/* Study hub layout (DTM-style course guides) — design tokens only */
*, *::before, *::after { box-sizing: border-box; }
html { scroll-padding-top: 96px; }
body.study-hub {
  margin: 0;
  font-family: var(--font-sans);
  color: var(--text);
  background: var(--bg);
  overflow-x: clip;
}
body.study-hub .hub-main a:not(.btn):not(.path-card):not(.stage-chip):not(.hub-help-card) {
  color: var(--content-link);
  font-weight: 650;
}
body.study-hub .hub-main a:not(.btn):not(.path-card):not(.stage-chip):not(.hub-help-card):hover {
  color: var(--content-link-hover);
}
.hub-bc { background: var(--card); border-bottom: 1px solid var(--line); padding: var(--space-3) 0; }
.hub-bc .inner { max-width: 1180px; margin: 0 auto; padding: 0 var(--space-5); }
.hub-bc ol { display: flex; flex-wrap: wrap; gap: var(--space-2) var(--space-2); list-style: none; margin: 0; padding: 0; font-size: 0.86rem; color: var(--muted); }
.hub-bc a { color: var(--content-link); text-decoration: none; }
.hub-bc a:hover { color: var(--navy); }
.hub-bc [aria-current="page"] { color: var(--content-link-hover); font-weight: 700; }
.hub-hero {
  background: linear-gradient(145deg, var(--navy) 0%, var(--navy-2) 48%, #2a35a3 100%);
  color: var(--white);
  padding: var(--space-10) var(--space-5) var(--space-12);
}
.hub-hero-grid { max-width: 1180px; margin: 0 auto; display: grid; grid-template-columns: minmax(0, 1.05fr) minmax(0, 0.95fr); gap: 28px; align-items: center; }
.hub-kicker { font-size: 0.72rem; font-weight: 800; letter-spacing: 0.1em; text-transform: uppercase; color: #ffd37a; margin: 0 0 var(--space-3); }
.hub-hero h1 { margin: 0 0 var(--space-3); font-size: clamp(1.45rem, 4.2vw, 2.2rem); line-height: 1.14; color: var(--white); max-width: none; }
.hub-progress-badge {
  display: inline-flex;
  flex-wrap: wrap;
  align-items: center;
  gap: var(--space-2);
  margin: 0 0 var(--space-3);
  padding: var(--space-2) var(--space-3);
  border-radius: var(--radius-pill);
  background: rgba(255, 255, 255, 0.12);
  border: 1px solid rgba(255, 255, 255, 0.22);
  font-size: 0.78rem;
  font-weight: 700;
  color: var(--white);
}
.hub-byline { margin: 0 0 var(--space-3); font-size: 0.84rem; color: var(--on-dark-muted); line-height: 1.45; }
.hub-hero-lead { margin: 0 0 var(--space-4); font-size: clamp(0.95rem, 2.8vw, 1.02rem); line-height: 1.58; color: var(--on-dark-body); max-width: none; }
.hub-hero-snippet { margin: 0 0 var(--space-4); padding: 14px var(--space-4); border-left: 4px solid var(--orange); background: rgba(255, 255, 255, 0.1); border-radius: 0 12px 12px 0; font-size: 0.95rem; line-height: 1.58; color: var(--on-dark-body); }
.hub-hero-snippet strong { color: var(--white); }
.hub-meta { display: flex; flex-wrap: wrap; gap: var(--space-2) 14px; font-size: 0.84rem; color: var(--on-dark-muted); margin: 0 0 var(--space-4); }
.hub-pills { display: flex; flex-wrap: wrap; gap: var(--space-2); margin: 0 0 var(--space-4); }
.hub-pills span { display: inline-flex; align-items: center; min-height: 44px; padding: 6px var(--space-3); border-radius: var(--radius-pill); background: rgba(255, 255, 255, 0.12); border: 1px solid rgba(255, 255, 255, 0.22); font-size: 0.78rem; font-weight: 700; color: var(--white); }
.hub-hero-actions { display: flex; flex-wrap: wrap; gap: 10px; margin-bottom: var(--space-4); }
.hub-btn { display: inline-flex; align-items: center; justify-content: center; min-height: 44px; padding: var(--space-3) 18px; border-radius: 12px; font-weight: 800; font-size: 0.9rem; text-decoration: none; border: 2px solid transparent; transition: transform 0.12s ease, box-shadow 0.12s ease; }
.hub-btn:hover { transform: translateY(-1px); }
.hub-btn-primary { background: var(--orange); color: var(--navy); box-shadow: 0 8px 20px rgba(245, 158, 11, 0.35); }
.hub-btn-ghost { background: transparent; color: var(--white); border-color: rgba(255, 255, 255, 0.45); }
.hub-jump-wrap { margin-top: var(--space-1); }
.hub-jump-label { display: block; font-size: 0.72rem; font-weight: 700; text-transform: uppercase; letter-spacing: 0.06em; color: var(--on-dark-muted); margin-bottom: 6px; }
.hub-jump-select { width: 100%; max-width: 320px; min-height: 44px; padding: 10px var(--space-3); border-radius: 12px; border: 1px solid rgba(255, 255, 255, 0.35); background: rgba(255, 255, 255, 0.12); color: var(--white); font-size: 0.9rem; font-weight: 600; }
.hub-jump-select option { color: var(--text); background: var(--card); }
.hub-hero-panel { display: grid; gap: var(--space-3); }
.hub-stat-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 10px; }
.hub-stat { padding: var(--space-3) 14px; border-radius: 14px; background: rgba(255, 255, 255, 0.1); border: 1px solid rgba(255, 255, 255, 0.2); }
.hub-stat strong { display: block; font-size: 1.05rem; color: var(--white); margin-bottom: 4px; }
.hub-stat span { font-size: 0.8rem; line-height: 1.4; color: var(--on-dark-muted); }
.hub-chart-wrap { background: rgba(255, 255, 255, 0.08); border: 1px solid rgba(255, 255, 255, 0.18); border-radius: var(--space-4); padding: var(--space-3); }
.hub-hero .hub-chart-wrap figcaption,
.hub-hero-panel .hub-chart-wrap figcaption {
  margin: var(--space-2) 0 0;
  font-size: 0.82rem;
  font-weight: 700;
  text-align: center;
  color: rgba(255, 255, 255, 0.92);
  line-height: 1.45;
  text-shadow: 0 1px 3px rgba(0, 0, 0, 0.42);
}

