/* ==========================================================================
   Learning Centre — docs-style layout. Builds on styles.css (tokens, header,
   footer, fonts). Two columns: a category-grouped article list on the left and
   the page content on the right.
   ========================================================================== */

/* ---------- two-column layout ---------- */
.learn-layout {
  display: flex;
  align-items: flex-start;
  gap: 3rem;
  max-width: 1160px;
  margin: 0 auto;
  padding: 2.5rem 1.5rem 5rem;
}
.learn-main {
  flex: 1 1 auto;
  min-width: 0;
  max-width: 760px;
}

/* ---------- sidebar ---------- */
.learn-sidebar {
  flex: 0 0 256px;
  position: sticky;
  top: 5.25rem;
  max-height: calc(100vh - 7rem);
  overflow-y: auto;
}
.learn-nav { font-size: 0.925rem; }
.learn-nav-all {
  display: block;
  font-weight: 600;
  color: var(--gray-900);
  text-decoration: none;
  padding: 0.35rem 0.6rem;
  border-radius: 0.4rem;
  border-left: 2px solid transparent;
}
.learn-nav-all:hover { background: var(--gray-50); }
.learn-nav-all.active {
  color: var(--primary-700);
  background: var(--primary-50);
  border-left-color: var(--primary-600);
}
.learn-nav-group { margin-top: 1.375rem; }
.learn-nav-cat {
  font-size: 0.72rem;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  font-weight: 700;
  color: var(--gray-500);
  margin: 0 0 0.4rem 0.6rem;
}
.learn-nav ul { list-style: none; margin: 0; padding: 0; }
.learn-nav li { margin: 0; }
.learn-nav li a {
  display: block;
  padding: 0.35rem 0.6rem;
  border-radius: 0.4rem;
  color: var(--gray-600);
  text-decoration: none;
  line-height: 1.4;
  border-left: 2px solid transparent;
  transition: background 0.15s ease, color 0.15s ease;
}
.learn-nav li a:hover { background: var(--gray-50); color: var(--gray-900); }
.learn-nav li a.active {
  color: var(--primary-700);
  background: var(--primary-50);
  font-weight: 600;
  border-left-color: var(--primary-600);
}

/* ---------- breadcrumb ---------- */
.learn-breadcrumb { font-size: 0.8125rem; color: var(--gray-500); margin-bottom: 1.25rem; }
.learn-breadcrumb a { color: var(--gray-500); text-decoration: none; }
.learn-breadcrumb a:hover { color: var(--primary-600); }
.learn-breadcrumb .current { color: var(--gray-700); }

/* ---------- chip ---------- */
.learn-chip {
  display: inline-block;
  font-size: 0.75rem;
  font-weight: 600;
  letter-spacing: 0.02em;
  text-transform: uppercase;
  color: var(--primary-700);
  background: var(--primary-50);
  border: 1px solid var(--primary-100);
  padding: 0.25rem 0.625rem;
  border-radius: 999px;
}

/* ---------- hub: header + featured ---------- */
.learn-hub-head { margin-bottom: 0.5rem; }
.learn-hub-head h1 {
  font-size: clamp(2rem, 4.5vw, 2.75rem);
  font-weight: 800;
  letter-spacing: -0.025em;
  color: var(--gray-900);
  margin: 0 0 0.75rem;
}
.learn-hub-head p { font-size: 1.0625rem; color: var(--gray-600); margin: 0; }
.learn-feed-link {
  display: inline-block;
  margin-left: 0.4rem;
  font-weight: 600;
  color: var(--primary-600);
  text-decoration: none;
}
.learn-feed-link::before { content: "\1F517\00a0"; }
.learn-feed-link:hover { text-decoration: underline; }

.learn-section-label {
  font-size: 0.72rem;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  font-weight: 700;
  color: var(--gray-500);
  margin: 2rem 0 0.75rem;
}

.learn-feature {
  display: block;
  background: #fff;
  border: 1px solid var(--gray-200);
  border-radius: 1rem;
  overflow: hidden;
  text-decoration: none;
  color: inherit;
  transition: transform 0.2s ease, box-shadow 0.2s ease, border-color 0.2s ease;
}
.learn-feature:hover {
  transform: translateY(-3px);
  box-shadow: 0 16px 40px rgba(2, 132, 199, 0.10);
  border-color: var(--primary-200);
}
.learn-feature-media {
  aspect-ratio: 1200 / 630;
  background: linear-gradient(135deg, var(--primary-500), var(--secondary-600));
}
.learn-feature-media img { width: 100%; height: 100%; object-fit: cover; display: block; }
.learn-feature-media--ph { display: flex; align-items: center; justify-content: center; }
.learn-feature-media--ph span {
  color: #fff;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.04em;
}
.learn-feature-body { padding: 1.5rem 1.625rem 1.75rem; display: flex; flex-direction: column; gap: 0.6rem; }
.learn-feature-body h2 {
  font-size: 1.5rem;
  font-weight: 800;
  letter-spacing: -0.02em;
  line-height: 1.25;
  color: var(--gray-900);
  margin: 0;
}
.learn-feature-body p { color: var(--gray-600); line-height: 1.6; margin: 0; }
.learn-feature-meta { font-size: 0.8125rem; color: var(--gray-500); }

