:root {
  --color-bg: #ffffff;
  --color-text: #1d2330;
  --color-muted: #5b6472;
  --color-accent: #2456a8;
  --color-accent-dark: #173a78;
  --color-panel: #f5f7fa;
  --color-border: #e3e7ee;
  --max-width: 1080px;
  --radius: 10px;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: "Source Sans 3", "Helvetica Neue", Arial, sans-serif;
  color: var(--color-text);
  background: var(--color-bg);
  line-height: 1.65;
  font-size: 17px;
}

h1, h2, h3 {
  font-family: "Source Serif 4", Georgia, "Times New Roman", serif;
  font-weight: 600;
  line-height: 1.25;
  color: #14182a;
}

a {
  color: var(--color-accent);
  text-decoration: none;
}

a:hover {
  color: var(--color-accent-dark);
  text-decoration: underline;
}

.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 24px;
}

/* ---------- Hero ---------- */

.hero {
  padding: 72px 0 40px;
  text-align: center;
  background: linear-gradient(180deg, #f7f9fc 0%, #ffffff 100%);
  border-bottom: 1px solid var(--color-border);
}

.hero .venue-tag {
  display: inline-block;
  font-size: 13px;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--color-accent);
  background: #e8f0fc;
  border-radius: 999px;
  padding: 5px 14px;
  margin-bottom: 22px;
  font-weight: 600;
}

.hero h1 {
  font-size: 2.35rem;
  max-width: 880px;
  margin: 0 auto 28px;
}

.authors {
  font-size: 1.05rem;
  margin: 0 auto 8px;
  max-width: 760px;
  color: #2a3142;
}

.authors a {
  color: inherit;
  border-bottom: 1px dotted #9aa6b8;
}

.authors a:hover {
  color: var(--color-accent);
}

.affiliation {
  color: var(--color-muted);
  font-size: 0.95rem;
  margin-bottom: 30px;
}

.hero-links {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 12px;
  margin-top: 10px;
}

.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 10px 20px;
  border-radius: 999px;
  border: 1px solid var(--color-border);
  background: #14182a;
  color: #fff;
  font-size: 0.95rem;
  font-weight: 600;
  transition: transform 0.15s ease, box-shadow 0.15s ease, background 0.15s ease;
}

.btn:hover {
  background: var(--color-accent-dark);
  color: #fff;
  text-decoration: none;
  transform: translateY(-1px);
  box-shadow: 0 6px 14px rgba(20, 24, 42, 0.18);
}

.btn.secondary {
  background: #fff;
  color: var(--color-text);
}

.btn.secondary:hover {
  background: var(--color-panel);
  color: var(--color-text);
}

.btn.disabled {
  background: var(--color-panel);
  color: var(--color-muted);
  border-color: var(--color-border);
  cursor: not-allowed;
  pointer-events: none;
  opacity: 0.7;
}

.btn svg {
  width: 16px;
  height: 16px;
  flex-shrink: 0;
}

/* ---------- Sections ---------- */

section {
  padding: 56px 0;
}

section.alt {
  background: var(--color-panel);
  border-top: 1px solid var(--color-border);
  border-bottom: 1px solid var(--color-border);
}

.section-title {
  font-size: 1.65rem;
  margin: 0 0 28px;
  text-align: center;
}

.section-kicker {
  text-align: center;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  font-size: 0.78rem;
  color: var(--color-muted);
  font-weight: 700;
  margin-bottom: 8px;
}

.lede {
  max-width: 760px;
  margin: 0 auto 20px;
  text-align: center;
  font-size: 1.12rem;
  color: #333a48;
}

.prose {
  max-width: 760px;
  margin: 0 auto;
}

.prose p {
  margin: 0 0 18px;
}

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

/* ---------- Video ---------- */

.video-wrap {
  max-width: 920px;
  margin: 0 auto;
  position: relative;
  width: 100%;
  aspect-ratio: 16 / 9;
  border-radius: var(--radius);
  overflow: hidden;
  border: 1px solid var(--color-border);
  background: #14182a;
}

.video-wrap iframe {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  border: 0;
}

/* ---------- Figures ---------- */

figure {
  margin: 0 0 14px;
  text-align: center;
}

figure img {
  max-width: 100%;
  border-radius: var(--radius);
  border: 1px solid var(--color-border);
  background: #fff;
}

figcaption {
  font-size: 0.92rem;
  color: var(--color-muted);
  margin-top: 12px;
  max-width: 820px;
  margin-left: auto;
  margin-right: auto;
  text-align: left;
}

figcaption strong {
  color: var(--color-text);
}

.figure-block {
  margin: 36px 0;
}

.figure-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 28px;
  align-items: start;
  margin: 36px 0;
}

