/* ============================================
   Knowledge-centered survey site styling
   restrained academic palette with clearer
   hierarchy for cards, filters, and tables.
   ============================================ */

:root {
  --c-ink: #111827;
  --c-paper: #ffffff;
  --c-muted: #52607a;
  --c-line: #d6deea;
  --c-surface: #f4f7fb;
  --c-surface-strong: #e8eef7;
  --c-accent: #0f4aa3;
  --c-accent-visited: #4c3d91;
  --c-l1: #e8f0fb;
  --c-l2: #edf7f0;
  --c-l3: #f8efe5;
}

.md-header {
  background: #101827 !important;
  box-shadow: none !important;
}

.md-tabs {
  background: #172338 !important;
}

.md-tabs__link {
  color: rgba(255, 255, 255, 0.76) !important;
  text-transform: none;
  letter-spacing: 0;
}

.md-tabs__link:hover,
.md-tabs__link--active {
  color: #fff !important;
}

.md-main,
.md-content,
.md-typeset {
  background: var(--c-paper);
  color: var(--c-ink);
}

.md-typeset h1,
.md-typeset h2 {
  color: var(--c-ink);
  border-bottom: 1px solid var(--c-line);
  padding-bottom: 0.28em;
}

.md-typeset h1 {
  font-weight: 700;
}

.md-typeset h2 {
  font-size: 1.32rem;
}

.md-typeset h3,
.md-typeset h4 {
  color: var(--c-ink);
}

.md-typeset a {
  color: var(--c-accent);
}

.md-typeset a:visited {
  color: var(--c-accent-visited);
}

.md-typeset table:not([class]) {
  border: 1px solid var(--c-line);
  border-radius: 0;
  box-shadow: none;
}

.md-typeset table:not([class]) th {
  background: var(--c-surface);
  font-weight: 600;
  border-bottom: 1px solid var(--c-line);
}

.md-grid {
  max-width: 96rem;
}

.home-hero {
  display: grid;
  gap: 1.5rem;
  margin: 0 0 2rem;
  padding: 2rem 0 1.5rem;
  border-bottom: 1px solid var(--c-line);
}

.hero-copy h1 {
  margin: 0 0 0.55rem;
  border-bottom: none;
  font-size: 1.85rem;
}

.home-eyebrow,
.section-kicker {
  margin: 0;
  color: var(--c-muted);
  font-size: 0.74rem;
  letter-spacing: 0.02em;
  text-transform: uppercase;
}

.hero-lead {
  max-width: 58rem;
  margin: 0 0 1rem;
  color: var(--c-muted);
  font-size: 0.95rem;
  line-height: 1.72;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
}

.hero-actions .md-button,
.explorer-toolbar .md-button {
  border-radius: 0;
  font-size: 0.82rem;
  font-weight: 600;
}

.hero-actions .md-button {
  background: #101827;
  border: 1px solid #101827;
  color: #fff;
}

.hero-actions .md-button:hover,
.hero-actions .md-button--primary:hover {
  background: #1c2c47;
}

.hero-metrics,
.home-flow,
.trend-grid,
.opportunity-list,
.entry-points,
.stats-card-grid,
.summary-card-grid,
.rep-systems-grid,
.resource-grid,
.download-grid {
  display: grid;
  gap: 1rem;
}

.hero-metrics {
  grid-template-columns: repeat(4, minmax(0, 1fr));
}

.metric-card,
.stats-card {
  display: block;
  padding: 1rem 1.1rem;
  border: 1px solid var(--c-line);
  background: var(--c-surface);
  text-decoration: none !important;
}

.metric-card span,
.stats-card span {
  display: block;
  color: var(--c-muted);
  font-size: 0.72rem;
  text-transform: uppercase;
  letter-spacing: 0.02em;
}

.metric-card strong,
.stats-card strong {
  display: block;
  margin-top: 0.22rem;
  font-size: 1.38rem;
  color: var(--c-ink);
}

.metric-card-link:hover,
.stats-card:hover {
  background: var(--c-surface-strong);
}

.home-flow {
  grid-template-columns: repeat(4, minmax(0, 1fr));
  margin: 1.4rem 0;
}

.home-flow article,
.trend-grid article,
.opportunity-list article,
.entry-points article,
.resource-card,
.download-grid article {
  padding: 1rem;
  border: 1px solid var(--c-line);
  background: var(--c-paper);
}

.flow-index,
.opportunity-list article span {
  display: inline-block;
  margin-bottom: 0.2rem;
  color: var(--c-muted);
  font-size: 0.72rem;
  text-transform: uppercase;
}

