/* ============================================================
   Perioperative Brain Optimization — pbo.css
   Prefix: pbo-
   Requires: global.css, header.css
   Style: Editorial médica — informativa, visualmente rica
   ============================================================ */

/* ── Layout helpers ── */
body{
  background: var(--bg-dark);
}

.pbo-container       { max-width: 1100px; margin: 0 auto; padding: 0 32px; }
.pbo-container--wide { max-width: 1200px; }
.pbo-container--narrow { max-width: 720px; }
.pbo-text-center     { text-align: center; }

/* ── Section backgrounds ── */
.pbo-section         { padding: 88px 0; }
.pbo-section--cream  { background: var(--warm-cream); }
.pbo-section--white  { background: #fff; }
.pbo-section--dark   { background: var(--bg-dark); }
.pbo-section--teal   { background: var(--brand-teal); }

/* ── Eyebrow ── */
.pbo-section-eyebrow {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 1.5rem;
}
.pbo-eyebrow-line {
  width: 28px; height: 1px;
  background: var(--brand-terracotta);
  flex-shrink: 0;
}
.pbo-section-eyebrow span {
  font-family: var(--font-ui);
  font-size: var(--type-tag);
  font-weight: 700;
  letter-spacing: var(--ls-eyebrow);
  text-transform: uppercase;
  color: var(--brand-terracotta);
}
.pbo-section-eyebrow--light .pbo-eyebrow-line { background: var(--brand-orange); }
.pbo-section-eyebrow--light span { color: var(--brand-orange); }

/* ── Section headings ── */
.pbo-section h2 {
  font-family: var(--font-display);
  font-size: clamp(1.9rem, 4vw, 2.8rem);
  font-weight: 600;
  color: var(--text-primary);
  line-height: 1.18;
  letter-spacing: -0.02em;
  margin-bottom: 1rem;
}
.pbo-section--dark h2,
.pbo-section--teal h2 { color: var(--text-inverse); }

.pbo-section h3 {
  font-family: var(--font-display);
  font-size: 1.4rem;
  font-weight: 600;
  color: var(--brand-teal);
  margin-bottom: 0.75rem;
  line-height: 1.3;
}
.pbo-section--dark h3 { color: var(--text-inverse); }

.pbo-lead {
  font-size: 1.08rem;
  color: var(--text-secondary);
  line-height: 1.8;
  max-width: 680px;
  margin-bottom: 2.5rem;
}
.pbo-lead--light { color: var(--text-inverse-dim); }
.pbo-section--teal .pbo-lead { color: var(--text-inverse-dim); }

.pbo-section p {
  font-size: var(--type-body);
  color: var(--text-secondary);
  line-height: 1.8;
  margin-bottom: 1rem;
}
.pbo-section--teal p { color: rgba(245,240,232,0.82); }

/* ── Buttons ── */
.pbo-btn-primary {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  background: var(--text-inverse);
  color: var(--brand-teal);
  font-family: var(--font-ui);
  font-size: var(--type-sm);
  font-weight: 600;
  letter-spacing: 0.04em;
  padding: 13px 28px;
  border-radius: var(--r-sm);
  text-decoration: none;
  transition: background var(--t-fast), transform var(--t-fast);
}
.pbo-btn-primary:hover { background: var(--warm-cream); transform: translateY(-1px); }

.pbo-btn-ghost {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  border: 1.5px solid rgba(245,240,232,0.4);
  color: rgba(245,240,232,0.85);
  font-family: var(--font-ui);
  font-size: var(--type-sm);
  font-weight: 400;
  padding: 12px 24px;
  border-radius: var(--r-sm);
  text-decoration: none;
  transition: border-color var(--t-fast), color var(--t-fast);
}
.pbo-btn-ghost:hover { border-color: rgba(245,240,232,0.8); color: var(--text-inverse); }

.pbo-cta-group {
  display: flex;
  gap: 0.75rem;
  flex-wrap: wrap;
  justify-content: center;
  margin-top: 2rem;
}

