/* STUDY article — editorial reading layout */
.study-article-hero {
  padding: calc(var(--header-height) + 92px) 0 88px;
  border-bottom: 1px solid var(--line);
}

.study-article-hero-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 320px;
  gap: clamp(56px, 8vw, 120px);
  align-items: end;
}

.study-article-hero h1 {
  max-width: 760px;
  margin-top: 22px;
  font-size: var(--fs-display, clamp(36px, 3.8vw, 50px));
  font-weight: 470;
  line-height: 1.12;
  letter-spacing: -.047em;
}

.study-article-lead {
  max-width: 720px;
  margin-top: 28px;
  color: var(--text-soft);
  font-size: 18px;
  line-height: 1.75;
}

.study-article-meta {
  display: grid;
  gap: 18px;
  border-top: 1px solid var(--line);
}

.study-article-meta div {
  display: grid;
  grid-template-columns: 88px 1fr;
  gap: 14px;
  padding-top: 15px;
  border-top: 1px solid var(--line);
}

.study-article-meta div:first-child { border-top: 0; }
.study-article-meta dt { color: var(--text-muted); font-size: 12px; letter-spacing: .08em; }
.study-article-meta dd { color: var(--text); font-size: 14px; }

.study-article-body {
  padding: 96px 0 128px;
}

.study-article-layout {
  display: grid;
  grid-template-columns: 220px minmax(0, 780px);
  gap: clamp(48px, 7vw, 120px);
  justify-content: center;
}

.study-article-toc {
  position: sticky;
  top: calc(var(--header-height) + 28px);
  align-self: start;
}

.study-article-toc p {
  margin-bottom: 18px;
  color: var(--text-muted);
  font-size: 12px;
  font-weight: 600;
  letter-spacing: .09em;
}

.study-article-toc a {
  display: block;
  padding: 8px 0;
  color: var(--text-muted);
  font-size: 14px;
  line-height: 1.45;
}

.study-article-toc a:hover { color: var(--text); }

.study-article-content > section + section {
  margin-top: 84px;
  padding-top: 84px;
  border-top: 1px solid var(--line);
}

.study-article-content .eyebrow { margin-bottom: 16px; }

.study-article-content h2 {
  max-width: 700px;
  margin-bottom: 28px;
  font-size: var(--fs-h2, clamp(26px, 2.25vw, 34px));
  font-weight: 510;
  line-height: 1.3;
  letter-spacing: -.038em;
}

.study-article-content h3 {
  margin: 42px 0 16px;
  font-size: 22px;
  font-weight: 540;
  line-height: 1.35;
  letter-spacing: -.03em;
}

.study-article-content p,
.study-article-content li {
  color: var(--text-soft);
  font-size: 17px;
  line-height: 1.8;
}

.study-article-content p + p { margin-top: 22px; }
.study-article-content ul { margin-top: 22px; }
.study-article-content li { position: relative; padding-left: 18px; }
.study-article-content li + li { margin-top: 10px; }
.study-article-content li::before {
  position: absolute;
  top: .82em;
  left: 0;
  width: 4px;
  height: 4px;
  border-radius: 50%;
  background: var(--point);
  content: '';
}

.study-note {
  margin-top: 34px;
  padding: 24px 26px;
  border-left: 2px solid var(--point);
  background: color-mix(in srgb, var(--point) 5%, var(--panel));
}

.study-note strong {
  display: block;
  margin-bottom: 8px;
  font-size: 15px;
  font-weight: 600;
}

.study-note p { font-size: 16px; }

.study-plain {
  margin: 30px 0 0;
  padding: 28px 30px;
  border: 1px solid color-mix(in srgb, var(--point) 24%, var(--line));
  background: color-mix(in srgb, var(--point) 4%, var(--panel));
}

.study-plain small {
  display: block;
  margin-bottom: 10px;
  color: var(--point);
  font-size: 12px;
  font-weight: 650;
  letter-spacing: .08em;
}

.study-plain strong {
  display: block;
  color: var(--text);
  font-size: 20px;
  font-weight: 540;
  line-height: 1.45;
  letter-spacing: -.025em;
}

