/* ══════════════════════════════════════
   LESSONS — Course & Lesson Pages
   Extends shared.css design system
══════════════════════════════════════ */

/* ── Breadcrumb ── */
.breadcrumb {
  padding-top: 96px;
  padding-bottom: 0;
  font-size: 13px;
  color: var(--color-text-muted);
  letter-spacing: 0.01em;
  max-width: 1100px;
  margin: 0 auto;
}

.breadcrumb a {
  color: var(--color-text-muted);
  text-decoration: none;
  transition: color 0.2s ease;
}

.breadcrumb a:hover {
  color: var(--color-text);
}

.breadcrumb-sep {
  margin: 0 8px;
  opacity: 0.35;
}

.breadcrumb-current {
  color: var(--color-text);
  font-weight: 500;
}

/* ══════════════════════════════════════
   COURSE OVERVIEW PAGE
══════════════════════════════════════ */

/* ── Course Hero ── */
/* ── Hero wrap (full-width dark bg) ── */
.course-hero-wrap {
  background: var(--color-bg-dark);
  position: relative;
  overflow: hidden;
}

.course-hero-glow {
  position: absolute;
  inset: 0;
  background: radial-gradient(ellipse 80% 100% at 75% 30%, rgba(232, 116, 32, 0.14) 0%, transparent 55%),
              radial-gradient(ellipse 60% 90% at 20% 80%, rgba(44, 70, 133, 0.12) 0%, transparent 50%);
  pointer-events: none;
}

.course-hero-grain {
  position: absolute;
  inset: 0;
  opacity: 0.35;
  background-image: url("data:image/svg+xml,%3Csvg viewBox='0 0 256 256' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.85' numOctaves='4' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)' opacity='0.5'/%3E%3C/svg%3E");
  background-repeat: repeat;
  background-size: 180px 180px;
  pointer-events: none;
}

.course-hero {
  padding: 56px var(--pad-section) 64px;
  max-width: calc(1100px + var(--pad-section) * 2);
  margin: 0 auto;
  position: relative;
  z-index: 1;
}

.course-hero-eyebrow {
  font-size: 11px;
  font-weight: 600;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--color-orange);
  margin-bottom: 20px;
  display: flex;
  align-items: center;
  gap: 10px;
}

.course-hero-eyebrow::before {
  content: '';
  width: 24px;
  height: 1.5px;
  background: var(--color-orange);
  flex-shrink: 0;
}

.course-hero-title {
  font-family: var(--font-sans);
  font-size: clamp(36px, 4.5vw, 56px);
  font-weight: 600;
  color: #fff;
  line-height: 1.08;
  letter-spacing: -0.035em;
  margin-bottom: 20px;
  max-width: 640px;
}

.course-hero-title em {
  font-family: var(--font-serif);
  font-style: italic;
  font-weight: 400;
  color: rgba(255, 255, 255, 0.55);
}

.course-hero-desc {
  font-family: var(--font-serif);
  font-size: clamp(16px, 1.3vw, 19px);
  color: rgba(255, 255, 255, 0.6);
  line-height: 1.7;
  max-width: 520px;
  margin-bottom: 36px;
}

.course-hero-actions {
  display: flex;
  align-items: center;
  gap: 16px;
  flex-wrap: wrap;
}

/* Notify button override for dark hero */
.course-hero-wrap .course-notify-btn {
  border-color: rgba(255, 255, 255, 0.15);
  color: rgba(255, 255, 255, 0.6);
}

.course-hero-wrap .course-notify-btn:hover {
  border-color: var(--color-orange);
  color: var(--color-orange);
}

.course-enrol-btn {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 14px 32px;
  border-radius: var(--radius-pill);
  border: none;
  background: linear-gradient(135deg, var(--color-orange) 0%, var(--color-orange-dark) 40%, var(--color-blue) 100%);
  color: #fff;
  font-size: 15px;
  font-weight: 600;
  font-family: var(--font-sans);
  text-decoration: none;
  letter-spacing: 0.01em;
  position: relative;
  overflow: hidden;
  transition: transform 0.2s ease, box-shadow 0.3s ease;
  box-shadow: 0 4px 20px rgba(232, 116, 32, 0.25), 0 2px 8px rgba(44, 70, 133, 0.15);
  cursor: pointer;
}

.course-enrol-btn::before {
  content: '';
  position: absolute;
  inset: 0;
  border-radius: var(--radius-pill);
  background: linear-gradient(135deg, rgba(255,255,255,0.3) 0%, rgba(255,255,255,0.05) 40%, rgba(255,255,255,0.12) 100%);
  pointer-events: none;
}

.course-enrol-btn:hover {
  transform: scale(1.03);
  box-shadow: 0 6px 28px rgba(232, 116, 32, 0.35), 0 3px 12px rgba(44, 70, 133, 0.2);
}

.course-enrol-btn svg {
  width: 14px;
  height: 14px;
  transition: transform 0.3s ease;
}

.course-enrol-btn:hover svg {
  transform: translateX(3px);
}

.course-free-badge {
  font-size: 11px;
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--color-orange);
  background: rgba(232, 116, 32, 0.08);
  padding: 6px 14px;
  border-radius: 20px;
}


/* ── Stats Bar ── */
/* ── About Section ── */
.course-about {
  max-width: 1100px;
  margin: 0 auto;
  padding: 56px 0 40px;
}

.course-about-title {
  font-family: var(--font-sans);
  font-size: clamp(24px, 2.5vw, 32px);
  font-weight: 500;
  color: var(--color-text);
  letter-spacing: -0.02em;
  margin-bottom: 24px;
}

.course-about-body {
  font-family: var(--font-serif);
  font-size: clamp(15px, 1.2vw, 18px);
  color: var(--color-text-mid);
  line-height: 1.75;
  max-width: 680px;
  margin-bottom: 40px;
}

.course-about h3 {
  font-family: var(--font-sans);
  font-size: 16px;
  font-weight: 600;
  color: var(--color-text);
  letter-spacing: -0.01em;
  margin-bottom: 16px;
  margin-top: 32px;
}

.course-about ul {
  list-style: none;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.course-about li {
  font-size: 15px;
  color: var(--color-text-mid);
  line-height: 1.6;
  padding-left: 24px;
  position: relative;
}

.course-about li::before {
  content: '';
  position: absolute;
  left: 0;
  top: 9px;
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--color-orange);
}

/* ── Course Sections ── */
.course-sections {
  max-width: 1100px;
  margin: 0 auto;
  padding: 32px 0 48px;
}

.course-sections-title {
  font-family: var(--font-sans);
  font-size: clamp(24px, 2.5vw, 32px);
  font-weight: 500;
  color: var(--color-text);
  letter-spacing: -0.02em;
  margin-bottom: 36px;
}