/* ════════════════════════════════════════════════════════
   HERO
   ════════════════════════════════════════════════════════ */
.pbo-hero {
  background: var(--bg-dark);
  position: relative;
  overflow: hidden;
  padding: 0;
}
.pbo-hero-bg {
  position: absolute;
  inset: 0;
  background:
    radial-gradient(ellipse 70% 60% at 75% 30%, rgba(0,88,89,0.18) 0%, transparent 60%),
    radial-gradient(ellipse 50% 70% at 10% 80%, rgba(1,68,37,0.22) 0%, transparent 55%);
  pointer-events: none;
}
.pbo-hero-inner {
  position: relative;
  z-index: 2;
  max-width: 1100px;
  margin: 0 auto;
  padding: 56px 32px 64px;
}

/* Breadcrumb */
.pbo-breadcrumb {
  font-family: var(--font-ui);
  font-size: var(--type-sm);
  color: rgba(245,240,232,0.38);
  margin-bottom: 2rem;
  display: flex;
  gap: 8px;
  align-items: center;
}
.pbo-breadcrumb a { color: rgba(245,240,232,0.55); text-decoration: none; }
.pbo-breadcrumb a:hover { color: var(--text-inverse); }
.pbo-bc-sep { opacity: 0.4; }

/* Hero label */
.pbo-hero-label-row {
  display: flex;
  align-items: center;
  gap: 8px;
  margin-bottom: 1.25rem;
}
.pbo-label {
  font-family: var(--font-ui);
  font-size: var(--type-tag);
  font-weight: 600;
  letter-spacing: var(--ls-eyebrow);
  text-transform: uppercase;
  color: var(--brand-orange);
}
.pbo-label-sep { color: rgba(245,240,232,0.25); font-size: var(--type-tag); }

/* Hero h1 */
.pbo-hero h1 {
  font-family: var(--font-display);
  font-size: clamp(2.8rem, 6vw, 4.4rem);
  font-weight: 600;
  color: var(--text-inverse);
  line-height: 1.08;
  letter-spacing: -0.025em;
  margin-bottom: 1.25rem;
}
.pbo-hero h1 em {
  font-style: italic;
  color: var(--brand-orange);
}

.pbo-hero-deck {
  font-family: var(--font-display);
  font-size: clamp(1.05rem, 2vw, 1.35rem);
  font-style: italic;
  color: var(--text-inverse-dim);
  line-height: 1.55;
  max-width: 680px;
  margin-bottom: 2rem;
}

/* Meta row */
.pbo-hero-meta {
  display: flex;
  align-items: center;
  gap: 20px;
  flex-wrap: wrap;
  margin-bottom: 2.5rem;
  padding-bottom: 2rem;
  border-bottom: 1px solid rgba(245,240,232,0.08);
}
.pbo-meta-item { display: flex; flex-direction: column; gap: 2px; }
.pbo-meta-label {
  font-family: var(--font-ui);
  font-size: 0.6rem;
  font-weight: 700;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: rgba(245,240,232,0.35);
}
.pbo-meta-val {
  font-family: var(--font-ui);
  font-size: var(--type-sm);
  color: rgba(245,240,232,0.72);
}
.pbo-meta-div {
  width: 1px; height: 32px;
  background: rgba(245,240,232,0.10);
  flex-shrink: 0;
}

/* Jump nav */
.pbo-jump-nav {
  display: flex;
  gap: 0;
  flex-wrap: wrap;
  overflow-x: auto;
}
.pbo-jump-link {
  font-family: var(--font-ui);
  font-size: var(--type-sm);
  font-weight: 400;
  color: rgba(245,240,232,0.45);
  text-decoration: none;
  padding: 8px 16px 8px 0;
  margin-right: 16px;
  border-bottom: 2px solid transparent;
  transition: color var(--t-fast), border-color var(--t-fast);
  white-space: nowrap;
}
.pbo-jump-link:hover { color: var(--text-inverse); }
.pbo-jump-link--active {
  color: var(--text-inverse);
  border-bottom-color: var(--brand-orange);
}

/* ════════════════════════════════════════════════════════
   TWO-COL LAYOUT
   ════════════════════════════════════════════════════════ */
.pbo-two-col {
  display: grid;
  grid-template-columns: 1fr 400px;
  gap: 64px;
  align-items: start;
}
.pbo-two-col--flip {
  grid-template-columns: 1fr 420px;
}