.hub-chart-wrap figcaption {
  margin: var(--space-2) 0 0;
  font-size: 0.78rem;
  text-align: center;
  color: var(--on-dark-muted);
  line-height: 1.4;
}
.hub-path-bar { max-width: 1180px; margin: -20px auto var(--space-6); padding: 0 var(--space-5); display: grid; grid-template-columns: repeat(4, minmax(0, 1fr)); gap: var(--space-3); position: relative; z-index: 2; }
.path-card { display: flex; flex-direction: column; gap: 4px; min-height: 88px; padding: var(--space-4); border-radius: var(--space-4); border: 1px solid var(--line); background: var(--card); text-decoration: none; color: var(--navy); box-shadow: 0 6px 18px rgba(10, 15, 90, 0.06); transition: border-color 0.15s ease, box-shadow 0.15s ease, transform 0.12s ease; }
.path-card:hover { border-color: var(--blue); box-shadow: 0 10px 24px rgba(10, 15, 90, 0.1); transform: translateY(-2px); color: var(--navy); }
.path-card em { font-style: normal; font-size: 0.72rem; font-weight: 800; text-transform: uppercase; letter-spacing: 0.05em; color: var(--orange-dark); }
.path-card strong { font-size: 1rem; line-height: 1.25; }
.path-card span { font-size: 0.84rem; color: var(--muted); line-height: 1.4; }
.path-card.is-primary { border-color: var(--orange); background: linear-gradient(180deg, #fffbf5, var(--card)); }
.hub-layout { width: 100%; max-width: 1180px; margin: 0 auto 80px; padding: 0 var(--space-5); display: grid; grid-template-columns: minmax(0, 1fr) minmax(0, 300px); gap: var(--space-6); align-items: start; box-sizing: border-box; }
.hub-main { display: grid; gap: var(--space-5); min-width: 0; max-width: 100%; width: 100%; }
.hub-main > * { min-width: 0; max-width: 100%; }
.hub-sidebar { position: sticky; top: 88px; display: grid; gap: 14px; }
.hub-sidebar .premium-card {
  padding: 14px 16px;
  border-radius: 14px;
  background: linear-gradient(145deg, var(--navy), #1c2580);
  color: rgba(255, 255, 255, 0.88);
}
.hub-sidebar .premium-card h3 { margin: 0 0 8px; color: #ffffff; font-size: 0.92rem; }
.hub-sidebar .premium-card p { margin: 0 0 10px; font-size: 0.88rem; color: rgba(255, 255, 255, 0.88); }
.hub-sidebar .premium-card a { color: #ffd37a; font-weight: 800; }
.hub-frq-card { margin-bottom: 14px; }
.side-card { background: var(--card); border: 1px solid var(--line); border-radius: 18px; padding: 18px; box-shadow: 0 8px 24px rgba(10, 15, 90, 0.06); }
.side-card h3 { margin: 0 0 var(--space-3); font-size: 0.92rem; color: var(--navy); }
.hub-checklist-progress { margin: 0 0 var(--space-3); font-size: 0.86rem; font-weight: 800; color: var(--navy); }
.side-toc { list-style: none; margin: 0; padding: 0; }
.side-toc a { display: block; padding: 10px var(--space-3); margin-bottom: 4px; border-radius: 10px; text-decoration: none; font-size: 0.86rem; font-weight: 650; color: var(--sidebar-link); min-height: 44px; line-height: 1.35; border: 1px solid transparent; }
.side-toc a:hover { background: var(--blue-light); border-color: var(--line); color: var(--sidebar-link-hover); }
.side-toc a.is-active { background: var(--blue-light); border-color: var(--blue); color: var(--sidebar-link-hover); font-weight: 800; }
.checklist { list-style: none; margin: 0; padding: 0; }
.checklist li { display: flex; gap: 10px; align-items: flex-start; padding: var(--space-2) 0; font-size: 0.86rem; line-height: 1.45; color: var(--text); border-bottom: 1px solid var(--line); }
.checklist li:last-child { border-bottom: 0; }
.checklist input { margin-top: 3px; width: 18px; height: 18px; accent-color: var(--navy); flex-shrink: 0; }
.section { background: var(--card); border: 1px solid var(--line); border-radius: 20px; padding: 22px var(--space-6); box-shadow: 0 6px 20px rgba(10, 15, 90, 0.04); min-width: 0; max-width: 100%; width: 100%; box-sizing: border-box; overflow-x: clip; }
.section p, .section li, .section h2, .section h3 { overflow-wrap: break-word; word-wrap: break-word; }
.section-eyebrow { display: block; font-size: 0.7rem; font-weight: 800; letter-spacing: 0.08em; text-transform: uppercase; color: var(--orange-dark); margin-bottom: 6px; }
.section h2 { margin: 0 0 14px; font-size: clamp(1.22rem, 2.4vw, 1.5rem); color: var(--navy); line-height: 1.2; }
.section h3 { margin: 1.25em 0 0.45em; font-size: 1.05rem; color: var(--navy); }
.section h3:first-of-type { margin-top: 0.15em; }
.section h4 { margin: 1em 0 0.4em; font-size: 0.98rem; color: var(--navy); }
.section p, .section li { line-height: 1.68; color: var(--text); font-size: 0.95rem; margin: 0 0 0.95em; }
.section ul, .section ol { margin: 0 0 1em; padding-left: 1.25rem; }
.hub-direct-answer { margin: 0 0 var(--space-4); padding: 14px var(--space-4); border-left: 4px solid var(--orange); background: var(--blue-light); border-radius: 0 12px 12px 0; font-size: 0.95rem; line-height: 1.58; color: var(--text); }
.hub-direct-answer strong { color: var(--navy); }
.table-wrap { width: 100%; max-width: 100%; overflow-x: auto; -webkit-overflow-scrolling: touch; margin: 14px 0; border: 1px solid var(--line); border-radius: 14px; box-sizing: border-box; }
table.data { width: 100%; border-collapse: collapse; min-width: 560px; font-size: 0.88rem; }
table.data th, table.data td { padding: 11px var(--space-3); border-bottom: 1px solid var(--line); text-align: left; vertical-align: top; }
table.data th { background: var(--blue-light); color: var(--navy); font-size: 0.72rem; text-transform: uppercase; letter-spacing: 0.04em; }
table.data tr:last-child td { border-bottom: 0; }
.callout { margin: 14px 0; padding: 14px var(--space-4); border-radius: 14px; border: 1px solid #fdba74; background: #fff7ed; color: #7c2d12; line-height: 1.55; font-size: 0.92rem; }
.callout strong { color: #9a3412; }
.hub-pseudocode { margin: 14px 0; padding: var(--space-4); border-radius: 14px; background: var(--bg-2); border: 1px solid var(--line); font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, monospace; font-size: 0.86rem; line-height: 1.55; color: var(--text); overflow-x: auto; white-space: pre-wrap; }
.hub-prompt-block { margin: 14px 0; padding: 14px var(--space-4); border-radius: 14px; border: 1px solid var(--line); background: var(--bg); font-size: 0.9rem; line-height: 1.55; color: var(--text); }
.hub-prompt-block strong { color: var(--navy); }
.hub-plan-form { margin-top: var(--space-4); }
.hub-plan-form table.data { min-width: 0; }
.hub-plan-form table.data th { width: 38%; }
.hub-plan-form input[type="text"] { width: 100%; min-height: 44px; padding: 10px var(--space-3); border: 1px solid var(--line); border-radius: 10px; font-size: 0.9rem; font-family: inherit; color: var(--text); background: var(--card); }
.hub-plan-form input[type="text"]:focus { outline: 2px solid var(--blue); border-color: var(--blue); }
.hub-help-cards { display: grid; grid-template-columns: repeat(auto-fit, minmax(220px, 1fr)); gap: var(--space-3); margin-top: var(--space-4); }
.hub-help-card { display: block; padding: var(--space-4); border-radius: 14px; border: 1px solid var(--line); text-decoration: none; color: var(--navy); font-weight: 800; min-height: 44px; background: var(--bg); transition: border-color 0.12s ease; }
.hub-help-card:hover { border-color: var(--blue); background: var(--blue-light); color: var(--navy); }
.hub-help-card span { display: block; font-weight: 500; font-size: 0.84rem; color: var(--muted); margin-top: 5px; }
.related-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(200px, 1fr)); gap: var(--space-3); margin-top: var(--space-3); }
.related-grid a { display: block; padding: 14px var(--space-4); border-radius: 14px; border: 1px solid var(--line); text-decoration: none; color: var(--navy); font-weight: 800; min-height: 44px; background: var(--bg); transition: border-color 0.12s ease; }
.related-grid a:hover { border-color: var(--blue); background: var(--blue-light); }
.related-grid a span { display: block; font-weight: 500; font-size: 0.84rem; color: var(--muted); margin-top: 5px; }
.faq-block details { border: 1px solid var(--line); border-radius: 14px; padding: 14px var(--space-4); margin-bottom: var(--space-2); background: var(--card); }
.faq-block details summary { font-weight: 800; color: var(--navy); cursor: pointer; min-height: 44px; display: flex; align-items: center; list-style: none; }
.faq-block details summary::-webkit-details-marker { display: none; }
.faq-block details p { margin: var(--space-3) 0 0; line-height: 1.62; color: var(--text); }
.hub-next-step { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: var(--space-3); margin-top: var(--space-4); }
.hub-next-step .hub-btn { width: 100%; text-align: center; flex-direction: column; gap: 4px; }
.hub-next-step .hub-btn small { display: block; font-size: 0.72rem; font-weight: 700; opacity: 0.85; }
.btn-row { display: flex; flex-wrap: wrap; gap: 10px; margin-top: 14px; }
.btn-row .hub-btn { background: var(--navy); color: var(--white); }
.btn-row .hub-btn.alt { background: var(--blue-light); color: var(--navy); border: 1px solid var(--line); box-shadow: none; }
.hub-mobile-bar { display: none; position: fixed; bottom: 0; left: 0; right: 0; z-index: 80; padding: 10px 14px calc(10px + env(safe-area-inset-bottom)); background: rgba(255, 255, 255, 0.96); border-top: 1px solid var(--line); box-shadow: 0 -8px 24px rgba(10, 15, 90, 0.12); backdrop-filter: blur(10px); gap: 10px; grid-template-columns: 1fr 1fr; }
.hub-mobile-bar .hub-btn { width: 100%; font-size: 0.86rem; padding: var(--space-3) 10px; }
.hub-main, .section, .hub-hero { overflow-wrap: break-word; }

/* Unit 1 LEARN track — concept pages */
.hub-fits-badge {
  display: inline-flex;
  flex-wrap: wrap;
  align-items: center;
  gap: var(--space-2);
  margin: 0 0 var(--space-3);
  padding: var(--space-2) var(--space-3);
  border-radius: var(--radius-pill);
  background: rgba(255, 255, 255, 0.1);
  border: 1px solid rgba(255, 255, 255, 0.22);
  font-size: 0.78rem;
  font-weight: 700;
  color: var(--on-dark-muted);
}
.hub-ct-callout {
  margin: var(--space-5) 0;
  padding: var(--space-4) var(--space-4) var(--space-4) calc(var(--space-4) + 4px);
  border-radius: 14px;
  border: 1px solid var(--blue);
  border-left: 4px solid var(--blue);
  background: var(--blue-light);
  color: var(--text);
  line-height: 1.58;
  font-size: 0.94rem;
}
.hub-ct-callout-icon {
  display: block;
  font-size: 1.1rem;
  margin-bottom: var(--space-2);
}
.hub-ct-callout strong { color: var(--navy); }
.hub-ct-callout a { font-weight: 800; }
.hub-key-terms { list-style: none; margin: 0; padding: 0; }
.hub-key-terms li { padding: 10px 0; border-bottom: 1px solid var(--line); font-size: 0.86rem; line-height: 1.45; }
.hub-key-terms li:last-child { border-bottom: 0; }
.hub-key-terms a { font-weight: 800; color: var(--navy); }
.hub-key-terms span { color: var(--muted); font-weight: 500; }
.hub-key-terms-foot { margin: var(--space-3) 0 0; font-size: 0.84rem; }
.hub-key-terms-foot a { font-weight: 800; }
.hub-unit-progress-label { margin: 0 0 var(--space-2); font-size: 0.84rem; font-weight: 800; color: var(--navy); }
.hub-unit-progress-bar {
  height: 8px;
  border-radius: var(--radius-pill);
  background: var(--bg-2);
  overflow: hidden;
  margin-bottom: var(--space-3);
}
.hub-unit-progress-fill {
  height: 100%;
  background: linear-gradient(90deg, var(--navy), var(--blue));
  border-radius: var(--radius-pill);
  transition: width 0.2s ease;
}
.hub-unit-progress-list { list-style: none; margin: 0; padding: 0; }
.hub-unit-progress-list li { margin-bottom: 4px; }
.hub-unit-progress-list a,
.hub-unit-progress-list span {
  display: block;
  padding: 8px 10px;
  border-radius: 10px;
  font-size: 0.82rem;
  line-height: 1.35;
  text-decoration: none;
  color: var(--text);
  min-height: 40px;
}
.hub-unit-progress-list a:hover { background: var(--blue-light); color: var(--navy); }
.hub-unit-progress-list .is-current {
  background: var(--blue-light);
  border: 1px solid var(--blue);
  font-weight: 800;
  color: var(--navy);
}
.hub-unit-progress-list .is-visited::before { content: "✓ "; color: var(--success); font-weight: 800; }
.hub-unit-complete {
  margin-top: var(--space-3);
  padding: 12px 14px;
  border-radius: 12px;
  background: linear-gradient(135deg, #fef3c7, #fffbeb);
  border: 1px solid #f59e0b;
  font-size: 0.86rem;
  font-weight: 700;
  line-height: 1.45;
  color: var(--navy);
  text-align: center;
}
.hub-unit-complete a {
  color: var(--blue);
  font-weight: 800;
  text-decoration: underline;
}
.hub-step-quiz { margin-top: var(--space-4); }
.hub-step-quiz-list { list-style: none; margin: 0; padding: 0; display: grid; gap: var(--space-2); }
.hub-step-quiz-item {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  padding: var(--space-3) var(--space-4);
  border: 2px solid var(--line);
  border-radius: 12px;
  background: var(--bg);
  min-height: 52px;
  cursor: grab;
  touch-action: none;
}
.hub-step-quiz-item:active { cursor: grabbing; }
.hub-step-quiz-item.is-dragging { opacity: 0.55; border-style: dashed; }
.hub-step-quiz-item.is-correct { border-color: var(--success); background: #ecfdf5; }
.hub-step-quiz-item.is-wrong { border-color: var(--danger); background: #fef2f2; }
.hub-step-quiz-handle { font-size: 1.1rem; color: var(--muted); flex-shrink: 0; user-select: none; }
.hub-step-quiz-label { flex: 1; font-size: 0.92rem; font-weight: 650; color: var(--navy); }
.hub-step-quiz-feedback { margin: var(--space-3) 0 0; font-size: 0.9rem; line-height: 1.5; }
.hub-step-quiz-feedback.is-success { color: #065f46; }
.hub-step-quiz-feedback.is-hint { color: #7c2d12; }
.hub-step-quiz-answer-key { margin-top: var(--space-4); padding: var(--space-4); border-radius: 14px; background: var(--bg-2); border: 1px solid var(--line); }
.hub-step-quiz-answer-key ol { margin: var(--space-2) 0 0; padding-left: 1.2rem; }
.hub-step-quiz-answer-key li { margin-bottom: var(--space-2); font-size: 0.88rem; line-height: 1.45; }
/* Interactive AP-style MCQs (study-hub quiz-ui) */
body.study-hub .quiz-ui { margin-top: var(--space-4); }
body.study-hub .quiz-ui .q-card {
  border: 1px solid var(--line);
  border-radius: 16px;
  padding: var(--space-4);
  margin-bottom: var(--space-4);
  background: var(--card);
}
body.study-hub .quiz-ui .q-card.answered-correct {
  border-color: var(--success);
  background: color-mix(in srgb, var(--success) 8%, var(--card));
}
body.study-hub .quiz-ui .q-card.answered-wrong {
  border-color: var(--danger);
  background: color-mix(in srgb, var(--danger) 8%, var(--card));
}
body.study-hub .quiz-ui .q-head {
  display: flex;
  flex-wrap: wrap;
  align-items: flex-start;
  justify-content: space-between;
  gap: var(--space-3);
  margin-bottom: var(--space-2);
}
body.study-hub .quiz-ui .q-text {
  margin: 0;
  flex: 1 1 16rem;
  font-weight: 800;
  color: var(--navy);
  font-size: 0.95rem;
  line-height: 1.45;
}
body.study-hub .quiz-ui .q-difficulty {
  flex-shrink: 0;
  display: inline-flex;
  align-items: center;
  min-height: 28px;
  padding: 4px 10px;
  border-radius: 8px;
  font-size: 0.72rem;
  font-weight: 800;
  text-transform: uppercase;
  letter-spacing: 0.04em;
}
body.study-hub .quiz-ui .q-difficulty-easy {
  background: #fef3c7;
  color: #92400e;
  border: 1px solid #f59e0b;
}
body.study-hub .quiz-ui .q-difficulty-medium {
  background: #dbeafe;
  color: #1e3a8a;
  border: 1px solid #3b82f6;
}
body.study-hub .quiz-ui .q-difficulty-hard {
  background: var(--navy);
  color: #ffffff;
  border: 1px solid var(--navy);
}
body.study-hub .quiz-ui .opts {
  display: grid;
  gap: 8px;
  margin: var(--space-3) 0 0;
}
body.study-hub .quiz-ui .opt-btn {
  text-align: left;
  min-height: 44px;
  padding: 12px 14px;
  border-radius: 12px;
  border: 1px solid var(--line);
  background: var(--bg);
  cursor: pointer;
  font-size: 0.92rem;
  color: var(--text);
  font-family: inherit;
  line-height: 1.4;
}
body.study-hub .quiz-ui .opt-btn:hover:not(:disabled) {
  border-color: var(--blue);
}
body.study-hub .quiz-ui .opt-btn:focus-visible {
  outline: 2px solid var(--blue);
  outline-offset: 2px;
}
body.study-hub .quiz-ui .opt-btn[disabled] {
  opacity: 0.92;
  cursor: default;
}
body.study-hub .quiz-ui .opt-btn.is-correct {
  border-color: var(--success);
  background: #ecfdf5;
  color: var(--navy);
}
body.study-hub .quiz-ui .opt-btn.is-wrong {
  border-color: var(--danger);
  background: #fef2f2;
  color: var(--navy);
}
body.study-hub .quiz-ui .explain {
  display: none;
  margin-top: var(--space-3);
  padding: var(--space-3);
  border-radius: 12px;
  background: var(--blue-light);
  font-size: 0.9rem;
  line-height: 1.55;
  color: var(--text);
}
body.study-hub .quiz-ui .q-card.revealed .explain {
  display: block;
}
body.study-hub .quiz-ui .explain strong {
  color: var(--navy);
}
body.study-hub .quiz-ui .ap-tip {
  margin: var(--space-2) 0 0;
  font-size: 0.85rem;
  color: var(--muted);
}