/* Old individual section cards (kept for backwards compat) */
.course-section-card {
  display: grid;
  grid-template-columns: 64px 1fr auto;
  gap: 24px;
  align-items: start;
  padding: 32px;
  background: rgba(0, 0, 0, 0.02);
  border: 1px solid rgba(0, 0, 0, 0.05);
  border-radius: var(--radius-card);
  margin-bottom: 16px;
  text-decoration: none;
  color: inherit;
  transition: border-color 0.3s ease, box-shadow 0.3s ease, transform 0.2s ease;
  position: relative;
  overflow: hidden;
}

.course-section-card:hover {
  border-color: rgba(0, 0, 0, 0.12);
  box-shadow: 0 4px 24px rgba(0, 0, 0, 0.06);
  transform: translateY(-2px);
}

.course-section-num {
  font-family: var(--font-sans);
  font-size: 32px;
  font-weight: 700;
  color: rgba(0, 0, 0, 0.08);
  line-height: 1;
  letter-spacing: -0.02em;
}

.course-section-content h3 {
  font-family: var(--font-sans);
  font-size: 18px;
  font-weight: 600;
  color: var(--color-text);
  letter-spacing: -0.01em;
  margin-bottom: 6px;
}

.course-section-content p {
  font-size: 14px;
  color: var(--color-text-muted);
  line-height: 1.5;
}

.course-section-meta {
  display: flex;
  flex-direction: column;
  align-items: flex-end;
  gap: 8px;
}

.course-section-badge {
  font-size: 12px;
  font-weight: 500;
  padding: 4px 12px;
  border-radius: 20px;
  background: rgba(0, 0, 0, 0.05);
  color: var(--color-text-mid);
  white-space: nowrap;
}

.course-section-arrow {
  width: 20px;
  height: 20px;
  color: var(--color-text-muted);
  transition: transform 0.3s ease, color 0.3s ease;
}

.course-section-card:hover .course-section-arrow {
  transform: translateX(4px);
  color: var(--color-orange);
}

/* Accent stripe on left */
.course-section-card::before {
  content: '';
  position: absolute;
  left: 0;
  top: 0;
  bottom: 0;
  width: 4px;
  border-radius: 4px 0 0 4px;
  opacity: 0;
  transition: opacity 0.3s ease;
}

.course-section-card:hover::before {
  opacity: 1;
}

.course-section-card[data-accent="orange"]::before { background: var(--color-orange); }
.course-section-card[data-accent="blue"]::before { background: var(--color-blue-bright); }
.course-section-card[data-accent="purple"]::before { background: var(--color-purple); }

/* ── S3-style Course Sections Card ── */
.course-sections-card {
  background: rgba(0, 0, 0, 0.03);
  border: 1px solid rgba(0, 0, 0, 0.06);
  border-radius: var(--radius-card);
  padding: clamp(28px, 3vw, 40px);
  display: flex;
  flex-direction: column;
  position: relative;
  gap: 24px;
}

.course-sections-card-brand {
  position: absolute;
  top: clamp(20px, 2.5vw, 32px);
  right: clamp(20px, 2.5vw, 32px);
  font-size: 11px;
  font-weight: 500;
  letter-spacing: 0.04em;
  color: var(--color-text-muted);
  font-family: var(--font-sans);
}

.course-sections-card-icon {
  width: 40px;
  height: 40px;
  color: var(--color-text-muted);
}

.course-sections-card-title {
  font-family: var(--font-sans);
  font-size: clamp(18px, 1.6vw, 24px);
  font-weight: 500;
  color: var(--color-text);
  letter-spacing: -0.02em;
}

.course-sections-tiles {
  background: var(--color-text);
  border-radius: 16px;
  overflow: hidden;
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 12px;
  padding: 16px 18px;
}

.course-tile {
  border-radius: var(--radius-small);
  padding: 18px 16px;
  display: flex;
  flex-direction: column;
  justify-content: flex-end;
  min-height: 140px;
  position: relative;
  overflow: hidden;
  text-decoration: none;
  color: inherit;
  cursor: pointer;
  transition: transform 0.2s ease, filter 0.2s ease;
}

.course-tile:hover {
  transform: scale(1.03);
  filter: brightness(1.1);
}

.course-tile-orange {
  background: linear-gradient(135deg, var(--color-orange) 0%, var(--color-orange-burnt) 100%);
}

.course-tile-blue {
  background: linear-gradient(135deg, var(--color-blue-bright) 0%, var(--color-blue-dark) 100%);
}

.course-tile-purple {
  background: linear-gradient(135deg, var(--color-purple) 0%, var(--color-purple-dark) 100%);
}

.course-tile-label {
  font-size: 10px;
  color: rgba(255, 255, 255, 0.65);
  font-weight: 400;
  margin-bottom: 3px;
  line-height: 1.3;
}

.course-tile-name {
  font-size: 12px;
  color: #fff;
  font-weight: 600;
  line-height: 1.35;
}

.course-tile-num {
  position: absolute;
  top: 12px;
  left: 14px;
  font-size: 11px;
  font-weight: 600;
  color: rgba(255, 255, 255, 0.4);
  letter-spacing: 0.02em;
}

.course-tile-badge {
  position: absolute;
  top: 12px;
  right: 12px;
  font-size: 10px;
  padding: 2px 8px;
  border-radius: 6px;
  background: rgba(0, 0, 0, 0.25);
  color: rgba(255, 255, 255, 0.8);
  font-weight: 500;
}

.course-sections-card-desc {
  font-size: clamp(13px, 1vw, 15px);
  color: var(--color-text-muted);
  line-height: 1.6;
  font-weight: 300;
  font-style: italic;
}

/* ── Notify Button (ghost style next to enrol) ── */
.course-notify-btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 14px 28px;
  border-radius: var(--radius-pill);
  border: 1px solid rgba(0, 0, 0, 0.12);
  background: transparent;
  color: var(--color-text-mid);
  font-size: 14px;
  font-weight: 500;
  font-family: var(--font-sans);
  cursor: pointer;
  transition: border-color 0.3s ease, color 0.3s ease, transform 0.2s ease;
}

.course-notify-btn:hover {
  border-color: var(--color-orange);
  color: var(--color-orange);
  transform: scale(1.02);
}

.course-notify-btn svg {
  flex-shrink: 0;
}

/* ── Bottom CTA Bar ── */
.course-bottom-cta {
  max-width: 1100px;
  margin: 0 auto;
  padding: 16px 0 64px;
  text-align: center;
  border-bottom: 1px solid rgba(0, 0, 0, 0.08);
}

.course-bottom-cta-text {
  font-family: var(--font-sans);
  font-size: clamp(18px, 2vw, 24px);
  font-weight: 500;
  color: var(--color-text);
  letter-spacing: -0.02em;
  margin-bottom: 28px;
}

.course-bottom-cta-actions {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 16px;
  flex-wrap: wrap;
}