/* Pull quote */
.pbo-pullquote {
  background: var(--bg-dark);
  border-radius: var(--r-md);
  padding: 2rem 1.75rem;
  margin-bottom: 1.5rem;
  position: relative;
}
.pbo-pq-mark {
  font-family: var(--font-display);
  font-size: 5rem;
  line-height: 0.6;
  color: var(--brand-orange);
  opacity: 0.4;
  margin-bottom: 0.5rem;
}
.pbo-pullquote blockquote {
  font-family: var(--font-display);
  font-size: 1.15rem;
  font-style: italic;
  color: var(--text-inverse);
  line-height: 1.55;
  margin-bottom: 1rem;
  border: none;
  padding: 0;
}
.pbo-pullquote cite {
  font-family: var(--font-ui);
  font-size: var(--type-cap);
  color: rgba(245,240,232,0.45);
  letter-spacing: 0.04em;
  font-style: normal;
  line-height: 1.6;
}

/* VS card */
.pbo-vs-card {
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  gap: 12px;
  align-items: start;
  background: #fff;
  border: 1px solid var(--border);
  border-radius: var(--r-md);
  padding: 1.25rem;
}
.pbo-vs-old, .pbo-vs-new { flex: 1; }
.pbo-vs-label {
  font-family: var(--font-ui);
  font-size: var(--type-tag);
  font-weight: 700;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  margin-bottom: 0.75rem;
}
.pbo-vs-old .pbo-vs-label { color: var(--text-muted); }
.pbo-vs-new .pbo-vs-label { color: var(--brand-teal); }
.pbo-vs-card ul { list-style: none; padding: 0; margin: 0; display: flex; flex-direction: column; gap: 5px; }
.pbo-vs-card li {
  font-family: var(--font-ui);
  font-size: var(--type-cap);
  color: var(--text-secondary);
  padding-left: 0.9rem;
  position: relative;
  line-height: 1.5;
}
.pbo-vs-card li::before {
  content: '';
  position: absolute;
  left: 0; top: 0.5em;
  width: 5px; height: 5px;
  border-radius: 50%;
}
.pbo-vs-old li::before { background: var(--text-muted); opacity: 0.4; }
.pbo-vs-new li::before { background: var(--brand-teal); }
.pbo-vs-arrow {
  font-size: 1.2rem;
  color: var(--brand-terracotta);
  font-weight: 300;
  padding-top: 1.5rem;
}

/* ════════════════════════════════════════════════════════
   STAT GRID (dark section)
   ════════════════════════════════════════════════════════ */
.pbo-stat-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 16px;
  margin-bottom: 2.5rem;
}
.pbo-stat-card {
  background: rgba(255,255,255,0.04);
  border: 1px solid rgba(245,240,232,0.08);
  border-radius: var(--r-md);
  padding: 1.75rem 1.5rem;
  transition: background var(--t-base);
}
.pbo-stat-card:hover { background: rgba(255,255,255,0.07); }
.pbo-stat-card--accent { border-color: rgba(0,88,89,0.30); background: rgba(0,88,89,0.08); }
.pbo-stat-card--warn   { border-color: rgba(180,48,0,0.30); background: rgba(180,48,0,0.06); }

.pbo-stat-number {
  font-family: var(--font-display);
  font-size: clamp(2.4rem, 5vw, 3.4rem);
  font-weight: 700;
  color: var(--text-inverse);
  line-height: 1;
  margin-bottom: 0.5rem;
}
.pbo-stat-card--accent .pbo-stat-number { color: var(--brand-mint); }
.pbo-stat-card--warn .pbo-stat-number   { color: var(--brand-orange); }

.pbo-stat-desc {
  font-family: var(--font-ui);
  font-size: var(--type-sm);
  color: rgba(245,240,232,0.65);
  line-height: 1.55;
  margin-bottom: 0.75rem;
}
.pbo-stat-source {
  font-family: var(--font-ui);
  font-size: var(--type-cap);
  color: rgba(245,240,232,0.28);
  font-style: italic;
}

.pbo-dark-callout {
  background: rgba(255,255,255,0.04);
  border: 1px solid rgba(245,240,232,0.10);
  border-left: 4px solid var(--brand-terracotta);
  border-radius: 0 var(--r-sm) var(--r-sm) 0;
  padding: 1.5rem 2rem;
}
.pbo-dark-callout p {
  color: rgba(245,240,232,0.75) !important;
  font-size: 1rem !important;
  margin-bottom: 0.5rem !important;
}
.pbo-dark-callout p:last-child { margin-bottom: 0 !important; }
.pbo-dark-callout strong { color: var(--text-inverse); }

