/* ===========================================================
   Beyond the Average — stylesheet
   Modern data-journalism aesthetic: light, restrained, high hierarchy.
   =========================================================== */

:root {
  color-scheme: light;
  padding-top: env(safe-area-inset-top, 0px);
  padding-bottom: env(safe-area-inset-bottom, 0px);

  /* Palette — restrained, NYC/public-policy feel */
  --bg: #fbfaf7;
  --bg-alt: #f2efe8;
  --bg-dark: #16221f;
  --ink: #171a19;
  --ink-soft: #454e4c;
  --ink-faint: #767f7c;
  --line: #dcd7cb;
  --line-strong: #b9b2a0;
  --accent: #a13d2b;       /* muted brick/rust — traffic & alert */
  --accent-soft: #f3e2dc;
  --teal: #2c5f5a;         /* muted teal — air quality / policy */
  --teal-soft: #e2eeec;
  --gold: #b8862f;         /* muted gold — EJ / attention */
  --gold-soft: #f4ead3;
  --white: #ffffff;
  --shadow: 0 8px 30px rgba(23, 26, 25, 0.08);
  --radius: 10px;
  --serif: 'Newsreader', Georgia, 'Times New Roman', serif;
  --sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  --maxw: 1180px;
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --bg: #14171a;
    --bg-alt: #1a1e21;
    --bg-dark: #0c1210;
    --ink: #eee9e0;
    --ink-soft: #c7c2b7;
    --ink-faint: #918c81;
    --line: #33362f;
    --line-strong: #4a4c42;
    --accent: #e08b6f;
    --accent-soft: #2c1f1a;
    --teal: #7fb8b0;
    --teal-soft: #172422;
    --gold: #d9ac5c;
    --gold-soft: #2a2213;
    --white: #1c1f22;
    --shadow: 0 8px 30px rgba(0, 0, 0, 0.35);
  }
}
:root[data-theme="dark"] {
  --bg: #14171a;
  --bg-alt: #1a1e21;
  --bg-dark: #0c1210;
  --ink: #eee9e0;
  --ink-soft: #c7c2b7;
  --ink-faint: #918c81;
  --line: #33362f;
  --line-strong: #4a4c42;
  --accent: #e08b6f;
  --accent-soft: #2c1f1a;
  --teal: #7fb8b0;
  --teal-soft: #172422;
  --gold: #d9ac5c;
  --gold-soft: #2a2213;
  --white: #1c1f22;
  --shadow: 0 8px 30px rgba(0, 0, 0, 0.35);
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  * { animation-duration: 0.001ms !important; transition-duration: 0.001ms !important; }
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font-family: var(--sans);
  font-size: 16px;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

img { max-width: 100%; }
[hidden] { display: none !important; }

.skip-link {
  position: absolute;
  left: -999px;
  top: 0;
  background: var(--ink);
  color: var(--bg);
  padding: 0.75em 1.2em;
  z-index: 999;
  border-radius: 0 0 6px 0;
}
.skip-link:focus {
  left: 0;
}

a { color: var(--teal); }
a:focus-visible, button:focus-visible {
  outline: 3px solid var(--teal);
  outline-offset: 2px;
}

/* ---------- Top nav ---------- */
.topnav {
  position: sticky;
  top: env(safe-area-inset-top, 0px);
  z-index: 50;
  background: rgba(251, 250, 247, 0.92);
  backdrop-filter: saturate(150%) blur(8px);
  border-bottom: 1px solid var(--line);
}
:root[data-theme="dark"] .topnav {
  background: rgba(20, 23, 26, 0.9);
}
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) .topnav {
    background: rgba(20, 23, 26, 0.9);
  }
}
.topnav-inner {
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 0.85rem 1.5rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1.5rem;
}
.brand {
  font-family: var(--serif);
  font-weight: 600;
  font-size: 1.15rem;
  letter-spacing: 0.01em;
  white-space: nowrap;
  color: var(--ink);
}
.nav-links {
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem;
  justify-content: flex-end;
}
.nav-links a {
  color: var(--ink);
  text-decoration: none;
  font-size: 0.88rem;
  font-weight: 500;
  padding: 0.4rem 0.7rem;
  border-radius: 6px;
  white-space: nowrap;
}
.nav-links a:hover,
.nav-links a:focus-visible {
  background: var(--bg-alt);
  color: var(--ink);
}
.nav-links a[aria-current="true"] {
  background: var(--teal-soft);
  color: var(--teal);
}
.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 4px;
  background: none;
  border: none;
  padding: 8px;
  cursor: pointer;
}
.nav-toggle span {
  width: 22px;
  height: 2px;
  background: var(--ink);
  display: block;
}