/* Test case type quiz (program testing) */
body.study-hub .hub-type-quiz {
  margin-top: var(--space-4);
  padding: var(--space-4);
  border-radius: 16px;
  border: 1px solid var(--line);
  background: var(--card);
}
body.study-hub .hub-type-quiz-progress {
  margin: 0 0 var(--space-3);
  font-size: 0.84rem;
  font-weight: 800;
  color: var(--navy);
  text-transform: uppercase;
  letter-spacing: 0.04em;
}
body.study-hub .hub-type-quiz-scenario {
  margin: 0 0 var(--space-4);
  font-size: 0.95rem;
  line-height: 1.55;
  color: var(--text);
  font-weight: 650;
}
body.study-hub .hub-type-quiz-opts {
  display: grid;
  gap: 8px;
  margin-bottom: var(--space-3);
}
body.study-hub .hub-type-quiz-opt {
  display: flex;
  align-items: flex-start;
  gap: 12px;
  text-align: left;
  min-height: 44px;
  padding: 12px 14px;
  border-radius: 12px;
  border: 1px solid var(--line);
  background: var(--bg);
  cursor: pointer;
  font-size: 0.92rem;
  color: var(--text);
  font-family: inherit;
  font-weight: 650;
  line-height: 1.4;
}
body.study-hub .hub-opt-letter {
  flex-shrink: 0;
  width: 28px;
  height: 28px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border-radius: 8px;
  background: var(--navy);
  color: var(--white);
  font-size: 0.8rem;
  font-weight: 800;
  line-height: 1;
}
body.study-hub .hub-type-quiz-opt.is-correct .hub-opt-letter {
  background: #059669;
}
body.study-hub .hub-type-quiz-opt.is-wrong .hub-opt-letter {
  background: #dc2626;
}
body.study-hub .hub-opt-text {
  flex: 1;
  min-width: 0;
  padding-top: 3px;
  font-weight: 650;
}
body.study-hub .hub-type-quiz-opt:hover:not(:disabled) {
  border-color: var(--blue);
}
body.study-hub .hub-type-quiz-opt:focus-visible {
  outline: 2px solid var(--blue);
  outline-offset: 2px;
}
body.study-hub .hub-type-quiz-opt[disabled] {
  cursor: default;
}
body.study-hub .hub-type-quiz-opt.is-correct {
  border-color: var(--success);
  background: #ecfdf5;
  color: var(--navy);
}
body.study-hub .hub-type-quiz-opt.is-wrong {
  border-color: var(--danger);
  background: #fef2f2;
  color: var(--navy);
}
body.study-hub .hub-type-quiz-feedback {
  margin: 0 0 var(--space-3);
  padding: var(--space-3);
  border-radius: 12px;
  font-size: 0.9rem;
  line-height: 1.55;
}
body.study-hub .hub-type-quiz-feedback.is-success {
  background: #ecfdf5;
  color: #065f46;
  border: 1px solid var(--success);
}
body.study-hub .hub-type-quiz-feedback.is-hint {
  background: #fff7ed;
  color: #7c2d12;
  border: 1px solid #f59e0b;
}
body.study-hub .hub-type-quiz-summary {
  margin-top: var(--space-4);
  padding: var(--space-4);
  border-radius: 12px;
  background: var(--blue-light);
  border: 1px solid var(--line);
}
body.study-hub .hub-type-quiz-summary p {
  margin: 0 0 var(--space-2);
  line-height: 1.5;
  color: var(--text);
}
body.study-hub .hub-type-quiz-summary p:last-child {
  margin-bottom: 0;
}
body.study-hub .hub-type-quiz-actions {
  margin-top: var(--space-3);
}

/* Version-matching activity (iterative development) */
body.study-hub .hub-version-pair {
  margin-bottom: var(--space-4);
  padding: var(--space-3);
  border-radius: 12px;
  background: var(--bg);
  border: 1px solid var(--line);
}
body.study-hub .hub-version-before,
body.study-hub .hub-version-after {
  margin: 0 0 var(--space-2);
  font-size: 0.92rem;
  line-height: 1.55;
  color: var(--text);
}
body.study-hub .hub-version-after {
  margin-bottom: 0;
}
body.study-hub #diag-prompt,
body.study-hub #practice-prompt,
body.study-hub #scenario-prompt,
body.study-hub .hub-type-quiz-scenario {
  margin: 0 0 var(--space-4);
  font-size: 0.95rem;
  line-height: 1.55;
  color: var(--navy);
  font-weight: 650;
}
body.study-hub #diag-prompt p,
body.study-hub #practice-prompt p,
body.study-hub #scenario-prompt p,
body.study-hub .hub-type-quiz-scenario p {
  margin: 0 0 var(--space-2);
  color: var(--text);
  font-weight: 500;
}
body.study-hub .hub-practice-bank details.hub-bank-item {
  border: 1px solid var(--line);
  border-radius: 14px;
  margin-bottom: var(--space-2);
  background: var(--card);
  overflow: hidden;
}
body.study-hub .hub-practice-bank details.hub-bank-item summary {
  font-weight: 800;
  color: var(--navy);
  cursor: pointer;
  min-height: 44px;
  display: flex;
  align-items: center;
  padding: 14px var(--space-4);
  list-style: none;
}
body.study-hub .hub-practice-bank details.hub-bank-item summary::-webkit-details-marker {
  display: none;
}
body.study-hub .hub-practice-bank .hub-bank-panel {
  padding: 0 var(--space-4) var(--space-4);
  border-top: 1px solid var(--line);
}
body.study-hub .hub-practice-bank .hub-bank-q {
  margin: var(--space-3) 0 var(--space-2);
  line-height: 1.6;
  color: var(--navy);
  font-weight: 700;
}
body.study-hub .hub-practice-bank .hub-bank-opts {
  margin: 0 0 var(--space-3);
  font-size: 0.92rem;
  line-height: 1.55;
  color: var(--text);
}
body.study-hub .hub-practice-bank .hub-bank-expl {
  margin: 0;
  padding: var(--space-3);
  border-radius: 10px;
  background: var(--blue-light);
  line-height: 1.62;
  color: var(--text);
}
body.study-hub #diag-review,
body.study-hub #practice-review {
  margin: 0 0 var(--space-3);
  font-size: 0.9rem;
  font-weight: 700;
}
body.study-hub #diag-results,
body.study-hub #practice-results,
body.study-hub #scenario-results {
  margin-top: var(--space-4);
  padding: var(--space-4);
  border-radius: 12px;
  background: var(--blue-light);
  border: 1px solid var(--line);
}
body.study-hub #diag-results ul,
body.study-hub #practice-results ul {
  margin: var(--space-2) 0;
  padding-left: 1.2rem;
}
body.study-hub .hub-skill-overall {
  margin: 0 0 var(--space-3);
  font-size: 0.95rem;
  color: var(--navy);
}
body.study-hub .hub-skill-list {
  list-style: none;
  margin: 0 0 var(--space-3);
  padding: 0;
}
body.study-hub .hub-skill-row {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: var(--space-2);
  padding: 8px 0;
  border-bottom: 1px solid var(--line);
  font-size: 0.88rem;
}
body.study-hub .hub-skill-row.is-weakest {
  background: #fff7ed;
  margin: 0 -8px;
  padding: 8px;
  border-radius: 8px;
}
body.study-hub .hub-skill-name {
  color: var(--navy);
  font-weight: 700;
  flex: 1;
  min-width: 0;
}
body.study-hub .hub-skill-weakest {
  font-size: 0.68rem;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  color: #b45309;
  font-weight: 800;
}
body.study-hub .hub-skill-dots {
  font-size: 0.78rem;
  color: var(--muted);
  white-space: nowrap;
}
body.study-hub .hub-skill-suggest {
  margin: 0 0 var(--space-2);
  font-size: 0.88rem;
  line-height: 1.5;
  color: var(--text);
}
body.study-hub .hub-skill-actions {
  margin-top: var(--space-2);
}
body.study-hub .hub-skill-loading {
  margin: 0;
  font-size: 0.88rem;
  color: var(--muted);
  line-height: 1.45;
}
body.study-hub .hub-sidebar-reset-link {
  display: inline-flex;
  align-items: center;
  min-height: 44px;
  padding: 0;
  border: 0;
  background: none;
  font: inherit;
  font-weight: 700;
  color: var(--content-link);
  cursor: pointer;
  text-align: left;
}
body.study-hub .hub-sidebar-reset-link:hover {
  color: var(--content-link-hover);
}
body.study-hub .hub-next-step .hub-next-label {
  display: block;
  font-size: 0.95rem;
  font-weight: 800;
}
.hub-ready-checklist .checklist li label a { font-weight: 800; color: var(--content-link); }