/* ════════════════════════════════════════════════════════
   FINDINGS GRID
   ════════════════════════════════════════════════════════ */
.pbo-data-header { margin-bottom: 2.5rem; }

.pbo-findings-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 16px;
  margin-bottom: 1.5rem;
}
.pbo-finding-card {
  background: var(--warm-cream);
  border: 1px solid var(--border);
  border-radius: var(--r-md);
  padding: 1.5rem;
  border-top: 3px solid var(--brand-teal);
}
.pbo-finding-card--primary { background: var(--bg-dark); border-top-color: var(--brand-orange); }
.pbo-finding-card--strong  { border-top-color: var(--brand-terracotta); }

.pbo-finding-label {
  font-family: var(--font-ui);
  font-size: var(--type-tag);
  font-weight: 700;
  letter-spacing: var(--ls-eyebrow);
  text-transform: uppercase;
  color: var(--brand-teal);
  margin-bottom: 0.5rem;
}
.pbo-finding-card--primary .pbo-finding-label { color: var(--brand-orange); }

.pbo-finding-num {
  font-family: var(--font-display);
  font-size: clamp(2rem, 4vw, 2.8rem);
  font-weight: 700;
  color: var(--brand-teal);
  line-height: 1;
  margin-bottom: 0.2rem;
}
.pbo-finding-card--primary .pbo-finding-num { color: var(--text-inverse); }

.pbo-finding-unit {
  font-family: var(--font-ui);
  font-size: var(--type-sm);
  color: var(--text-muted);
  margin-bottom: 0.75rem;
}
.pbo-finding-card--primary .pbo-finding-unit { color: rgba(245,240,232,0.45); }

.pbo-finding-note {
  font-family: var(--font-ui);
  font-size: var(--type-cap);
  color: var(--text-muted);
  line-height: 1.5;
  font-style: italic;
}
.pbo-finding-card--primary .pbo-finding-note { color: rgba(245,240,232,0.38); }

.pbo-dataset-note {
  font-family: var(--font-ui);
  font-size: var(--type-cap);
  color: var(--text-muted);
  font-style: italic;
  text-align: center;
  margin-top: 0.5rem;
}
.pbo-dataset-note a { color: var(--mint-dark); text-decoration: underline; text-underline-offset: 2px; }

/* ════════════════════════════════════════════════════════
   EVIDENCE LIST
   ════════════════════════════════════════════════════════ */
.pbo-evidence-list {
  display: flex;
  flex-direction: column;
  gap: 0;
}
.pbo-evidence-item {
  display: grid;
  grid-template-columns: 56px 1fr;
  gap: 24px;
  padding: 2rem 0;
  border-bottom: 1px solid var(--border);
}
.pbo-evidence-item:last-child { border-bottom: none; }

.pbo-ev-num {
  font-family: var(--font-display);
  font-size: 2.4rem;
  font-weight: 700;
  color: rgba(0,88,89,0.12);
  line-height: 1;
  padding-top: 4px;
}
.pbo-ev-body h3 {
  font-family: var(--font-ui);
  font-size: var(--type-body);
  font-weight: 600;
  color: var(--brand-teal);
  margin-bottom: 0.5rem;
}
.pbo-ev-body p {
  font-size: var(--type-sm) !important;
  color: var(--text-secondary) !important;
  line-height: 1.75 !important;
  margin-bottom: 0.75rem !important;
}
.pbo-ev-refs { display: flex; flex-wrap: wrap; gap: 6px; margin-top: 0.5rem; }
.pbo-ref-chip {
  font-family: var(--font-ui);
  font-size: 0.68rem;
  color: var(--brand-teal);
  background: rgba(0,88,89,0.06);
  border: 1px solid rgba(0,88,89,0.14);
  border-radius: var(--r-full);
  padding: 3px 10px;
  letter-spacing: 0.02em;
}

