/* ==========================================================================
   POCUS Knowledge Hub — Design System
   Clinical, premium, spacious. No gradients, no decorative shadows.
   ========================================================================== */

:root {
  /* Primary palette */
  --navy: #071A2E;
  --medical-blue: #0067B1;
  --clinical-blue: #00AEEF;

  /* Secondary */
  --aqua: #00C2D1;
  --white: #FFFFFF;
  --gray-bg: #F4F6F8;
  --gray-border: #E1E6EB;
  --charcoal: #1F2937;
  --charcoal-soft: #4B5563;

  /* Optional highlight */
  --clinical-green: #1E9E6B;
  --warning-amber: #B7791F;

  /* Type */
  --font-display: "Source Serif Pro", Georgia, "Times New Roman", serif;
  --font-body: "Inter", -apple-system, "Segoe UI", Roboto, sans-serif;

  /* Layout */
  --max-width: 1280px;
  --article-width: 800px;
  --radius: 6px;
  --space-1: 8px;
  --space-2: 16px;
  --space-3: 24px;
  --space-4: 40px;
  --space-5: 64px;
  --space-6: 96px;

  --header-height: 76px;
}

/* ---------- Base ---------- */
html { scroll-behavior: smooth; }
body {
  font-family: var(--font-body);
  color: var(--charcoal);
  background: var(--white);
  line-height: 1.6;
  font-size: 16px;
}
h1, h2, h3, h4 {
  font-family: var(--font-display);
  color: var(--navy);
  line-height: 1.25;
  margin: 0 0 var(--space-2);
  font-weight: 600;
}
h1 { font-size: clamp(2rem, 4vw, 3.25rem); }
h2 { font-size: clamp(1.5rem, 3vw, 2.25rem); }
h3 { font-size: 1.375rem; }
p { margin: 0 0 var(--space-2); color: var(--charcoal-soft); }
a { color: var(--medical-blue); text-decoration: none; }
a:hover { color: var(--clinical-blue); }
.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 var(--space-3);
}
.section { padding: var(--space-6) 0; }
.section--alt { background: var(--gray-bg); }
.section-head { max-width: 720px; margin: 0 auto var(--space-4); text-align: center; }
.section-head p { font-size: 1.05rem; }
.eyebrow {
  display: inline-block;
  font-size: 0.75rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--clinical-blue);
  margin-bottom: var(--space-1);
}

/* ---------- Buttons ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 13px 26px;
  border-radius: var(--radius);
  font-weight: 600;
  font-size: 0.95rem;
  border: 1.5px solid transparent;
  cursor: pointer;
  transition: background-color .15s ease, color .15s ease, border-color .15s ease;
}
.btn--primary { background: var(--medical-blue); color: var(--white); }
.btn--primary:hover { background: var(--navy); color: var(--white); }
.btn--outline { background: transparent; border-color: var(--white); color: var(--white); }
.btn--outline:hover { background: var(--white); color: var(--navy); }
.btn--ghost { background: transparent; border-color: var(--gray-border); color: var(--navy); }
.btn--ghost:hover { border-color: var(--medical-blue); color: var(--medical-blue); }
.btn-row { display: flex; flex-wrap: wrap; gap: var(--space-2); }

/* ---------- Header ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 500;
  background: var(--white);
  border-bottom: 1px solid var(--gray-border);
  height: var(--header-height);
}
.site-header .container {
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-4);
}
.header-left { display: flex; align-items: center; gap: var(--space-5); min-width: 0; }
.site-logo { display: flex; align-items: center; gap: 10px; flex-shrink: 0; }
.site-logo img { height: 36px; width: auto; display: block; }
.site-logo .site-title { font-family: var(--font-display); font-weight: 700; color: var(--navy); font-size: 1.15rem; }

.primary-nav { display: none; }
.primary-nav ul { display: flex; align-items: center; gap: var(--space-3); list-style: none; margin: 0; padding: 0; }
.primary-nav > ul > li { position: relative; }
.primary-nav a { color: var(--charcoal); font-weight: 500; font-size: 0.95rem; padding: 8px 2px; display: inline-block; }
.primary-nav a:hover, .primary-nav .current-menu-item > a { color: var(--medical-blue); }
.primary-nav li.menu-item-has-children > a::after {
  content: "";
  display: inline-block;
  margin-left: 6px;
  border: solid var(--charcoal-soft);
  border-width: 0 1.5px 1.5px 0;
  padding: 3px;
  transform: rotate(45deg);
  vertical-align: middle;
}