.home-section-intro,
.navigation-section {
  margin: 1.8rem 0;
}

.home-section-intro p,
.navigation-section > p:not(.section-kicker) {
  color: var(--c-muted);
  line-height: 1.7;
}

.paper-category {
  margin: 0.7rem 0;
  border: 1px solid var(--c-line);
  background: var(--c-paper);
}

.paper-category summary {
  cursor: pointer;
  display: flex;
  align-items: center;
  gap: 0.8rem;
  padding: 0.7rem 0.9rem;
  list-style: none;
  background: var(--c-surface);
}

.paper-category summary::-webkit-details-marker {
  display: none;
}

.paper-category summary::before {
  content: "+";
  color: var(--c-muted);
  font-weight: 700;
}

.paper-category[open] summary::before {
  content: "−";
}

.category-name {
  flex: 1 1 auto;
  font-weight: 700;
}

.category-count {
  color: var(--c-muted);
  font-size: 0.76rem;
}

.category-definition,
.subcategory-note,
.category-action,
.section-tail-link,
.catalog-status {
  color: var(--c-muted);
}

.category-definition,
.subcategory-note,
.category-action {
  padding: 0.65rem 0.9rem 0;
}

.subcategory-block {
  padding: 0.65rem 0.9rem 0.2rem;
  border-top: 1px solid var(--c-line);
  background: #fbfdff;
}

.subcategory-header strong {
  display: block;
  margin-bottom: 0.18rem;
}

.subcategory-header p,
.summary-card-desc,
.rep-system-summary,
.resource-card p,
.download-grid article p {
  color: var(--c-muted);
  line-height: 1.62;
}

.subcategory-empty {
  color: var(--c-muted);
  font-style: italic;
}

.paper-list {
  display: grid;
}

.paper-row {
  display: grid;
  grid-template-columns: 9rem 1fr auto;
  gap: 0.8rem;
  align-items: start;
  padding: 0.65rem 0;
  border-bottom: 1px solid var(--c-line);
}

.paper-row:last-child,
.rep-system-paper:last-child,
.resource-item:last-child {
  border-bottom: none;
}

.paper-row-tag {
  color: var(--c-muted);
  font-size: 0.72rem;
}

.paper-title {
  color: var(--c-accent) !important;
  font-weight: 600;
  text-decoration: none;
}

.paper-title:hover,
.summary-paper-link:hover {
  text-decoration: underline;
}

.paper-meta {
  margin: 0.16rem 0 0;
  color: var(--c-muted);
  font-size: 0.72rem;
}

.paper-link {
  display: inline-block;
  padding: 0.22rem 0.52rem;
  color: #fff !important;
  background: #233550;
  font-size: 0.68rem;
  text-decoration: none;
  white-space: nowrap;
}

.paper-link:hover {
  background: #101827;
}

.paper-link-doi {
  background: #385274;
}

.paper-link-scholar {
  background: #5d6d87;
}

.paper-link-table {
  background: #6c7c44;
}

.stage-filter-bar,
.taxonomy-stage-links,
.tag-list {
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem;
}

.stage-filter-bar {
  padding: 0.7rem 0.9rem 0.8rem;
  border-top: 1px solid var(--c-line);
  font-size: 0.72rem;
}

.stage-filter-link,
.taxonomy-stage-links a {
  text-decoration: none;
}

.summary-card-grid {
  grid-template-columns: repeat(3, minmax(0, 1fr));
  margin-top: 1rem;
}

.summary-card-stack {
  grid-template-columns: 1fr;
}

.summary-card,
.taxonomy-card {
  padding: 1rem;
  border: 1px solid var(--c-line);
  background: var(--c-paper);
}

.home-rq-card {
  display: flex;
  flex-direction: column;
  gap: 0.55rem;
}

.summary-card-head,
.taxonomy-card-head,
.rep-system-head {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: 0.5rem;
  align-items: baseline;
}

.summary-card-head h3,
.taxonomy-card-head h4 {
  margin: 0;
}

.summary-card-head span,
.taxonomy-card-head span {
  color: var(--c-muted);
  font-size: 0.75rem;
}

.summary-paper-list,
.resource-list {
  display: grid;
  gap: 0.35rem;
  margin: 0.7rem 0 0.9rem;
}

.summary-paper-list-detailed {
  margin-top: 0.55rem;
  padding-top: 0.55rem;
  border-top: 1px solid var(--c-line);
}

.summary-paper-item {
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 0.7rem;
  align-items: start;
  padding: 0.35rem 0;
  border-bottom: 1px solid var(--c-line);
}

