.ai-course-overview,
.ai-lesson-page {
  --ai-course-ink: #26231f;
  --ai-course-muted: #686056;
  --ai-course-line: #ddd7ce;
  --ai-course-soft: #f7f4ee;
  --ai-course-panel: #ffffff;
  --ai-course-accent: #1f7a72;
  --ai-course-accent-strong: #185f59;
  --ai-course-warm: #c56f2d;
  color: var(--ai-course-ink);
}

.ai-course-overview *,
.ai-lesson-page * {
  box-sizing: border-box;
}

.ai-course-overview h1,
.ai-course-overview h2,
.ai-course-overview h3,
.ai-lesson-page h1,
.ai-lesson-page h2,
.ai-lesson-page h3 {
  letter-spacing: 0;
}

#article.ai-course-overview h1,
#article.ai-course-overview h2,
#article.ai-course-overview h3,
#article.ai-lesson-page h1,
#article.ai-lesson-page h2,
#article.ai-lesson-page h3,
.ai-course-overview h1,
.ai-course-overview h2,
.ai-course-overview h3,
.ai-lesson-page h1,
.ai-lesson-page h2,
.ai-lesson-page h3 {
  background: transparent;
  border: 0;
  box-shadow: none;
  color: var(--ai-course-ink);
  margin: 0;
  padding: 0 !important;
}

.ai-course-overview h1::before,
.ai-course-overview h1::after,
.ai-course-overview h2::before,
.ai-course-overview h2::after,
.ai-lesson-page h1::before,
.ai-lesson-page h1::after,
.ai-lesson-page h2::before,
.ai-lesson-page h2::after {
  content: none;
}

.ai-course-overview__hero,
.ai-lesson-hero {
  margin: 0 0 22px;
  padding: 28px;
  background: linear-gradient(135deg, #f9f6ef 0%, #eef7f5 56%, #fff 100%);
  border: 1px solid var(--ai-course-line);
  border-radius: 8px;
}

.ai-course-kicker {
  display: inline-flex;
  align-items: center;
  min-height: 26px;
  margin: 0 0 12px;
  padding: 4px 9px;
  background: #e7f4f1;
  border: 1px solid #c6e4df;
  border-radius: 6px;
  color: var(--ai-course-accent-strong);
  font-size: 13px;
  font-weight: 700;
  line-height: 1.3;
}

.ai-course-overview__hero h1,
.ai-lesson-hero h1 {
  margin: 0;
  font-size: clamp(28px, 4vw, 44px);
  line-height: 1.2;
}

.ai-course-overview__hero p,
.ai-lesson-hero p {
  max-width: 780px;
  margin: 14px 0 0;
  color: var(--ai-course-muted);
  font-size: 16px;
  line-height: 1.9;
}

.ai-course-overview__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 20px;
}

.ai-course-button,
.ai-course-button:link,
.ai-course-button:visited {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 42px;
  padding: 10px 16px;
  background: var(--ai-course-accent);
  border: 1px solid var(--ai-course-accent);
  border-radius: 6px;
  color: #fff !important;
  font-size: 14px;
  font-weight: 700;
  line-height: 1.35;
  text-decoration: none;
  cursor: pointer;
}

.ai-course-button:hover,
.ai-course-button:focus-visible {
  background: var(--ai-course-accent-strong);
  border-color: var(--ai-course-accent-strong);
  color: #fff !important;
}

.ai-course-button--secondary,
.ai-course-button--secondary:link,
.ai-course-button--secondary:visited {
  background: #fff;
  color: var(--ai-course-accent-strong) !important;
}

.ai-course-button--secondary:hover,
.ai-course-button--secondary:focus-visible {
  background: #eef7f5;
  color: var(--ai-course-accent-strong) !important;
}

.ai-course-progress {
  margin: 0 0 18px;
  padding: 14px;
  background: var(--ai-course-soft);
  border: 1px solid var(--ai-course-line);
  border-radius: 8px;
}

.ai-course-progress__text {
  display: flex;
  justify-content: space-between;
  gap: 12px;
  margin: 0 0 9px;
  color: var(--ai-course-muted);
  font-size: 14px;
  font-weight: 700;
}

.ai-course-progress__bar {
  width: 100%;
  height: 9px;
  overflow: hidden;
  background: #e5ded3;
  border-radius: 999px;
}

.ai-course-progress__bar span {
  display: block;
  width: 0%;
  height: 100%;
  background: linear-gradient(90deg, var(--ai-course-accent), var(--ai-course-warm));
  transition: width 180ms ease;
}

.ai-course-lesson-list {
  display: grid;
  gap: 10px;
}

.ai-course-lesson-card,
.ai-course-lesson-card:link,
.ai-course-lesson-card:visited {
  display: grid;
  grid-template-columns: minmax(74px, 90px) minmax(0, 1fr) auto;
  gap: 10px 14px;
  align-items: center;
  min-height: 76px;
  padding: 14px;
  background: var(--ai-course-panel);
  border: 1px solid var(--ai-course-line);
  border-radius: 8px;
  color: var(--ai-course-ink) !important;
  text-decoration: none;
}

.ai-course-lesson-card:hover,
.ai-course-lesson-card:focus-visible {
  border-color: #adcfc9;
  box-shadow: 0 8px 22px rgba(40, 35, 28, 0.08);
}