/* ---------- Hero ---------- */
.hero {
  min-height: 92vh;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  text-align: center;
  padding: 6rem 1.5rem 4rem;
  background:
    radial-gradient(circle at 20% 15%, var(--teal-soft) 0%, transparent 45%),
    radial-gradient(circle at 85% 80%, var(--accent-soft) 0%, transparent 50%),
    var(--bg);
  position: relative;
}
.hero-inner {
  max-width: 880px;
}
.eyebrow {
  font-size: 0.85rem;
  font-weight: 600;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--teal);
  margin: 0 0 1.25rem;
}
.hero h1 {
  font-family: var(--serif);
  font-size: clamp(2.75rem, 6vw, 5rem);
  font-weight: 600;
  line-height: 1.05;
  margin: 0 0 0.75rem;
  letter-spacing: -0.01em;
}
.subtitle {
  font-size: clamp(1.1rem, 2vw, 1.4rem);
  color: var(--ink-soft);
  max-width: 680px;
  margin: 0 auto 2.5rem;
  font-weight: 400;
}
.author-line {
  font-size: 0.85rem;
  color: var(--ink-faint);
  max-width: 680px;
  margin: -1.5rem auto 2rem;
  line-height: 1.5;
}
.research-question {
  background: var(--white);
  border: 1px solid var(--line);
  border-left: 4px solid var(--teal);
  border-radius: var(--radius);
  padding: 1.75rem 2rem;
  max-width: 720px;
  margin: 0 auto 2rem;
  text-align: left;
  box-shadow: var(--shadow);
}
.research-question p {
  font-family: var(--serif);
  font-style: italic;
  font-size: clamp(1.05rem, 1.6vw, 1.25rem);
  line-height: 1.55;
  margin: 0;
  color: var(--ink);
}
.hero-intro {
  max-width: 680px;
  margin: 0 auto;
  color: var(--ink-soft);
  font-size: 1.02rem;
}
.scroll-cue {
  position: absolute;
  bottom: 2rem;
  left: 50%;
  transform: translateX(-50%);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.4rem;
  color: var(--ink-faint);
  text-decoration: none;
  font-size: 0.8rem;
  font-weight: 500;
  letter-spacing: 0.05em;
  text-transform: uppercase;
  animation: bob 2.2s ease-in-out infinite;
}
.scroll-cue:hover { color: var(--teal); }
@keyframes bob {
  0%, 100% { transform: translate(-50%, 0); }
  50% { transform: translate(-50%, 8px); }
}

/* ---------- Sections ---------- */
.section {
  padding: 5.5rem 1.5rem;
  scroll-margin-top: 4.5rem;
  border-bottom: 1px solid var(--line);
}
.section-alt { background: var(--bg-alt); }
.section-inner {
  max-width: var(--maxw);
  margin: 0 auto;
}
.section-kicker {
  font-size: 0.82rem;
  font-weight: 700;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--accent);
  margin: 0 0 0.75rem;
}
.section-kicker-light { color: var(--gold); }
.section h2 {
  font-family: var(--serif);
  font-size: clamp(1.9rem, 3.2vw, 2.6rem);
  font-weight: 600;
  line-height: 1.15;
  margin: 0 0 1.25rem;
  max-width: 850px;
}
.lede {
  font-size: 1.15rem;
  color: var(--ink-soft);
  max-width: 780px;
  margin: 0 0 2.5rem;
}
.lede-light { color: #d6d9d7; }

.text-block { max-width: 780px; margin: 2rem 0; }
.text-block p { margin: 0 0 1rem; }
.text-block ul { margin: 0 0 1rem; padding-left: 1.2rem; }
.text-block li { margin-bottom: 0.5rem; }

.callout {
  background: var(--gold-soft);
  border-left: 4px solid var(--gold);
  border-radius: 6px;
  padding: 1.1rem 1.4rem;
  font-weight: 500;
  color: var(--ink);
}

.method-list { list-style: none; margin: 0; padding: 0; }
.method-list li {
  padding: 0.9rem 0 0.9rem 1.6rem;
  position: relative;
  border-bottom: 1px solid var(--line);
}
.method-list li:last-child { border-bottom: none; }
.method-list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 1.35rem;
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--teal);
}