/* Mega menu */
.mega-menu {
  display: none;
  position: absolute;
  top: 100%;
  left: 0;
  background: var(--white);
  border: 1px solid var(--gray-border);
  border-radius: var(--radius);
  padding: var(--space-3);
  min-width: 640px;
  box-shadow: 0 12px 28px rgba(7, 26, 46, 0.08);
}
.menu-item-has-children:hover .mega-menu,
.menu-item-has-children:focus-within .mega-menu { display: block; }
.mega-menu-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 4px 24px; }
.mega-menu-grid a { font-size: 0.9rem; padding: 6px 0; border-bottom: 1px solid transparent; }
.mega-menu-grid a:hover { border-color: var(--gray-border); }

.header-right { display: flex; align-items: center; gap: var(--space-2); flex-shrink: 0; }
.header-search-toggle {
  background: none; border: none; cursor: pointer; color: var(--navy);
  width: 38px; height: 38px; display: flex; align-items: center; justify-content: center;
}
.header-cta .btn { padding: 10px 20px; font-size: 0.9rem; }
.menu-toggle {
  display: flex; align-items: center; justify-content: center;
  background: none; border: 1px solid var(--gray-border); border-radius: var(--radius);
  width: 42px; height: 42px; cursor: pointer;
}

.header-search-panel {
  display: none;
  position: absolute;
  top: var(--header-height);
  left: 0; right: 0;
  background: var(--white);
  border-bottom: 1px solid var(--gray-border);
  padding: var(--space-3);
}
.header-search-panel.is-open { display: block; }
.header-search-panel form { display: flex; max-width: var(--max-width); margin: 0 auto; gap: 8px; }
.header-search-panel input[type="search"] {
  flex: 1; padding: 12px 16px; border: 1.5px solid var(--gray-border); border-radius: var(--radius); font-size: 1rem;
}
.search-suggestions { max-width: var(--max-width); margin: 8px auto 0; font-size: 0.9rem; color: var(--charcoal-soft); }

/* Mobile nav */
.mobile-nav {
  display: none;
  position: fixed;
  inset: 0 0 0 auto;
  width: min(340px, 88vw);
  background: var(--navy);
  color: var(--white);
  z-index: 700;
  padding: var(--space-3);
  overflow-y: auto;
  transform: translateX(100%);
  transition: transform .25s ease;
}
.mobile-nav.is-open { display: block; transform: translateX(0); }
.mobile-nav ul { list-style: none; margin: 0; padding: 0; }
.mobile-nav a { color: var(--white); display: block; padding: 12px 0; border-bottom: 1px solid rgba(255,255,255,0.12); font-weight: 500; }
.mobile-nav .close-mobile-nav { background: none; border: none; color: var(--white); font-size: 1.5rem; cursor: pointer; margin-bottom: var(--space-2); }
.mobile-nav-overlay { display: none; position: fixed; inset: 0; background: rgba(7,26,46,0.5); z-index: 600; }
.mobile-nav-overlay.is-open { display: block; }

@media (min-width: 992px) {
  .primary-nav { display: block; }
  .menu-toggle { display: none; }
}

/* ---------- Hero ---------- */
.hero {
  background: linear-gradient(180deg, var(--navy) 0%, #0B2947 100%);
  color: var(--white);
  padding: var(--space-6) 0;
}
.hero .container { display: grid; grid-template-columns: 1fr; gap: var(--space-4); align-items: center; }
.hero-eyebrow { color: var(--clinical-blue); }
.hero h1 { color: var(--white); }
.hero .subhead { color: var(--clinical-blue); font-size: 1.25rem; font-weight: 600; margin-bottom: var(--space-2); }
.hero p.lead { color: rgba(255,255,255,0.82); font-size: 1.05rem; max-width: 640px; }
.hero-media img { border-radius: var(--radius); display: block; width: 100%; }
@media (min-width: 992px) {
  .hero .container { grid-template-columns: 1.1fr 0.9fr; }
}