/* ── FAQ Accordion ── */
.course-faq {
  max-width: 1100px;
  margin: 0 auto;
  padding: 64px 0 80px;
  border-top: 1px solid rgba(0, 0, 0, 0.08);
}

.course-faq-title {
  font-family: var(--font-sans);
  font-size: clamp(24px, 2.5vw, 32px);
  font-weight: 500;
  color: var(--color-text);
  letter-spacing: -0.02em;
  margin-bottom: 32px;
}

.faq-item {
  border-bottom: 1px solid rgba(0, 0, 0, 0.07);
}

.faq-question {
  display: flex;
  align-items: center;
  justify-content: space-between;
  width: 100%;
  padding: 20px 0;
  background: none;
  border: none;
  cursor: pointer;
  font-family: var(--font-sans);
  font-size: 16px;
  font-weight: 500;
  color: var(--color-text);
  text-align: left;
  line-height: 1.4;
  transition: color 0.2s ease;
}

.faq-question:hover {
  color: var(--color-orange);
}

.faq-icon {
  width: 20px;
  height: 20px;
  flex-shrink: 0;
  margin-left: 16px;
  transition: transform 0.3s ease;
  color: var(--color-text-muted);
}

.faq-item.open .faq-icon {
  transform: rotate(45deg);
}

.faq-answer {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.4s ease, padding 0.3s ease;
}

.faq-answer-inner {
  padding-bottom: 20px;
  font-size: 15px;
  color: var(--color-text-mid);
  line-height: 1.7;
  font-family: var(--font-serif);
}

.faq-item.open .faq-answer {
  max-height: 1200px;
}

/* ══════════════════════════════════════
   LESSON 1: BUILDING BLOCKS
══════════════════════════════════════ */

/* ── Responds vs Works Compare Cards ── */
.compare-cards {
  display: flex;
  gap: 16px;
  align-items: stretch;
  margin: 28px 0 36px;
}

.compare-card {
  flex: 1 1 0;
  min-width: 0;
  padding: 24px;
  border-radius: 14px;
  text-align: center;
}

.compare-card-outline {
  border: 2px solid rgba(0, 0, 0, 0.08);
}

.compare-card-accent {
  background: rgba(0, 0, 0, 0.02);
  border: 1px solid rgba(0, 0, 0, 0.06);
  border-left: 5px solid var(--color-orange);
}

.compare-label {
  font-family: var(--font-sans);
  font-size: 11px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--color-text-muted);
  display: block;
  margin-bottom: 10px;
}

.compare-card strong {
  font-family: var(--font-sans);
  font-size: 28px;
  font-weight: 800;
  display: block;
  margin-bottom: 8px;
}

.compare-card-outline strong { color: var(--color-text-muted); }
.compare-card-accent strong { color: var(--color-orange); }

.compare-card p {
  font-size: 13px;
  color: var(--color-text-muted);
  line-height: 1.5;
  margin-bottom: 0;
}

.compare-vs {
  width: 32px;
  height: 32px;
  background: var(--color-orange);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  align-self: center;
  font-family: var(--font-sans);
  font-weight: 800;
  font-size: 11px;
  color: #fff;
  flex-shrink: 0;
}

/* ── "You've Used All Four" List ── */
.used-four-list {
  display: flex;
  flex-direction: column;
  gap: 10px;
  margin: 24px 0 32px;
}

.used-four-item {
  display: flex;
  align-items: center;
  gap: 14px;
  padding: 14px 16px;
  background: rgba(0, 0, 0, 0.02);
  border: 1px solid rgba(0, 0, 0, 0.06);
  border-radius: 10px;
}

.used-four-icon {
  width: 36px;
  height: 36px;
  border-radius: 10px;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
}

.used-four-icon-orange { background: rgba(232, 116, 32, 0.10); color: var(--color-orange); }
.used-four-icon-blue { background: rgba(44, 70, 133, 0.08); color: var(--color-blue-bright); }
.used-four-icon-orange svg { stroke: var(--color-orange); }
.used-four-icon-blue svg { stroke: var(--color-blue-bright); }

.used-four-text {
  font-family: var(--font-sans);
  font-size: 15px;
  font-weight: 600;
  color: var(--color-text);
}

.used-four-label {
  margin-left: auto;
  font-family: var(--font-sans);
  font-size: 11px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--color-text-muted);
}

/* ── Levels Pyramid ── */
.levels-pyramid {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 16px;
  margin: 32px 0 48px;
}

.level-pyramid-row {
  margin: 0 auto;
}

.level-pyramid-row .level-card {
  width: 100%;
}

/* ── Where We Are List (progress steps) ── */
.where-we-are-list {
  display: flex;
  flex-direction: column;
  gap: 0;
  margin: 24px 0 32px;
  position: relative;
}

.where-item {
  display: flex;
  align-items: center;
  gap: 16px;
  padding: 14px 20px 14px 16px;
  position: relative;
  border-bottom: 1px solid rgba(0, 0, 0, 0.06);
}

.where-item:last-child {
  border-bottom: none;
}

.where-check {
  width: 22px;
  height: 22px;
  border-radius: 6px;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
  border: 2px solid rgba(0, 0, 0, 0.12);
  background: transparent;
  transition: all 0.2s ease;
}

.where-check-done {
  background: rgba(0, 0, 0, 0.25);
  border-color: rgba(0, 0, 0, 0.25);
}

.where-check-active {
  background: var(--color-orange);
  border-color: var(--color-orange);
}

.where-item-text {
  display: flex;
  flex-direction: column;
  gap: 2px;
  flex: 1;
  min-width: 0;
}

.where-item-name {
  font-family: var(--font-sans);
  font-weight: 600;
  font-size: 14px;
  color: var(--color-text);
  line-height: 1.3;
}

.where-item-detail {
  font-size: 13px;
  color: var(--color-text-muted);
  line-height: 1.4;
}

.where-item-badge {
  font-family: var(--font-sans);
  font-size: 11px;
  font-weight: 500;
  color: var(--color-text-muted);
  padding: 3px 10px;
  border-radius: 20px;
  background: rgba(0, 0, 0, 0.04);
  white-space: nowrap;
  flex-shrink: 0;
}

/* Active state */
.where-item-active {
  background: rgba(232, 116, 32, 0.04);
  border-bottom-color: rgba(232, 116, 32, 0.12);
}

.where-item-active .where-item-name {
  color: var(--color-orange);
}

.where-item-active .where-item-badge {
  background: rgba(232, 116, 32, 0.1);
  color: var(--color-orange);
  font-weight: 600;
}

/* Done state */
.where-item-done .where-item-name {
  color: var(--color-text-muted);
}