/* ---------- Figures / images ---------- */
.figure {
  margin: 0 0 1rem;
}
.figure-hero { margin-top: 1rem; }
.img-button {
  display: flex;
  flex-direction: column;
  width: 100%;
  padding: 0;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
  background: var(--white);
  cursor: zoom-in;
  position: relative;
  box-shadow: var(--shadow);
  transition: box-shadow 0.15s ease, transform 0.15s ease;
}
.img-button:hover, .img-button:focus-visible {
  box-shadow: 0 12px 36px rgba(23, 26, 25, 0.14);
  transform: translateY(-2px);
}
.img-button img {
  display: block;
  width: 100%;
  height: auto;
}
.zoom-hint {
  align-self: flex-end;
  margin: 0.6rem 0.75rem;
  background: rgba(23, 26, 25, 0.78);
  color: #fff;
  font-size: 0.78rem;
  font-weight: 500;
  padding: 0.35rem 0.7rem;
  border-radius: 999px;
  pointer-events: none;
}
figcaption {
  font-size: 0.9rem;
  color: var(--ink-faint);
  margin-top: 0.75rem;
  font-style: italic;
}

/* ---------- Stat rows ---------- */
.stat-row {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1rem;
  margin: 2.5rem 0;
}
.stat-row-two { grid-template-columns: repeat(2, 1fr); max-width: 700px; }
.stat-row-three { grid-template-columns: repeat(3, 1fr); }
.stat-card {
  background: var(--white);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 1.5rem 1.25rem;
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}
.stat-card-highlight {
  background: var(--accent-soft);
  border-color: var(--accent);
}
.stat-num {
  font-family: var(--serif);
  font-size: clamp(1.6rem, 2.4vw, 2.1rem);
  font-weight: 600;
  color: var(--ink);
}
.stat-card-highlight .stat-num { color: var(--accent); }
.stat-label {
  font-size: 0.88rem;
  color: var(--ink-soft);
  line-height: 1.4;
}

.note-box {
  background: var(--teal-soft);
  border: 1px solid var(--teal);
  border-radius: var(--radius);
  padding: 1.1rem 1.4rem;
  max-width: 780px;
  margin-bottom: 2rem;
  font-size: 0.96rem;
}
.note-box p { margin: 0; }

/* ---------- PM2.5 explainer ---------- */
.explainer-box {
  background: var(--teal-soft);
  border: 1px solid var(--teal);
  border-radius: var(--radius);
  padding: 1.5rem 1.6rem;
  margin: 2rem 0;
}
.explainer-box h3 {
  font-family: var(--serif);
  font-size: 1.15rem;
  font-weight: 600;
  color: var(--ink);
  margin: 0 0 1.1rem;
}
.explainer-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.4rem;
}
.explainer-item h4 {
  font-size: 0.92rem;
  font-weight: 700;
  color: var(--teal);
  margin: 0 0 0.4rem;
}
.explainer-item p {
  font-size: 0.92rem;
  color: var(--ink-soft);
  line-height: 1.5;
  margin: 0;
}
.source-note {
  font-size: 0.82rem;
  color: var(--ink-faint);
  font-style: italic;
  margin: 1.2rem 0 0;
}
.explainer-text {
  font-size: 0.95rem;
  color: var(--ink-soft);
  line-height: 1.6;
  margin: 0 0 0.9rem;
}
.explainer-subtext {
  font-size: 0.85rem;
  color: var(--ink-faint);
  line-height: 1.5;
  margin: 0 0 1rem;
}
.asthma-stat-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 1rem;
  margin: 0 0 1.2rem;
}
.asthma-stat-card {
  background: var(--white);
  border: 1px solid var(--teal);
  border-radius: var(--radius);
  padding: 1.1rem 1.25rem;
  display: flex;
  flex-direction: column;
  gap: 0.3rem;
}
.asthma-stat-num {
  font-family: var(--serif);
  font-size: clamp(1.5rem, 2.2vw, 1.9rem);
  font-weight: 600;
  color: var(--teal);
}
.asthma-stat-sub {
  font-size: 0.78rem;
  font-weight: 600;
  color: var(--ink-faint);
  text-transform: uppercase;
  letter-spacing: 0.03em;
  margin-top: -0.3rem;
}
.asthma-stat-metric {
  font-size: 0.88rem;
  font-weight: 600;
  color: var(--ink);
  margin-top: 0.3rem;
}
.asthma-stat-detail {
  font-size: 0.85rem;
  color: var(--ink-soft);
  line-height: 1.5;
}
@media (max-width: 720px) {
  .asthma-stat-grid { grid-template-columns: 1fr; }
}
@media (max-width: 720px) {
  .explainer-grid { grid-template-columns: 1fr; }
}

