/* ============================================================
   BiosystemsHub — Global Stylesheet
   Scientific journal two-column layout · Responsive
   ============================================================ */

/* ── Custom Properties ──────────────────────────────────────── */
:root {
  --cream:        #FAFAF7;
  --cream-dark:   #F0EFE8;
  --cream-border: #E2DFD6;
  --navy:         #1a2e4a;
  --navy-light:   #2c4a72;
  --navy-hover:   #0f1e30;
  --gold:         #c5942a;
  --gold-light:   #dba83a;
  --gold-pale:    #fdf3df;
  --text:         #2d2d2d;
  --text-muted:   #6b6b6b;
  --text-light:   #999;
  --card-bg:      #ffffff;
  --border:       #dddad0;

  --font-serif: 'Merriweather', Georgia, 'Times New Roman', serif;
  --font-sans:  'Source Sans Pro', 'Segoe UI', system-ui, sans-serif;

  --nav-h:     64px;
  --max-w:     1180px;
  --gap:       2rem;
  --col-main:  68%;
  --radius:    4px;
  --radius-lg: 8px;
  --shadow:       0 2px 8px rgba(0,0,0,.07);
  --shadow-hover: 0 6px 20px rgba(0,0,0,.13);
  --transition:   .2s ease;
}

/* ── Reset ──────────────────────────────────────────────────── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }
body {
  background: var(--cream);
  color: var(--text);
  font-family: var(--font-serif);
  font-size: 1rem;
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}
img, iframe { max-width: 100%; display: block; }
a { color: var(--navy-light); text-decoration: none; transition: color var(--transition); }
a:hover { color: var(--gold); }
ul { list-style: none; }

/* ── Layout ─────────────────────────────────────────────────── */
.container {
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 0 1.5rem;
}
.page-wrap {
  padding-top: var(--nav-h);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}
.page-main { flex: 1; }

/* Two-column layout */
.two-col {
  display: grid;
  grid-template-columns: var(--col-main) 1fr;
  gap: var(--gap);
  align-items: start;
}

/* ── Navigation ─────────────────────────────────────────────── */
.site-nav {
  position: fixed;
  top: 0; left: 0; right: 0;
  height: var(--nav-h);
  background: var(--navy);
  z-index: 100;
  box-shadow: 0 2px 12px rgba(0,0,0,.25);
}
.nav-inner {
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 0 1.5rem;
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
}
.nav-brand {
  display: flex;
  align-items: center;
  gap: .6rem;
  text-decoration: none;
}
.nav-brand-icon {
  width: 36px;
  height: 36px;
  background: var(--gold);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.1rem;
  color: var(--navy);
  font-weight: 700;
  font-family: var(--font-sans);
  flex-shrink: 0;
}
.nav-brand-name {
  font-family: var(--font-sans);
  font-size: 1.2rem;
  font-weight: 700;
  color: #fff;
  letter-spacing: -.3px;
}
.nav-brand-name span { color: var(--gold); }
.nav-links {
  display: flex;
  align-items: center;
}
.nav-links a {
  color: rgba(255,255,255,.82);
  font-family: var(--font-sans);
  font-size: .95rem;
  font-weight: 600;
  padding: .5rem .9rem;
  border-radius: var(--radius);
  transition: color var(--transition), background var(--transition);
}
.nav-links a:hover,
.nav-links a.active {
  color: #fff;
  background: rgba(255,255,255,.1);
}
.nav-links a.active { color: var(--gold); }
.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  cursor: pointer;
  padding: .4rem;
  border: none;
  background: transparent;
}
.nav-toggle span {
  display: block;
  width: 24px;
  height: 2px;
  background: #fff;
  border-radius: 2px;
  transition: all .25s;
}
.nav-toggle.open span:nth-child(1) { transform: rotate(45deg) translate(5px, 5px); }
.nav-toggle.open span:nth-child(2) { opacity: 0; }
.nav-toggle.open span:nth-child(3) { transform: rotate(-45deg) translate(5px, -5px); }

