:root {
  --bg: #f5f7f4;
  --bg-alt: #ffffff;
  --text: #182022;
  --muted: #4d5a60;
  --line: #d4dcdf;
  --brand: #0f5f66;
  --brand-dark: #08363a;
  --accent: #f2b84b;
  --radius: 14px;
  --shadow: 0 14px 30px rgba(7, 37, 45, 0.08);
}

* {
  box-sizing: border-box;
}

html,
body {
  margin: 0;
  padding: 0;
  background: radial-gradient(circle at 15% 0%, #eaf1f2 0%, var(--bg) 35%, #eef2ec 100%);
  color: var(--text);
  font-family: "IBM Plex Sans", "Helvetica Neue", Helvetica, sans-serif;
}

a {
  color: var(--brand);
}

.container {
  width: min(1100px, 92vw);
  margin: 0 auto;
}

.hero {
  position: relative;
  overflow: hidden;
  padding: 76px 0 46px;
  border-bottom: 1px solid var(--line);
}

.hero-bg {
  position: absolute;
  inset: 0;
  background:
    radial-gradient(circle at 75% 10%, rgba(242, 184, 75, 0.24), transparent 35%),
    linear-gradient(180deg, rgba(9, 70, 76, 0.05) 0%, rgba(9, 70, 76, 0) 80%);
  pointer-events: none;
}

.badge {
  display: inline-block;
  margin: 0 0 14px;
  padding: 6px 10px;
  border: 1px solid #96afb3;
  border-radius: 999px;
  font-size: 13px;
  letter-spacing: 0.05em;
  text-transform: uppercase;
  color: #26474d;
  background: rgba(255, 255, 255, 0.7);
}

h1,
h2,
h3 {
  font-family: "Source Serif 4", Georgia, serif;
  margin: 0;
}

h1 {
  font-size: clamp(2rem, 4vw, 3rem);
  line-height: 1.1;
  max-width: 980px;
  text-align: center;
  margin-left: auto;
  margin-right: auto;
}

.authors,
.affiliation {
  margin: 14px 0 0;
  color: var(--muted);
  font-size: 1rem;
  text-align: center;
}

.authors {
  display: flex;
  flex-wrap: wrap;
  gap: 6px 14px;
  margin-top: 18px;
  justify-content: center;
}

.authors span {
  white-space: nowrap;
}

.author-link {
  color: inherit;
  text-decoration: none;
  border-bottom: 1px dashed #9cb0b5;
}

.author-link:hover {
  color: var(--brand);
  border-bottom-color: var(--brand);
}

.author-notes {
  margin-top: 8px;
  color: var(--muted);
  font-size: 0.95rem;
  text-align: center;
}

.actions {
  display: flex;
  gap: 10px;
  margin-top: 24px;
  flex-wrap: wrap;
  justify-content: center;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  text-decoration: none;
  padding: 10px 18px;
  border-radius: 10px;
  border: 1px solid var(--brand);
  background: var(--brand);
  color: #fff;
  font-weight: 600;
}

.btn-ghost {
  background: transparent;
  color: var(--brand);
}

.section {
  padding: 40px 0;
}

h2 {
  font-size: clamp(1.6rem, 2.5vw, 2.1rem);
  margin-bottom: 14px;
}

h3 {
  font-size: 1.2rem;
  margin-bottom: 8px;
  display: flex;
  align-items: center;
  gap: 8px;
}

.card-icon {
  position: absolute;
  bottom: 18px;
  right: 18px;
  width: 2rem;
  height: 2rem;
  object-fit: contain;
}

p {
  margin: 0;
  line-height: 1.75;
}

.subtext {
  color: var(--muted);
  margin-bottom: 14px;
}

.feature-image {
  width: 100%;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  background: #fff;
}

.compact-figure {
  max-width: 520px;
  margin: 0 auto;
  display: block;
}

.figure-pair {
  align-items: start;
}

.figure-frame {
  background: #fff;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  min-height: 330px;
  padding: 14px;
  display: flex;
  align-items: center;
  justify-content: center;
}