.ai-course-lesson-card__number {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 30px;
  padding: 5px 8px;
  background: #f2ede5;
  border-radius: 6px;
  color: #6f4c2b;
  font-size: 13px;
  font-weight: 800;
  line-height: 1.35;
  white-space: nowrap;
}

.ai-course-lesson-card__title {
  min-width: 0;
  font-size: 16px;
  font-weight: 800;
  line-height: 1.55;
}

.ai-course-lesson-card__meta,
.ai-course-lesson-card__status {
  color: var(--ai-course-muted);
  font-size: 13px;
  line-height: 1.45;
}

.ai-course-lesson-card__meta {
  grid-column: 2;
}

.ai-course-lesson-card__status {
  grid-column: 3;
  grid-row: 1 / span 2;
  justify-self: end;
  min-width: 68px;
  padding: 5px 8px;
  background: #f4f4f4;
  border-radius: 6px;
  text-align: center;
  white-space: nowrap;
}

.ai-course-lesson-card.is-complete .ai-course-lesson-card__status {
  background: #e7f4f1;
  color: var(--ai-course-accent-strong);
  font-weight: 800;
}

.ai-course-notice {
  padding: 16px;
  background: #fff8e9;
  border: 1px solid #ead6a8;
  border-radius: 8px;
  color: #6a4a18;
  line-height: 1.75;
}

.ai-lesson-main {
  max-width: 980px;
  width: min(980px, calc(100% - 40px));
}

.ai-lesson-main #article.ai-lesson-page {
  width: 100%;
}

.ai-lesson-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-top: 16px;
}

.ai-lesson-meta span,
.ai-lesson-meta time {
  display: inline-flex;
  align-items: center;
  min-height: 28px;
  padding: 5px 9px;
  background: rgba(255, 255, 255, 0.78);
  border: 1px solid var(--ai-course-line);
  border-radius: 6px;
  color: var(--ai-course-muted);
  font-size: 13px;
  font-weight: 700;
  line-height: 1.35;
}

.ai-lesson-summary {
  display: grid;
  grid-template-columns: minmax(0, 1.4fr) minmax(220px, 0.6fr);
  gap: 14px;
  margin: 0 0 24px;
}

.ai-lesson-summary > div,
.ai-lesson-complete,
.ai-lesson-update-note {
  padding: 18px;
  background: #fff;
  border: 1px solid var(--ai-course-line);
  border-radius: 8px;
}

.ai-lesson-summary h2,
.ai-lesson-update-note h2 {
  margin: 0 0 10px;
  font-size: 17px;
  line-height: 1.45;
}

.ai-lesson-summary ul {
  margin: 0;
  padding-left: 1.35em;
}

.ai-lesson-summary li,
.ai-lesson-summary p,
.ai-lesson-complete p,
.ai-lesson-update-note p {
  margin: 0;
  color: var(--ai-course-muted);
  font-size: 15px;
  line-height: 1.85;
}

.ai-lesson-content {
  margin-top: 22px;
}

#article.ai-lesson-page .ai-lesson-content h2 {
  margin: 38px 0 14px;
  padding: 14px 16px !important;
  background: #f2ede5;
  border-left: 5px solid var(--ai-course-warm);
  border-radius: 6px;
  color: var(--ai-course-ink);
  font-size: 24px;
  line-height: 1.45;
}

#article.ai-lesson-page .ai-lesson-content h3 {
  margin: 28px 0 12px;
  padding: 0 0 8px !important;
  background: transparent;
  border: 0;
  border-bottom: 2px solid var(--ai-course-line);
  color: var(--ai-course-accent-strong);
  font-size: 20px;
  line-height: 1.5;
}

.ai-lesson-complete {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 12px;
  margin: 32px 0 18px;
}

.ai-lesson-page.is-complete .ai-lesson-complete {
  background: #f0f9f6;
  border-color: #bddfd9;
}

.ai-lesson-nav {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 12px;
  margin: 0 0 24px;
}

.ai-lesson-nav__item,
.ai-lesson-nav__item:link,
.ai-lesson-nav__item:visited {
  display: grid;
  gap: 4px;
  min-height: 86px;
  padding: 16px;
  background: #fff;
  border: 1px solid var(--ai-course-line);
  border-radius: 8px;
  color: var(--ai-course-ink) !important;
  text-decoration: none;
}

.ai-lesson-nav__item:hover,
.ai-lesson-nav__item:focus-visible {
  border-color: #adcfc9;
}

.ai-lesson-nav__item--next {
  text-align: right;
}

.ai-lesson-nav__item span {
  color: var(--ai-course-muted);
  font-size: 13px;
  font-weight: 700;
}

.ai-lesson-nav__item strong {
  font-size: 15px;
  line-height: 1.55;
}

@media (max-width: 720px) {
  .ai-course-overview__hero,
  .ai-lesson-hero {
    padding: 22px 18px;
  }

  .ai-course-lesson-card {
    grid-template-columns: 1fr;
  }

  .ai-course-lesson-card__meta,
  .ai-course-lesson-card__status {
    grid-column: auto;
    grid-row: auto;
    justify-self: start;
  }

  .ai-lesson-summary,
  .ai-lesson-nav {
    grid-template-columns: 1fr;
  }

  .ai-lesson-nav__item--next {
    text-align: left;
  }
}