.summary-paper-item:last-child {
  border-bottom: none;
}

.summary-paper-main {
  min-width: 0;
}

.summary-paper-link {
  color: var(--c-accent) !important;
  text-decoration: none;
  font-size: 0.84rem;
}

.summary-highlights {
  margin: 0;
  padding-left: 1rem;
  color: var(--c-muted);
  font-size: 0.76rem;
}

.summary-highlights li + li {
  margin-top: 0.2rem;
}

.home-rq-card .subcategory-block {
  padding: 0.6rem 0 0.1rem;
  border-top: 1px solid var(--c-line);
  background: transparent;
}

.home-rq1-card .stage-filter-bar {
  padding: 0.6rem 0 0.2rem;
  border-top: 1px solid var(--c-line);
}

.home-rq1-card .category-action {
  padding: 0.2rem 0 0;
}

.home-rq-card .paper-row {
  grid-template-columns: 1fr;
  padding: 0.45rem 0;
}

.home-rq-card .paper-link {
  justify-self: start;
}

.home-rq-card .summary-paper-item .paper-link {
  justify-self: end;
}

.summary-card-action {
  font-weight: 600;
}

.section-tail-link {
  margin-top: 0.8rem;
}

.trend-grid {
  grid-template-columns: repeat(3, minmax(0, 1fr));
}

.opportunity-list,
.download-grid {
  grid-template-columns: repeat(2, minmax(0, 1fr));
}

.entry-points {
  grid-template-columns: repeat(3, minmax(0, 1fr));
  margin-top: 2rem;
}

.rep-systems-grid,
.resource-grid {
  grid-template-columns: repeat(2, minmax(0, 1fr));
  margin-top: 1rem;
}

.rep-system-card {
  padding: 1rem;
  border: 1px solid var(--c-line);
  background: var(--c-paper);
}

.rep-knowledge-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 0.3rem;
}

.knowledge-tag,
.table-tag {
  display: inline-block;
  padding: 0.15rem 0.48rem;
  border: 1px solid var(--c-line);
  background: var(--c-surface);
  font-size: 0.67rem;
}

.rep-system-paper,
.resource-item {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.45rem;
  padding: 0.55rem 0 0;
  border-top: 1px solid var(--c-line);
}

.stats-card-grid {
  grid-template-columns: repeat(3, minmax(0, 1fr));
  margin: 1rem 0 1.5rem;
}

.preset-filter-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 0.85rem;
  margin: 1rem 0 1.4rem;
}

.preset-filter-card {
  display: block;
  padding: 0.9rem 1rem;
  border: 1px solid var(--c-line);
  background: var(--c-surface);
  color: var(--c-accent) !important;
  text-decoration: none;
  font-weight: 600;
}

.preset-filter-card:hover {
  background: var(--c-surface-strong);
}

.legend-strip {
  display: flex;
  flex-wrap: wrap;
  gap: 0.6rem;
  margin: 0.8rem 0 1rem;
}

.legend-item {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  padding: 0.3rem 0.55rem;
  border: 1px solid var(--c-line);
  background: var(--c-paper);
  font-size: 0.74rem;
  color: var(--c-muted);
}

.taxonomy-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 1rem;
  margin: 0.9rem 0 1.5rem;
}

.taxonomy-grid:nth-of-type(1) .taxonomy-card {
  background: var(--c-l1);
}

.taxonomy-grid:nth-of-type(2) .taxonomy-card {
  background: var(--c-l2);
}

.taxonomy-grid:nth-of-type(3) .taxonomy-card {
  background: var(--c-l3);
}

.explorer-toolbar {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 0.85rem;
  margin: 1rem 0 0.7rem;
}

.explorer-toolbar > * {
  min-width: 0;
}

.explorer-toolbar label {
  display: grid;
  gap: 0.28rem;
}

.explorer-toolbar span {
  color: var(--c-muted);
  font-size: 0.74rem;
  font-weight: 600;
}

.explorer-toolbar input,
.explorer-toolbar select {
  width: 100%;
  min-height: 2.4rem;
  padding: 0.45rem 0.55rem;
  border: 1px solid var(--c-line);
  border-radius: 0;
  background: var(--c-paper);
  color: var(--c-ink);
}

.catalog-status {
  margin: 0.25rem 0 1rem;
}

.catalog-table-wrap,
.matrix-table-wrap {
  overflow-x: auto;
  border: 1px solid var(--c-line);
}

.catalog-table,
.matrix-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.83rem;
}

.catalog-table th,
.catalog-table td,
.matrix-table th,
.matrix-table td {
  padding: 0.75rem;
  border-bottom: 1px solid var(--c-line);
  vertical-align: top;
}