/* —— AP CSP Unit 1 Practice Hub (interactive UX) —— */
body.practice-hub-unit1 .hub-live-strip {
  max-width: 1180px;
  margin: -8px auto var(--space-5);
  padding: 0 var(--space-5);
  position: relative;
  z-index: 3;
}
body.practice-hub-unit1 .hub-live-strip-inner {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 10px;
  padding: 12px var(--space-4);
  border-radius: 16px;
  border: 1px solid var(--line);
  background: linear-gradient(135deg, #f8faff 0%, #fff 55%, #fff7ed 100%);
  box-shadow: 0 10px 28px rgba(10, 15, 90, 0.08);
}
body.practice-hub-unit1 .hub-live-chip {
  flex: 1 1 120px;
  min-width: 0;
  padding: 8px 12px;
  border-radius: 12px;
  background: var(--card);
  border: 1px solid var(--line);
}
body.practice-hub-unit1 .hub-live-chip-overall {
  border-color: var(--orange);
  background: linear-gradient(180deg, #fffbf5, var(--card));
}
body.practice-hub-unit1 .hub-live-label {
  display: block;
  font-size: 0.68rem;
  font-weight: 800;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--muted);
  margin-bottom: 2px;
}
body.practice-hub-unit1 .hub-live-chip strong {
  font-size: 1rem;
  color: var(--navy);
}
body.practice-hub-unit1 .hub-live-chip.is-done {
  border-color: #86efac;
  background: #ecfdf5;
}
body.practice-hub-unit1 .hub-live-chip.is-done strong {
  color: #065f46;
}
body.practice-hub-unit1 .hub-live-cta {
  flex: 0 0 auto;
  min-height: 44px;
  padding: 10px 16px;
  border-radius: 12px;
  background: var(--navy);
  color: var(--white);
  font-weight: 800;
  font-size: 0.86rem;
  text-decoration: none;
  white-space: nowrap;
}
body.practice-hub-unit1 .hub-live-cta:hover {
  background: var(--navy-2);
  color: var(--white);
}
body.practice-hub-unit1 .hub-section-status {
  display: inline-block;
  margin-left: 8px;
  padding: 4px 10px;
  border-radius: var(--radius-pill);
  font-size: 0.65rem;
  font-weight: 800;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  vertical-align: middle;
  background: var(--bg);
  border: 1px solid var(--line);
  color: var(--muted);
}
body.practice-hub-unit1 .hub-quiz-section.is-active .hub-section-status {
  background: #eff6ff;
  border-color: var(--blue);
  color: var(--navy);
}
body.practice-hub-unit1 .hub-quiz-section.is-complete .hub-section-status {
  background: #ecfdf5;
  border-color: var(--success);
  color: #065f46;
}
body.practice-hub-unit1 .hub-practice-quiz {
  border: 2px solid var(--line);
  box-shadow: 0 12px 32px rgba(10, 15, 90, 0.07);
}
body.practice-hub-unit1 .hub-practice-quiz.hub-quiz-pulse {
  animation: hub-quiz-enter 0.35s ease;
}
@keyframes hub-quiz-enter {
  from { opacity: 0.4; transform: translateY(6px); }
  to { opacity: 1; transform: translateY(0); }
}
body.practice-hub-unit1 .hub-quiz-top {
  display: flex;
  flex-wrap: wrap;
  align-items: flex-end;
  justify-content: space-between;
  gap: var(--space-2);
  margin-bottom: var(--space-3);
}
body.practice-hub-unit1 .hub-quiz-progress-wrap {
  flex: 1 1 200px;
  min-width: 0;
}
body.practice-hub-unit1 .hub-quiz-progress-track {
  height: 8px;
  border-radius: 999px;
  background: var(--bg);
  border: 1px solid var(--line);
  overflow: hidden;
  margin-bottom: 8px;
}
body.practice-hub-unit1 .hub-quiz-progress-fill {
  display: block;
  height: 100%;
  width: var(--quiz-progress, 0%);
  border-radius: 999px;
  background: linear-gradient(90deg, var(--navy), #3b5bdb);
  transition: width 0.35s ease;
}
body.practice-hub-unit1 .hub-quiz-streak {
  margin: 0;
  padding: 6px 12px;
  border-radius: var(--radius-pill);
  background: #ecfdf5;
  border: 1px solid var(--success);
  font-size: 0.8rem;
  font-weight: 800;
  color: #065f46;
}
body.practice-hub-unit1 .hub-quiz-hint {
  margin: 0 0 var(--space-3);
  font-size: 0.82rem;
  color: var(--muted);
}
body.practice-hub-unit1 .hub-quiz-hint kbd {
  display: inline-block;
  min-width: 1.4em;
  padding: 2px 6px;
  border-radius: 6px;
  border: 1px solid var(--line);
  background: var(--bg);
  font-size: 0.78rem;
  font-weight: 800;
  color: var(--navy);
  font-family: inherit;
}
body.practice-hub-unit1 .hub-topic-badge {
  display: inline-block;
  margin: 0 0 var(--space-3);
  padding: 6px 12px;
  border-radius: var(--radius-pill);
  font-size: 0.72rem;
  font-weight: 800;
  text-transform: uppercase;
  letter-spacing: 0.04em;
}
body.practice-hub-unit1 .hub-topic-badge.topic-collab { background: #ede9fe; color: #5b21b6; }
body.practice-hub-unit1 .hub-topic-badge.topic-pdp { background: #dbeafe; color: #1e40af; }
body.practice-hub-unit1 .hub-topic-badge.topic-iter { background: #d1fae5; color: #065f46; }
body.practice-hub-unit1 .hub-topic-badge.topic-test { background: #ffedd5; color: #9a3412; }
body.practice-hub-unit1 .hub-topic-badge.topic-docs { background: #fce7f3; color: #9d174d; }
body.practice-hub-unit1 .hub-type-quiz-opt {
  display: flex;
  align-items: flex-start;
  gap: 12px;
  text-align: left;
}
body.practice-hub-unit1 .hub-opt-letter {
  flex-shrink: 0;
  width: 28px;
  height: 28px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border-radius: 8px;
  background: var(--navy);
  color: var(--white);
  font-size: 0.8rem;
  font-weight: 800;
}
body.practice-hub-unit1 .hub-type-quiz-opt.is-correct .hub-opt-letter {
  background: #059669;
}
body.practice-hub-unit1 .hub-type-quiz-opt.is-wrong .hub-opt-letter {
  background: #dc2626;
}
body.practice-hub-unit1 .hub-opt-text {
  flex: 1;
  min-width: 0;
  padding-top: 3px;
}
body.practice-hub-unit1 .hub-review-card {
  margin: 0 0 var(--space-3);
  padding: var(--space-3) var(--space-4);
  border-radius: 12px;
  background: #fff7ed;
  border: 1px solid #fdba74;
  font-size: 0.9rem;
  font-weight: 700;
  color: #7c2d12;
}
body.practice-hub-unit1 .hub-review-card a {
  color: #9a3412;
  font-weight: 800;
}
body.practice-hub-unit1 .hub-quiz-next.is-ready {
  animation: hub-next-pulse 1.2s ease infinite;
  box-shadow: 0 0 0 3px rgba(245, 158, 11, 0.35);
}
@keyframes hub-next-pulse {
  0%, 100% { box-shadow: 0 0 0 3px rgba(245, 158, 11, 0.25); }
  50% { box-shadow: 0 0 0 6px rgba(245, 158, 11, 0.45); }
}
body.practice-hub-unit1 .hub-quiz-results-panel {
  margin-top: var(--space-4);
  padding: var(--space-5);
  border-radius: 16px;
  background: linear-gradient(160deg, #eff6ff 0%, #fff 40%, #ecfdf5 100%);
  border: 2px solid var(--line);
}
body.practice-hub-unit1 .hub-result-hero {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: var(--space-4);
  margin-bottom: var(--space-4);
}
body.practice-hub-unit1 .hub-score-ring {
  width: 88px;
  height: 88px;
  border-radius: 50%;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  background: var(--navy);
  color: var(--white);
  flex-shrink: 0;
}
body.practice-hub-unit1 .hub-score-ring strong {
  font-size: 1.5rem;
  line-height: 1;
  color: var(--white);
}
body.practice-hub-unit1 .hub-score-ring span {
  font-size: 0.68rem;
  font-weight: 700;
  color: rgba(255, 255, 255, 0.88);
  text-transform: uppercase;
  letter-spacing: 0.04em;
}
body.practice-hub-unit1 .hub-result-msg {
  flex: 1;
  min-width: 180px;
  margin: 0;
  font-size: 1rem;
  font-weight: 800;
  color: var(--navy);
  line-height: 1.35;
}
body.practice-hub-unit1 .hub-result-sub {
  margin: 6px 0 0;
  font-size: 0.9rem;
  font-weight: 500;
  color: var(--text);
  line-height: 1.5;
}
body.practice-hub-unit1 .hub-topic-bars {
  list-style: none;
  margin: 0 0 var(--space-4);
  padding: 0;
  display: grid;
  gap: 10px;
}
body.practice-hub-unit1 .hub-topic-bar-row {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  gap: 6px 12px;
  align-items: center;
  font-size: 0.86rem;
}
body.practice-hub-unit1 .hub-topic-bar-row .bar-track {
  grid-column: 1 / -1;
  height: 8px;
  border-radius: 999px;
  background: var(--bg);
  border: 1px solid var(--line);
  overflow: hidden;
}
body.practice-hub-unit1 .hub-topic-bar-row .bar-fill {
  display: block;
  height: 100%;
  border-radius: 999px;
  background: var(--navy);
  transition: width 0.4s ease;
}
body.practice-hub-unit1 .hub-topic-bar-row.is-weak .bar-fill {
  background: #f59e0b;
}
body.practice-hub-unit1 .hub-topic-bar-row.is-strong .bar-fill {
  background: #059669;
}
body.practice-hub-unit1 .hub-result-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}
body.practice-hub-unit1 .hub-score-dashboard {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(140px, 1fr));
  gap: var(--space-3);
  margin-bottom: var(--space-4);
}
body.practice-hub-unit1 .hub-score-card {
  padding: var(--space-4);
  border-radius: 14px;
  border: 1px solid var(--line);
  background: var(--bg);
  text-align: center;
}
body.practice-hub-unit1 .hub-score-card strong {
  display: block;
  font-size: 1.6rem;
  color: var(--navy);
  line-height: 1.1;
}
body.practice-hub-unit1 .hub-score-card span {
  font-size: 0.78rem;
  font-weight: 700;
  color: var(--muted);
  text-transform: uppercase;
  letter-spacing: 0.04em;
}
body.practice-hub-unit1 .hub-score-card.is-highlight {
  border-color: var(--orange);
  background: linear-gradient(180deg, #fffbf5, var(--card));
}
body.practice-hub-unit1 .hub-skill-ring-wrap {
  text-align: center;
  margin-bottom: var(--space-3);
}
body.practice-hub-unit1 .hub-skill-ring {
  width: 72px;
  height: 72px;
  margin: 0 auto 8px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.1rem;
  font-weight: 900;
  color: var(--white);
  background: conic-gradient(var(--orange) var(--skill-pct, 0%), var(--line) 0);
  position: relative;
}
body.practice-hub-unit1 .hub-skill-ring::after {
  content: attr(data-label);
  position: absolute;
  inset: 6px;
  border-radius: 50%;
  background: var(--card);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.95rem;
  font-weight: 900;
  color: var(--navy);
}
body.practice-hub-unit1 .hub-skill-bar-track {
  flex: 1;
  max-width: 100px;
  height: 6px;
  border-radius: 999px;
  background: var(--bg);
  border: 1px solid var(--line);
  overflow: hidden;
}
body.practice-hub-unit1 .hub-skill-bar-fill {
  display: block;
  height: 100%;
  background: var(--navy);
  border-radius: 999px;
}
body.practice-hub-unit1 .hub-skill-row.is-weakest .hub-skill-bar-fill {
  background: #f59e0b;
}