.where-item-done .where-item-detail {
  color: rgba(0, 0, 0, 0.3);
}

/* Linked checklist items */
a.where-item-link,
a.where-item-link:visited,
a.where-item-link:hover,
a.where-item-link:active,
a.where-item-link *,
a.where-item-link:visited *,
a.where-item-link:hover *,
a.where-item-link:active * {
  text-decoration: none !important;
}

a.where-item-link {
  color: inherit;
  transition: background 0.2s ease;
  border-radius: 8px;
  display: flex;
  align-items: center;
}

a.where-item-link:hover {
  background: rgba(0, 0, 0, 0.025);
}

a.where-item-link:hover .where-item-name {
  color: var(--color-text);
}

a.where-item-link:hover .where-item-badge {
  color: var(--color-orange);
  background: rgba(232, 116, 32, 0.08);
}

/* ── Table of Contents ── */
.lesson-content .lesson-toc {
  margin: 32px 0 40px;
  padding: 24px 28px;
  background: rgba(0, 0, 0, 0.018);
  border: 1px solid rgba(0, 0, 0, 0.05);
  border-radius: 14px;
}

.lesson-content .lesson-toc .lesson-toc-label {
  font-family: var(--font-sans);
  font-size: 11px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--color-text-muted);
  margin-bottom: 14px;
}

.lesson-content .lesson-toc .lesson-toc-list {
  list-style: none !important;
  padding: 0 !important;
  margin: 0 !important;
  display: flex;
  flex-direction: column;
  gap: 0px !important;
  counter-reset: toc-counter;
}

.lesson-content .lesson-toc .lesson-toc-list li {
  counter-increment: toc-counter;
  padding: 0 !important;
  position: static;
  font-size: 14px;
  line-height: 1.4;
}

.lesson-content .lesson-toc .lesson-toc-list li::before {
  display: none !important;
  content: none !important;
}

.lesson-content .lesson-toc .lesson-toc-list li a {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 8px 12px;
  margin: 0 -12px;
  border-radius: 8px;
  text-decoration: none !important;
  color: var(--color-text-mid) !important;
  font-family: var(--font-sans);
  font-size: 14px;
  font-weight: 450;
  letter-spacing: -0.01em;
  line-height: 1.4;
  transition: color 0.2s ease, background 0.2s ease;
}

.lesson-content .lesson-toc .lesson-toc-list li a:visited {
  color: var(--color-text-mid) !important;
  text-decoration: none !important;
}

.lesson-content .lesson-toc .lesson-toc-list li a:hover {
  color: var(--color-text) !important;
  background: rgba(0, 0, 0, 0.028);
  text-decoration: none !important;
}

.lesson-content .lesson-toc .lesson-toc-list li a::before {
  content: counter(toc-counter, decimal-leading-zero);
  font-family: var(--font-sans);
  font-size: 11px;
  font-weight: 600;
  color: var(--color-orange);
  opacity: 0.6;
  min-width: 20px;
  flex-shrink: 0;
  position: static;
  width: auto;
  height: auto;
  border-radius: 0;
  background: none;
  transition: opacity 0.2s ease;
}

.lesson-content .lesson-toc .lesson-toc-list li a:hover::before {
  opacity: 1;
}

@media (max-width: 768px) {
  .lesson-content .lesson-toc {
    padding: 20px;
    margin: 24px 0 32px;
  }

  .lesson-content .lesson-toc .lesson-toc-list li a {
    font-size: 13.5px;
    padding: 7px 10px;
    margin: 0 -10px;
  }
}

/* ── AT4D Intro Block ── */
.at4d-intro {
  margin: 24px 0;
  padding: 24px 28px;
  background: rgba(0, 0, 0, 0.02);
  border: 1px solid rgba(0, 0, 0, 0.06);
  border-radius: 14px;
}

.at4d-intro p {
  margin-bottom: 0;
}

/* ── Building Block 2x2 Grid ── */
.bb-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 12px;
  margin: 24px 0 32px;
}

.bb-card {
  display: flex;
  align-items: flex-start;
  gap: 14px;
  padding: 20px;
  background: rgba(0, 0, 0, 0.02);
  border: 1px solid rgba(0, 0, 0, 0.06);
  border-radius: 14px;
  border-left: 4px solid transparent;
  transition: border-color 0.3s ease, box-shadow 0.3s ease;
}

.bb-card[data-accent="orange"] { border-left-color: var(--color-orange); }
.bb-card[data-accent="blue"] { border-left-color: var(--color-blue-bright); }

.bb-card-icon {
  width: 40px;
  height: 40px;
  border-radius: 10px;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
  background: rgba(0, 0, 0, 0.03);
  color: var(--color-text-muted);
}

.bb-card[data-accent="orange"] .bb-card-icon { background: rgba(232, 116, 32, 0.08); color: var(--color-orange); }
.bb-card[data-accent="blue"] .bb-card-icon { background: rgba(44, 70, 133, 0.08); color: var(--color-blue-bright); }

.bb-card-text h3 {
  font-family: var(--font-sans);
  font-size: 15px;
  font-weight: 600;
  color: var(--color-text);
  margin-bottom: 4px;
}

.bb-card-text p {
  font-size: 13px;
  color: var(--color-text-muted);
  line-height: 1.5;
  margin-bottom: 0;
}

/* ── 95% Stat Visual ── */
.stat-visual {
  display: flex;
  align-items: center;
  gap: 32px;
  margin: 40px 0;
  padding: 32px;
  background: rgba(0, 0, 0, 0.02);
  border: 1px solid rgba(0, 0, 0, 0.06);
  border-radius: var(--radius-card);
}

.stat-donut {
  width: 160px;
  height: 160px;
  border-radius: 50%;
  background: conic-gradient(from 0deg, var(--color-orange) 0deg, var(--color-blue-bright) 342deg, rgba(0,0,0,0.06) 342deg 360deg);
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
}

.stat-donut-inner {
  width: 104px;
  height: 104px;
  border-radius: 50%;
  background: var(--color-bg-light);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
}

.stat-number {
  font-family: var(--font-sans);
  font-weight: 800;
  font-size: 36px;
  background: linear-gradient(135deg, var(--color-orange), var(--color-blue-bright));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  line-height: 1;
}

.stat-label {
  font-size: 11px;
  color: var(--color-text-muted);
  margin-top: 2px;
}

.stat-text p {
  font-family: var(--font-serif);
  font-size: 15px;
  color: var(--color-text-mid);
  line-height: 1.7;
  margin-bottom: 12px;
}

.stat-text p:last-child { margin-bottom: 0; }

/* ── Three Levels Stack ── */
.levels-stack {
  display: flex;
  flex-direction: column;
  gap: 12px;
  margin: 24px 0 40px;
}

.level-card {
  padding: 20px 24px;
  border-radius: 14px;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 10px;
}

.level-card p {
  width: 100%;
  font-size: 14px;
  line-height: 1.6;
  margin-bottom: 0;
  margin-top: 4px;
}

.level-badge {
  font-size: 11px;
  font-weight: 600;
  letter-spacing: 0.06em;
  text-transform: uppercase;
}

.level-card strong {
  font-family: var(--font-sans);
  font-size: 16px;
  font-weight: 600;
}