/* ---------- Stat strip (EJ percentiles) ---------- */
.stat-strip {
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  gap: 0;
  background: var(--white);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
  margin: 2rem 0;
  box-shadow: var(--shadow);
}
.stat-strip-item {
  padding: 1.75rem 1rem;
  text-align: center;
  border-right: 1px solid var(--line);
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}
.stat-strip-item:last-child { border-right: none; }
.stat-strip-num {
  font-family: var(--serif);
  font-weight: 700;
  font-size: clamp(1.6rem, 2.6vw, 2.3rem);
  color: var(--gold);
}
.stat-strip-num sup { font-size: 0.55em; }
.stat-strip-label {
  font-size: 0.82rem;
  color: var(--ink-soft);
  line-height: 1.35;
}

/* ---------- Pollutant grid ---------- */
.pollutant-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1rem;
  margin: 2rem 0;
}
.pollutant-card {
  background: var(--white);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 1.5rem;
  display: flex;
  flex-direction: column;
  gap: 0.4rem;
  text-align: center;
}
.pollutant-name {
  font-size: 0.85rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--ink-faint);
}
.pollutant-est {
  font-family: var(--serif);
  font-size: 1.9rem;
  font-weight: 600;
  color: var(--accent);
}
.pollutant-unit { font-size: 1rem; font-weight: 400; color: var(--ink-soft); }
.pollutant-ci {
  font-size: 0.82rem;
  color: var(--ink-faint);
  font-weight: 500;
}

.conclusion-box {
  background: var(--ink);
  color: var(--bg);
  border-radius: var(--radius);
  padding: 1.75rem 2rem;
  max-width: 820px;
  margin-top: 1rem;
}
.conclusion-box p { margin: 0 0 0.75rem; }
.conclusion-box p:last-child { margin-bottom: 0; }
.conclusion-box strong { color: var(--gold); }

/* ---------- Workflow list ---------- */
.workflow {
  list-style: none;
  margin: 0 0 2.5rem;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 0.75rem;
}
.workflow li {
  background: var(--white);
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 1rem;
  display: flex;
  align-items: center;
  gap: 0.75rem;
}
.wf-num {
  font-family: var(--serif);
  font-weight: 700;
  font-size: 1.15rem;
  color: var(--teal);
  flex-shrink: 0;
  width: 1.6em;
}
.wf-text { font-size: 0.92rem; color: var(--ink); }

.expert-section { margin-top: 3rem; }
.expert-section h3 {
  font-family: var(--serif);
  font-size: 1.5rem;
  margin: 0 0 1.25rem;
}
.expert-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.25rem;
}
.expert-card {
  background: var(--white);
  border: 1px solid var(--line);
  border-top: 3px solid var(--teal);
  border-radius: var(--radius);
  padding: 1.5rem;
}
.expert-name {
  display: block;
  font-weight: 700;
  font-size: 1.02rem;
}
.expert-affil {
  display: block;
  font-size: 0.85rem;
  color: var(--ink-faint);
  margin-bottom: 0.75rem;
}
.expert-card p { margin: 0; font-size: 0.94rem; color: var(--ink-soft); }