@media print {
  .topbar, .hub-bc, .hub-hero, .hub-path-bar, .hub-sidebar, .hub-mobile-bar, .footer, .hub-next-step, .btn-row { display: none !important; }
  .hub-layout { grid-template-columns: 1fr; max-width: 100%; padding: 0; }
  .hub-plan-form input { border: 1px solid var(--text); }
}

@media (min-width: 981px) {
  .hub-hero h1 { max-width: 28ch; }
  .hub-hero-lead { max-width: 48ch; }
}

@media (max-width: 980px) {
  html { scroll-padding-top: 92px; }
  .hub-bc .inner, .hub-hero-grid, .hub-path-bar, .hub-layout { padding-left: var(--space-4); padding-right: var(--space-4); width: 100%; max-width: 100%; overflow-x: clip; box-sizing: border-box; }
  .hub-hero { padding: 28px 0 36px; }
  .hub-hero-grid { grid-template-columns: 1fr; gap: var(--space-5); }
  .hub-hero-panel { order: 2; }
  .hub-path-bar { grid-template-columns: 1fr 1fr; margin: -12px auto var(--space-5); gap: 10px; }
  .hub-layout { grid-template-columns: 1fr; padding-bottom: calc(100px + env(safe-area-inset-bottom)); margin-bottom: 48px; }
  .hub-sidebar { position: static; display: grid; grid-template-columns: 1fr 1fr; gap: var(--space-3); }
  .hub-mobile-bar { display: grid; }
  .hub-next-step { grid-template-columns: 1fr; }
  .related-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}

@media (max-width: 760px) {
  body.practice-hub-unit1 .hub-live-strip-inner {
    flex-direction: column;
    align-items: stretch;
  }
  body.practice-hub-unit1 .hub-live-cta {
    width: 100%;
    justify-content: center;
  }
  body.practice-hub-unit1 .hub-result-hero {
    flex-direction: column;
    text-align: center;
  }
  .hub-bc { padding: 10px 0; }
  .hub-bc ol { font-size: 0.8rem; gap: 4px 6px; line-height: 1.45; }
  .hub-hero { padding: var(--space-6) 0 var(--space-8); }
  .hub-hero-snippet { font-size: 0.9rem; padding: var(--space-3) 14px; }
  .hub-meta { flex-direction: column; align-items: flex-start; gap: 6px; }
  .hub-hero-actions { flex-direction: column; align-items: stretch; }
  .hub-hero-actions .hub-btn { width: 100%; justify-content: center; }
  .hub-jump-select { max-width: none; width: 100%; }
  .hub-path-bar { grid-template-columns: 1fr; margin-top: 0; }
  .btn-row { flex-direction: column; align-items: stretch; }
  .btn-row .hub-btn { width: 100%; justify-content: center; }
  .faq-block details summary { font-size: 0.92rem; line-height: 1.4; align-items: flex-start; padding-top: var(--space-3); padding-bottom: var(--space-3); }
  .hub-plan-form table.data, .hub-plan-form table.data thead, .hub-plan-form table.data tbody, .hub-plan-form table.data tr, .hub-plan-form table.data th, .hub-plan-form table.data td { display: block; width: 100%; }
  .hub-plan-form table.data thead { display: none; }
  .hub-plan-form table.data tr { margin-bottom: var(--space-4); border-bottom: 1px solid var(--line); padding-bottom: var(--space-3); }
  .hub-plan-form table.data td { border: 0; padding: var(--space-2) 0; }
  .hub-plan-form table.data td::before { content: attr(data-label); display: block; font-weight: 800; font-size: 0.8rem; color: var(--navy); margin-bottom: 6px; }
}

@media (max-width: 640px) {
  .hub-sidebar { grid-template-columns: 1fr; }
  .section { padding: 18px 14px; border-radius: var(--space-4); width: 100%; max-width: 100%; }
  .section h2 { font-size: 1.2rem; }
  .section h3 { font-size: 1rem; }
  .section p, .section li { font-size: 0.92rem; }
  .related-grid { grid-template-columns: 1fr; }
  table.data { min-width: 480px; font-size: 0.82rem; }
  table.data th, table.data td { padding: 9px 10px; }
  .hub-chart-wrap figcaption { font-size: 0.84rem; max-width: none; }
}

@media (max-width: 380px) {
  html { scroll-padding-top: 84px; }
  .hub-bc .inner, .hub-path-bar, .hub-layout { padding-left: var(--space-3); padding-right: var(--space-3); }
  .hub-hero { padding: var(--space-5) 0 28px; }
  .hub-hero h1 { font-size: 1.38rem; }
  .hub-pills { gap: 6px; }
  .hub-pills span { font-size: 0.7rem; padding: 5px 10px; min-height: 32px; }
  .hub-stat-grid { grid-template-columns: 1fr; }
  .hub-mobile-bar { grid-template-columns: 1fr; }
}