/* ── Hero ───────────────────────────────────────────────────── */
.hero {
  background: linear-gradient(135deg, var(--navy) 0%, var(--navy-light) 60%, #2a5080 100%);
  color: #fff;
  padding: 5rem 0 4rem;
  position: relative;
  overflow: hidden;
}
.hero::before {
  content: '';
  position: absolute;
  inset: 0;
  z-index: 1;
  background-image:
    radial-gradient(circle at 20% 50%, rgba(197,148,42,.14) 0%, transparent 55%),
    radial-gradient(circle at 80% 20%, rgba(255,255,255,.05) 0%, transparent 45%);
  pointer-events: none;
}
/* Left-side gradient to keep hero text legible over the network illustration */
.hero::after {
  content: '';
  position: absolute;
  inset: 0;
  z-index: 2;
  background: linear-gradient(
    to right,
    rgba(26,46,74,.97) 0%,
    rgba(26,46,74,.85) 28%,
    rgba(26,46,74,.50) 52%,
    rgba(26,46,74,.18) 76%,
    transparent 100%
  );
  pointer-events: none;
}
.hero-inner { position: relative; z-index: 3; }
/* Biological network canvas — sits behind all overlays */
.hero-canvas {
  position: absolute;
  inset: 0;
  overflow: hidden;
  z-index: 0;
}
.hero-canvas svg {
  width: 100%;
  height: 100%;
  display: block;
  opacity: .72;
}
.hero-label {
  display: inline-block;
  font-family: var(--font-sans);
  font-size: .75rem;
  font-weight: 700;
  letter-spacing: 1.5px;
  text-transform: uppercase;
  color: var(--gold-light);
  border: 1px solid rgba(197,148,42,.4);
  padding: .25rem .75rem;
  border-radius: 2rem;
  margin-bottom: 1.2rem;
}
.hero h1 {
  font-family: var(--font-serif);
  font-size: clamp(2rem, 4vw, 3.2rem);
  font-weight: 700;
  line-height: 1.2;
  margin-bottom: 1.2rem;
  max-width: 700px;
}
.hero-tagline {
  font-family: var(--font-sans);
  font-size: 1.15rem;
  color: rgba(255,255,255,.8);
  max-width: 560px;
  margin-bottom: 2.2rem;
  line-height: 1.6;
}
.hero-actions { display: flex; gap: 1rem; flex-wrap: wrap; }
.btn {
  display: inline-flex;
  align-items: center;
  gap: .4rem;
  font-family: var(--font-sans);
  font-size: .95rem;
  font-weight: 600;
  padding: .7rem 1.6rem;
  border-radius: var(--radius);
  cursor: pointer;
  border: 2px solid transparent;
  transition: all var(--transition);
  text-decoration: none;
}
.btn-primary {
  background: var(--gold);
  color: var(--navy);
  border-color: var(--gold);
}
.btn-primary:hover {
  background: var(--gold-light);
  border-color: var(--gold-light);
  color: var(--navy);
}
.btn-outline {
  background: transparent;
  color: #fff;
  border-color: rgba(255,255,255,.5);
}
.btn-outline:hover {
  background: rgba(255,255,255,.1);
  border-color: #fff;
  color: #fff;
}

/* ── Section Header ─────────────────────────────────────────── */
.section { padding: 3.5rem 0; }
.section + .section { border-top: 1px solid var(--border); }
.section-header {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  margin-bottom: 2rem;
  padding-bottom: .75rem;
  border-bottom: 2px solid var(--border);
}
.section-header h2 {
  font-family: var(--font-sans);
  font-size: 1.1rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 1px;
  color: var(--navy);
}
.section-header a {
  font-family: var(--font-sans);
  font-size: .88rem;
  font-weight: 600;
  color: var(--gold);
}
.section-header a:hover { color: var(--gold-light); text-decoration: underline; }

