fff;
  clip-path: polygon(14% 44%, 0 65%, 40% 100%, 100% 18%, 80% 0%, 39% 73%);
}
.prose li.task-list-item input[type="checkbox"]:checked {
  background: var(--primary);
  border-color: var(--primary);
}
.prose li.task-list-item input[type="checkbox"]:checked::before { transform: scale(1); }
.prose li.task-list-item label { cursor: pointer; }
.prose li.task-list-item:has(input:checked) {
  color: var(--text-faint);
  text-decoration: line-through;
  text-decoration-color: var(--text-faint);
}

/* FAQ accordions */
.faq-heading { /* inherits h2 */ }
.faq-accordion { display: grid; gap: 12px; margin: 1.2em 0; }
.faq-item {
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: var(--surface);
  box-shadow: var(--shadow-sm);
  overflow: hidden;
}
.faq-item summary {
  cursor: pointer;
  list-style: none;
  padding: 16px 20px;
  font-weight: 650;
  color: var(--primary-strong);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
}
.faq-item summary::-webkit-details-marker { display: none; }
.faq-item summary::after {
  content: "+";
  font-size: 1.4rem;
  line-height: 1;
  color: var(--primary);
  transition: transform 0.2s ease;
}
.faq-item[open] summary::after { transform: rotate(45deg); }
.faq-item summary:hover { background: var(--primary-soft); }
.faq-answer { padding: 0 20px 18px; color: var(--text-soft); }
.faq-answer > :first-child { margin-top: 0; }

/* Mermaid */
.mermaid {
  margin: 1.6em 0;
  text-align: center;
  background: var(--surface-2);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 18px;
  overflow-x: auto;
}
.mermaid:not([data-processed]) { color: transparent; min-height: 60px; }

/* KaTeX */
.katex-display { overflow-x: auto; overflow-y: hidden; padding: 4px 0; }

/* Related content */
.related {
  margin-top: 40px;
  padding-top: 28px;
  border-top: 1px solid var(--border);
}
.related h2 { font-size: 1.2rem; color: var(--primary-strong); margin: 0 0 16px; }
.related-grid {
  display: grid;
  gap: 14px;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
}
.related-card {
  display: block;
  padding: 16px 18px;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: var(--surface);
  color: var(--text);
  box-shadow: var(--shadow-sm);
  transition: transform 0.18s ease, box-shadow 0.18s ease, border-color 0.18s ease;
}
.related-card:hover {
  transform: translateY(-3px);
  box-shadow: var(--shadow);
  border-color: var(--primary-soft);
  color: var(--text);
}
.related-card .rc-title {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-weight: 650;
  color: var(--primary-strong);
}
.related-card .rc-title .icon { width: 17px; height: 17px; color: var(--primary); }
.related-card p { margin: 8px 0 0; font-size: 0.9rem; color: var(--text-soft); }

.section-children { margin-top: 8px; }