.study-plain p {
  margin-top: 12px !important;
  font-size: 16px;
}

.study-term-grid,
.study-step-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 12px;
  margin-top: 30px;
}

.study-term,
.study-step {
  padding: 22px;
  border: 1px solid var(--line);
  background: color-mix(in srgb, var(--panel) 86%, transparent);
}

.study-term small,
.study-step small {
  display: block;
  color: var(--point);
  font-size: 11px;
  font-weight: 650;
  letter-spacing: .08em;
}

.study-term strong,
.study-step strong {
  display: block;
  margin-top: 10px;
  color: var(--text);
  font-size: 17px;
  font-weight: 560;
  line-height: 1.45;
}

.study-term p,
.study-step p {
  margin-top: 10px !important;
  font-size: 15px;
  line-height: 1.7;
}

.study-flow {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 8px;
  margin-top: 30px;
}

.study-flow div {
  position: relative;
  padding: 18px 16px;
  border: 1px solid var(--line);
  text-align: center;
}

.study-flow div:not(:last-child)::after {
  position: absolute;
  top: 50%;
  right: -9px;
  z-index: 2;
  color: var(--point);
  content: '→';
  transform: translateY(-50%);
}

.study-flow small {
  display: block;
  color: var(--text-muted);
  font-size: 10px;
  letter-spacing: .08em;
}

.study-flow strong {
  display: block;
  margin-top: 7px;
  color: var(--text);
  font-size: 14px;
  font-weight: 560;
  line-height: 1.4;
}

.study-example {
  margin-top: 30px;
  padding-top: 24px;
  border-top: 1px solid var(--line);
}

.study-example > small {
  display: block;
  margin-bottom: 14px;
  color: var(--text-muted);
  font-size: 11px;
  font-weight: 650;
  letter-spacing: .08em;
}

.study-example dl {
  display: grid;
  gap: 0;
  border-top: 1px solid var(--line);
}

.study-example dl > div {
  display: grid;
  grid-template-columns: 170px minmax(0, 1fr);
  gap: 22px;
  padding: 14px 0;
  border-bottom: 1px solid var(--line);
}

.study-example dt {
  color: var(--text-muted);
  font-size: 13px;
  font-weight: 560;
}

.study-example dd {
  margin: 0;
  color: var(--text);
  font-size: 15px;
  line-height: 1.65;
}

.study-code {
  margin-top: 28px;
  padding: 22px 24px;
  overflow-x: auto;
  border: 1px solid var(--line);
  background: var(--panel);
  color: var(--text);
  font: 14px/1.7 ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  white-space: pre;
}

.study-article-next {
  padding: 72px 0;
  border-top: 1px solid var(--line);
}

.study-article-next a {
  display: flex;
  align-items: end;
  justify-content: space-between;
  gap: 32px;
}

.study-article-next small { color: var(--text-muted); font-size: 12px; letter-spacing: .09em; }
.study-article-next h2 { margin-top: 12px; font-size: var(--fs-h2); font-weight: 510; line-height: 1.3; }
.study-article-next strong { color: var(--point); font-size: 28px; font-weight: 450; }

@media (max-width: 900px) {
  .study-article-hero-grid,
  .study-article-layout {
    grid-template-columns: 1fr;
  }
  .study-article-meta { margin-top: 18px; }
  .study-article-toc { position: static; }
  .study-article-toc nav { display: flex; flex-wrap: wrap; gap: 8px 18px; }
  .study-flow { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .study-flow div:nth-child(2)::after { display: none; }
}

@media (max-width: 760px) {
  .study-article-hero { padding-top: calc(var(--header-height) + 64px); padding-bottom: 64px; }
  .study-article-lead { font-size: 17px; }
  .study-article-body { padding: 72px 0 96px; }
  .study-article-content > section + section { margin-top: 64px; padding-top: 64px; }
  .study-article-content p,
  .study-article-content li { font-size: 16px; }
  .study-note,
  .study-plain { padding: 20px; }
  .study-term-grid,
  .study-step-grid,
  .study-flow { grid-template-columns: 1fr; }
  .study-flow div::after { display: none !important; }
  .study-example dl > div { grid-template-columns: 1fr; gap: 6px; }
}