/* ── Article Cards ──────────────────────────────────────────── */
.cards-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: 1.5rem;
}
.card {
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: var(--shadow);
  transition: box-shadow var(--transition), transform var(--transition);
  display: flex;
  flex-direction: column;
}
.card:hover {
  box-shadow: var(--shadow-hover);
  transform: translateY(-2px);
}
.card-thumb {
  aspect-ratio: 16/9;
  background: linear-gradient(135deg, var(--cream-dark), var(--cream-border));
  overflow: hidden;
  flex-shrink: 0;
}
.card-thumb img { width: 100%; height: 100%; object-fit: cover; }
.card-thumb-placeholder {
  width: 100%;
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 2.5rem;
  color: var(--border);
}
.card-body {
  padding: 1.25rem;
  display: flex;
  flex-direction: column;
  flex: 1;
}
.card-meta {
  display: flex;
  align-items: center;
  gap: .5rem;
  margin-bottom: .6rem;
  flex-wrap: wrap;
}
.badge {
  display: inline-block;
  font-family: var(--font-sans);
  font-size: .7rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: .7px;
  padding: .2rem .6rem;
  border-radius: 2rem;
  background: var(--gold-pale);
  color: var(--gold);
  border: 1px solid rgba(197,148,42,.3);
  white-space: nowrap;
}
.card-date {
  font-family: var(--font-sans);
  font-size: .78rem;
  color: var(--text-light);
}
.card h3 {
  font-family: var(--font-serif);
  font-size: 1.05rem;
  font-weight: 700;
  line-height: 1.4;
  margin-bottom: .5rem;
  color: var(--text);
}
.card h3 a { color: inherit; }
.card h3 a:hover { color: var(--navy-light); }
.card-author {
  font-family: var(--font-sans);
  font-size: .82rem;
  color: var(--text-muted);
  margin-bottom: .6rem;
}
.card-desc {
  font-size: .88rem;
  line-height: 1.6;
  color: var(--text-muted);
  margin-bottom: 1rem;
  flex: 1;
}
.card-footer {
  margin-top: auto;
  padding-top: .75rem;
  border-top: 1px solid var(--cream-border);
}
.card-link {
  font-family: var(--font-sans);
  font-size: .85rem;
  font-weight: 600;
  color: var(--navy-light);
  display: inline-flex;
  align-items: center;
  gap: .3rem;
}
.card-link:hover { color: var(--gold); }
.card-link::after { content: '→'; }

/* ── Video Cards ────────────────────────────────────────────── */
.video-card {
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: var(--shadow);
  transition: box-shadow var(--transition), transform var(--transition);
}
.video-card:hover {
  box-shadow: var(--shadow-hover);
  transform: translateY(-2px);
}
.video-embed-wrap {
  position: relative;
  aspect-ratio: 16/9;
  background: #000;
  overflow: hidden;
}
.video-embed-wrap iframe {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  border: none;
}
.video-embed-wrap.lazy-video { cursor: pointer; }
.video-thumb-overlay {
  position: absolute;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--navy);
}
.video-thumb-overlay img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  opacity: .75;
}
.play-btn {
  position: absolute;
  width: 60px;
  height: 60px;
  background: rgba(197,148,42,.92);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 2;
  transition: transform .2s, background .2s;
}
.play-btn::after {
  content: '';
  width: 0;
  height: 0;
  border-style: solid;
  border-width: 10px 0 10px 18px;
  border-color: transparent transparent transparent #fff;
  margin-left: 4px;
}
.video-embed-wrap.lazy-video:hover .play-btn {
  transform: scale(1.1);
  background: var(--gold);
}
.video-info { padding: 1rem 1.25rem; }
.video-info .badge { margin-bottom: .5rem; }
.video-info h3 {
  font-family: var(--font-sans);
  font-size: 1rem;
  font-weight: 600;
  line-height: 1.4;
  color: var(--text);
  margin-bottom: .3rem;
}
.video-info p {
  font-size: .85rem;
  color: var(--text-muted);
  line-height: 1.5;
}