/* ---------- Deep-dive sensitivity explainer ---------- */
.deep-dive-explainer { margin-top: 3rem; }
.deep-dive-explainer h3 {
  font-family: var(--serif);
  font-size: 1.5rem;
  margin: 0 0 0.5rem;
  max-width: 780px;
}
.deep-dive-intro {
  font-size: 0.98rem;
  color: var(--ink-soft);
  max-width: 720px;
  margin: 0 0 1.5rem;
}
.sensitivity-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 1.25rem;
  margin-bottom: 2rem;
}
.sensitivity-card {
  background: var(--white);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 1.35rem 1.5rem;
}
.sensitivity-card-wide { grid-column: 1 / -1; }
.sensitivity-eyebrow {
  display: block;
  font-size: 0.72rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--teal);
  margin-bottom: 0.4rem;
}
.sensitivity-card h4 {
  font-family: var(--serif);
  font-size: 1.05rem;
  font-weight: 600;
  color: var(--ink);
  line-height: 1.3;
  margin: 0 0 0.75rem;
}
.sensitivity-caveat {
  font-size: 0.85rem;
  font-style: italic;
  color: var(--ink-faint);
  margin: 0 0 0.9rem;
}
.sensitivity-stats {
  list-style: none;
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem;
  margin: 0 0 0.85rem;
  padding: 0;
}
.sensitivity-stats li {
  background: var(--teal-soft);
  color: var(--ink);
  font-size: 0.8rem;
  font-weight: 600;
  padding: 0.3rem 0.6rem;
  border-radius: 999px;
}
.sensitivity-card > p {
  font-size: 0.88rem;
  color: var(--ink-soft);
  line-height: 1.5;
  margin: 0;
}
.sensitivity-cols {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 1.5rem;
  margin-bottom: 0.9rem;
}
.sensitivity-subgroup-label {
  display: block;
  font-size: 0.76rem;
  font-weight: 700;
  color: var(--ink-faint);
  text-transform: uppercase;
  letter-spacing: 0.03em;
  margin-bottom: 0.45rem;
}
.sensitivity-table { width: 100%; border-collapse: collapse; font-size: 0.83rem; }
.sensitivity-table td {
  padding: 0.35rem 0;
  border-bottom: 1px solid var(--line);
  color: var(--ink-soft);
}
.sensitivity-table tr:last-child td { border-bottom: none; }
.sensitivity-table td:last-child {
  text-align: right;
  font-weight: 600;
  color: var(--ink);
  white-space: nowrap;
}

/* ---------- Window-alignment table (season matching) ---------- */
.window-table-wrap { overflow-x: auto; margin: 1.1rem 0 0.6rem; }
.window-table { width: 100%; border-collapse: collapse; font-size: 0.86rem; min-width: 480px; }
.window-table caption {
  caption-side: top;
  text-align: left;
  font-size: 0.78rem;
  font-weight: 700;
  color: var(--ink-faint);
  text-transform: uppercase;
  letter-spacing: 0.03em;
  margin-bottom: 0.5rem;
}
.window-table th {
  text-align: left;
  font-size: 0.78rem;
  font-weight: 700;
  color: var(--teal);
  text-transform: uppercase;
  letter-spacing: 0.02em;
  padding: 0.5rem 0.7rem;
  border-bottom: 2px solid var(--line-strong);
  white-space: nowrap;
}
.window-table td {
  padding: 0.5rem 0.7rem;
  border-bottom: 1px solid var(--line);
  color: var(--ink-soft);
  white-space: nowrap;
}
.window-table tr:last-child td { border-bottom: none; }
.window-table td:first-child { color: var(--ink); font-weight: 600; }
.window-table .status-pill {
  display: inline-block;
  font-size: 0.72rem;
  font-weight: 700;
  padding: 0.15rem 0.55rem;
  border-radius: 999px;
  background: var(--teal-soft);
  color: var(--teal);
}
@media (max-width: 720px) {
  .sensitivity-grid { grid-template-columns: 1fr; }
  .sensitivity-cols { grid-template-columns: 1fr; gap: 1rem; }
}

/* ---------- Limitations ---------- */
.limitations-box {
  background: var(--white);
  border: 2px solid var(--accent);
  border-radius: var(--radius);
  padding: 2rem 2.25rem;
  max-width: 900px;
}
.limitations-box ul { margin: 0; padding-left: 1.2rem; }
.limitations-box li { margin-bottom: 0.9rem; font-size: 1.02rem; }
.limitations-box li:last-child { margin-bottom: 0; }

/* ---------- Dark "why it matters" section ---------- */
.section-dark {
  background: var(--bg-dark);
  color: #f2f0ea;
  border-bottom: none;
}
.section-dark h2 { color: #fff; }
.closing-line {
  font-family: var(--serif);
  font-style: italic;
  font-size: clamp(1.4rem, 2.6vw, 2rem);
  line-height: 1.5;
  max-width: 780px;
  margin-top: 2.5rem;
  color: #fff;
}