.equalized-figure {
  box-shadow: none;
  border: none;
  border-radius: 8px;
  max-height: 300px;
  width: 100%;
  object-fit: contain;
}

.video-placeholder {
  border: 1px dashed #9ab0b6;
  border-radius: var(--radius);
  min-height: 360px;
  background: #fff;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--muted);
  box-shadow: var(--shadow);
  overflow: hidden;
}

.video-placeholder iframe {
  width: 100%;
  aspect-ratio: 16 / 9;
  border: 0;
}

.youtube-link-card {
  display: block;
  width: 100%;
  text-decoration: none;
  color: #fff;
  position: relative;
}

.youtube-link-card img {
  width: 100%;
  aspect-ratio: 16 / 9;
  object-fit: cover;
  display: block;
}

.youtube-link-card span {
  position: absolute;
  left: 16px;
  bottom: 16px;
  background: rgba(15, 95, 102, 0.9);
  border: 1px solid rgba(255, 255, 255, 0.35);
  padding: 8px 12px;
  border-radius: 999px;
  font-weight: 600;
  letter-spacing: 0.01em;
}

.grid {
  display: grid;
  gap: 16px;
}

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

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

.card,
.video-card {
  background: var(--bg-alt);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 18px;
  box-shadow: var(--shadow);
  position: relative;
  min-height: 140px;
}

.table-wrap {
  overflow-x: auto;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--bg-alt);
  box-shadow: var(--shadow);
}

table {
  width: 100%;
  border-collapse: collapse;
}

th,
td {
  text-align: left;
  padding: 13px 16px;
  border-bottom: 1px solid #e3eaed;
}

th {
  background: #f1f5f5;
}

tr:last-child td {
  border-bottom: none;
}

video {
  width: 100%;
  border-radius: 10px;
  border: 1px solid var(--line);
  background: #000;
}

.task-block {
  margin-bottom: 18px;
}

.video-row {
  display: flex;
  gap: 12px;
}

.video-item {
  flex: 0 0 calc(50% - 6px);
}

.video-instruction {
  margin-top: 10px;
  border: 1px solid #b9c8cd;
  background: #f4f8f9;
  border-radius: 10px;
  padding: 10px 12px;
  color: #16262a;
  line-height: 1.45;
  font-size: 0.94rem;
}

.carousel {
  display: flex;
  align-items: center;
  gap: 10px;
}

.carousel-viewport {
  overflow: hidden;
  flex: 1;
}

.carousel-track {
  display: flex;
  gap: 12px;
  transition: transform 0.35s ease;
  will-change: transform;
}

.carousel-btn {
  width: 34px;
  height: 34px;
  border: 1px solid #b7c6ca;
  background: #fff;
  color: #27484e;
  border-radius: 50%;
  cursor: pointer;
  font-size: 1.25rem;
  line-height: 1;
  display: inline-flex;
  align-items: center;
  justify-content: center;
}

.carousel-btn:disabled {
  opacity: 0.35;
  cursor: not-allowed;
}

.bibtex {
  margin: 0;
  padding: 18px;
  background: #112127;
  color: #e4f1f4;
  border-radius: var(--radius);
  overflow-x: auto;
  font-size: 0.92rem;
}

footer {
  margin-top: 10px;
  border-top: 1px solid var(--line);
  background: #f0f3ef;
}

.footer-inner {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 12px;
  padding: 20px 0 30px;
  color: var(--muted);
}

.reveal {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity 0.55s ease, transform 0.55s ease;
}

.reveal.visible {
  opacity: 1;
  transform: translateY(0);
}

@media (max-width: 980px) {
  .grid.four {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (max-width: 720px) {
  .hero {
    padding-top: 56px;
  }

  .grid.two,
  .grid.four {
    grid-template-columns: 1fr;
  }

  .footer-inner {
    flex-direction: column;
    align-items: flex-start;
  }

  .authors {
    gap: 4px 10px;
    font-size: 0.94rem;
  }

  .video-row {
    flex-direction: column;
  }

  .video-item {
    flex-basis: 100%;
  }
}