/* —— AP CSP Unit 1 Vocabulary hub —— */
body.vocab-hub-unit1 .vocab-table-tools {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(0, 200px);
  gap: var(--space-3);
  align-items: end;
  margin-bottom: var(--space-4);
}
body.vocab-hub-unit1 .vocab-search-label {
  display: block;
  font-size: 0.72rem;
  font-weight: 800;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--orange-dark);
  margin-bottom: 6px;
}
body.vocab-hub-unit1 .vocab-table-search,
body.vocab-hub-unit1 .vocab-table-topic {
  width: 100%;
  min-height: 44px;
  padding: 10px var(--space-3);
  border-radius: 12px;
  border: 1px solid var(--line);
  font-size: 0.92rem;
  font-family: inherit;
  color: var(--text);
  background: var(--card);
}
body.vocab-hub-unit1 .vocab-table-hint {
  grid-column: 1 / -1;
  margin: 0;
  font-size: 0.84rem;
  color: var(--muted);
}
body.vocab-hub-unit1 .vocab-term-table tbody tr[data-term-id] {
  cursor: pointer;
  transition: background 0.12s ease;
}
body.vocab-hub-unit1 .vocab-term-table tbody tr[data-term-id]:hover {
  background: var(--blue-light);
}
body.vocab-hub-unit1 .vocab-topic-heading th {
  background: var(--bg);
  color: var(--navy);
  font-size: 0.88rem;
  text-align: left;
  padding-top: var(--space-4);
}
body.vocab-hub-unit1 .vocab-chip-row {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-2);
  margin-bottom: var(--space-4);
}
body.vocab-hub-unit1 .vocab-chip {
  min-height: 44px;
  padding: 8px 14px;
  border-radius: var(--radius-pill);
  border: 1px solid var(--line);
  background: var(--card);
  color: var(--navy);
  font-size: 0.82rem;
  font-weight: 700;
  cursor: pointer;
  font-family: inherit;
  transition: border-color 0.12s ease, background 0.12s ease;
}
body.vocab-hub-unit1 .vocab-chip:hover {
  border-color: var(--blue);
}
body.vocab-hub-unit1 .vocab-chip.is-active {
  border-color: var(--orange);
  background: #fffbf5;
  color: var(--navy);
}
body.vocab-hub-unit1 .vocab-flash-stage {
  max-width: 520px;
  margin: 0 auto;
}
body.vocab-hub-unit1 .vocab-flash-progress {
  text-align: center;
  font-size: 0.84rem;
  color: var(--muted);
  margin: 0 0 var(--space-3);
}
body.vocab-hub-unit1 .vocab-flash-card {
  perspective: 1000px;
  min-height: 220px;
  border: none;
  background: transparent;
  padding: 0;
  width: 100%;
  cursor: pointer;
  font-family: inherit;
  text-align: left;
}
body.vocab-hub-unit1 .vocab-flash-inner {
  position: relative;
  min-height: 220px;
  border-radius: 18px;
  border: 2px solid var(--line);
  background: linear-gradient(180deg, var(--card) 0%, var(--bg) 100%);
  box-shadow: 0 12px 32px rgba(10, 15, 90, 0.08);
  padding: var(--space-6) var(--space-5);
  transition: transform 0.3s ease, box-shadow 0.2s ease;
  transform-style: preserve-3d;
}
body.vocab-hub-unit1 .vocab-flash-card:hover .vocab-flash-inner {
  box-shadow: 0 16px 36px rgba(10, 15, 90, 0.12);
}
body.vocab-hub-unit1 .vocab-flash-inner.is-flipped {
  transform: rotateY(180deg);
}
body.vocab-hub-unit1 .vocab-flash-front,
body.vocab-hub-unit1 .vocab-flash-back {
  backface-visibility: hidden;
}
body.vocab-hub-unit1 .vocab-flash-back {
  position: absolute;
  inset: 0;
  padding: var(--space-6) var(--space-5);
  transform: rotateY(180deg);
  overflow-y: auto;
  display: flex;
  flex-direction: column;
  justify-content: center;
}
body.vocab-hub-unit1 .vocab-flash-front {
  display: flex;
  flex-direction: column;
  justify-content: center;
  min-height: 160px;
}
body.vocab-hub-unit1 .vocab-flash-label {
  margin: 0 0 var(--space-2);
  font-size: 0.72rem;
  font-weight: 800;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--orange-dark);
}
body.vocab-hub-unit1 .vocab-flash-term {
  margin: 0;
  font-size: clamp(1.35rem, 4vw, 1.75rem);
  font-weight: 800;
  color: var(--navy);
  text-align: center;
  line-height: 1.2;
}
body.vocab-hub-unit1 .vocab-flash-hint {
  margin: var(--space-4) 0 0;
  text-align: center;
  font-size: 0.88rem;
  color: var(--muted);
}
body.vocab-hub-unit1 .vocab-flash-def,
body.vocab-hub-unit1 .vocab-flash-ex {
  margin: 0 0 var(--space-3);
  font-size: 0.95rem;
  line-height: 1.55;
  color: var(--text);
}
body.vocab-hub-unit1 .vocab-rate-row {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: var(--space-2);
  margin-top: var(--space-4);
}
body.vocab-hub-unit1 .vocab-rate {
  min-height: 48px;
  padding: 10px var(--space-2);
  border-radius: 12px;
  border: 2px solid transparent;
  font-size: 0.88rem;
  font-weight: 800;
  cursor: pointer;
  font-family: inherit;
  transition: transform 0.1s ease, box-shadow 0.12s ease;
}
body.vocab-hub-unit1 .vocab-rate:hover {
  transform: translateY(-1px);
}
body.vocab-hub-unit1 .vocab-rate-got {
  background: #ecfdf5;
  border-color: #34d399;
  color: #065f46;
}
body.vocab-hub-unit1 .vocab-rate-unsure {
  background: #fffbeb;
  border-color: #fbbf24;
  color: #92400e;
}
body.vocab-hub-unit1 .vocab-rate-nope {
  background: #fef2f2;
  border-color: #f87171;
  color: #991b1b;
}
body.vocab-hub-unit1 .vocab-flash-start {
  text-align: center;
  padding: var(--space-6) var(--space-4);
  border: 1px dashed var(--line);
  border-radius: 18px;
  background: var(--bg);
}
body.vocab-hub-unit1 .vocab-flash-start-lead {
  margin: 0 0 var(--space-4);
  color: var(--text);
  line-height: 1.55;
}
body.vocab-hub-unit1 .vocab-flash-start-actions {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-2);
  justify-content: center;
}
body.vocab-hub-unit1 .vocab-summary-stats {
  list-style: none;
  margin: var(--space-3) 0;
  padding: 0;
  display: grid;
  gap: var(--space-2);
}
body.vocab-hub-unit1 .vocab-mastery-counts {
  display: grid;
  gap: var(--space-2);
  margin-bottom: var(--space-3);
}
body.vocab-hub-unit1 .vocab-mastery-line {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin: 0;
  font-size: 0.88rem;
  color: var(--text);
}
body.vocab-hub-unit1 .vocab-mastery-line strong {
  font-size: 1rem;
  color: var(--navy);
}
body.vocab-hub-unit1 .vocab-mastery-got span { color: #059669; font-weight: 700; }
body.vocab-hub-unit1 .vocab-mastery-unsure span { color: #d97706; font-weight: 700; }
body.vocab-hub-unit1 .vocab-mastery-nope span { color: #dc2626; font-weight: 700; }
body.vocab-hub-unit1 .vocab-mastery-total {
  margin: var(--space-2) 0 0;
  padding-top: var(--space-2);
  border-top: 1px solid var(--line);
  font-size: 0.88rem;
  color: var(--muted);
}
body.vocab-hub-unit1 .vocab-topic-breakdown {
  list-style: none;
  margin: 0 0 var(--space-3);
  padding: 0;
  display: grid;
  gap: 10px;
}
body.vocab-hub-unit1 .vocab-topic-row {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(0, 72px) 40px;
  gap: var(--space-2);
  align-items: center;
  font-size: 0.78rem;
}
body.vocab-hub-unit1 .vocab-topic-row.is-weakest .vocab-topic-name {
  font-weight: 800;
}
body.vocab-hub-unit1 .vocab-topic-bar {
  display: block;
  height: 8px;
  border-radius: var(--radius-pill);
  background: var(--line);
  overflow: hidden;
}
body.vocab-hub-unit1 .vocab-topic-bar span {
  display: block;
  height: 100%;
  background: linear-gradient(90deg, var(--navy), var(--blue));
  border-radius: var(--radius-pill);
}
body.vocab-hub-unit1 .vocab-topic-score {
  text-align: right;
  font-weight: 700;
  color: var(--navy);
}
body.vocab-hub-unit1 .vocab-mastery-actions {
  margin-top: var(--space-3);
}
body.vocab-hub-unit1 .vocab-mastery-actions .hub-btn,
body.vocab-hub-unit1 #vocab-open-weak {
  width: 100%;
  justify-content: center;
}
body.vocab-hub-unit1 .vocab-weak-btn {
  margin-bottom: var(--space-2);
}

/* Content figures in study-hub main column and hero */
body.study-hub .hub-content-figure {
  margin: var(--space-5) 0;
  text-align: center;
}
body.study-hub .hub-content-figure picture,
body.study-hub .hub-content-figure img {
  display: block;
  max-width: min(100%, 716px);
  width: 100%;
  height: auto;
  margin: 0 auto;
  border-radius: 14px;
}
body.study-hub .hub-main .hub-content-figure img {
  border: 1px solid var(--line);
  box-shadow: 0 8px 24px rgba(10, 15, 90, 0.08);
}
body.study-hub .hub-chart-wrap.hub-content-figure img {
  border: 1px solid rgba(255, 255, 255, 0.22);
  box-shadow: none;
}
body.study-hub .hub-content-figure figcaption {
  margin: var(--space-2) auto 0;
  max-width: min(100%, 716px);
  font-size: 0.84rem;
  text-align: center;
  line-height: 1.45;
  color: var(--muted);
}
body.study-hub .hub-hero .hub-chart-wrap.hub-content-figure figcaption {
  color: rgba(255, 255, 255, 0.92);
  font-weight: 700;
  text-shadow: 0 1px 3px rgba(0, 0, 0, 0.42);
}

body.study-hub .hub-main .hub-chart-wrap.hub-content-figure figcaption {
  color: var(--muted);
  font-weight: 500;
  text-shadow: none;
}

/* Flashcards + dynamic MCQ blocks (population pyramids / unit hub pattern) */
body.study-hub .flash-ui,
body.study-hub .quiz-ui {
  margin-top: var(--space-4);
  padding: 22px;
  border: 1px solid #eef2ff;
  border-radius: 22px;
  background: #fbfcff;
  box-shadow: 0 4px 14px rgba(10, 15, 90, 0.04);
}

body.study-hub .flash-top,
body.study-hub .quiz-top {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 10px;
  margin-bottom: 14px;
  font-size: 0.88rem;
  color: #4a5276;
}

body.study-hub .flash-top strong,
body.study-hub .quiz-top strong {
  color: var(--navy);
  font-size: 0.95rem;
}

body.study-hub .flash-top .tag,
body.study-hub .quiz-top .tag {
  padding: 5px 12px;
  border-radius: 999px;
  background: #eef2ff;
  color: #4a5276;
  font-size: 0.74rem;
  font-weight: 800;
}

body.study-hub .flash-card-wrap {
  position: relative;
  width: 100%;
}

body.study-hub .flash-fullscreen-btn {
  position: absolute;
  top: 12px;
  right: 12px;
  z-index: 8;
  width: 40px;
  height: 40px;
  min-height: 40px;
  padding: 0;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border: 1px solid #e0e7ff;
  border-radius: 999px;
  background: #ffffff;
  color: var(--navy);
  font-size: 1rem;
  font-weight: 700;
  line-height: 1;
  cursor: pointer;
  box-shadow: 0 4px 12px rgba(10, 15, 90, 0.1);
  transition: background 0.15s ease, border-color 0.15s ease, transform 0.12s ease;
}

body.study-hub .flash-fullscreen-btn:hover {
  border-color: var(--navy);
  background: var(--blue-light);
}

body.study-hub .flash-card-wrap.is-fullscreen {
  position: fixed !important;
  inset: 0;
  z-index: 1200;
  display: flex !important;
  align-items: center;
  justify-content: center;
  padding: clamp(16px, 3vw, 32px);
  background: rgba(7, 11, 67, 0.96);
  box-sizing: border-box;
}

body.study-hub .flash-card-wrap.is-fullscreen .flash-card {
  width: min(920px, 100%);
  max-height: min(78vh, 640px);
  min-height: min(60vh, 480px);
  padding: 56px 100px 32px 32px;
}

body.study-hub .flash-card-wrap.is-fullscreen .flash-fullscreen-btn {
  top: 16px;
  right: 16px;
}

body.study-hub .flash-card-wrap.is-fullscreen .flash-next-arrow {
  right: 24px;
}

