.answer-block {
  margin: 1.75rem 0 2.5rem;
  padding: 1.5rem 1.75rem;
  border-left: 4px solid #ef7f1a;
  background: #eef3f4;
  color: #071118;
}

.answer-block strong {
  display: block;
  margin-bottom: .45rem;
  font-size: .78rem;
  letter-spacing: .12em;
  text-transform: uppercase;
}

.answer-block p:last-child { margin-bottom: 0; }

.guide-grid,
.definition-grid,
.metric-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 1.25rem;
}

.guide-card,
.definition-grid article,
.metric-grid article {
  padding: 1.5rem;
  border: 1px solid rgba(7, 17, 24, .14);
  background: #fff;
}

.guide-card > span,
.definition-grid article > span,
.metric-grid article > span {
  display: block;
  margin-bottom: 1rem;
  color: #d96300;
  font-size: .76rem;
  font-weight: 700;
  letter-spacing: .12em;
  text-transform: uppercase;
}

.guide-card h3,
.definition-grid h3,
.metric-grid h3 { margin-top: 0; }

.guide-card b {
  display: inline-block;
  margin-top: .75rem;
  color: #071118;
}

.article-shell {
  display: grid;
  grid-template-columns: minmax(0, 2.35fr) minmax(240px, .75fr);
  gap: clamp(2rem, 5vw, 5rem);
  align-items: start;
}

.article-body { max-width: 860px; }
.article-body h2 { margin-top: 3rem; }
.article-body h3 { margin-top: 2rem; }
.article-body ul,
.article-body ol { padding-left: 1.3rem; }
.article-body li { margin: .55rem 0; }

.article-aside {
  position: sticky;
  top: 7rem;
  padding: 1.4rem;
  border: 1px solid rgba(7, 17, 24, .14);
  background: #f6f8f8;
}

.article-aside h2 {
  margin-top: 0;
  font-size: 1.15rem;
}

.article-aside a {
  display: block;
  padding: .55rem 0;
  border-bottom: 1px solid rgba(7, 17, 24, .1);
}

.article-aside a:last-child { border-bottom: 0; }

.comparison-wrap {
  margin: 1.75rem 0 2.5rem;
  overflow-x: auto;
  border: 1px solid rgba(7, 17, 24, .14);
}

.comparison-table {
  width: 100%;
  min-width: 720px;
  border-collapse: collapse;
  background: #fff;
}

.comparison-table th,
.comparison-table td {
  padding: 1rem;
  border-bottom: 1px solid rgba(7, 17, 24, .12);
  text-align: left;
  vertical-align: top;
}

.comparison-table th {
  background: #071118;
  color: #fff;
  font-size: .78rem;
  letter-spacing: .08em;
  text-transform: uppercase;
}

.comparison-table tr:last-child td { border-bottom: 0; }

.topic-list {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1rem;
  margin: 1.75rem 0;
  padding: 0;
  list-style: none;
}

.topic-list li {
  margin: 0;
  padding: 1rem 1.1rem;
  border-left: 3px solid #ef7f1a;
  background: #eef3f4;
}

.formula-box {
  margin: 1.75rem 0;
  padding: 1.5rem;
  background: #071118;
  color: #fff;
}

.formula-box code {
  display: block;
  margin: .75rem 0;
  color: #ffad60;
  font-family: inherit;
  font-size: clamp(1.05rem, 2vw, 1.35rem);
  font-weight: 700;
}

.source-note {
  padding: 1rem 1.15rem;
  border: 1px solid rgba(7, 17, 24, .12);
  background: #fff;
  font-size: .92rem;
}

@media (max-width: 900px) {
  .guide-grid,
  .definition-grid,
  .metric-grid { grid-template-columns: 1fr 1fr; }
  .article-shell { grid-template-columns: 1fr; }
  .article-aside { position: static; }
}

@media (max-width: 620px) {
  .guide-grid,
  .definition-grid,
  .metric-grid,
  .topic-list { grid-template-columns: 1fr; }
  .answer-block { padding: 1.25rem; }
}