.catalog-table th,
.matrix-table th {
  background: var(--c-surface);
  text-align: left;
  font-size: 0.76rem;
  text-transform: uppercase;
  letter-spacing: 0.02em;
}

.catalog-paper-cell {
  min-width: 18rem;
}

.catalog-table td[data-label="Knowledge Profile"] .tag-list {
  gap: 0.25rem;
}

.insight-table th:nth-child(1),
.insight-table td:nth-child(1) {
  width: 19%;
}

.insight-table th:nth-child(3),
.insight-table td:nth-child(3) {
  width: 24%;
}

.catalog-empty td,
.cell-note {
  color: var(--c-muted);
  font-size: 0.73rem;
}

.cell-stack {
  display: grid;
  gap: 0.28rem;
}

.cell-stack > div {
  line-height: 1.45;
}

.rq6-table th:last-child,
.rq6-table td:last-child {
  text-align: left;
  white-space: nowrap;
}

.dense-table td strong {
  display: block;
  margin-bottom: 0.22rem;
}

.resource-card h3 {
  margin-top: 0;
}

.paper-hero {
  display: grid;
  gap: 1.5rem;
  margin: 0 0 1.8rem;
  padding: 2rem 0 1.3rem;
  border-bottom: 1px solid var(--c-line);
}

.paper-preview-grid {
  display: grid;
  grid-template-columns: minmax(0, 1.7fr) minmax(18rem, 0.9fr);
  gap: 1rem;
  margin: 1.2rem 0 2rem;
}

.paper-preview-panel,
.paper-side-panel {
  min-width: 0;
}

.paper-preview-panel h2,
.paper-side-panel h3 {
  margin-top: 0;
}

.paper-frame {
  width: 100%;
  min-height: 52rem;
  border: 1px solid var(--c-line);
  background: #f6f8fb;
}

.paper-info-card p {
  margin: 0 0 0.9rem;
  line-height: 1.65;
}

.paper-info-card p:last-child {
  margin-bottom: 0;
}

.paper-note {
  color: var(--c-muted);
  font-size: 0.82rem;
}

.paper-flow {
  grid-template-columns: repeat(3, minmax(0, 1fr));
}

.paper-rq-grid {
  grid-template-columns: repeat(3, minmax(0, 1fr));
}

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

.paper-figure-card {
  padding: 1rem;
  border: 1px solid var(--c-line);
  background: var(--c-paper);
}

.paper-figure-card h3 {
  margin-top: 0;
}

.paper-figure-card p {
  color: var(--c-muted);
  line-height: 1.62;
}

.paper-figure-card img {
  display: block;
  width: 100%;
  margin-top: 0.8rem;
  border: 1px solid var(--c-line);
  background: #fff;
}

@media screen and (max-width: 1100px) {
  .hero-metrics,
  .stats-card-grid,
  .preset-filter-grid,
  .summary-card-grid,
  .taxonomy-grid,
  .resource-grid,
  .rep-systems-grid,
  .home-flow,
  .trend-grid,
  .entry-points {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .explorer-toolbar {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
}

@media screen and (max-width: 900px) {
  .explorer-toolbar {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .paper-preview-grid,
  .paper-rq-grid,
  .paper-flow,
  .paper-figure-grid {
    grid-template-columns: 1fr;
  }
}

@media screen and (max-width: 820px) {
  .paper-row {
    grid-template-columns: 1fr;
  }

  .opportunity-list,
  .download-grid {
    grid-template-columns: 1fr;
  }

  .catalog-table thead {
    display: none;
  }

  .catalog-table,
  .catalog-table tbody,
  .catalog-table tr,
  .catalog-table td {
    display: block;
    width: 100%;
  }

  .catalog-table tr {
    border-bottom: 1px solid var(--c-line);
  }

  .catalog-table td {
    padding: 0.55rem 0.75rem;
  }

  .catalog-table td::before {
    content: attr(data-label);
    display: block;
    margin-bottom: 0.16rem;
    color: var(--c-muted);
    font-size: 0.72rem;
    text-transform: uppercase;
  }

  .preset-filter-grid {
    grid-template-columns: 1fr;
  }

  .legend-strip {
    flex-direction: column;
  }

  .paper-frame {
    min-height: 34rem;
  }
}

@media screen and (max-width: 640px) {
  .hero-copy h1 {
    font-size: 1.48rem;
  }

  .hero-metrics,
  .stats-card-grid,
  .preset-filter-grid,
  .summary-card-grid,
  .taxonomy-grid,
  .resource-grid,
  .rep-systems-grid,
  .home-flow,
  .trend-grid,
  .entry-points,
  .explorer-toolbar {
    grid-template-columns: 1fr;
  }
}