.article-layout {
  max-width: 1380px;
  display: grid;
  grid-template-columns: 280px minmax(0, 1fr);
  gap: 1.1rem;
  align-items: start;
}

.article-hero {
  position: relative;
  isolation: isolate;
}

.page-mode-label {
  position: absolute;
  top: clamp(1rem, 2.4vw, 1.8rem);
  right: clamp(1rem, 2.4vw, 1.8rem);
  z-index: 2;
  padding: 0.42rem 0.72rem;
  border-radius: 999px;
  border: 1px solid rgba(255,255,255,0.34);
  background: rgba(255,255,255,0.12);
  color: rgba(255,255,255,0.94);
  font-size: 0.82rem;
  font-weight: 900;
}

.article-hero h1 {
  max-width: 980px;
}

.chapter-meta strong {
  color: #fff;
}

.article-card {
  font-size: 1.03rem;
  max-width: 920px;
  margin: 0 auto;
  grid-column: 2;
}

.article-card h2 {
  margin-top: 0.35rem;
}

.lesson-section {
  scroll-margin-top: 7rem;
  padding: 1.4rem 0 2.4rem;
  border-bottom: 1px solid var(--line);
}

.lesson-section:last-child {
  border-bottom: 0;
}

.section-kicker {
  margin: 0 0 0.45rem;
  color: var(--orange-dark);
  font-size: 0.78rem;
  font-weight: 900;
  letter-spacing: 0.13em;
  text-transform: uppercase;
}

.definition-box,
.example-box,
.warning-box,
.procedure-box,
.summary-box,
.formula-box,
.figure-spec {
  margin: 1.15rem 0;
  padding: 1.15rem 1.25rem;
  border-radius: 22px;
  border: 1px solid var(--line);
  background: rgba(255, 253, 242, 0.92);
}

.definition-box {
  border-left: 7px solid var(--green-700);
  background: linear-gradient(90deg, rgba(183, 217, 155, 0.28), rgba(255, 253, 242, 0.92));
}

.example-box {
  border-left: 7px solid var(--orange);
}

.warning-box {
  border-left: 7px solid var(--orange-dark);
  background: linear-gradient(90deg, rgba(214, 122, 31, 0.15), rgba(255, 253, 242, 0.94));
}

.formula-box {
  background: linear-gradient(180deg, rgba(227, 237, 210, 0.96), rgba(247, 241, 216, 0.92));
  border-color: rgba(53, 107, 52, 0.28);
  box-shadow: inset 0 0 0 1px rgba(255,255,255,0.5);
}

.formula-title {
  margin: 0 0 0.55rem;
  color: var(--green-900);
  font-weight: 900;
}

.formula-box .MathJax,
.formula-box mjx-container {
  font-size: 112% !important;
}

.concept-card mjx-container[display="true"] {
  max-width: 100%;
  overflow-x: auto;
  overflow-y: hidden;
}

.concept-card .MathJax,
.concept-card mjx-container {
  font-size: 96% !important;
}

.side-panel {
  position: sticky;
  top: 6.2rem;
  max-width: none;
  margin: 0;
  grid-column: 1;
  padding: 1.25rem;
  border: 1px solid var(--line);
  background: rgba(255, 253, 242, 0.88);
  box-shadow: var(--soft-shadow);
  border-radius: var(--radius);
}

.side-panel details {
  border-bottom: 1px solid var(--line);
  padding-bottom: 0.95rem;
  margin-bottom: 0.95rem;
}

.side-panel details:last-child {
  border-bottom: 0;
  padding-bottom: 0;
  margin-bottom: 0;
}

.side-panel summary {
  cursor: pointer;
  color: var(--green-900);
  font-size: 1rem;
  font-weight: 900;
  line-height: 1.25;
  list-style-position: outside;
}

.side-panel summary::marker {
  color: var(--orange-dark);
}

.course-links,
.topic-links {
  display: grid;
  gap: 0.38rem;
  margin-top: 0.85rem;
}

.course-links a,
.topic-links a {
  position: relative;
  display: block;
  padding: 0.38rem 0.55rem 0.38rem 1.05rem;
  border-radius: 14px;
  color: var(--green-800);
  font-size: 0.88rem;
  font-weight: 650;
  line-height: 1.16;
  text-decoration: none;
}

.course-links a::before,
.topic-links a::before {
  content: "";
  position: absolute;
  left: 0.45rem;
  top: 0.82em;
  width: 0.28rem;
  height: 0.28rem;
  border-radius: 999px;
  background: var(--orange-dark);
}

.course-links a:hover,
.course-links a.active,
.topic-links a:hover {
  color: var(--white);
  background: var(--green-800);
}

.course-links a:hover::before,
.course-links a.active::before,
.topic-links a:hover::before {
  background: var(--white);
}

.figure-citation {
  margin: 0.95rem 0 1.15rem;
  padding: 0.85rem 1rem;
  border-radius: 18px;
  border: 1px dashed rgba(53, 107, 52, 0.42);
  background: rgba(227, 237, 210, 0.55);
  color: var(--green-900);
  font-weight: 800;
}