body.study-hub .flash-card {
  min-height: 280px;
  width: 100%;
  padding: 48px 100px 28px 24px;
  border: 2px solid #e0e7ff;
  border-radius: 18px;
  background: linear-gradient(160deg, #ffffff 0%, #f8faff 100%);
  box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.9);
  cursor: pointer;
  transition: border-color 0.15s ease, box-shadow 0.15s ease;
}

body.study-hub .flash-card:hover {
  border-color: var(--navy);
  box-shadow: 0 8px 24px rgba(10, 15, 90, 0.08);
}

body.study-hub .flash-card .label {
  margin-bottom: 10px;
  color: #f59e0b;
  font-size: 0.78rem;
  font-weight: 900;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

body.study-hub .flash-card .term {
  color: var(--navy);
  font-size: clamp(1.5rem, 3vw, 2rem);
  font-weight: 900;
  letter-spacing: -0.03em;
}

body.study-hub .flash-card .definition {
  max-width: 52rem;
  color: #1f2545;
  font-size: 1.15rem;
  line-height: 1.5;
}

body.study-hub .flash-card-wrap > .flash-next-arrow,
body.study-hub .flash-card-wrap .flash-next-arrow {
  position: absolute;
  top: 50%;
  right: 18px;
  left: auto;
  bottom: auto;
  z-index: 5;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 68px;
  height: 68px;
  margin: 0;
  padding: 0;
  border: 2px solid #e0e7ff;
  border-radius: 999px;
  background: #ffffff;
  color: var(--navy);
  font-size: 1.92rem;
  font-weight: 800;
  line-height: 1;
  cursor: pointer;
  box-shadow: 0 6px 14px rgba(10, 15, 90, 0.1);
  transform: translateY(-50%);
  transition: transform 0.15s ease, background-color 0.15s ease, border-color 0.15s ease;
}

body.study-hub .flash-card-wrap .flash-next-arrow:hover:not(:disabled) {
  border-color: var(--navy);
  background: var(--navy);
  color: #ffffff;
  transform: translateY(-50%) translateX(3px);
}

body.study-hub .flash-card-wrap .flash-next-arrow:disabled {
  opacity: 0.4;
  cursor: not-allowed;
  transform: translateY(-50%);
}

body.study-hub .score-card {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 12px;
  margin: var(--space-4) 0;
}

body.study-hub .score-card .metric {
  padding: 16px;
  border: 1px solid #e2e8f0;
  border-radius: 16px;
  background: linear-gradient(180deg, #ffffff 0%, #f8faff 100%);
  text-align: center;
}

body.study-hub .score-card .metric strong {
  display: block;
  margin-bottom: 4px;
  color: var(--navy);
  font-size: 1.6rem;
}

body.study-hub .score-card .metric span {
  display: block;
  color: #64748b;
  font-size: 0.78rem;
  font-weight: 700;
  letter-spacing: 0.04em;
  text-transform: uppercase;
}

body.study-hub .question-box {
  padding: 20px;
  border: 1px solid #eef2ff;
  border-radius: 18px;
  background: #ffffff;
}

body.study-hub .question-box .q-head {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  flex-wrap: wrap;
  gap: 10px;
  margin-bottom: 14px;
}

body.study-hub .question-box .q-text {
  flex: 1 1 220px;
  margin: 0;
  color: var(--navy);
  font-size: 1rem;
  line-height: 1.55;
}

body.study-hub .question-box .q-difficulty {
  flex-shrink: 0;
  padding: 4px 10px;
  border-radius: 999px;
  font-size: 0.72rem;
  font-weight: 800;
  letter-spacing: 0.04em;
  text-transform: uppercase;
}

body.study-hub .question-box .q-difficulty-easy {
  background: #ecfdf5;
  color: #166534;
}

body.study-hub .question-box .q-difficulty-medium {
  background: #fff7ed;
  color: #9a3412;
}

body.study-hub .question-box .q-difficulty-hard {
  background: #fef2f2;
  color: #991b1b;
}

body.study-hub .question-box .option {
  display: block;
  width: 100%;
  margin-top: 10px;
  padding: 13px 16px;
  border: 1.5px solid #eef2ff;
  border-radius: 14px;
  background: #ffffff;
  color: #1f2545;
  font-family: inherit;
  font-size: 0.96rem;
  font-weight: 500;
  line-height: 1.45;
  text-align: left;
  cursor: pointer;
  transition: border-color 0.15s ease, background 0.15s ease;
}

body.study-hub .question-box .option:hover:not(:disabled) {
  border-color: var(--navy);
  background: #f8faff;
}

body.study-hub .question-box .option.correct {
  border-color: #16a34a;
  background: #dcfce7;
  color: #14532d;
  font-weight: 700;
}

body.study-hub .question-box .option.wrong {
  border-color: #dc2626;
  background: #fee2e2;
  color: #7f1d1d;
  font-weight: 700;
}

body.study-hub .question-box .explanation {
  display: none;
  margin-top: 14px;
  padding: 14px 16px;
  border: 1px solid #e0e7ff;
  border-radius: 12px;
  background: #f8faff;
  color: #1f2545;
  font-size: 0.95rem;
  line-height: 1.55;
}

body.study-hub .controls {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 16px;
}

body.study-hub .controls .btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 44px;
  padding: 12px 20px;
  border: 2px solid var(--line);
  border-radius: 12px;
  background: var(--card);
  color: var(--navy);
  font-family: inherit;
  font-size: 0.9rem;
  font-weight: 800;
  cursor: pointer;
  transition: border-color 0.12s ease, background 0.12s ease, transform 0.12s ease;
}

body.study-hub .controls .btn:hover:not(:disabled) {
  border-color: var(--blue);
  background: var(--blue-light);
}

body.study-hub .controls .btn.btn-blue {
  border-color: #c7d2fe;
  background: #eef2ff;
  color: var(--navy);
}

body.study-hub .controls .btn:disabled {
  opacity: 0.55;
  cursor: not-allowed;
}

body.study-hub .full-ad {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 10px;
  min-height: 245px;
  width: 100%;
  padding: 24px;
  border: 2px dashed #cbd5e1;
  border-radius: 22px;
  background: linear-gradient(135deg, #f8fafc, #eef2ff);
  color: #475467;
  text-align: center;
}

body.study-hub .full-ad strong {
  display: block;
  margin-bottom: 8px;
  color: var(--navy);
  font-size: 1.25rem;
}

body.study-hub .full-ad .countdown {
  color: #f59e0b;
  font-weight: 900;
}

@media (max-width: 980px) {
  body.study-hub .score-card {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (max-width: 640px) {
  body.study-hub .flash-card {
    min-height: 245px;
    padding: 20px 88px 20px 18px;
  }

  body.study-hub .flash-card-wrap .flash-next-arrow {
    width: 58px;
    height: 58px;
    right: 12px;
    font-size: 1.65rem;
  }

  body.study-hub .controls {
    display: grid;
    grid-template-columns: 1fr;
  }

  body.study-hub .controls .btn {
    width: 100%;
  }

  body.study-hub .score-card {
    grid-template-columns: 1fr;
  }
}

body.diffusion-learning-hub .hub-diffusion-hero-art {
  margin: 0;
}

body.diffusion-learning-hub .hub-diffusion-hero-art img {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  margin: 0 auto;
  border-radius: 12px;
}

body.diffusion-learning-hub .hub-main-guide-figure {
  margin: var(--space-4) 0 var(--space-5);
}

/* Diffusion hub — journey strip (population pyramids pattern) */
body.diffusion-learning-hub .hub-journey-h2-wrap,
body.diffusion-learning-hub .journey-strip,
body.diffusion-learning-hub .hub-page-callout {
  max-width: 1180px;
  margin-left: auto;
  margin-right: auto;
  padding-left: var(--space-5);
  padding-right: var(--space-5);
  box-sizing: border-box;
}

body.diffusion-learning-hub .hub-journey-h2-wrap {
  padding-top: var(--space-6);
  padding-bottom: var(--space-2);
}

body.diffusion-learning-hub .hub-journey-h2-wrap h2 {
  margin: 0;
  color: var(--navy);
  font-size: clamp(1.45rem, 2.8vw, 1.95rem);
  font-weight: 800;
  line-height: 1.2;
  letter-spacing: -0.022em;
}

body.diffusion-learning-hub .journey-strip {
  margin: var(--space-4) auto var(--space-5);
  padding: var(--space-6) var(--space-6) var(--space-5);
  border: 1px solid #e2e8f0;
  border-radius: 22px;
  background: #ffffff;
  box-shadow: 0 12px 32px rgba(10, 15, 90, 0.07);
}

body.diffusion-learning-hub .journey-strip .section-eyebrow {
  display: block;
  font-size: 0.74rem;
  font-weight: 800;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: #f59e0b;
  margin-bottom: 8px;
}

body.diffusion-learning-hub .journey-strip .roadmap-title {
  margin: 0 0 var(--space-2);
  color: var(--navy);
  font-size: clamp(1.25rem, 2.2vw, 1.55rem);
  font-weight: 800;
}

body.diffusion-learning-hub .journey-strip .roadmap-subtitle,
body.diffusion-learning-hub .journey-strip .roadmap-caption {
  margin: 0;
  color: #4a5276;
  font-size: 0.95rem;
  line-height: 1.55;
}

body.diffusion-learning-hub .journey-strip-grid {
  display: grid;
  grid-template-columns: repeat(6, minmax(0, 1fr));
  gap: 12px;
  margin-top: var(--space-4);
}

body.diffusion-learning-hub .journey-chip {
  display: flex;
  flex-direction: column;
  gap: 8px;
  padding: 14px 12px;
  border-radius: 16px;
  border: 2px solid #e2e8f0;
  background: #fbfcff;
  text-decoration: none;
  color: var(--navy);
  min-height: 44px;
  transition: border-color 0.15s ease, transform 0.15s ease, box-shadow 0.15s ease;
}

body.diffusion-learning-hub .journey-chip:hover,
body.diffusion-learning-hub .journey-chip:focus-visible {
  border-color: var(--blue);
  transform: translateY(-3px);
  box-shadow: 0 10px 24px rgba(47, 102, 208, 0.12);
  color: var(--navy);
}

body.diffusion-learning-hub .journey-chip.is-here {
  border-color: #f59e0b;
  background: linear-gradient(145deg, #fffbeb 0%, #ffffff 55%);
  box-shadow: 0 8px 20px rgba(245, 158, 11, 0.15);
}

body.diffusion-learning-hub .journey-chip em {
  font-style: normal;
  font-size: 0.66rem;
  font-weight: 800;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: #b45309;
}

body.diffusion-learning-hub .journey-chip strong {
  font-size: 0.88rem;
  line-height: 1.3;
}

body.diffusion-learning-hub .journey-chip span {
  font-size: 0.78rem;
  color: #4a5276;
  line-height: 1.4;
  font-weight: 500;
}

body.diffusion-learning-hub .roadmap-caption {
  margin-top: var(--space-4);
}

body.diffusion-learning-hub .hub-page-callout {
  margin-bottom: var(--space-5);
  padding: 14px 18px 16px;
  background: linear-gradient(90deg, #eef2ff 0%, #fff7ed 55%, #fffbeb 100%);
  border: 1px solid #c7d2fe;
  border-radius: 16px;
  box-shadow: 0 4px 16px rgba(10, 15, 90, 0.04);
}

body.diffusion-learning-hub .hub-page-callout p {
  margin: 0 0 8px;
  color: #1f2545;
  font-size: 0.95rem;
  line-height: 1.55;
}

body.diffusion-learning-hub .hub-page-callout p:last-child {
  margin-bottom: 0;
}

body.diffusion-learning-hub .hub-page-callout a {
  font-weight: 800;
  color: #0a0f5a;
}

body.diffusion-learning-hub .hub-page-callout-icon {
  margin-right: 4px;
}

@media (max-width: 1024px) {
  body.diffusion-learning-hub .journey-strip-grid {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
}