.learn-empty { color: var(--gray-600); font-size: 1.0625rem; }

/* ---------- article ---------- */
.learn-article-head { margin-bottom: 1.75rem; }
.learn-article-head h1 {
  font-size: clamp(1.9rem, 4.5vw, 2.6rem);
  font-weight: 800;
  letter-spacing: -0.025em;
  line-height: 1.2;
  color: var(--gray-900);
  margin: 0.75rem 0 0.75rem;
}
.learn-article-meta { font-size: 0.9rem; color: var(--gray-500); margin: 0; }

/* prose typography */
.learn-prose { font-size: 1.0938rem; line-height: 1.8; color: var(--gray-700); }
.learn-prose > * + * { margin-top: 1.25rem; }
.learn-prose h2 {
  font-size: 1.5rem;
  font-weight: 700;
  letter-spacing: -0.015em;
  color: var(--gray-900);
  margin-top: 2.5rem;
}
.learn-prose h3 { font-size: 1.2rem; font-weight: 700; color: var(--gray-900); margin-top: 2rem; }
.learn-prose a { color: var(--primary-600); text-decoration: underline; text-underline-offset: 2px; }
.learn-prose a:hover { color: var(--primary-700); }
.learn-prose ul, .learn-prose ol { padding-left: 1.4rem; }
.learn-prose li { margin-top: 0.5rem; }
.learn-prose blockquote {
  border-left: 4px solid var(--primary-300);
  background: var(--primary-50);
  padding: 0.75rem 1.25rem;
  border-radius: 0 0.5rem 0.5rem 0;
  color: var(--gray-700);
}
.learn-prose blockquote p { margin: 0; }
.learn-prose code {
  font-family: ui-monospace, SFMono-Regular, Menlo, monospace;
  font-size: 0.9em;
  background: var(--gray-100);
  padding: 0.1rem 0.35rem;
  border-radius: 0.3rem;
}
.learn-prose pre {
  background: var(--gray-900);
  color: #f3f4f6;
  padding: 1rem 1.25rem;
  border-radius: 0.6rem;
  overflow-x: auto;
}
.learn-prose pre code { background: none; padding: 0; font-size: 0.875rem; }
.learn-prose img { max-width: 100%; height: auto; border-radius: 0.6rem; }
.learn-prose hr { border: none; border-top: 1px solid var(--gray-200); margin: 2.5rem 0; }

/* end-of-article CTA */
.learn-cta {
  margin-top: 3rem;
  padding: 2rem;
  text-align: center;
  background: linear-gradient(135deg, var(--primary-50), var(--gray-50));
  border: 1px solid var(--primary-100);
  border-radius: 1rem;
}
.learn-cta h2 { font-size: 1.375rem; font-weight: 700; color: var(--gray-900); margin: 0 0 0.5rem; }
.learn-cta p { color: var(--gray-600); margin: 0 0 1.25rem; }
.learn-cta-btn {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  background: var(--primary-600);
  color: #fff;
  font-weight: 600;
  padding: 0.75rem 1.5rem;
  border-radius: 0.6rem;
  text-decoration: none;
  transition: background 0.2s ease;
}
.learn-cta-btn:hover { background: var(--primary-700); }

.learn-back { margin-top: 2rem; }
.learn-back a { color: var(--gray-500); text-decoration: none; font-weight: 500; }
.learn-back a:hover { color: var(--primary-600); }

/* ---------- responsive: stack, list moves below content ---------- */
@media (max-width: 860px) {
  .learn-layout { flex-direction: column; gap: 2rem; }
  .learn-main { order: 1; max-width: none; }
  .learn-sidebar {
    order: 2;
    position: static;
    max-height: none;
    flex-basis: auto;
    width: 100%;
    border-top: 1px solid var(--gray-200);
    padding-top: 1.5rem;
  }
}

@media (prefers-reduced-motion: reduce) {
  .learn-feature, .learn-cta-btn, .learn-nav li a { transition: none; }
  .learn-feature:hover { transform: none; }
}