/* ---------- Cards / Grids ---------- */
.grid { display: grid; gap: var(--space-3); }
.grid--2 { grid-template-columns: 1fr; }
.grid--3 { grid-template-columns: 1fr; }
.grid--4 { grid-template-columns: 1fr; }
@media (min-width: 700px) {
  .grid--2 { grid-template-columns: repeat(2, 1fr); }
  .grid--3 { grid-template-columns: repeat(2, 1fr); }
  .grid--4 { grid-template-columns: repeat(2, 1fr); }
}
@media (min-width: 992px) {
  .grid--3 { grid-template-columns: repeat(3, 1fr); }
  .grid--4 { grid-template-columns: repeat(4, 1fr); }
}

.card {
  background: var(--white);
  border: 1px solid var(--gray-border);
  border-radius: var(--radius);
  padding: var(--space-3);
  transition: border-color .15s ease, transform .15s ease;
  height: 100%;
}
.card:hover { border-color: var(--medical-blue); transform: translateY(-2px); }
.card-icon {
  width: 44px; height: 44px; border-radius: var(--radius);
  background: rgba(0,103,177,0.08); color: var(--medical-blue);
  display: flex; align-items: center; justify-content: center;
  margin-bottom: var(--space-2);
}
.card h3 { font-size: 1.1rem; margin-bottom: 6px; }
.card p { font-size: 0.92rem; margin-bottom: var(--space-1); }
.card .card-link { font-size: 0.85rem; font-weight: 600; }

/* Article cards */
.article-card { display: flex; flex-direction: column; }
.article-card img { border-radius: var(--radius) var(--radius) 0 0; aspect-ratio: 16/10; object-fit: cover; }
.article-card .article-body { padding: var(--space-2) 0; }
.article-meta { font-size: 0.8rem; color: var(--charcoal-soft); display: flex; gap: 10px; flex-wrap: wrap; margin-top: var(--space-1); }
.article-category { color: var(--medical-blue); font-weight: 700; font-size: 0.75rem; text-transform: uppercase; letter-spacing: 0.05em; }

/* Featured article */
.featured-article { display: grid; grid-template-columns: 1fr; gap: var(--space-4); align-items: center; }
.featured-article img { border-radius: var(--radius); width: 100%; aspect-ratio: 4/3; object-fit: cover; }
@media (min-width: 900px) { .featured-article { grid-template-columns: 1fr 1fr; } }

/* Why POCUS infographic */
.why-grid { display: grid; grid-template-columns: 1fr; gap: var(--space-3); text-align: center; }
@media (min-width: 700px) { .why-grid { grid-template-columns: repeat(3, 1fr); } }
.why-item .why-number { font-family: var(--font-display); font-size: 2rem; color: var(--clinical-blue); }

/* Newsletter */
.newsletter { background: var(--navy); color: var(--white); border-radius: var(--radius); padding: var(--space-4); text-align: center; }
.newsletter h2 { color: var(--white); }
.newsletter form { display: flex; flex-wrap: wrap; gap: 10px; justify-content: center; margin-top: var(--space-3); }
.newsletter input { padding: 12px 16px; border-radius: var(--radius); border: none; min-width: 220px; font-size: 0.95rem; }

/* Final CTA */
.final-cta { background: var(--medical-blue); color: var(--white); text-align: center; padding: var(--space-6) 0; }
.final-cta h2, .final-cta p { color: var(--white); }
.final-cta p { max-width: 620px; margin: 0 auto var(--space-3); color: rgba(255,255,255,0.9); }

/* ---------- Footer ---------- */
.site-footer { background: var(--navy); color: rgba(255,255,255,0.78); padding: var(--space-6) 0 var(--space-3); }
.footer-grid { display: grid; grid-template-columns: 1fr; gap: var(--space-4); margin-bottom: var(--space-4); }
.footer-grid h4 { color: var(--white); font-family: var(--font-body); font-size: 0.85rem; text-transform: uppercase; letter-spacing: 0.06em; margin-bottom: var(--space-2); }
.footer-grid ul { list-style: none; margin: 0; padding: 0; }
.footer-grid li { margin-bottom: 8px; }
.footer-grid a { color: rgba(255,255,255,0.78); font-size: 0.9rem; }
.footer-grid a:hover { color: var(--clinical-blue); }
@media (min-width: 700px) { .footer-grid { grid-template-columns: repeat(3, 1fr); } }
@media (min-width: 992px) { .footer-grid { grid-template-columns: 1.4fr repeat(4, 1fr); } }
.footer-bottom { border-top: 1px solid rgba(255,255,255,0.14); padding-top: var(--space-3); display: flex; flex-wrap: wrap; justify-content: space-between; gap: var(--space-2); font-size: 0.85rem; }
.social-icons { display: flex; gap: 12px; }
.social-icons a { width: 34px; height: 34px; border: 1px solid rgba(255,255,255,0.25); border-radius: 50%; display: flex; align-items: center; justify-content: center; color: var(--white); }