.level-target {
  margin-left: auto;
  font-size: 10px;
  font-weight: 600;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  padding: 3px 10px;
  border-radius: 8px;
  background: rgba(232, 116, 32, 0.08);
  color: var(--color-orange);
}

.level-here {
  margin-left: auto;
  font-size: 10px;
  font-weight: 600;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  padding: 3px 10px;
  border-radius: 8px;
  background: rgba(0, 0, 0, 0.04);
  color: var(--color-text-muted);
}

.level-1 {
  border: 2px solid rgba(0, 0, 0, 0.08);
  background: transparent;
}

.level-1 .level-badge { color: var(--color-text-muted); }
.level-1 strong { color: var(--color-text); }
.level-1 p { color: var(--color-text-muted); }

.level-2 {
  border: 3px solid transparent;
  background: linear-gradient(var(--color-bg-light), var(--color-bg-light)) padding-box,
              linear-gradient(135deg, var(--color-orange), var(--color-blue-bright)) border-box;
}

.level-2 .level-badge { color: var(--color-orange); }
.level-2 strong { color: var(--color-text); }
.level-2 p { color: var(--color-text-mid); }

.level-3 {
  border: 2px solid rgba(0, 0, 0, 0.08);
  background: transparent;
}

.level-3 .level-badge { color: var(--color-text-muted); }
.level-3 strong { color: var(--color-text); }
.level-3 p { color: var(--color-text-muted); }

/* ── Building Block Accordion Content ── */
.bb-accordion {
  margin: 24px 0 40px;
}

.bb-accordion .faq-answer-inner {
  padding-bottom: 24px;
}

.bb-accordion .faq-answer-inner p {
  font-family: var(--font-serif);
  font-size: 15px;
  color: var(--color-text-mid);
  line-height: 1.7;
  margin-bottom: 16px;
}

.bb-accordion-title {
  display: flex;
  align-items: center;
  gap: 12px;
}

.bb-accordion-num {
  width: 28px;
  height: 28px;
  border-radius: 50%;
  background: var(--color-orange);
  color: #fff;
  font-size: 13px;
  font-weight: 700;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
}

.bb-levels {
  display: flex;
  flex-direction: column;
  gap: 10px;
  margin-top: 20px;
}

.bb-level {
  padding: 16px 20px;
  border-radius: 10px;
  border: 1px solid rgba(0, 0, 0, 0.06);
  background: rgba(0, 0, 0, 0.01);
}

.bb-level-target {
  border: 3px solid transparent;
  background: linear-gradient(var(--color-bg-light), var(--color-bg-light)) padding-box,
              linear-gradient(135deg, var(--color-orange), var(--color-blue-bright)) border-box;
}

.bb-level-badge {
  font-size: 10px;
  font-weight: 600;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--color-text-muted);
  display: block;
  margin-bottom: 4px;
}

.bb-level-target .bb-level-badge { color: var(--color-orange); }

.bb-level strong {
  font-family: var(--font-sans);
  font-size: 14px;
  font-weight: 600;
  color: var(--color-text);
  display: block;
  margin-bottom: 6px;
}

.bb-level p {
  font-size: 13px !important;
  color: var(--color-text-muted) !important;
  line-height: 1.55 !important;
  margin-bottom: 0 !important;
}

.bb-level-target p { color: var(--color-text-mid) !important; }

/* ── Constraint Cards ── */
.constraint-cards {
  display: flex;
  gap: 16px;
  margin: 24px 0;
}

.constraint-card {
  flex: 1;
  padding: 24px;
  background: rgba(0, 0, 0, 0.02);
  border: 1px solid rgba(0, 0, 0, 0.06);
  border-radius: 14px;
  border-left: 4px solid var(--color-orange);
}

.constraint-card:last-child { border-left-color: var(--color-blue-bright); }

.constraint-label {
  font-size: 11px;
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--color-text-muted);
  display: block;
  margin-bottom: 8px;
}

.constraint-card strong {
  font-family: var(--font-sans);
  font-size: 22px;
  font-weight: 700;
  color: var(--color-text);
  display: block;
  margin-bottom: 4px;
}

.constraint-card:first-child strong { color: var(--color-orange); }
.constraint-card:last-child strong { color: var(--color-blue-bright); }

.constraint-card p {
  font-size: 13px;
  color: var(--color-text-muted);
  line-height: 1.5;
  margin-bottom: 0;
}

/* ══════════════════════════════════════
   INDIVIDUAL LESSON PAGE
══════════════════════════════════════ */

/* ── Lesson Header ── */
.lesson-header {
  max-width: 1100px;
  margin: 0 auto;
  padding-top: 40px;
  padding-bottom: 48px;
}

.lesson-meta {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 16px;
}

.lesson-number {
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--color-orange);
}

.lesson-duration {
  font-size: 12px;
  font-weight: 500;
  color: var(--color-text-muted);
  padding: 3px 10px;
  background: rgba(0, 0, 0, 0.04);
  border-radius: 20px;
}

.lesson-title {
  font-family: var(--font-sans);
  font-size: clamp(32px, 4vw, 48px);
  font-weight: 600;
  color: var(--color-text);
  line-height: 1.1;
  letter-spacing: -0.035em;
  margin-bottom: 12px;
}

.lesson-subtitle {
  font-family: var(--font-serif);
  font-size: clamp(15px, 1.2vw, 18px);
  color: var(--color-text-mid);
  line-height: 1.6;
  max-width: 560px;
}

/* ── Lesson Top Bar (video + series nav) ── */
.lesson-top-bar {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 24px;
  max-width: 1100px;
  margin: 0 auto;
  padding-bottom: 32px;
}

/* ── Lesson Action Buttons ── */
.lesson-actions {
  display: flex;
  gap: 12px;
  max-width: 1100px;
  margin: 0 auto;
  padding-bottom: 40px;
}

.lesson-action-btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 10px 20px;
  border-radius: var(--radius-pill);
  font-family: var(--font-sans);
  font-size: 13px;
  font-weight: 500;
  text-decoration: none;
  transition: all 0.2s ease;
  cursor: pointer;
}

.lesson-action-btn svg {
  flex-shrink: 0;
}

.lesson-action-outline {
  border: 1px solid rgba(0, 0, 0, 0.12);
  color: var(--color-text-mid);
  background: transparent;
}

.lesson-action-outline:hover {
  border-color: var(--color-orange);
  color: var(--color-orange);
}

.lesson-action-fill {
  border: 1px solid var(--color-orange);
  background: var(--color-orange);
  color: #fff;
}

.lesson-action-fill:hover {
  background: var(--color-orange-dark);
  border-color: var(--color-orange-dark);
}

/* ── Lesson Body: Single Column ── */
.lesson-body {
  display: block;
  max-width: 1100px;
  margin: 0 auto;
  padding-top: 8px;
  padding-bottom: 80px;
}

