/* ── Design tokens ─────────────────────────────────────── */
:root {
  --bg:          #1f2230;
  --surface:     #2f3445;
  --surface-alt: #262a3a;
  --border:      #3c4259;
  --text:        #dde1ea;
  --text-muted:  #8892a4;
  --accent:      #6478b8;
  --nav-h:       64px;
}

/* ── Reset ──────────────────────────────────────────────── */
*, *::before, *::after { box-sizing: border-box; }
body {
  margin: 0;
  padding-top: var(--nav-h);
  background: var(--bg);
  color: var(--text);
  font-family: 'Mulish', sans-serif;
  font-size: 14px;
  line-height: 1.6;
}

/* ── Navbar ─────────────────────────────────────────────── */
.site-nav {
  position: fixed;
  top: 0; left: 0; right: 0;
  height: var(--nav-h);
  background: var(--surface);
  border-bottom: 1px solid var(--border);
  display: flex;
  align-items: center;
  padding: 0 24px;
  gap: 16px;
  z-index: 100;
}

.brand {
  display: flex;
  align-items: center;
  text-decoration: none;
  flex-shrink: 0;
}

.brand img {
  max-height: 48px;
  width: auto;
  display: block;
}

.nav-links {
  flex: 1;
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 4px;
  flex-wrap: wrap;
}

.nav-links a {
  display: block;
  padding: 5px 10px;
  font-size: 13px;
  font-weight: 600;
  letter-spacing: 0.03em;
  color: var(--text-muted);
  text-decoration: none;
  border-radius: 4px;
  white-space: nowrap;
  transition: color 0.15s, background 0.15s;
}

.nav-links a:hover {
  color: var(--text);
  background: rgba(255, 255, 255, 0.07);
}

.nav-toggle {
  display: none;
  background: none;
  border: none;
  cursor: pointer;
  padding: 6px;
  flex-direction: column;
  gap: 5px;
  margin-left: auto;
}

.nav-toggle span {
  display: block;
  width: 20px;
  height: 2px;
  background: var(--text);
  border-radius: 2px;
}

/* ── Footer ─────────────────────────────────────────────── */
.site-footer {
  background: #12131a;
  border-top: 1px solid var(--border);
  padding: 10px 24px;
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 4px;
}

.site-footer ul {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  gap: 2px;
}

.site-footer a {
  color: var(--text-muted);
  text-decoration: none;
  font-size: 12px;
  padding: 3px 8px;
  border-radius: 3px;
  transition: color 0.15s;
}

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

/* .footer-right groups contact + logo, pushes right */
.site-footer > .footer-right,
.site-footer > .contact {
  margin-left: auto;
}

.site-footer .contact {
  color: var(--text-muted);
  font-size: 12px;
}

/* ── Scrollbar ───────────────────────────────────────────── */
*::-webkit-scrollbar { width: 6px; height: 6px; }
*::-webkit-scrollbar-track { background: transparent; }
*::-webkit-scrollbar-thumb {
  background-color: rgba(255, 255, 255, 0.2);
  border-radius: 3px;
}
* {
  scrollbar-width: thin;
  scrollbar-color: rgba(255, 255, 255, 0.2) transparent;
}

/* ── Page hero (shared, all content pages) ───────────────── */
.page-hero {
  padding: 2.75rem 2rem 2.25rem;
  text-align: center;
  border-bottom: 1px solid var(--border);
}
.page-hero h1 {
  font-size: 1.75rem;
  font-weight: 700;
  color: #fff;
  margin: 0 0 0.35rem;
}
.page-hero .page-subtitle {
  font-size: 0.85rem;
  color: var(--text-muted);
  margin: 0;
}

/* ── Page content wrapper (shared) ───────────────────────── */
.page-content {
  max-width: 960px;
  margin: 0 auto;
  padding: 2.5rem 2rem 3.5rem;
}