/* ---------- Single Article ---------- */
.single-article-header { max-width: var(--article-width); margin: 0 auto var(--space-3); text-align: left; }
.single-article-header .article-meta { margin-bottom: var(--space-2); }
.article-featured-image { max-width: var(--max-width); margin: 0 auto var(--space-4); }
.article-featured-image img { border-radius: var(--radius); width: 100%; aspect-ratio: 16/7; object-fit: cover; }
.article-layout { display: grid; grid-template-columns: 1fr; gap: var(--space-5); }
@media (min-width: 992px) { .article-layout { grid-template-columns: var(--article-width) 1fr; } }
.article-body { font-size: 1.05rem; }
.article-body p { color: var(--charcoal); }
.article-body h2 { margin-top: var(--space-4); }
.article-body h3 { margin-top: var(--space-3); }
.toc { background: var(--gray-bg); border: 1px solid var(--gray-border); border-radius: var(--radius); padding: var(--space-3); margin: var(--space-3) 0; }
.toc h4 { margin-bottom: 8px; font-size: 0.9rem; text-transform: uppercase; letter-spacing: 0.05em; }
.toc ol { margin: 0; padding-left: 20px; font-size: 0.92rem; }

/* Medical article components */
.med-block { border-left: 4px solid var(--medical-blue); background: var(--gray-bg); padding: var(--space-2) var(--space-3); border-radius: 0 var(--radius) var(--radius) 0; margin: var(--space-3) 0; }
.med-block h4 { font-family: var(--font-body); text-transform: uppercase; font-size: 0.75rem; letter-spacing: 0.06em; margin-bottom: 6px; color: var(--medical-blue); }
.med-block--pearl { border-color: var(--clinical-green); }
.med-block--pearl h4 { color: var(--clinical-green); }
.med-block--warning { border-color: var(--warning-amber); background: #FEF6E7; }
.med-block--warning h4 { color: var(--warning-amber); }
.med-block--tip { border-color: var(--clinical-blue); }
.med-block--tip h4 { color: var(--clinical-blue); }

.author-box { display: flex; gap: var(--space-2); align-items: center; border: 1px solid var(--gray-border); border-radius: var(--radius); padding: var(--space-3); margin-top: var(--space-4); }
.author-box img { width: 56px; height: 56px; border-radius: 50%; object-fit: cover; }

.social-share-floating { position: sticky; top: calc(var(--header-height) + 24px); display: flex; flex-direction: column; gap: 10px; }

/* Sidebar */
.sidebar-widget { margin-bottom: var(--space-4); }
.sidebar-widget h4 { font-size: 0.85rem; text-transform: uppercase; letter-spacing: 0.05em; margin-bottom: var(--space-2); }

/* Breadcrumbs */
.breadcrumbs { font-size: 0.82rem; color: var(--charcoal-soft); margin-bottom: var(--space-2); }
.breadcrumbs a { color: var(--charcoal-soft); }
.breadcrumbs a:hover { color: var(--medical-blue); }

/* Disclaimer strip */
.medical-disclaimer { background: var(--gray-bg); border-top: 1px solid var(--gray-border); font-size: 0.8rem; color: var(--charcoal-soft); padding: var(--space-2) 0; text-align: center; }

/* Utility */
.text-center { text-align: center; }
.mt-0 { margin-top: 0; }
.visually-hidden { position: absolute; width: 1px; height: 1px; overflow: hidden; clip: rect(0 0 0 0); }
.skip-link { position: absolute; left: -9999px; top: 0; background: var(--white); color: var(--navy); padding: 10px 16px; z-index: 1000; }
.skip-link:focus { left: 10px; top: 10px; }

/* Accessible focus states */
a:focus-visible, button:focus-visible, input:focus-visible { outline: 2px solid var(--clinical-blue); outline-offset: 2px; }