/* Content column */
.lesson-content h2 {
  font-family: var(--font-sans);
  font-size: clamp(20px, 2vw, 26px);
  font-weight: 600;
  color: var(--color-text);
  letter-spacing: -0.02em;
  margin-bottom: 16px;
  margin-top: 48px;
}

.lesson-content h2:first-child {
  margin-top: 0;
}

.lesson-content p {
  font-family: var(--font-serif);
  font-size: clamp(15px, 1.15vw, 17px);
  color: var(--color-text-mid);
  line-height: 1.8;
  margin-bottom: 20px;
}

.lesson-content ul,
.lesson-content ol {
  padding-left: 0;
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 10px;
  margin-bottom: 24px;
}

.lesson-content li {
  font-size: 15px;
  color: var(--color-text-mid);
  line-height: 1.65;
  padding-left: 24px;
  position: relative;
}

.lesson-content li::before {
  content: '';
  position: absolute;
  left: 0;
  top: 10px;
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--color-orange);
}

/* Key Insight Card */
.key-insight {
  background: rgba(232, 116, 32, 0.04);
  border-left: 3px solid var(--color-orange);
  border-radius: 0 var(--radius-small) var(--radius-small) 0;
  padding: 24px 28px;
  margin: 32px 0;
}

.key-insight-label {
  font-size: 11px;
  font-weight: 600;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--color-orange);
  margin-bottom: 10px;
}

.key-insight p {
  font-family: var(--font-serif);
  font-size: 15px;
  color: var(--color-text);
  line-height: 1.7;
  margin-bottom: 0;
}

/* Sidebar (now used inside top bar) */
.lesson-sidebar {
  display: flex;
  flex-direction: column;
  gap: 24px;
}

/* Video Tile */
.video-tile {
  border-radius: var(--radius-tile);
  overflow: hidden;
  background: var(--color-bg-dark);
  cursor: pointer;
  position: relative;
  aspect-ratio: 16 / 10;
}

.video-tile-thumb {
  width: 100%;
  height: 100%;
  position: relative;
  display: flex;
  align-items: center;
  justify-content: center;
  background: linear-gradient(135deg, #1a1a1a 0%, #2a2a2a 100%);
}

.video-tile-thumb::before {
  content: '';
  position: absolute;
  inset: 0;
  opacity: 0.3;
  background-image: url("data:image/svg+xml,%3Csvg viewBox='0 0 256 256' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.85' numOctaves='4' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)' opacity='0.5'/%3E%3C/svg%3E");
  background-repeat: repeat;
  background-size: 180px 180px;
  pointer-events: none;
}

.video-play-btn {
  width: 56px;
  height: 56px;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.15);
  border: 2px solid rgba(255, 255, 255, 0.3);
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: background 0.3s ease, transform 0.2s ease;
  position: relative;
  z-index: 1;
  backdrop-filter: blur(8px);
}

.video-play-btn:hover {
  background: rgba(255, 255, 255, 0.25);
  transform: scale(1.08);
}

.video-play-btn svg {
  width: 22px;
  height: 22px;
  color: #fff;
  margin-left: 3px;
}

.video-tile-label {
  font-size: 12px;
  color: var(--color-text-muted);
  text-align: center;
  padding: 10px;
  background: rgba(0, 0, 0, 0.02);
  font-weight: 400;
}

.video-tile iframe {
  width: 100%;
  height: 100%;
  border: none;
  position: absolute;
  inset: 0;
}

/* Series Navigation Card */
.series-nav {
  background: rgba(0, 0, 0, 0.02);
  border: 1px solid rgba(0, 0, 0, 0.06);
  border-radius: var(--radius-tile);
  padding: 20px;
}

.series-nav-title {
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--color-text-muted);
  margin-bottom: 16px;
}

.series-nav-list {
  list-style: none;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.series-nav-item {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 10px 12px;
  border-radius: 10px;
  text-decoration: none;
  color: var(--color-text-muted);
  font-size: 13px;
  font-weight: 400;
  transition: background 0.2s ease, color 0.2s ease;
}

.series-nav-item:hover {
  background: rgba(0, 0, 0, 0.04);
  color: var(--color-text);
}

.series-nav-item.active {
  background: rgba(232, 116, 32, 0.06);
  color: var(--color-text);
  font-weight: 500;
}

.series-nav-dot {
  width: 7px;
  height: 7px;
  border-radius: 50%;
  border: 1.5px solid var(--color-text-muted);
  flex-shrink: 0;
  transition: background 0.2s ease, border-color 0.2s ease;
}

.series-nav-item.active .series-nav-dot {
  background: var(--color-orange);
  border-color: var(--color-orange);
}

/* ── Prev/Next Navigation ── */
.lesson-prev-next {
  display: flex;
  justify-content: space-between;
  align-items: center;
  max-width: 1100px;
  margin: 0 auto;
  padding: 32px 0 80px;
  border-top: 1px solid rgba(0, 0, 0, 0.08);
}

.lesson-prev-next a {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-size: 14px;
  font-weight: 500;
  color: var(--color-text-mid);
  text-decoration: none;
  padding: 10px 20px;
  border-radius: var(--radius-pill);
  border: 1px solid rgba(0, 0, 0, 0.1);
  transition: border-color 0.3s ease, color 0.3s ease, transform 0.2s ease;
}

.lesson-prev-next a:hover {
  border-color: var(--color-orange);
  color: var(--color-orange);
  transform: translateY(-1px);
}

.lesson-prev-next a svg {
  width: 14px;
  height: 14px;
  transition: transform 0.3s ease;
}

.lesson-prev-next a.next:hover svg {
  transform: translateX(3px);
}

.lesson-prev-next a.prev:hover svg {
  transform: translateX(-3px);
}

.lesson-prev-next .spacer {
  flex: 1;
}

/* ══════════════════════════════════════
   LESSON 3: PILL-TAB NAV
══════════════════════════════════════ */
.lesson-parts-nav {
  display: flex;
  gap: 4px;
  background: rgba(0, 0, 0, 0.04);
  border-radius: var(--radius-pill);
  padding: 4px;
  width: fit-content;
  margin-bottom: 8px;
  max-width: 1100px;
}

.lesson-parts-nav-wrap {
  max-width: 1100px;
  margin: -24px auto 0;
  padding-bottom: 16px;
}

.part-link {
  padding: 8px 18px;
  border-radius: var(--radius-pill);
  font-size: 13px;
  font-weight: 500;
  color: var(--color-text-muted);
  text-decoration: none;
  transition: all 0.2s ease;
  white-space: nowrap;
}

.part-link:hover {
  color: var(--color-text);
  background: rgba(0, 0, 0, 0.04);
}

.part-link.active {
  background: var(--color-text);
  color: #fff;
}

/* ── Lesson 3 Parts Grid (overview page) ── */
/* ── Parts Showcase (individual dark cards with colored hues) ── */
.parts-showcase {
  margin-top: 32px;
}