/* ── Prose text (shared) ──────────────────────────────────── */
.prose p {
  font-size: 13px;
  color: var(--text-muted);
  line-height: 1.65;
  margin: 0 0 0.75rem;
  text-align: justify;
}
.prose p:last-child { margin-bottom: 0; }
.prose h2 {
  font-size: 0.9rem;
  font-weight: 700;
  color: var(--text);
  margin: 1.5rem 0 0.4rem;
}
.prose h2:first-child { margin-top: 0; }
.prose ul {
  font-size: 13px;
  color: var(--text-muted);
  line-height: 1.65;
  padding-left: 1.4em;
  margin: 0 0 0.75rem;
}
.prose a { color: var(--accent); text-decoration: none; }
.prose a:hover { text-decoration: underline; }
.prose hr {
  border: none;
  border-top: 1px solid var(--border);
  margin: 1.5rem 0;
}

/* ── Responsive ──────────────────────────────────────────── */
@media (max-width: 767px) {
  :root { --nav-h: 56px; }

  .nav-links {
    display: none;
    position: fixed;
    top: var(--nav-h);
    left: 0; right: 0;
    flex-direction: column;
    align-items: flex-start;
    background: var(--surface);
    border-bottom: 1px solid var(--border);
    padding: 8px 16px;
    gap: 2px;
    z-index: 99;
  }

  .nav-links.open { display: flex; }
  .nav-toggle { display: flex; }

  .site-footer .contact { display: none; }
}

@media (max-width: 767px) {
  .page-hero { padding: 2rem 1.25rem 1.75rem; }
  .page-hero h1 { font-size: 1.45rem; }
  .page-content { padding: 2rem 1.25rem 2.5rem; }
}

/* ══════════════════════════════════════════════════════════
   index.html
   ══════════════════════════════════════════════════════════ */

/* ── Page background (spans hero + cards) ────────────── */
.page-bg {
  position: relative;
  background: url('../../img/index_pic.jpg') center top / cover no-repeat;
}
.page-bg::before {
  content: '';
  position: absolute;
  inset: 0;
  background: rgba(15, 17, 28, 0.70);
  pointer-events: none;
}

/* ── Hero ───────────────────────────────────────────── */
.hero {
  position: relative;
  z-index: 1;
  padding: 3.5rem 2rem 2.5rem;
}
.hero-inner {
  max-width: 960px;
  margin: 0 auto;
}
.hero h1 {
  font-size: 2.6rem;
  font-weight: 700;
  text-align: center;
  color: #fff;
  margin: 0 0 0.6rem;
  text-shadow: 0 1px 4px rgba(0,0,0,0.5);
}
.hero-subtitle {
  text-align: center;
  font-size: 0.95rem;
  color: #e2e8f2;
  margin: 0 0 2rem;
  text-shadow: 0 1px 4px rgba(0,0,0,0.55);
}
.hero-description {
  font-size: 0.9rem;
  line-height: 1.65;
  color: #e4e9f4;
  margin: 0 0 1.75rem;
  text-align: justify;
  text-shadow: 0 1px 4px rgba(0,0,0,0.55);
}
.features-label {
  font-size: 0.85rem;
  font-weight: 700;
  color: #fff;
  margin: 0 0 0.9rem;
}
.feature-cols {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 2rem;
}
.feature-col h3 {
  font-size: 0.9rem;
  font-weight: 700;
  color: #f0f2f8;
  margin: 0 0 0.45rem;
  text-shadow: 0 1px 4px rgba(0,0,0,0.55);
}
.feature-col p {
  font-size: 0.85rem;
  color: #ccd4e4;
  margin: 0;
  line-height: 1.55;
  text-align: justify;
  text-shadow: 0 1px 4px rgba(0,0,0,0.55);
}