/* ── Category Filter ────────────────────────────────────────── */
.filter-bar {
  display: flex;
  align-items: center;
  gap: .5rem;
  flex-wrap: wrap;
  margin-bottom: 2rem;
  padding: 1rem 1.25rem;
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
}
.filter-label {
  font-family: var(--font-sans);
  font-size: .82rem;
  font-weight: 700;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: .7px;
  margin-right: .25rem;
  white-space: nowrap;
}
.filter-btn {
  font-family: var(--font-sans);
  font-size: .8rem;
  font-weight: 600;
  padding: .3rem .85rem;
  border-radius: 2rem;
  border: 1.5px solid var(--border);
  background: transparent;
  color: var(--text-muted);
  cursor: pointer;
  transition: all var(--transition);
  white-space: nowrap;
}
.filter-btn:hover { border-color: var(--gold); color: var(--gold); }
.filter-btn.active {
  background: var(--navy);
  border-color: var(--navy);
  color: #fff;
}
.card[data-hidden="true"],
.video-card[data-hidden="true"] { display: none; }

/* ── Page Header ────────────────────────────────────────────── */
.page-header {
  background: var(--navy);
  color: #fff;
  padding: 3rem 0 2.5rem;
}
.page-header h1 {
  font-family: var(--font-serif);
  font-size: clamp(1.6rem, 3vw, 2.4rem);
  margin-bottom: .5rem;
}
.page-header p {
  font-family: var(--font-sans);
  color: rgba(255,255,255,.7);
  font-size: 1rem;
  max-width: 600px;
}
.breadcrumb {
  font-family: var(--font-sans);
  font-size: .82rem;
  color: rgba(255,255,255,.55);
  margin-bottom: .75rem;
}
.breadcrumb a { color: rgba(255,255,255,.7); }
.breadcrumb a:hover { color: var(--gold); }
.breadcrumb .sep { color: rgba(255,255,255,.4); margin: 0 .4rem; }

/* ── Article Page ───────────────────────────────────────────── */
.article-header {
  margin-bottom: 2.5rem;
  padding-bottom: 2rem;
  border-bottom: 1px solid var(--border);
}
.article-header h1 {
  font-family: var(--font-serif);
  font-size: clamp(1.6rem, 3vw, 2.4rem);
  line-height: 1.25;
  color: var(--navy);
  margin-bottom: 1rem;
}
.article-byline {
  display: flex;
  align-items: center;
  gap: 1rem;
  flex-wrap: wrap;
  font-family: var(--font-sans);
  font-size: .88rem;
  color: var(--text-muted);
}
.article-byline strong { color: var(--text); }
.article-body { font-size: 1rem; line-height: 1.8; }
.article-body h2 {
  font-family: var(--font-serif);
  font-size: 1.4rem;
  color: var(--navy);
  margin: 2rem 0 .75rem;
  padding-bottom: .4rem;
  border-bottom: 1px solid var(--cream-border);
}
.article-body h3 {
  font-family: var(--font-serif);
  font-size: 1.15rem;
  color: var(--text);
  margin: 1.5rem 0 .5rem;
}
.article-body p { margin-bottom: 1.2rem; }
.article-body ul, .article-body ol {
  margin: 0 0 1.2rem 1.5rem;
  list-style: revert;
}
.article-body li { margin-bottom: .3rem; }
.article-body blockquote {
  border-left: 3px solid var(--gold);
  padding: .75rem 1.25rem;
  margin: 1.5rem 0;
  background: var(--gold-pale);
  border-radius: 0 var(--radius) var(--radius) 0;
  font-style: italic;
  color: var(--text-muted);
}
.article-body figure { margin: 1.5rem 0; text-align: center; }
.article-body figcaption {
  font-family: var(--font-sans);
  font-size: .82rem;
  color: var(--text-muted);
  margin-top: .4rem;
  font-style: italic;
}
.article-body code {
  background: var(--cream-dark);
  border: 1px solid var(--cream-border);
  border-radius: 3px;
  padding: .1rem .4rem;
  font-size: .88em;
}
.article-body pre {
  background: var(--navy);
  color: #e0e0e0;
  border-radius: var(--radius-lg);
  padding: 1.25rem;
  overflow-x: auto;
  margin: 1.5rem 0;
}
.article-body pre code {
  background: none;
  border: none;
  padding: 0;
  font-size: .88rem;
  color: inherit;
}