.note {
  color: var(--muted);
  font-size: 0.96rem;
}

.concept-grid,
.practice-grid,
.figure-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1rem;
  margin: 1.15rem 0;
}

.concept-card,
.exercise-card,
.figure-spec {
  min-width: 0;
}

.concept-card {
  padding: 1rem;
  border-radius: 20px;
  background: var(--cream-200);
  border: 1px solid var(--line);
}

.concept-card h3,
.exercise-card h3,
.figure-spec h3 {
  margin-bottom: 0.4rem;
}

.badge {
  display: inline-flex;
  align-items: center;
  width: fit-content;
  margin-bottom: 0.6rem;
  padding: 0.28rem 0.62rem;
  border-radius: 999px;
  background: var(--green-800);
  color: white;
  font-size: 0.78rem;
  font-weight: 900;
}

.table-wrap {
  overflow-x: auto;
  margin: 1.25rem 0;
}

.table-wrap table {
  min-width: 760px;
}

.topic-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.7rem;
  margin-top: 1.25rem;
}

.topic-actions .button.primary {
  box-shadow: none;
}

.top-practice-action {
  margin-top: 0;
  margin-bottom: 1.2rem;
}

.top-practice-action,
.bottom-theory-action,
#bibliografia .topic-actions {
  justify-content: flex-end;
}

.topic-actions .button.outline {
  border: 1px solid rgba(255,255,255,0.38);
  color: white;
  background: rgba(255,255,255,0.09);
}

.resource-list li,
.summary-list li {
  margin-bottom: 0.55rem;
}

.practice-layout {
  max-width: 1160px;
  width: min(1160px, calc(100% - 2rem));
  margin: 0 auto;
  padding: clamp(2rem, 5vw, 4rem) 0;
}

.practice-hero {
  padding: clamp(2rem, 5vw, 4rem);
  color: white;
  border-radius: var(--radius);
  background:
    linear-gradient(135deg, rgba(37, 76, 41, 0.98), rgba(53, 107, 52, 0.94)),
    radial-gradient(circle at bottom right, rgba(214, 122, 31, 0.5), transparent 20rem);
  box-shadow: var(--shadow);
  margin-bottom: 1.1rem;
}

.practice-content-layout {
  display: grid;
  grid-template-columns: 280px minmax(0, 1fr);
  gap: 1.1rem;
  align-items: start;
}

.practice-main {
  min-width: 0;
}

.practice-panel {
  padding: clamp(1.2rem, 3vw, 2rem);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: rgba(255, 253, 242, 0.88);
  box-shadow: var(--soft-shadow);
  margin-bottom: 1.2rem;
}

.practice-panel > h2 {
  margin-bottom: 1.25rem;
}

.practice-lesson-group {
  padding: 1rem 0 1.2rem;
  border-top: 1px solid var(--line);
}

.practice-lesson-group:first-of-type {
  border-top: 0;
  padding-top: 0;
}

.practice-lesson-group h3 {
  color: var(--orange-dark);
  font-size: 1.02rem;
  margin-bottom: 0.85rem;
}

.practice-list {
  display: grid;
  gap: 0.85rem;
}

.practice-item {
  padding-bottom: 0.85rem;
  border-bottom: 1px solid rgba(37, 76, 41, 0.12);
}

.practice-item:last-child {
  border-bottom: 0;
  padding-bottom: 0;
}

.practice-item h4 {
  margin: 0 0 0.35rem;
  color: var(--green-900);
  font-size: 1rem;
}

.exercise-grid,
.grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1rem;
}

.exercise-card,
.exercise {
  padding: 1.05rem;
  border: 1px solid var(--line);
  border-radius: 20px;
  background: rgba(255,253,242,0.9);
  box-shadow: 0 8px 18px rgba(19,42,24,0.06);
}

.answer {
  color: var(--green-900);
  background: rgba(183, 217, 155, 0.22);
  border-radius: 14px;
  padding: 0.75rem 0.85rem;
}

.lesson-nav,
.nav {
  display: flex;
  flex-wrap: wrap;
  gap: 0.7rem;
  margin: 1.2rem 0;
}

.lesson-nav a,
.nav a,
.nav-card {
  display: inline-flex;
  align-items: center;
  min-height: 2.8rem;
  padding: 0.72rem 1rem;
  border-radius: 999px;
  background: rgba(255,253,242,0.9);
  border: 1px solid var(--line);
  color: var(--green-800);
  font-weight: 900;
  text-decoration: none;
}

@media (max-width: 980px) {
  .article-layout {
    grid-template-columns: 1fr;
  }

  .practice-content-layout {
    grid-template-columns: 1fr;
  }

  .article-hero,
  .side-panel,
  .article-card {
    grid-column: 1;
  }

  .side-panel,
  .article-card {
    max-width: 100%;
  }

  .side-panel {
    position: static;
  }
}

@media (max-width: 760px) {
  .concept-grid,
  .practice-grid,
  .figure-grid,
  .exercise-grid,
  .grid {
    grid-template-columns: 1fr;
  }
}