/* ── Cards section ──────────────────────────────────── */
.cards-section {
  position: relative;
  z-index: 1;
  padding: 2rem 2rem 3.5rem;
}
.cards-box {
  max-width: 960px;
  margin: 0 auto;
  background: rgba(22, 25, 42, 0.90);
  border: 1px solid rgba(55, 62, 95, 0.6);
  border-radius: 20px;
  padding: 2rem 2rem 1.75rem;
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1.75rem;
}
.card-item a {
  display: block;
  text-decoration: none;
  color: inherit;
  text-align: center;
}
.card-item img {
  width: 100%;
  height: auto;
  display: block;
  border-radius: 5px;
}
.card-item h4 {
  font-size: 1.35rem;
  font-weight: 700;
  color: #fff;
  margin: 0.8rem 0 0.3rem;
}
.card-item p {
  font-size: 0.82rem;
  color: #9aa3b6;
  margin: 0;
  line-height: 1.5;
}
.card-item a:hover h4 { color: var(--accent); }

/* ── Footer logo ────────────────────────────────────── */
.footer-right {
  display: flex;
  align-items: center;
  gap: 20px;
  margin-left: auto;
}
.footer-logo {
  max-height: 34px;
  width: auto;
  opacity: 0.7;
  display: block;
}
.footer-logo:hover { opacity: 0.9; }

@media (max-width: 768px) {
  .hero { padding: 2.5rem 1.25rem 2rem; }
  .hero h1 { font-size: 1.8rem; }
  .feature-cols { grid-template-columns: 1fr; gap: 1.25rem; }
  .cards-box { grid-template-columns: repeat(2, 1fr); padding: 1.25rem; }
  .card-item h4 { font-size: 1.1rem; }
}
@media (max-width: 480px) {
  .cards-box { grid-template-columns: 1fr; }
}

/* ══════════════════════════════════════════════════════════
   concept.html
   ══════════════════════════════════════════════════════════ */

.concept-body {
  max-width: 960px;
  margin: 0 auto;
  padding: 2.5rem 2rem 3.5rem;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 2rem 3rem;
  align-items: start;
}
.concept-col {
  display: flex;
  flex-direction: column;
  gap: 2rem;
}
.concept-section h2 {
  font-size: 0.9rem;
  font-weight: 700;
  color: var(--text);
  margin: 0 0 0.55rem;
}
.concept-section p {
  font-size: 13px;
  color: var(--text-muted);
  line-height: 1.65;
  margin: 0 0 0.55rem;
  text-align: justify;
}
.concept-section p:last-child { margin-bottom: 0; }
.codebook-note {
  font-size: 13px;
  color: var(--text-muted);
  margin: 0 0 1.5rem;
}
.codebook-note a { color: var(--accent); text-decoration: none; }
.codebook-note a:hover { text-decoration: underline; }
.terminology-label {
  font-size: 0.9rem;
  font-weight: 700;
  color: var(--text);
  margin: 0 0 0.75rem;
}
.terminology-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0.3rem 1rem;
  list-style: none;
  margin: 0;
  padding: 0;
}
.terminology-grid li {
  font-size: 13px;
  color: var(--text-muted);
  padding-left: 1.1em;
  position: relative;
  line-height: 1.5;
}
.terminology-grid li::before {
  content: '•';
  position: absolute;
  left: 0;
  color: var(--text-muted);
}
@media (max-width: 768px) {
  .concept-body {
    grid-template-columns: 1fr;
    padding: 2rem 1.25rem 2.5rem;
    gap: 0;
  }
  .concept-col { gap: 1.75rem; margin-bottom: 1.75rem; }
  .concept-col:last-child { margin-bottom: 0; }
  .terminology-grid { grid-template-columns: 1fr; }
}

/* ══════════════════════════════════════════════════════════
   charts.html
   ══════════════════════════════════════════════════════════ */

.charts-intro {
  font-size: 13px;
  color: var(--text-muted);
  line-height: 1.65;
  text-align: justify;
  max-width: 680px;
  margin: 0 auto 2.5rem;
}
.chart-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 2rem;
}
.chart-card a {
  display: block;
  text-decoration: none;
  color: inherit;
}
.chart-card img {
  width: 100%;
  height: 200px;
  object-fit: cover;
  object-position: top;
  display: block;
  border-radius: 6px;
  border: 1px solid var(--border);
}
.chart-card h2 {
  font-size: 0.95rem;
  font-weight: 700;
  color: var(--text);
  margin: 0.75rem 0 0.3rem;
}
.chart-card p {
  font-size: 13px;
  color: var(--text-muted);
  margin: 0;
  line-height: 1.55;
}
.chart-card a:hover h2 { color: var(--accent); }
.chart-card a:hover img { border-color: var(--accent); }
@media (max-width: 600px) {
  .chart-grid { grid-template-columns: 1fr; }
}

