.research-page {
  --reading: 760px;
  background: #fff;
}

.research-header {
  border-bottom: 1px solid var(--line);
  position: sticky;
  top: 0;
  background: rgba(255, 255, 255, .94);
  backdrop-filter: blur(14px);
}

.main-nav a.active::after {
  width: 100%;
}

.reading-column {
  width: min(var(--reading), calc(100% - 48px));
  margin: 0 auto;
}

.research-hero {
  padding: clamp(90px, 12vw, 170px) 0 clamp(80px, 10vw, 130px);
  border-bottom: 1px solid var(--line);
}

.publication-kicker {
  margin: 0 0 24px;
  color: var(--coral);
  font: 700 11px/1.2 "DM Sans", sans-serif;
  letter-spacing: 2px;
  text-transform: uppercase;
}

.research-hero h1 {
  max-width: 750px;
  font-size: clamp(48px, 6.3vw, 84px);
  line-height: 1.03;
}

.research-hero h1 em {
  color: var(--coral);
  font-style: normal;
}

.research-lede {
  max-width: 680px;
  margin: 32px 0 0;
  color: #53636a;
  font: 400 clamp(20px, 2vw, 25px)/1.55 "Source Serif 4", Georgia, serif;
}

.research-actions {
  display: flex;
  align-items: center;
  gap: 30px;
  margin-top: 42px;
}

.research-button {
  display: inline-flex;
  align-items: center;
  gap: 18px;
  padding: 13px 20px;
  border-radius: 999px;
  background: var(--coral);
  font-weight: 700;
  transition: transform .2s, box-shadow .2s;
}

.research-button:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 20px rgba(20, 43, 54, .13);
}

.research-button.dark {
  background: var(--navy);
  color: white;
}

.tree-link {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  font-size: 14px;
  font-weight: 700;
  border-bottom: 1px solid var(--line);
  padding-bottom: 4px;
}

.tree-link-icon {
  width: 25px;
  height: 25px;
  position: relative;
}

.tree-link-icon::before,
.tree-link-icon::after {
  content: "";
  position: absolute;
  background: var(--navy);
}

.tree-link-icon::before { width: 1px; height: 18px; left: 12px; top: 3px; }
.tree-link-icon::after { width: 18px; height: 1px; left: 4px; top: 12px; transform: rotate(-25deg); }
.tree-link-icon i { position: absolute; width: 7px; height: 7px; border-radius: 50%; background: var(--coral); z-index: 1; }
.tree-link-icon i:first-child { left: 9px; top: 0; }
.tree-link-icon i:nth-child(2) { left: 0; bottom: 1px; }
.tree-link-icon i:last-child { right: 0; bottom: 7px; }

.research-section {
  padding: clamp(80px, 10vw, 130px) 0;
}

.research-section-head {
  display: flex;
  align-items: end;
  justify-content: space-between;
  gap: 30px;
  padding-bottom: 30px;
  border-bottom: 1px solid var(--line);
}

.research-section-head .publication-kicker { margin-bottom: 12px; }
.research-section h2,
.tree-section h2,
.research-invite h2 {
  font-size: clamp(34px, 4vw, 52px);
}

.research-section-head > p {
  margin: 0 0 6px;
  color: var(--muted);
  font: 400 18px "Source Serif 4", Georgia, serif;
}

.topic-filters {
  display: flex;
  gap: 9px;
  padding: 28px 0 12px;
  overflow-x: auto;
  scrollbar-width: none;
}

.topic-filters::-webkit-scrollbar { display: none; }

.topic-filter {
  flex: 0 0 auto;
  padding: 8px 13px;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: white;
  color: var(--muted);
  font-size: 12px;
  cursor: pointer;
}

.topic-filter:hover,
.topic-filter.active {
  background: var(--navy);
  border-color: var(--navy);
  color: white;
}

.article-list {
  margin-top: 15px;
}

.research-entry {
  display: grid;
  grid-template-columns: 150px 1fr;
  gap: 34px;
  padding: 38px 0;
  border-bottom: 1px solid var(--line);
}

.research-entry[hidden] { display: none; }

.featured-article {
  grid-template-columns: 1fr 170px;
  background: var(--cream);
  margin: 20px -34px 0;
  padding: 42px 34px;
  border: 0;
}

.article-meta {
  margin: 0 0 12px;
  color: #829096;
  font-size: 12px;
}

.article-meta span {
  color: var(--coral);
  font-weight: 700;
}

.article-copy h3 {
  font: 600 clamp(26px, 3vw, 37px)/1.2 "Source Serif 4", Georgia, serif;
  letter-spacing: -.025em;
}

.article-copy > p:not(.article-meta) {
  margin: 14px 0 20px;
  color: #53636a;
  font: 400 18px/1.6 "Source Serif 4", Georgia, serif;
}

.article-copy > a {
  font-size: 13px;
  font-weight: 700;
}

.article-copy > a span { margin-left: 8px; color: var(--coral); }

.article-signal {
  min-height: 170px;
  display: flex;
  flex-direction: column;
  justify-content: center;
  gap: 9px;
}

.article-signal span {
  display: block;
  padding: 9px 12px;
  background: var(--navy);
  color: white;
  font-size: 11px;
  letter-spacing: 1px;
  text-transform: uppercase;
}

.article-signal span:nth-child(2) { margin-left: 22px; background: var(--coral); color: var(--navy); }
.article-signal span:nth-child(3) { margin-left: 44px; background: var(--yellow); color: var(--navy); }

.entry-mark {
  width: 150px;
  height: 110px;
  align-self: center;
  background: var(--cream);
  position: relative;
  overflow: hidden;
}