/* Article sidebar widgets */
.widget {
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 1.25rem;
  margin-bottom: 1.5rem;
}
.widget-title {
  font-family: var(--font-sans);
  font-size: .78rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 1px;
  color: var(--text-muted);
  margin-bottom: 1rem;
  padding-bottom: .5rem;
  border-bottom: 1px solid var(--cream-border);
}
.widget-tags { display: flex; flex-wrap: wrap; gap: .4rem; }
.tag {
  display: inline-block;
  font-family: var(--font-sans);
  font-size: .75rem;
  font-weight: 600;
  padding: .2rem .6rem;
  border-radius: 2rem;
  background: var(--cream-dark);
  color: var(--text-muted);
  border: 1px solid var(--cream-border);
}
.related-list { padding: 0; }
.related-list li {
  padding: .5rem 0;
  border-bottom: 1px solid var(--cream-border);
}
.related-list li:last-child { border-bottom: none; }
.related-list a {
  font-family: var(--font-sans);
  font-size: .9rem;
  color: var(--navy-light);
  font-weight: 600;
  display: block;
  margin-bottom: .15rem;
}
.related-list .related-date {
  font-size: .78rem;
  color: var(--text-light);
}

/* Related video in article */
.related-video-embed {
  margin: 2rem 0;
  border-radius: var(--radius-lg);
  overflow: hidden;
  border: 1px solid var(--border);
}
.related-video-embed iframe {
  aspect-ratio: 16/9;
  width: 100%;
  border: none;
}

/* Sidebar sticky wrapper */
.sidebar-sticky { position: sticky; top: calc(var(--nav-h) + 1.5rem); }

/* ── Forms ──────────────────────────────────────────────────── */
.form-group { margin-bottom: 1.25rem; }
.form-group label {
  display: block;
  font-family: var(--font-sans);
  font-size: .88rem;
  font-weight: 600;
  color: var(--text);
  margin-bottom: .4rem;
}
.form-group input,
.form-group select,
.form-group textarea {
  width: 100%;
  font-family: var(--font-sans);
  font-size: .95rem;
  color: var(--text);
  background: var(--card-bg);
  border: 1.5px solid var(--border);
  border-radius: var(--radius);
  padding: .6rem .9rem;
  transition: border-color var(--transition);
}
.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus {
  outline: none;
  border-color: var(--navy-light);
  box-shadow: 0 0 0 3px rgba(44,74,114,.1);
}
.form-group textarea { resize: vertical; min-height: 120px; }
.form-hint {
  font-family: var(--font-sans);
  font-size: .8rem;
  color: var(--text-muted);
  margin-top: .3rem;
}
.btn-submit {
  background: var(--navy);
  color: #fff;
  border: 2px solid var(--navy);
  font-family: var(--font-sans);
  font-size: 1rem;
  font-weight: 600;
  padding: .75rem 2rem;
  border-radius: var(--radius);
  cursor: pointer;
  transition: all var(--transition);
}
.btn-submit:hover {
  background: var(--navy-light);
  border-color: var(--navy-light);
}
.form-success {
  display: none;
  padding: 1rem 1.25rem;
  background: #eaf7ee;
  border: 1px solid #a8d8b9;
  border-radius: var(--radius);
  font-family: var(--font-sans);
  font-size: .95rem;
  color: #1a5c35;
  margin-top: 1rem;
}