.parts-showcase-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 16px;
  position: relative;
  z-index: 1;
}

.part-card {
  display: flex;
  flex-direction: column;
  align-items: center;
  text-align: center;
  padding: 28px 20px 24px;
  border-radius: 16px;
  min-height: 180px;
  text-decoration: none;
  color: #fff;
  position: relative;
  overflow: hidden;
  background: #1a1a1a;
  border: 1px solid rgba(255, 255, 255, 0.06);
  transition: transform 0.25s cubic-bezier(0.22, 1, 0.36, 1), box-shadow 0.3s ease, border-color 0.3s ease;
}

.part-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 12px 40px rgba(0, 0, 0, 0.3);
  border-color: rgba(255, 255, 255, 0.12);
}

/* Grain texture on each card */
.part-card::after {
  content: '';
  position: absolute;
  inset: 0;
  opacity: 0.3;
  background-image: url("data:image/svg+xml,%3Csvg viewBox='0 0 256 256' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.85' numOctaves='4' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)' opacity='0.5'/%3E%3C/svg%3E");
  background-repeat: repeat;
  background-size: 180px 180px;
  pointer-events: none;
  border-radius: inherit;
}

/* Colored radial hue glow behind each card */
.part-card::before {
  content: '';
  position: absolute;
  width: 160%;
  height: 160%;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  border-radius: 50%;
  filter: blur(50px);
  opacity: 0.28;
  pointer-events: none;
  transition: opacity 0.3s ease;
}

.part-card:hover::before {
  opacity: 0.4;
}

.part-card[data-hue="orange"]::before { background: radial-gradient(circle, #E87420 0%, transparent 65%); }
.part-card[data-hue="blue"]::before { background: radial-gradient(circle, #3a5fad 0%, transparent 65%); }
.part-card[data-hue="purple"]::before { background: radial-gradient(circle, #7c3aed 0%, transparent 65%); }
.part-card[data-hue="brown"]::before { background: radial-gradient(circle, #c04e14 0%, transparent 65%); }
.part-card[data-hue="green"]::before { background: radial-gradient(circle, #2a8a4a 0%, transparent 65%); }

/* Bottom row: 2 cards span evenly across 3-col grid */
.parts-showcase-grid .part-card:nth-child(4) {
  grid-column: 1 / 2;
  justify-self: stretch;
}
.parts-showcase-grid .part-card:nth-child(5) {
  grid-column: 2 / 3;
  justify-self: stretch;
}

.part-card-icon {
  position: relative;
  z-index: 1;
  color: rgba(255, 255, 255, 0.7);
  margin-bottom: 16px;
  transition: color 0.3s ease;
}

.part-card:hover .part-card-icon {
  color: rgba(255, 255, 255, 0.9);
}

.part-card-num {
  font-size: 11px;
  font-weight: 600;
  color: rgba(255, 255, 255, 0.4);
  letter-spacing: 0.08em;
  text-transform: uppercase;
  margin-bottom: 8px;
  position: relative;
  z-index: 1;
}

.part-card-badge {
  position: absolute;
  top: 14px;
  right: 14px;
  font-size: 10px;
  padding: 3px 9px;
  border-radius: 6px;
  background: rgba(255, 255, 255, 0.08);
  color: rgba(255, 255, 255, 0.5);
  font-weight: 500;
  z-index: 1;
  letter-spacing: 0.02em;
}

.part-card-title {
  font-size: 15px;
  font-weight: 600;
  line-height: 1.35;
  position: relative;
  z-index: 1;
  color: rgba(255, 255, 255, 0.9);
}

/* ══════════════════════════════════════
   LESSON 2: OS TOGGLE & SETUP STEPS
══════════════════════════════════════ */

/* OS Toggle Pills */
.os-toggle {
  display: flex;
  gap: 4px;
  background: rgba(0, 0, 0, 0.04);
  border-radius: var(--radius-pill);
  padding: 4px;
  width: fit-content;
  margin: 32px 0 24px;
}

.os-toggle-btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 10px 22px;
  border-radius: var(--radius-pill);
  font-family: var(--font-sans);
  font-size: 14px;
  font-weight: 500;
  color: var(--color-text-muted);
  background: none;
  border: none;
  cursor: pointer;
  transition: all 0.2s ease;
  white-space: nowrap;
}

.os-toggle-btn:hover {
  color: var(--color-text);
}

.os-toggle-btn.active {
  background: var(--color-text);
  color: #fff;
}

.os-toggle-btn svg {
  width: 16px;
  height: 16px;
  flex-shrink: 0;
}

/* OS-specific content blocks */
.os-content {
  display: none;
}

.os-content.active {
  display: block;
}

/* Setup Step Cards */
.setup-step {
  margin: 28px 0;
  padding: 28px;
  background: rgba(0, 0, 0, 0.02);
  border: 1px solid rgba(0, 0, 0, 0.06);
  border-radius: var(--radius-card);
  position: relative;
}

.setup-step-header {
  display: flex;
  align-items: center;
  gap: 14px;
  margin-bottom: 16px;
}

.setup-step-num {
  width: 32px;
  height: 32px;
  border-radius: 50%;
  background: var(--color-orange);
  color: #fff;
  font-family: var(--font-sans);
  font-size: 14px;
  font-weight: 700;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
}

.setup-step-title {
  font-family: var(--font-sans);
  font-size: 17px;
  font-weight: 600;
  color: var(--color-text);
}

.setup-step p {
  font-family: var(--font-serif);
  font-size: 15px;
  color: var(--color-text-mid);
  line-height: 1.75;
  margin-bottom: 14px;
}

.setup-step p:last-child {
  margin-bottom: 0;
}

.setup-step ol {
  padding-left: 0;
  list-style: none;
  counter-reset: setup-counter;
  display: flex;
  flex-direction: column;
  gap: 8px;
  margin-bottom: 16px;
}

.setup-step ol li {
  counter-increment: setup-counter;
  font-size: 15px;
  color: var(--color-text-mid);
  line-height: 1.65;
  padding-left: 32px;
  position: relative;
}

.setup-step ol li::before {
  content: counter(setup-counter);
  position: absolute;
  left: 0;
  top: 1px;
  width: 22px;
  height: 22px;
  border-radius: 50%;
  background: rgba(232, 116, 32, 0.08);
  color: var(--color-orange);
  font-family: var(--font-sans);
  font-size: 12px;
  font-weight: 600;
  display: flex;
  align-items: center;
  justify-content: center;
}

.setup-step code {
  font-family: 'SF Mono', 'Consolas', 'Monaco', monospace;
  font-size: 13px;
  background: rgba(0, 0, 0, 0.05);
  padding: 2px 8px;
  border-radius: 4px;
  color: var(--color-text);
}