.remote-mark::before,
.remote-mark::after {
  content: "";
  position: absolute;
  border: 2px solid var(--navy);
  width: 58px;
  height: 42px;
}

.remote-mark::before { left: 20px; top: 24px; }
.remote-mark::after { right: 20px; bottom: 20px; background: var(--coral); }

.language-mark {
  display: grid;
  place-content: center;
  text-align: center;
  font: 600 39px/27px "Source Serif 4", Georgia, serif;
}

.language-mark small { color: var(--coral); font-size: 23px; }

.inclusion-mark {
  display: flex;
  justify-content: center;
  align-items: center;
}

.inclusion-mark i {
  width: 43px;
  height: 43px;
  border-radius: 50%;
  border: 2px solid var(--navy);
  margin: 0 -7px;
}

.inclusion-mark i:nth-child(2) { background: var(--coral); }

.no-results {
  padding: 50px 0;
  color: var(--muted);
  font-family: "Source Serif 4", Georgia, serif;
}

.tree-section {
  background: var(--navy);
  color: white;
  padding: clamp(85px, 11vw, 145px) 0;
}

.tree-intro > p:not(.publication-kicker) {
  max-width: 680px;
  color: rgba(255,255,255,.65);
  font: 400 19px/1.6 "Source Serif 4", Georgia, serif;
}

.tree-legend {
  display: flex;
  flex-wrap: wrap;
  gap: 22px;
  margin: 35px 0 55px;
  color: rgba(255,255,255,.65);
  font-size: 11px;
}

.tree-legend span { display: flex; align-items: center; gap: 8px; }
.tree-legend i { width: 8px; height: 8px; border-radius: 50%; display: block; }
.tree-legend i.complete { background: var(--mint); }
.tree-legend i.active { background: var(--coral); }
.tree-legend i.next { border: 1px solid rgba(255,255,255,.5); }

.research-tree {
  list-style: none;
  margin: 0;
  padding: 0;
  position: relative;
}

.research-tree::before {
  content: "";
  position: absolute;
  left: 15px;
  top: 23px;
  bottom: 23px;
  width: 1px;
  background: rgba(255,255,255,.2);
}

.tree-node {
  position: relative;
  padding-left: 58px;
}

.tree-node button {
  width: 100%;
  min-height: 86px;
  padding: 20px 0;
  display: grid;
  grid-template-columns: 1fr auto;
  align-items: center;
  text-align: left;
  background: transparent;
  color: white;
  border: 0;
  border-top: 1px solid rgba(255,255,255,.17);
  cursor: pointer;
}

.tree-node:last-child button { border-bottom: 1px solid rgba(255,255,255,.17); }

.node-dot {
  position: absolute;
  left: 7px;
  top: 34px;
  width: 17px;
  height: 17px;
  border-radius: 50%;
  background: var(--navy);
  border: 2px solid rgba(255,255,255,.5);
  z-index: 1;
}

.tree-node.complete .node-dot { background: var(--mint); border-color: var(--mint); }
.tree-node.active .node-dot { background: var(--coral); border-color: var(--coral); box-shadow: 0 0 0 7px rgba(248,117,93,.14); }

.node-copy { display: flex; flex-direction: column; gap: 5px; }
.node-copy small { color: var(--coral); font-size: 10px; letter-spacing: 1.5px; text-transform: uppercase; }
.tree-node.complete .node-copy small { color: var(--mint); }
.tree-node.next .node-copy { opacity: .6; }
.node-copy strong { font: 600 clamp(19px, 2.3vw, 27px)/1.3 "Source Serif 4", Georgia, serif; }
.node-action { color: var(--coral); font-size: 26px; font-weight: 300; padding-left: 20px; }

.node-detail {
  display: none;
  padding: 0 50px 27px 0;
}

.tree-node.open .node-detail { display: block; }
.node-detail p { margin: 0 0 12px; color: rgba(255,255,255,.68); font: 400 17px/1.6 "Source Serif 4", Georgia, serif; }
.evidence { color: var(--yellow); font-size: 11px; text-transform: uppercase; letter-spacing: 1px; }

.research-note-section { padding: clamp(80px, 10vw, 130px) 0; }
.mini-note { padding: 70px 0; border-bottom: 1px solid var(--line); scroll-margin-top: 100px; }
.mini-note:first-child { padding-top: 0; }
.mini-note h2 { max-width: 700px; font: 600 clamp(32px, 4.3vw, 53px)/1.16 "Source Serif 4", Georgia, serif; letter-spacing: -.03em; }
.mini-note > p:last-child { max-width: 680px; color: #53636a; font: 400 20px/1.65 "Source Serif 4", Georgia, serif; }

.research-invite {
  background: var(--coral);
  padding: clamp(80px, 10vw, 120px) 0;
}

.research-invite .publication-kicker { color: var(--navy); }
.research-invite p:not(.publication-kicker) { max-width: 600px; font: 400 20px/1.6 "Source Serif 4", Georgia, serif; }

@media (max-width: 650px) {
  .research-header { position: relative; }
  .research-actions { flex-direction: column; align-items: flex-start; }
  .research-section-head { display: block; }
  .research-section-head > p { margin-top: 15px; }
  .featured-article,
  .research-entry {
    grid-template-columns: 1fr;
  }
  .featured-article {
    margin-inline: -16px;
    padding: 30px 16px;
  }
  .article-signal { min-height: 0; }
  .entry-mark { width: 100%; }
  .research-entry { gap: 23px; }
  .tree-legend { gap: 12px 18px; }
  .tree-node { padding-left: 42px; }
  .research-tree::before { left: 11px; }
  .node-dot { left: 3px; }
  .node-detail { padding-right: 0; }
}