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

.figure-row figcaption {
  margin-left: 0;
  margin-right: 0;
}

/* ---------- Contributions list ---------- */

.contrib-list {
  max-width: 760px;
  margin: 28px auto 0;
  padding: 0;
  list-style: none;
  display: grid;
  gap: 14px;
}

.contrib-list li {
  display: flex;
  gap: 14px;
  background: #fff;
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 16px 18px;
}

.contrib-list .num {
  flex-shrink: 0;
  width: 30px;
  height: 30px;
  border-radius: 50%;
  background: var(--color-accent);
  color: #fff;
  font-weight: 700;
  font-size: 0.9rem;
  display: flex;
  align-items: center;
  justify-content: center;
}

/* ---------- Cards / stats ---------- */

.stat-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 16px;
  max-width: 920px;
  margin: 0 auto 40px;
}

@media (max-width: 760px) {
  .stat-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

.stat-card {
  background: #fff;
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 20px 16px;
  text-align: center;
}

.stat-card .stat-value {
  font-family: "Source Serif 4", Georgia, serif;
  font-size: 1.7rem;
  font-weight: 700;
  color: var(--color-accent-dark);
  display: block;
}

.stat-card .stat-label {
  font-size: 0.85rem;
  color: var(--color-muted);
  margin-top: 4px;
}

/* ---------- Tables ---------- */

.table-wrap {
  overflow-x: auto;
  margin: 0 auto 14px;
  max-width: 900px;
}

table.results {
  border-collapse: collapse;
  width: 100%;
  font-size: 0.93rem;
  background: #fff;
}

table.results caption {
  text-align: left;
  font-size: 0.85rem;
  color: var(--color-muted);
  margin-bottom: 8px;
  caption-side: top;
}

table.results th,
table.results td {
  border-bottom: 1px solid var(--color-border);
  padding: 9px 14px;
  text-align: center;
}

table.results th {
  background: var(--color-panel);
  font-weight: 700;
  color: #222a3a;
}

table.results td:first-child,
table.results th:first-child {
  text-align: left;
}

table.results tr.highlight td {
  font-weight: 700;
  background: #eef4fd;
}

/* ---------- Sub-experiment blocks ---------- */

.exp-block {
  margin: 0 0 64px;
}

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

.exp-block h3 {
  font-size: 1.3rem;
  margin-bottom: 6px;
  text-align: center;
}

.exp-sub {
  text-align: center;
  color: var(--color-muted);
  font-size: 0.95rem;
  margin-bottom: 28px;
}

.platform-photos {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 16px;
  margin: 24px 0;
}

@media (max-width: 760px) {
  .platform-photos {
    grid-template-columns: 1fr;
  }
}

/* ---------- BibTeX ---------- */

.bibtex-wrap {
  max-width: 760px;
  margin: 0 auto;
  position: relative;
}

pre.bibtex {
  background: #14182a;
  color: #d7def0;
  padding: 22px 24px;
  border-radius: var(--radius);
  font-size: 0.85rem;
  overflow-x: auto;
  font-family: "SFMono-Regular", Consolas, "Liberation Mono", Menlo, monospace;
  line-height: 1.55;
}

.copy-btn {
  position: absolute;
  top: 14px;
  right: 14px;
  background: rgba(255, 255, 255, 0.1);
  color: #d7def0;
  border: 1px solid rgba(255, 255, 255, 0.2);
  border-radius: 6px;
  padding: 6px 12px;
  font-size: 0.78rem;
  cursor: pointer;
  font-family: inherit;
}

.copy-btn:hover {
  background: rgba(255, 255, 255, 0.2);
}

/* ---------- Footer ---------- */

footer {
  padding: 36px 0 48px;
  text-align: center;
  color: var(--color-muted);
  font-size: 0.88rem;
}

footer a {
  color: var(--color-muted);
}

/* ---------- Misc ---------- */

.note-card {
  max-width: 760px;
  margin: 28px auto 0;
  background: #fff7e6;
  border: 1px solid #f0e0b0;
  border-radius: var(--radius);
  padding: 16px 20px;
  font-size: 0.93rem;
  color: #5c4a16;
}

.toc {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 18px;
  margin: 28px 0 0;
  font-size: 0.92rem;
}

.back-to-top {
  display: block;
  text-align: center;
  margin-top: 18px;
  font-size: 0.85rem;
}