/* Checklist within setup steps */
.setup-checklist {
  display: flex;
  flex-direction: column;
  gap: 8px;
  margin: 16px 0;
  padding-left: 0;
  list-style: none;
}

.setup-checklist li {
  display: flex;
  align-items: flex-start;
  gap: 10px;
  font-size: 14px;
  color: var(--color-text-mid);
  line-height: 1.6;
  padding-left: 0;
}

.setup-checklist li::before {
  content: '';
  width: 18px;
  height: 18px;
  border-radius: 4px;
  border: 2px solid rgba(0, 0, 0, 0.12);
  flex-shrink: 0;
  margin-top: 2px;
  background: none;
  position: static;
}

/* Troubleshoot Card */
.troubleshoot-card {
  margin: 40px 0;
  padding: 28px;
  background: rgba(44, 70, 133, 0.04);
  border-left: 3px solid var(--color-blue-bright);
  border-radius: 0 var(--radius-small) var(--radius-small) 0;
}

.troubleshoot-card-label {
  font-size: 11px;
  font-weight: 600;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--color-blue-bright);
  margin-bottom: 10px;
}

.troubleshoot-card p {
  font-family: var(--font-serif);
  font-size: 15px;
  color: var(--color-text);
  line-height: 1.7;
  margin-bottom: 12px;
}

.troubleshoot-card p:last-child {
  margin-bottom: 0;
}

/* Requirements pills */
.requirements-list {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin: 20px 0 28px;
}

.requirement-pill {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 10px 18px;
  background: rgba(0, 0, 0, 0.03);
  border: 1px solid rgba(0, 0, 0, 0.06);
  border-radius: var(--radius-pill);
  font-size: 13px;
  font-weight: 500;
  color: var(--color-text-mid);
}

.requirement-pill svg {
  width: 16px;
  height: 16px;
  flex-shrink: 0;
  color: var(--color-orange);
}

/* Git options table */
.git-options-table {
  width: 100%;
  border-collapse: collapse;
  margin: 16px 0;
  font-size: 13px;
}

.git-options-table th {
  font-family: var(--font-sans);
  font-weight: 600;
  text-align: left;
  padding: 10px 14px;
  background: rgba(0, 0, 0, 0.04);
  color: var(--color-text);
  border-bottom: 1px solid rgba(0, 0, 0, 0.08);
}

.git-options-table th:first-child {
  border-radius: 8px 0 0 0;
}

.git-options-table th:last-child {
  border-radius: 0 8px 0 0;
}

.git-options-table td {
  padding: 10px 14px;
  border-bottom: 1px solid rgba(0, 0, 0, 0.05);
  color: var(--color-text-mid);
  line-height: 1.5;
  vertical-align: top;
}

.git-options-table tr:last-child td {
  border-bottom: none;
}

.git-rec {
  display: inline-block;
  font-size: 10px;
  font-weight: 600;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  padding: 2px 8px;
  border-radius: 4px;
  background: rgba(232, 116, 32, 0.08);
  color: var(--color-orange);
  margin-top: 4px;
}

/* ══════════════════════════════════════
   MOBILE
══════════════════════════════════════ */
@media (max-width: 768px) {
  .breadcrumb {
    padding-top: 80px;
  }

  /* Course overview */
  .course-hero-title {
    font-size: clamp(28px, 7vw, 40px);
  }

  .course-about,
  .course-sections,
  .course-bottom-cta {
    padding-left: var(--pad-section);
    padding-right: var(--pad-section);
  }

  .course-section-card {
    grid-template-columns: 48px 1fr;
    gap: 16px;
    padding: 20px;
  }

  .course-section-meta {
    grid-column: 1 / -1;
    flex-direction: row;
    align-items: center;
  }

  /* S3-style card mobile */
  .course-sections-tiles {
    grid-template-columns: 1fr;
  }

  .course-tile {
    min-height: 100px;
  }

  .course-sections-card {
    padding: 20px;
  }

  .course-hero-actions {
    flex-direction: column;
    align-items: stretch;
  }

  .course-hero-actions .course-enrol-btn {
    justify-content: center;
  }

  .course-notify-btn {
    justify-content: center;
    padding: 12px 24px;
    font-size: 13px;
  }

  .course-bottom-cta-actions {
    flex-direction: column;
    align-items: stretch;
  }

  /* Building blocks */
  .compare-cards {
    flex-direction: column;
  }

  .compare-vs {
    transform: rotate(90deg);
  }

  .bb-grid {
    grid-template-columns: 1fr;
  }

  .used-four-label {
    display: none;
  }

  .where-item-detail {
    display: none;
  }

  .where-item-badge {
    font-size: 10px;
    padding: 2px 8px;
  }

  .levels-pyramid .level-pyramid-row {
    width: 100% !important;
  }

  .stat-visual {
    flex-direction: column;
    text-align: center;
    padding: 24px;
    gap: 20px;
  }

  .stat-donut {
    width: 140px;
    height: 140px;
  }

  .stat-donut-inner {
    width: 92px;
    height: 92px;
  }

  .stat-number {
    font-size: 30px;
  }

  .constraint-cards {
    flex-direction: column;
  }

  /* Lesson page */
  .lesson-top-bar {
    grid-template-columns: 1fr;
  }

  .lesson-title {
    font-size: clamp(26px, 7vw, 36px);
  }

  .lesson-prev-next {
    flex-direction: column;
    gap: 12px;
  }

  .lesson-prev-next a {
    width: 100%;
    justify-content: center;
  }

  /* Parts nav scrollable on mobile */
  .lesson-parts-nav {
    overflow-x: auto;
    -webkit-overflow-scrolling: touch;
    scrollbar-width: none;
    width: 100% !important;
    max-width: none;
  }

  .lesson-parts-nav::-webkit-scrollbar {
    display: none;
  }

  .part-link {
    padding: 6px 12px;
    font-size: 11px;
  }

  .parts-showcase-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .parts-showcase-grid .part-card:nth-child(4),
  .parts-showcase-grid .part-card:nth-child(5) {
    grid-column: auto;
  }

  /* Last card (5th) spans full width on mobile 2-col */
  .parts-showcase-grid .part-card:nth-child(5) {
    grid-column: 1 / -1;
  }

  .part-card {
    min-height: 140px;
    padding: 22px 16px 20px;
  }

  /* Lesson 2 setup */
  .setup-step {
    padding: 20px;
  }

  .git-options-table {
    font-size: 12px;
  }

  .git-options-table th,
  .git-options-table td {
    padding: 8px 10px;
  }

  .requirements-list {
    gap: 8px;
  }

  /* Code badges smaller on mobile */
  .setup-step code {
    font-size: 11px;
    padding: 1px 4px;
    word-break: keep-all;
  }

  .setup-checklist li {
    font-size: 13px;
    display: block;
    padding-left: 28px;
    position: relative;
  }

  .setup-checklist li::before {
    position: absolute;
    left: 0;
    top: 2px;
  }
}