/* Shared lesson layout */
:root {
  --lesson-bg: #f5f4f0;
  --lesson-text: #1a1a1a;
  --lesson-panel: #ffffff;
  --lesson-border: #e0ddd6;
  --lesson-heading: #1a1a2e;
  --lesson-muted: #777;
  --lesson-shadow: 0 14px 30px rgba(15, 23, 42, 0.06);
}

body {
  font-size: 18px;
  background: var(--lesson-bg);
  color: var(--lesson-text);
}

.page {
  max-width: 1180px !important;
  margin: 0 auto !important;
  padding: 1.75rem 1.75rem 4.5rem !important;
}

a.back,
.back {
  font-size: 16px !important;
  margin-bottom: 1.75rem !important;
}

.lesson-header,
.hero {
  border-radius: 22px !important;
  padding: 3rem 2.75rem !important;
  box-shadow: var(--lesson-shadow);
}

.tag {
  font-size: 13px !important;
  font-weight: 700 !important;
  padding: 6px 14px !important;
}

.lesson-header h1,
.hero h1 {
  font-size: 3rem !important;
  line-height: 1.15 !important;
}

.lesson-header p,
.hero p {
  font-size: 18px !important;
  line-height: 1.8 !important;
  max-width: 48ch;
}

.toc {
  position: relative;
  overflow: hidden;
  background: linear-gradient(180deg, #ffffff, #fbfaf7) !important;
  border: 1px solid rgba(26, 26, 46, 0.08) !important;
  border-radius: 16px !important;
  padding: 1.35rem 1.5rem !important;
  margin-bottom: 2.4rem !important;
  box-shadow: var(--lesson-shadow);
}

.toc::before {
  content: "";
  position: absolute;
  right: -48px;
  top: -48px;
  width: 160px;
  height: 160px;
  border-radius: 50%;
  background: radial-gradient(circle, rgba(99, 102, 241, 0.14), rgba(99, 102, 241, 0) 68%);
  pointer-events: none;
}

.toc-title {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  position: relative;
  z-index: 1;
  background: rgba(26, 26, 46, 0.06);
  color: #2f3650 !important;
  padding: 0.45rem 0.8rem;
  border-radius: 999px;
  font-size: 11px !important;
  font-weight: 600 !important;
  margin-bottom: 0.8rem !important;
  letter-spacing: 0.06em;
  text-transform: uppercase;
}

.toc-title::before {
  content: "";
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: #f5a76c;
  box-shadow: 0 0 0 3px rgba(245, 167, 108, 0.14);
}

.toc-list {
  display: grid !important;
  grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
  gap: 12px !important;
  margin: 0.9rem 0 0 !important;
  padding: 0 !important;
  position: relative;
  z-index: 1;
}

.toc-list li {
  list-style: none;
}

.toc-list a {
  display: flex !important;
  align-items: center;
  justify-content: space-between;
  min-height: 56px;
  width: 100%;
  background: rgba(255, 255, 255, 0.92) !important;
  border: 1px solid rgba(26, 26, 46, 0.09) !important;
  border-radius: 16px !important;
  font-size: 14px !important;
  font-weight: 500;
  padding: 0.9rem 1rem !important;
  box-shadow: 0 8px 16px rgba(15, 23, 42, 0.05);
  transition: transform 0.18s ease, border-color 0.18s ease, box-shadow 0.18s ease, background 0.18s ease;
}

.toc-list a::after {
  content: "→";
  font-size: 15px;
  color: rgba(26, 26, 46, 0.42);
  margin-left: 0.8rem;
}

.toc-list a:hover {
  transform: translateY(-2px);
  border-color: rgba(99, 102, 241, 0.32) !important;
  box-shadow: 0 12px 22px rgba(15, 23, 42, 0.08);
  background: #ffffff !important;
}

.section {
  margin-bottom: 3rem !important;
}

.section-title,
.section h2 {
  font-size: 2rem !important;
  margin-bottom: 1.2rem !important;
}

.card,
.explain,
.quiz-box,
.quiz,
.note,
.tip,
.exception,
.exam-tip,
.dep-card,
.prep-box,
.mini,
.box,
.timeline-visual,
.module-block {
  border-radius: 18px !important;
  box-shadow: var(--lesson-shadow);
}

.card,
.explain,
.quiz-box,
.quiz,
.note,
.tip,
.exception,
.exam-tip,
.dep-card,
.prep-box,
.mini,
.box,
.timeline-visual {
  padding: 1.6rem !important;
}

.explain h3,
.card h3,
.card h4,
.dep-card h4,
.mini h3,
.box h3,
.prep-box h4 {
  font-size: 1.3rem !important;
  margin-bottom: 0.9rem !important;
}

.card p,
.card li,
.explain p,
.explain li,
.exception p,
.exception li,
.exam-tip p,
.exam-tip li,
.tip p,
.tip li,
.note p,
.note li,
.dep-card .deg,
.prep-box li,
.prep-box li em,
.cbox ul,
.cbox .ceg,
.wr-box,
.wr,
.qtext,
.question,
.fb,
.feedback,
.expl,
.explanation-text {
  font-size: 16px !important;
  line-height: 1.85 !important;
}