.pbo-stat-callout-inline {
  background: rgba(180,48,0,0.05);
  border-left: 3px solid var(--brand-terracotta);
  padding: 10px 16px;
  margin: 0.75rem 0;
  font-family: var(--font-ui);
  font-size: var(--type-sm);
  font-weight: 600;
  color: var(--brand-terracotta);
  border-radius: 0 var(--r-xs) var(--r-xs) 0;
}

/* ════════════════════════════════════════════════════════
   DOMAIN TABS (dark section)
   ════════════════════════════════════════════════════════ */
.pbo-tabs {
  display: flex;
  gap: 4px;
  margin-bottom: 0;
  overflow-x: auto;
  padding-bottom: 1px;
  border-bottom: 1px solid rgba(245,240,232,0.10);
  margin-top: 2rem;
}
.pbo-tab {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 12px 20px;
  background: transparent;
  border: none;
  border-bottom: 2px solid transparent;
  cursor: pointer;
  white-space: nowrap;
  transition: border-color var(--t-fast), background var(--t-fast);
  margin-bottom: -1px;
}
.pbo-tab:hover { background: rgba(255,255,255,0.04); }
.pbo-tab--active {
  border-bottom-color: var(--brand-orange);
  background: rgba(255,255,255,0.05);
}
.pbo-tab-code {
  font-family: var(--font-ui);
  font-size: var(--type-tag);
  font-weight: 700;
  letter-spacing: 0.1em;
  color: var(--brand-orange);
}
.pbo-tab-name {
  font-family: var(--font-ui);
  font-size: var(--type-sm);
  color: rgba(245,240,232,0.55);
}
.pbo-tab--active .pbo-tab-name { color: var(--text-inverse); }

.pbo-tab-panels { padding-top: 2.5rem; }
.pbo-tab-panel { display: none; }
.pbo-tab-panel--active { display: block; animation: pboFadeIn 0.22s ease both; }

@keyframes pboFadeIn {
  from { opacity: 0; transform: translateY(6px); }
  to   { opacity: 1; transform: translateY(0); }
}

.pbo-domain-layout {
  display: grid;
  grid-template-columns: 1fr 280px;
  gap: 48px;
  align-items: start;
}
.pbo-domain-copy h3 {
  font-family: var(--font-display);
  font-size: 1.75rem;
  font-weight: 600;
  color: var(--text-inverse);
  margin-bottom: 1rem;
}
.pbo-domain-copy p {
  font-size: var(--type-body) !important;
  color: rgba(245,240,232,0.72) !important;
  line-height: 1.8 !important;
  margin-bottom: 1rem !important;
}
.pbo-domain-insight {
  background: rgba(255,255,255,0.04);
  border: 1px solid rgba(245,240,232,0.08);
  border-radius: var(--r-sm);
  padding: 1rem 1.25rem;
  margin-top: 0.75rem;
  font-family: var(--font-ui);
  font-size: var(--type-sm);
  color: rgba(245,240,232,0.62);
  line-height: 1.6;
}
.pbo-domain-insight strong { color: var(--text-inverse); }
.pbo-domain-insight--highlight {
  border-color: rgba(251,122,2,0.25);
  background: rgba(251,122,2,0.06);
}

.pbo-domain-stats {
  display: flex;
  flex-direction: column;
  gap: 12px;
}
.pbo-ds-item {
  background: rgba(255,255,255,0.05);
  border: 1px solid rgba(245,240,232,0.08);
  border-radius: var(--r-sm);
  padding: 1rem 1.25rem;
  text-align: center;
}
.pbo-ds-item--highlight {
  border-color: rgba(251,122,2,0.30);
  background: rgba(251,122,2,0.08);
}
.pbo-ds-num {
  font-family: var(--font-display);
  font-size: 1.8rem;
  font-weight: 700;
  color: var(--text-inverse);
  line-height: 1;
  margin-bottom: 4px;
}
.pbo-ds-item--highlight .pbo-ds-num { color: var(--brand-orange); }
.pbo-ds-label {
  font-family: var(--font-ui);
  font-size: var(--type-cap);
  color: rgba(245,240,232,0.38);
  line-height: 1.5;
}