/* ── Resources page ─────────────────────────────────────────── */
.resource-section { margin-bottom: 2.5rem; }
.resource-section h3 {
  font-family: var(--font-sans);
  font-size: 1rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: .7px;
  color: var(--navy);
  margin-bottom: 1rem;
  padding-bottom: .5rem;
  border-bottom: 2px solid var(--cream-border);
}
.resource-list { padding: 0; }
.resource-list li {
  padding: .9rem 0;
  border-bottom: 1px solid var(--cream-border);
  display: flex;
  align-items: flex-start;
  gap: 1rem;
}
.resource-list li:last-child { border-bottom: none; }
.resource-icon {
  width: 38px;
  height: 38px;
  background: var(--gold-pale);
  border-radius: var(--radius);
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
  font-size: 1.2rem;
}
.resource-info strong {
  font-family: var(--font-sans);
  font-size: .95rem;
  color: var(--navy-light);
  display: block;
  margin-bottom: .2rem;
}
.resource-info span {
  font-family: var(--font-sans);
  font-size: .85rem;
  color: var(--text-muted);
}

/* ── About page ─────────────────────────────────────────────── */
.about-mission {
  font-size: 1.1rem;
  line-height: 1.8;
  color: var(--navy);
  padding: 1.25rem 1.5rem;
  border-left: 4px solid var(--gold);
  background: var(--gold-pale);
  border-radius: 0 var(--radius-lg) var(--radius-lg) 0;
  margin-bottom: 2rem;
  font-style: italic;
}
.team-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
  gap: 1.5rem;
  margin-top: 1.5rem;
}
.team-card {
  text-align: center;
  padding: 1.5rem 1rem;
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
}
.team-avatar {
  width: 72px;
  height: 72px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--navy-light), var(--gold));
  margin: 0 auto 1rem;
  display: flex;
  align-items: center;
  justify-content: center;
  color: #fff;
  font-family: var(--font-sans);
  font-size: 1.5rem;
  font-weight: 700;
}
.team-card h4 {
  font-family: var(--font-sans);
  font-size: .95rem;
  font-weight: 700;
  margin-bottom: .25rem;
}
.team-card p {
  font-family: var(--font-sans);
  font-size: .82rem;
  color: var(--text-muted);
}

/* ── Info box (sidebar widget variant) ─────────────────────── */
.info-box {
  background: var(--navy);
  color: rgba(255,255,255,.85);
  border-radius: var(--radius-lg);
  padding: 1.5rem;
  margin-bottom: 1.5rem;
}
.info-box h3 {
  font-family: var(--font-sans);
  font-size: .85rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 1px;
  color: var(--gold-light);
  margin-bottom: .75rem;
}
.info-box p {
  font-family: var(--font-sans);
  font-size: .88rem;
  line-height: 1.6;
}
.info-box a { color: var(--gold-light); }
.info-box a:hover { color: #fff; }

/* ── Footer ─────────────────────────────────────────────────── */
.site-footer {
  background: var(--navy);
  color: rgba(255,255,255,.75);
  padding: 3rem 0 1.5rem;
  margin-top: auto;
}
.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr;
  gap: 2.5rem;
  margin-bottom: 2.5rem;
}
.footer-about h3 {
  font-family: var(--font-sans);
  font-size: 1rem;
  font-weight: 700;
  color: #fff;
  margin-bottom: .75rem;
}
.footer-about p {
  font-family: var(--font-sans);
  font-size: .88rem;
  line-height: 1.65;
}
.footer-col h4 {
  font-family: var(--font-sans);
  font-size: .8rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 1px;
  color: var(--gold);
  margin-bottom: .75rem;
}
.footer-col ul { padding: 0; }
.footer-col li { margin-bottom: .4rem; }
.footer-col a {
  font-family: var(--font-sans);
  font-size: .88rem;
  color: rgba(255,255,255,.65);
  transition: color var(--transition);
}
.footer-col a:hover { color: var(--gold-light); }
.footer-bottom {
  border-top: 1px solid rgba(255,255,255,.12);
  padding-top: 1.25rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-family: var(--font-sans);
  font-size: .82rem;
  color: rgba(255,255,255,.4);
  flex-wrap: wrap;
  gap: .5rem;
}
.footer-bottom a { color: rgba(255,255,255,.55); }
.footer-bottom a:hover { color: var(--gold-light); }