@media (max-width: 700px) {
  body.diffusion-learning-hub .journey-strip-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (max-width: 640px) {
  body.diffusion-learning-hub .journey-strip-grid {
    grid-template-columns: 1fr;
  }

  body.diffusion-learning-hub .journey-strip,
  body.diffusion-learning-hub .hub-journey-h2-wrap,
  body.diffusion-learning-hub .hub-page-callout {
    padding-left: 18px;
    padding-right: 18px;
  }
}

@media (max-width: 700px) {
  body.vocab-hub-unit1 .vocab-table-tools {
    grid-template-columns: 1fr;
  }
  body.vocab-hub-unit1 .vocab-rate-row {
    grid-template-columns: 1fr;
  }
}

/* Relocation diffusion spoke — section polish + cluster chrome */
body.relocation-diffusion-spoke.diffusion-learning-hub .hub-journey-h2-wrap,
body.relocation-diffusion-spoke.diffusion-learning-hub .journey-strip,
body.relocation-diffusion-spoke.diffusion-learning-hub .hub-page-callout {
  max-width: 1180px;
  margin-left: auto;
  margin-right: auto;
  padding-left: var(--space-5);
  padding-right: var(--space-5);
  box-sizing: border-box;
}

body.relocation-diffusion-spoke .hub-main .hub-section {
  position: relative;
  border-radius: 22px;
  overflow: hidden;
}

body.relocation-diffusion-spoke .hub-main .hub-section::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 5px;
  height: 100%;
  background: var(--blue);
  border-radius: 22px 0 0 22px;
}

body.relocation-diffusion-spoke .hub-section--answer::before {
  background: linear-gradient(180deg, #f59e0b 0%, #ea580c 100%);
}

body.relocation-diffusion-spoke .hub-section--definition::before {
  background: #3b82f6;
}

body.relocation-diffusion-spoke .hub-section--landscape::before {
  background: #0ea5e9;
}

body.relocation-diffusion-spoke .hub-section--process::before {
  background: #6366f1;
}

body.relocation-diffusion-spoke .hub-section--migration::before {
  background: #8b5cf6;
}

body.relocation-diffusion-spoke .hub-section--examples::before {
  background: #10b981;
}

body.relocation-diffusion-spoke .hub-section--compare::before {
  background: #f59e0b;
}

body.relocation-diffusion-spoke .hub-section--exam::before {
  background: #ef4444;
}

body.relocation-diffusion-spoke .hub-section--mistakes::before {
  background: #b45309;
}

body.relocation-diffusion-spoke .hub-section--flash::before,
body.relocation-diffusion-spoke .hub-section--practice::before {
  background: var(--navy);
}

body.relocation-diffusion-spoke .hub-section--frq::before,
body.relocation-diffusion-spoke .hub-section--terms::before {
  background: #64748b;
}

body.relocation-diffusion-spoke .hub-section--faq::before {
  background: #f59e0b;
}

body.relocation-diffusion-spoke .hub-section--path::before,
body.relocation-diffusion-spoke .hub-section--next::before {
  background: var(--blue);
}

body.relocation-diffusion-spoke .section-lead {
  margin: 0 0 1em;
  color: #4a5276;
  font-size: 0.98rem;
  line-height: 1.6;
}

body.relocation-diffusion-spoke .relocation-tip-card {
  display: grid;
  gap: 10px;
  margin: var(--space-4) 0;
  padding: 16px 18px;
  border-radius: 16px;
  border: 1px solid #fde68a;
  background: linear-gradient(135deg, #fffbeb 0%, #ffffff 70%);
}

body.relocation-diffusion-spoke .relocation-tip-card p {
  margin: 0;
  color: #1f2545;
  font-size: 0.94rem;
  line-height: 1.55;
}

body.relocation-diffusion-spoke .relocation-tip-card strong {
  color: var(--navy);
}

body.relocation-diffusion-spoke .relocation-definition-pill {
  margin: var(--space-3) 0 var(--space-4);
  padding: 18px 20px;
  border-radius: 16px;
  border: 2px solid #c7d2fe;
  background: linear-gradient(135deg, #eef2ff 0%, #ffffff 55%);
  color: var(--navy);
  font-size: 1.05rem;
  line-height: 1.5;
  text-align: center;
}

body.relocation-diffusion-spoke .relocation-rule-callout {
  margin: var(--space-4) 0 0;
  padding: 14px 18px;
  border-radius: 14px;
  border: 1px solid #fed7aa;
  background: #fff7ed;
  color: #1f2545;
  font-size: 0.95rem;
  line-height: 1.55;
}

body.relocation-diffusion-spoke .relocation-rule-callout strong {
  color: #9a3412;
}

body.relocation-diffusion-spoke .relocation-process-table table.data tbody tr td:first-child {
  font-weight: 800;
  color: var(--navy);
  white-space: nowrap;
  width: 28%;
}

body.relocation-diffusion-spoke .relocation-process-table table.data tbody tr:nth-child(odd) td {
  background: #f8faff;
}

body.relocation-diffusion-spoke .relocation-compare-table table.data th:nth-child(2),
body.relocation-diffusion-spoke .relocation-compare-table table.data td:nth-child(2) {
  background: #eff6ff;
}

body.relocation-diffusion-spoke .relocation-compare-table table.data th:nth-child(3),
body.relocation-diffusion-spoke .relocation-compare-table table.data td:nth-child(3) {
  background: #fff7ed;
}

body.relocation-diffusion-spoke .relocation-checklist {
  margin: var(--space-4) 0 0;
  padding: 18px 20px 18px 2.5rem;
  border-radius: 16px;
  border: 1px solid #e2e8f0;
  background: #f8faff;
  list-style: none;
  counter-reset: relocation-step;
}

body.relocation-diffusion-spoke .relocation-checklist li {
  position: relative;
  margin: 0 0 12px;
  padding-left: 8px;
  color: #1f2545;
  font-size: 0.95rem;
  line-height: 1.55;
  counter-increment: relocation-step;
}

body.relocation-diffusion-spoke .relocation-checklist li:last-child {
  margin-bottom: 0;
}

body.relocation-diffusion-spoke .relocation-checklist li::before {
  content: counter(relocation-step);
  position: absolute;
  left: -2.15rem;
  top: 0;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 1.65rem;
  height: 1.65rem;
  border-radius: 999px;
  background: var(--navy);
  color: #ffffff;
  font-size: 0.78rem;
  font-weight: 800;
}

body.relocation-diffusion-spoke .relocation-mistake-grid .concept-card {
  height: 100%;
  padding: 18px;
  border-radius: 18px;
  border: 1px solid #e2e8f0;
  background: linear-gradient(180deg, #ffffff 0%, #f8faff 100%);
  box-shadow: 0 6px 18px rgba(10, 15, 90, 0.05);
}

body.relocation-diffusion-spoke .relocation-mistake-grid .concept-card h4 {
  margin: 0 0 10px;
  color: var(--navy);
  font-size: 1rem;
  line-height: 1.35;
}

body.relocation-diffusion-spoke .relocation-mistake-grid .concept-card p {
  margin: 0;
  font-size: 0.9rem;
  line-height: 1.55;
}

body.relocation-diffusion-spoke .exam-tip-callout {
  margin-top: var(--space-4);
  padding: 16px 18px;
  border-radius: 16px;
  border: 1px solid #86efac;
  background: linear-gradient(135deg, #ecfdf5 0%, #ffffff 70%);
  color: #1f2545;
}

body.relocation-diffusion-spoke .exam-tip-callout strong {
  color: #065f46;
}

body.relocation-diffusion-spoke .hub-section--flash,
body.relocation-diffusion-spoke .hub-section--practice {
  background: linear-gradient(180deg, #ffffff 0%, #f8faff 100%);
}

body.relocation-diffusion-spoke .hub-section.conversion-box {
  background: linear-gradient(135deg, #0a0f5a 0%, #1c2580 55%, #243091 100%);
  border-color: rgba(255, 255, 255, 0.12);
}

body.relocation-diffusion-spoke .hub-section.conversion-box h2,
body.relocation-diffusion-spoke .hub-section.conversion-box p,
body.relocation-diffusion-spoke .hub-section.conversion-box li {
  color: rgba(255, 255, 255, 0.92);
}

body.relocation-diffusion-spoke .hub-section.conversion-box .section-eyebrow {
  color: #ffd37a;
}

body.relocation-diffusion-spoke .hub-section--path .score-path-card {
  border: 1px solid #e2e8f0;
  background: #ffffff;
  box-shadow: 0 4px 14px rgba(10, 15, 90, 0.04);
}

body.relocation-diffusion-spoke .hub-section--next .related-grid a {
  border-width: 2px;
  background: #ffffff;
}

body.relocation-diffusion-spoke .hub-section--next .related-grid a:hover {
  border-color: var(--orange);
  background: #fffbeb;
}

body.relocation-diffusion-spoke .flash-card-inner {
  position: relative;
  height: 100%;
  min-height: 200px;
}

body.relocation-diffusion-spoke .flash-card-tag {
  position: absolute;
  top: 0;
  left: 0;
}

body.relocation-diffusion-spoke .flash-card-body {
  padding-top: 28px;
}

body.relocation-diffusion-spoke .hub-frq-card {
  border-left: 4px solid var(--navy);
}

@media (max-width: 700px) {
  body.relocation-diffusion-spoke .relocation-mistake-grid {
    grid-template-columns: 1fr;
  }
}