.formula-tag,
.cbox .cformula,
.dep-card .chip,
.chip,
.pbadge,
.dlabel,
.exception-label,
.exam-label,
.exc-lbl,
.tip-lbl,
.wr-label,
.wlbl,
.qctr,
.q-counter,
.qsc,
.q-score {
  font-size: 13px !important;
}

.compare-grid,
.wr-grid {
  gap: 16px !important;
}

.cbox,
.wr-box,
.wr {
  border-radius: 16px !important;
  padding: 1.4rem !important;
}

.table-wrap {
  border-radius: 18px !important;
  margin-bottom: 1.5rem !important;
  box-shadow: var(--lesson-shadow);
}

.uses-table,
.t,
.table {
  font-size: 15px !important;
}

.uses-table th,
.uses-table td,
.t th,
.t td,
.table th,
.table td {
  padding: 14px 18px !important;
  line-height: 1.75 !important;
}

.question,
.qtext {
  font-size: 1.3rem !important;
  font-weight: 700 !important;
  line-height: 1.6 !important;
}

.option,
.opt {
  font-size: 15px !important;
  padding: 15px 18px !important;
  border-radius: 12px !important;
  line-height: 1.6 !important;
}

.btn {
  font-size: 16px !important;
  font-weight: 700 !important;
  padding: 13px 30px !important;
}

.score-box .score-num,
.score-box .snum {
  font-size: 3.5rem !important;
}

.score-box .score-msg,
.score-box .smsg {
  font-size: 16px !important;
}

.lesson-content-shell {
  display: block;
}

.lesson-main-column {
  min-width: 0;
}

.lesson-inline-nav {
  margin-bottom: 1.35rem;
  padding: 0 0.25rem;
}

.lesson-inline-nav-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  margin-bottom: 0.8rem;
}

.lesson-inline-kicker {
  font-size: 11px;
  font-weight: 600;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: #6d7486;
}

.lesson-inline-module {
  font-size: 14px;
  color: #3d4360;
  text-decoration: none;
  border-bottom: 1px solid rgba(61, 67, 96, 0.2);
  padding-bottom: 2px;
}

.lesson-inline-module:hover {
  color: #1a1a2e;
  border-bottom-color: rgba(26, 26, 46, 0.45);
}

.lesson-inline-links {
  list-style: none;
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin: 0;
  padding: 0;
}

.lesson-inline-links a {
  display: inline-flex;
  align-items: center;
  min-height: 38px;
  padding: 0.6rem 0.95rem;
  border-radius: 999px;
  background: #f6f3ed;
  border: 1px solid rgba(26, 26, 46, 0.08);
  color: #3a415c;
  text-decoration: none;
  font-size: 14px;
  font-weight: 500;
  transition: background 0.18s ease, border-color 0.18s ease, transform 0.18s ease;
}

.lesson-inline-links a:hover {
  background: #ffffff;
  border-color: rgba(109, 74, 255, 0.22);
  transform: translateY(-1px);
}

.lesson-pager {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 16px;
  margin-top: 2rem;
}

.lesson-pager-link {
  display: flex;
  flex-direction: column;
  gap: 0.35rem;
  min-height: 108px;
  padding: 1.1rem 1.2rem;
  border-radius: 18px;
  text-decoration: none;
  background: linear-gradient(180deg, #ffffff, #fbfaf7);
  border: 1px solid rgba(26, 26, 46, 0.08);
  box-shadow: var(--lesson-shadow);
  color: var(--lesson-heading);
  transition: transform 0.18s ease, border-color 0.18s ease, box-shadow 0.18s ease;
}

.lesson-pager-link:hover {
  transform: translateY(-2px);
  border-color: rgba(109, 74, 255, 0.2);
  box-shadow: 0 14px 24px rgba(15, 23, 42, 0.08);
}

.lesson-pager-link.is-module {
  background: linear-gradient(145deg, #1a1a2e, #2e2a57);
  color: #fff;
}

.lesson-pager-link.is-disabled {
  opacity: 0.58;
  pointer-events: none;
}

.lesson-pager-label {
  font-size: 0.75rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: #7a8498;
}

.lesson-pager-link.is-module .lesson-pager-label {
  color: rgba(255, 255, 255, 0.72);
}

.lesson-pager-link strong {
  font-size: 1.05rem;
  line-height: 1.45;
}

@media (max-width: 900px) {
  .page {
    max-width: 100% !important;
    padding: 1.25rem 1rem 3rem !important;
  }

  .lesson-header,
  .hero {
    padding: 2.25rem 1.5rem !important;
  }

  .lesson-header h1,
  .hero h1 {
    font-size: 2.1rem !important;
  }

  .lesson-header p,
  .hero p {
    font-size: 16px !important;
  }

  .section-title,
  .section h2 {
    font-size: 1.65rem !important;
  }

  .compare-grid,
  .wr-grid,
  .grid,
  .prep-grid {
    grid-template-columns: 1fr !important;
  }

  .toc-list {
    grid-template-columns: 1fr !important;
  }

  .lesson-pager {
    grid-template-columns: 1fr !important;
  }

  .lesson-inline-nav-head {
    flex-direction: column;
    align-items: flex-start;
  }
}