/* ══════════════════════════════════════════════════════════
   faq.html
   ══════════════════════════════════════════════════════════ */

.faq-cat-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 12px;
  margin-bottom: 2rem;
}
.faq-cat-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 1rem 1rem 0.85rem;
  text-align: left;
  cursor: pointer;
  transition: border-color 0.15s, background 0.15s;
  font-family: 'Mulish', sans-serif;
  color: var(--text);
  display: flex;
  flex-direction: column;
  gap: 5px;
}
.faq-cat-card:hover {
  border-color: var(--accent);
  background: rgba(100, 120, 184, 0.07);
}
.faq-cat-card.active {
  border-color: var(--accent);
  background: rgba(100, 120, 184, 0.13);
}
.faq-cat-title {
  font-size: 13px;
  font-weight: 700;
  color: var(--text);
  line-height: 1.3;
}
.faq-cat-desc {
  font-size: 11.5px;
  color: var(--text-muted);
  line-height: 1.5;
  flex: 1;
}
.faq-cat-n {
  font-size: 10.5px;
  font-weight: 700;
  color: var(--accent);
  letter-spacing: 0.04em;
  margin-top: 2px;
}
.faq-toolbar {
  margin-bottom: 1.5rem;
  display: flex;
  flex-direction: column;
  gap: 8px;
}
.faq-search-wrap { position: relative; }
#faqSearch {
  width: 100%;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 6px;
  color: var(--text);
  padding: 8px 80px 8px 12px;
  font-size: 13.5px;
  font-family: 'Mulish', sans-serif;
  outline: none;
  appearance: none;
  -webkit-appearance: none;
  transition: border-color 0.15s;
}
#faqSearch:focus { border-color: var(--accent); }
#faqSearch::placeholder { color: var(--text-muted); }
#faqSearch::-webkit-search-cancel-button { display: none; }
#faqSearchHint {
  position: absolute;
  right: 10px;
  top: 50%;
  transform: translateY(-50%);
  font-size: 11px;
  color: var(--text-muted);
  pointer-events: none;
  white-space: nowrap;
}
.faq-tabs {
  display: flex;
  flex-wrap: wrap;
  gap: 4px;
}
.faq-tab {
  background: transparent;
  border: 1px solid var(--border);
  border-radius: 4px;
  color: var(--text-muted);
  font-size: 11.5px;
  font-family: 'Mulish', sans-serif;
  font-weight: 600;
  padding: 4px 10px;
  cursor: pointer;
  transition: color 0.15s, border-color 0.15s, background 0.15s;
  white-space: nowrap;
}
.faq-tab:hover { color: var(--text); border-color: #556080; background: rgba(255,255,255,0.04); }
.faq-tab.active { color: var(--accent); border-color: var(--accent); background: rgba(100,120,184,0.1); }
.faq-badge {
  display: inline-block;
  background: rgba(100,120,184,0.2);
  color: var(--accent);
  font-size: 10px;
  font-weight: 700;
  border-radius: 3px;
  padding: 0 5px;
  margin-left: 4px;
  vertical-align: middle;
}
#faqNoResults {
  font-size: 13px;
  color: var(--text-muted);
  text-align: center;
  padding: 2.5rem 0;
}
.faq-question {
  border-bottom: 1px solid rgba(60, 66, 89, 0.4);
}
.faq-question:last-child { border-bottom: none; }
details > summary {
  list-style: none;
  cursor: pointer;
  padding: 0.85rem 0;
}
details > summary::-webkit-details-marker { display: none; }
details > summary::after {
  content: "▾ Show answer";
  display: block;
  font-size: 0.78rem;
  font-weight: 400;
  color: var(--accent);
  margin-top: 0.15rem;
  letter-spacing: 0.02em;
}
details[open] > summary::after { content: "▴ Hide answer"; }
details > summary h2 {
  display: inline;
  font-size: 0.88rem;
  font-weight: 700;
  color: var(--text);
  margin: 0;
}
details > summary:hover h2 { color: var(--accent); }
details details > summary { padding: 0.3rem 0; }
details details > summary::after { content: "▾ Show"; }
details details[open] > summary::after { content: "▴ Hide"; }
.faq-answer {
  font-size: 13px;
  color: var(--text-muted);
  line-height: 1.65;
  text-align: justify;
  padding-bottom: 0.85rem;
}
.faq-answer p { margin: 0 0 0.65rem; }
.faq-answer p:last-child { margin-bottom: 0; }
.faq-answer ul { margin: 0.5rem 0 0; padding-left: 1.4em; }
.faq-answer li { margin-bottom: 0.2rem; }
mark {
  background: rgba(100, 120, 184, 0.35);
  color: var(--text);
  border-radius: 2px;
  padding: 0 1px;
}
.country-list ul {
  list-style: none;
  padding: 0;
  margin: 0.5rem 0 0.5rem;
  columns: 3;
  -webkit-columns: 3;
}
.country-list li {
  font-size: 12px;
  color: var(--text-muted);
  padding: 0.1rem 0;
}
@media (max-width: 900px) {
  .faq-cat-grid { grid-template-columns: repeat(2, 1fr); }
  .country-list ul { columns: 2; -webkit-columns: 2; }
}
@media (max-width: 500px) {
  .faq-cat-grid { grid-template-columns: 1fr 1fr; }
  .country-list ul { columns: 1; -webkit-columns: 1; }
}
@media (max-width: 380px) {
  .faq-cat-grid { grid-template-columns: 1fr; }
}