/* ── Utility ─────────────────────────────────────────────────── */
.visually-hidden { position: absolute; width: 1px; height: 1px; overflow: hidden; clip: rect(0,0,0,0); }
.text-center { text-align: center; }
.mt-2 { margin-top: 1rem; }
.mt-3 { margin-top: 1.5rem; }
.mb-3 { margin-bottom: 1.5rem; }

/* ── Loading spinner ────────────────────────────────────────── */
.skeleton {
  background: linear-gradient(90deg, var(--cream-dark) 25%, var(--cream-border) 50%, var(--cream-dark) 75%);
  background-size: 200% 100%;
  animation: shimmer 1.4s infinite;
  border-radius: var(--radius);
}
@keyframes shimmer { 0% { background-position: 200% 0; } 100% { background-position: -200% 0; } }

/* ── No-results message ─────────────────────────────────────── */
.no-results {
  text-align: center;
  padding: 3rem 1rem;
  color: var(--text-muted);
  font-family: var(--font-sans);
  display: none;
  grid-column: 1 / -1;
}
.no-results.visible { display: block; }

/* ── Topics grid (homepage) ─────────────────────────────────── */
.topics-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(180px, 1fr));
  gap: 1rem;
}
.topic-card {
  padding: 1.5rem 1rem;
  text-align: center;
  text-decoration: none;
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow);
  transition: box-shadow var(--transition), transform var(--transition);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: .6rem;
}
.topic-card:hover {
  box-shadow: var(--shadow-hover);
  transform: translateY(-2px);
  color: var(--navy);
}
.topic-card .topic-icon { font-size: 2rem; }
.topic-card strong {
  font-family: var(--font-sans);
  font-size: .9rem;
  font-weight: 700;
  color: var(--navy);
}

/* ── Responsive ─────────────────────────────────────────────── */
@media (max-width: 900px) {
  .two-col {
    grid-template-columns: 1fr;
  }
  .sidebar { order: -1; }
  .sidebar-sticky { position: static; }
  .footer-grid { grid-template-columns: 1fr 1fr; }
  .cards-grid { grid-template-columns: repeat(auto-fill, minmax(260px, 1fr)); }
}
@media (max-width: 600px) {
  :root { --gap: 1.25rem; }
  .nav-links {
    display: none;
    flex-direction: column;
    position: absolute;
    top: var(--nav-h);
    left: 0;
    right: 0;
    background: var(--navy);
    padding: 1rem;
    border-top: 1px solid rgba(255,255,255,.1);
  }
  .nav-links.open { display: flex; }
  .nav-links a { padding: .65rem 1rem; border-radius: var(--radius); }
  .nav-toggle { display: flex; }
  .hero { padding: 3.5rem 0 3rem; }
  .hero h1 { font-size: 1.75rem; }
  .hero-canvas { opacity: .35; }
  .footer-grid { grid-template-columns: 1fr; }
  .cards-grid { grid-template-columns: 1fr; }
  .topics-grid { grid-template-columns: repeat(3, 1fr); }
  .filter-bar { padding: .75rem 1rem; }
  .section-header { flex-direction: column; align-items: flex-start; gap: .5rem; }
}