/* ---------- Phase 2 question shift ---------- */
.question-shift {
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  gap: 1.5rem;
  align-items: stretch;
  margin: 2rem 0 2.5rem;
}
.question-old, .question-new {
  background: var(--white);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 1.5rem 1.75rem;
}
.question-new { border-color: var(--teal); background: var(--teal-soft); }
.question-label {
  display: block;
  font-size: 0.78rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--ink-faint);
  margin-bottom: 0.6rem;
}
.question-old p, .question-new p {
  font-family: var(--serif);
  font-style: italic;
  font-size: 1.1rem;
  margin: 0;
}
.question-arrow {
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.8rem;
  color: var(--ink-faint);
}
.intervention-list {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 0.5rem 1.5rem;
  list-style: none;
  padding: 0;
  margin: 1rem 0 1.5rem;
}
.intervention-list li {
  padding: 0.6rem 0 0.6rem 1.4rem;
  position: relative;
  border-bottom: 1px solid var(--line);
  font-weight: 500;
}
.intervention-list li::before {
  content: "\2192";
  position: absolute;
  left: 0;
  color: var(--teal);
}

/* ---------- Sources ---------- */
.sources-list {
  list-style: none;
  padding: 0;
  margin: 0;
  max-width: 780px;
}
.sources-list li {
  padding: 1rem 0;
  border-bottom: 1px solid var(--line);
  font-size: 1rem;
}
.sources-list li:first-child { padding-top: 0; }

.site-footer {
  text-align: center;
  padding: 2.5rem 1.5rem;
  color: var(--ink-faint);
  font-size: 0.85rem;
}

/* ---------- Lightbox ---------- */
.lightbox {
  position: fixed;
  inset: 0;
  z-index: 200;
  background: rgba(10, 12, 11, 0.92);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: 2rem;
  padding-top: calc(2rem + env(safe-area-inset-top, 0px));
  padding-bottom: calc(2rem + env(safe-area-inset-bottom, 0px));
}
.lightbox-stage {
  max-width: 100%;
  max-height: 82vh;
  overflow: auto;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: zoom-in;
  touch-action: pinch-zoom;
}
.lightbox-stage.zoomed { cursor: zoom-out; }
.lightbox-stage img {
  max-width: 100%;
  max-height: 82vh;
  object-fit: contain;
  border-radius: 4px;
  transition: transform 0.15s ease;
  transform-origin: center center;
}
.lightbox-stage.zoomed img {
  max-width: none;
  max-height: none;
  transform: scale(1.9);
  cursor: zoom-out;
}
.lightbox-close {
  position: absolute;
  top: calc(1.25rem + env(safe-area-inset-top, 0px));
  right: 1.5rem;
  background: rgba(255, 255, 255, 0.12);
  color: #fff;
  border: none;
  width: 44px;
  height: 44px;
  border-radius: 50%;
  font-size: 1.6rem;
  line-height: 1;
  cursor: pointer;
}
.lightbox-close:hover { background: rgba(255, 255, 255, 0.22); }
.lightbox-hint {
  color: rgba(255, 255, 255, 0.65);
  font-size: 0.82rem;
  margin-top: 1.25rem;
}

/* ===========================================================
   Responsive
   =========================================================== */
@media (max-width: 1024px) {
  .stat-row { grid-template-columns: repeat(2, 1fr); }
  .workflow { grid-template-columns: repeat(2, 1fr); }
  .expert-grid { grid-template-columns: 1fr; }
  .stat-strip { grid-template-columns: repeat(3, 1fr); }
  .stat-strip-item:nth-child(3) { border-right: none; }
  .pollutant-grid { grid-template-columns: 1fr; }
}

@media (max-width: 860px) {
  .nav-links {
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    background: var(--bg);
    border-bottom: 1px solid var(--line);
    flex-direction: column;
    padding: 0.5rem;
  }
  .nav-links.open { display: flex; }
  .nav-links a { padding: 0.75rem 1rem; }
  .nav-toggle { display: flex; }
  .question-shift { grid-template-columns: 1fr; }
  .question-arrow { transform: rotate(90deg); padding: 0.25rem 0; }
}

@media (max-width: 640px) {
  .section { padding: 3.5rem 1.25rem; }
  .hero { padding: 5rem 1.25rem 3.5rem; min-height: unset; }
  .stat-row, .stat-row-two, .stat-row-three { grid-template-columns: 1fr; }
  .stat-strip { grid-template-columns: repeat(2, 1fr); }
  .stat-strip-item { border-right: none; border-bottom: 1px solid var(--line); }
  .stat-strip-item:nth-child(even) { border-left: 1px solid var(--line); }
  .workflow { grid-template-columns: 1fr; }
  .intervention-list { grid-template-columns: 1fr; }
  .research-question { padding: 1.25rem 1.4rem; }
  body { font-size: 15.5px; }
}