/* ══════════════════════════════════════════════════════════
   funding.html
   ══════════════════════════════════════════════════════════ */

.funding-block {
  display: flex;
  align-items: flex-start;
  gap: 2rem;
}
.funding-block img {
  width: 120px;
  height: auto;
  flex-shrink: 0;
  opacity: 0.9;
}
.funding-block p {
  font-size: 13px;
  color: var(--text-muted);
  line-height: 1.65;
  margin: 0;
}
@media (max-width: 480px) {
  .funding-block { flex-direction: column; }
}

/* ══════════════════════════════════════════════════════════
   imprint.html
   ══════════════════════════════════════════════════════════ */

.imprint-logo {
  display: block;
  max-width: 240px;
  height: auto;
  margin-bottom: 1.5rem;
  opacity: 0.85;
}

/* ══════════════════════════════════════════════════════════
   publications.html
   ══════════════════════════════════════════════════════════ */

.pub-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: 0;
}
.pub-list li {
  font-size: 13px;
  color: var(--text-muted);
  line-height: 1.65;
  padding: 0.85rem 0;
  border-bottom: 1px solid rgba(60, 66, 89, 0.4);
  display: flex;
  flex-direction: column;
  gap: 0.45rem;
}
.pub-list li:last-child { border-bottom: none; }
.pub-links {
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem;
}
.pub-links a {
  font-size: 11px;
  font-weight: 700;
  color: var(--accent);
  text-decoration: none;
  border: 1px solid rgba(100, 120, 184, 0.4);
  border-radius: 3px;
  padding: 1px 7px;
  letter-spacing: 0.03em;
  transition: background 0.15s, border-color 0.15s;
}
.pub-links a:hover {
  background: rgba(100, 120, 184, 0.14);
  border-color: var(--accent);
  text-decoration: none;
}

/* ══════════════════════════════════════════════════════════
   team.html
   ══════════════════════════════════════════════════════════ */

.team-section { margin-bottom: 1.5rem; }
.team-section:last-child { margin-bottom: 0; }
.team-section h2 {
  font-size: 0.82rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.07em;
  color: var(--text-muted);
  margin: 0 0 0.4rem;
}
.team-section p {
  font-size: 13px;
  color: var(--text);
  line-height: 1.65;
  margin: 0;
}