/* ════════════════════════════════════════════════════════
   BOTTLENECK DOSE TABLE
   ════════════════════════════════════════════════════════ */
.pbo-bottleneck-callout {
  background: rgba(180,48,0,0.06);
  border: 1px solid rgba(180,48,0,0.18);
  border-left: 4px solid var(--brand-terracotta);
  border-radius: 0 var(--r-sm) var(--r-sm) 0;
  padding: 1rem 1.5rem;
  margin-top: 1.5rem;
  font-family: var(--font-ui);
  font-size: var(--type-sm);
  color: var(--text-secondary);
  line-height: 1.65;
}
.pbo-bottleneck-callout strong { color: var(--brand-terracotta); }

.pbo-dose-table {
  background: #fff;
  border: 1px solid var(--border);
  border-radius: var(--r-md);
  overflow: hidden;
}
.pbo-dose-header {
  display: flex;
  justify-content: space-between;
  padding: 12px 16px;
  background: var(--brand-teal);
  font-family: var(--font-ui);
  font-size: var(--type-tag);
  font-weight: 700;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--text-inverse);
}
.pbo-dose-rows { padding: 8px 16px 4px; }
.pbo-dose-row {
  display: grid;
  grid-template-columns: 140px 1fr 40px;
  align-items: center;
  gap: 10px;
  padding: 7px 0;
  border-bottom: 1px solid rgba(0,88,89,0.06);
}
.pbo-dose-row:last-child { border-bottom: none; }
.pbo-dose-n {
  font-family: var(--font-ui);
  font-size: var(--type-cap);
  color: var(--text-secondary);
}
.pbo-dose-n em { color: var(--text-muted); font-style: normal; }
.pbo-dose-bar-wrap {
  height: 6px;
  background: rgba(0,88,89,0.08);
  border-radius: var(--r-full);
  overflow: hidden;
}
.pbo-dose-bar {
  height: 100%;
  width: 0;
  background: var(--brand-teal);
  border-radius: var(--r-full);
  transition: width 0.8s cubic-bezier(0.16,1,0.3,1);
}
.pbo-dose-bar--warn   { background: var(--brand-terracotta); }
.pbo-dose-bar--danger { background: #8C2400; }

/* Trigger bars via JS class */
.pbo-bars-visible .pbo-dose-bar { width: var(--w); }

.pbo-dose-val {
  font-family: var(--font-display);
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--brand-teal);
  text-align: right;
}
.pbo-dose-source {
  font-family: var(--font-ui);
  font-size: var(--type-cap);
  color: var(--text-muted);
  font-style: italic;
  padding: 8px 16px 12px;
  border-top: 1px solid var(--border);
}

/* ════════════════════════════════════════════════════════
   TEAL SECTION CALLOUT
   ════════════════════════════════════════════════════════ */
.pbo-teal-callout {
  display: flex;
  align-items: center;
  gap: 1.5rem;
  background: rgba(255,255,255,0.08);
  border-radius: var(--r-md);
  padding: 1.5rem 2rem;
  margin: 1.75rem auto;
  max-width: 560px;
  text-align: left;
}
.pbo-teal-callout-stat {
  font-family: var(--font-display);
  font-size: 3rem;
  font-weight: 700;
  color: var(--brand-orange);
  line-height: 1;
  flex-shrink: 0;
}
.pbo-teal-callout-text {
  font-family: var(--font-ui);
  font-size: var(--type-sm);
  color: rgba(245,240,232,0.78);
  line-height: 1.65;
}

/* ════════════════════════════════════════════════════════
   REFERENCE ACCORDION
   ════════════════════════════════════════════════════════ */
.pbo-ref-accordion {
  display: flex;
  flex-direction: column;
  margin: 1.5rem 0;
}
.pbo-ref-group {
  border-bottom: 1px solid var(--border);
}
.pbo-ref-group:first-child { border-top: 1px solid var(--border); }
.pbo-ref-group summary {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 1rem 0;
  cursor: pointer;
  list-style: none;
  font-family: var(--font-ui);
  font-size: var(--type-body);
  font-weight: 600;
  color: var(--brand-teal);
  user-select: none;
  gap: 1rem;
}
.pbo-ref-group summary::-webkit-details-marker { display: none; }
.pbo-ref-group summary::after {
  content: '+';
  font-size: 1.3rem;
  font-weight: 300;
  color: var(--brand-terracotta);
  flex-shrink: 0;
}
.pbo-ref-group[open] summary::after { content: '−'; }
.pbo-ref-count {
  font-family: var(--font-ui);
  font-size: var(--type-tag);
  font-weight: 500;
  background: rgba(0,88,89,0.08);
  color: var(--brand-teal);
  border-radius: var(--r-full);
  padding: 2px 8px;
  letter-spacing: 0;
  margin-left: auto;
}
.pbo-ref-list {
  list-style: decimal;
  padding: 0 0 1.25rem 1.5rem;
}
.pbo-ref-list li {
  font-family: var(--font-ui);
  font-size: var(--type-cap);
  font-style: italic;
  color: var(--text-muted);
  padding: 4px 0;
  line-height: 1.6;
  border-bottom: 1px solid rgba(0,88,89,0.05);
}
.pbo-ref-list li:last-child { border-bottom: none; }

/* ════════════════════════════════════════════════════════
   CROSS-PAGE NAV
   ════════════════════════════════════════════════════════ */
.pbo-page-nav {
  background: var(--bg-dark);
  padding: 48px 0;
}
.pbo-page-nav-label {
  font-family: var(--font-ui);
  font-size: var(--type-tag);
  font-weight: 700;
  letter-spacing: var(--ls-eyebrow);
  text-transform: uppercase;
  color: rgba(245,240,232,0.35);
  margin-bottom: 1.5rem;
}
.pbo-nav-links {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 16px;
}
.pbo-nav-link {
  display: flex;
  flex-direction: column;
  background: rgba(255,255,255,0.04);
  border: 1px solid rgba(245,240,232,0.08);
  border-radius: var(--r-sm);
  padding: 1.25rem 1.5rem;
  text-decoration: none;
  transition: background var(--t-fast), border-color var(--t-fast);
  gap: 6px;
}
.pbo-nav-link:hover {
  background: rgba(255,255,255,0.08);
  border-color: rgba(245,240,232,0.16);
}
.pbo-nav-link-tag {
  font-family: var(--font-ui);
  font-size: var(--type-tag);
  font-weight: 700;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--brand-orange);
}
.pbo-nav-link-title {
  font-family: var(--font-display);
  font-size: 1.15rem;
  color: var(--text-inverse);
  line-height: 1.3;
  flex: 1;
}
.pbo-nav-link-arrow {
  font-size: 1rem;
  color: rgba(245,240,232,0.30);
  margin-top: 4px;
  transition: color var(--t-fast), transform var(--t-fast);
}
.pbo-nav-link:hover .pbo-nav-link-arrow {
  color: var(--brand-orange);
  transform: translateX(4px);
}

/* ════════════════════════════════════════════════════════
   RESPONSIVE
   ════════════════════════════════════════════════════════ */
@media (max-width: 960px) {
  .pbo-container { padding: 0 24px; }
  .pbo-section { padding: 64px 0; }
  .pbo-two-col,
  .pbo-two-col--flip { grid-template-columns: 1fr; gap: 40px; }
  .pbo-stat-grid    { grid-template-columns: repeat(2, 1fr); }
  .pbo-findings-grid { grid-template-columns: repeat(2, 1fr); }
  .pbo-domain-layout { grid-template-columns: 1fr; gap: 32px; }
  .pbo-domain-stats  { flex-direction: row; flex-wrap: wrap; }
  .pbo-ds-item       { flex: 1; min-width: 120px; }
  .pbo-nav-links     { grid-template-columns: 1fr; }
  .pbo-hero-meta     { gap: 14px; }
  .pbo-meta-div      { display: none; }
  .pbo-teal-callout  { flex-direction: column; text-align: center; }
}

@media (max-width: 640px) {
  .pbo-hero-inner  { padding: 40px 20px 48px; }
  .pbo-hero h1     { font-size: clamp(2.2rem, 10vw, 3rem); }
  .pbo-stat-grid   { grid-template-columns: 1fr; }
  .pbo-findings-grid { grid-template-columns: 1fr; }
  .pbo-tabs        { gap: 0; }
  .pbo-tab         { padding: 10px 14px; }
  .pbo-tab-name    { display: none; }
  .pbo-dose-row    { grid-template-columns: 120px 1fr 36px; }
  .pbo-evidence-item { grid-template-columns: 1fr; gap: 8px; }
  .pbo-ev-num      { font-size: 1.4rem; }
}