:root {
  --bg: #f6f7f2;
  --bg-alt: #eef1e6;
  --card: #ffffff;
  --ink: #1f2a24;
  --ink-soft: #516159;
  --line: #d5ddd0;
  --brand: #0f766e;
  --brand-dark: #115e59;
  --accent: #d97706;
  --shadow: 0 14px 36px rgba(19, 40, 32, 0.12);
  --radius: 16px;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: 'IBM Plex Sans', sans-serif;
  color: var(--ink);
  background:
    radial-gradient(circle at 10% 0%, rgba(15, 118, 110, 0.12), transparent 36%),
    radial-gradient(circle at 90% 20%, rgba(217, 119, 6, 0.14), transparent 32%),
    var(--bg);
}

.hero-section {
  padding: 4.6rem 1.25rem 2.4rem;
  text-align: center;
}

.project-title {
  margin: 0 0 1.1rem;
  font-family: 'Space Grotesk', sans-serif;
  font-size: clamp(1.9rem, 4.2vw, 2.55rem);
  letter-spacing: -0.03em;
  line-height: 1.15;
}

.project-title .title-line {
  display: block;
  white-space: nowrap;
}

.project-title {
  background: linear-gradient(90deg, #0f766e 0%, #0ea5e9 45%, #d97706 100%);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

.authors-line {
  margin: 0 auto;
  max-width: 960px;
  font-size: 1.18rem;
  font-weight: 500;
  line-height: 1.5;
}

.authors-row {
  display: block;
}

.affiliations-line {
  margin: 1rem auto 0;
  max-width: 920px;
  display: flex;
  flex-wrap: wrap;
  gap: 0.45rem 0.8rem;
  justify-content: center;
  font-size: 1rem;
  color: var(--ink-soft);
}

.hero-links {
  margin-top: 1.5rem;
  display: flex;
  gap: 0.7rem;
  justify-content: center;
  flex-wrap: wrap;
}

.action-btn {
  text-decoration: none;
  border-radius: 999px;
  padding: 0.62rem 1.05rem;
  background: var(--brand);
  color: #fff;
  font-weight: 600;
  transition: transform 0.16s ease, background-color 0.16s ease;
  display: inline-flex;
  align-items: center;
  gap: 0.45rem;
}

.action-btn:hover {
  transform: translateY(-1px);
  background: var(--brand-dark);
  color: #fff;
}

.action-btn-light {
  background: #fff;
  color: var(--brand-dark);
  border: 1px solid var(--line);
}

.btn-with-icon .github-icon {
  width: 0.95rem;
  height: 0.95rem;
  fill: currentColor;
}

.action-btn-disabled {
  opacity: 0.72;
  cursor: not-allowed;
  pointer-events: none;
}

.section-block {
  padding: 2.4rem 1.25rem;
}

.section-block-alt {
  background: linear-gradient(180deg, rgba(238, 241, 230, 0.75), rgba(238, 241, 230, 0.4));
  border-top: 1px solid rgba(31, 42, 36, 0.06);
  border-bottom: 1px solid rgba(31, 42, 36, 0.06);
}

.section-head h2 {
  margin: 0;
  font-family: 'Space Grotesk', sans-serif;
  font-size: clamp(1.4rem, 3.2vw, 2rem);
}

.section-head p {
  margin: 0.55rem 0 0;
  color: var(--ink-soft);
}

.video-frame {
  margin-top: 1rem;
  border-radius: var(--radius);
  overflow: hidden;
  box-shadow: var(--shadow);
  border: 1px solid var(--line);
  background: #fff;
}

.video-frame video {
  display: block;
  width: 100%;
  height: auto;
}

.failure-explorer-root {
  margin-top: 1.25rem;
  display: grid;
  grid-template-columns: 1fr;
  gap: 1rem;
}

.loading-state {
  background: #fff;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 1rem;
  color: var(--ink-soft);
}

.failure-card {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  overflow: hidden;
}

.failure-card-head {
  padding: 1rem;
  border-bottom: 1px solid var(--line);
  background: linear-gradient(90deg, rgba(15, 118, 110, 0.1), rgba(217, 119, 6, 0.08));
}

.failure-card-head h3 {
  margin: 0;
  font-family: 'Space Grotesk', sans-serif;
  font-size: 1.2rem;
}

.failure-card-head p {
  margin: 0.4rem 0 0;
  color: var(--ink-soft);
  font-size: 0.9rem;
}

.failure-card-body {
  padding: 1rem;
  display: grid;
  gap: 0.9rem;
}

.control-row {
  display: grid;
  gap: 0.5rem;
}

.control-row label {
  font-weight: 600;
  font-size: 0.9rem;
}

.control-row select {
  width: 100%;
  border: 1px solid var(--line);
  border-radius: 10px;
  background: #fff;
  color: var(--ink);
  padding: 0.58rem 0.65rem;
  font-size: 0.95rem;
}

.compare-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0.75rem;
}

.video-card {
  border: 1px solid var(--line);
  border-radius: 12px;
  overflow: hidden;
  background: #fafcf8;
}

.video-card .video-label {
  margin: 0;
  padding: 0.5rem 0.65rem;
  font-weight: 600;
  font-size: 0.85rem;
  color: var(--ink-soft);
  border-bottom: 1px solid var(--line);
}

.video-card video {
  display: block;
  width: 100%;
  height: auto;
}

.label-block {
  border: 1px solid var(--line);
  border-radius: 12px;
  background: #fafcf8;
  padding: 0.75rem;
  display: grid;
  gap: 0.7rem;
}

.label-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(185px, 1fr));
  gap: 0.45rem;
}

.label-item {
  border-radius: 10px;
  background: #fff;
  border: 1px solid var(--line);
  padding: 0.5rem;
  line-height: 1.35;
}

.label-key {
  display: block;
  color: var(--ink-soft);
  font-size: 0.75rem;
  letter-spacing: 0.03em;
  text-transform: uppercase;
}

.label-value {
  display: block;
  margin-top: 0.2rem;
  font-size: 0.9rem;
  font-weight: 600;
  word-break: break-word;
}

.summary-box {
  border-left: 3px solid var(--accent);
  padding: 0.35rem 0 0.35rem 0.6rem;
  color: var(--ink);
  font-size: 0.92rem;
}

.footer-note {
  padding: 1.6rem 1.25rem 2rem;
  text-align: center;
  color: var(--ink-soft);
}

.scroll-to-top {
  position: fixed;
  right: 1.2rem;
  bottom: 1.2rem;
  width: 42px;
  height: 42px;
  border: none;
  border-radius: 999px;
  background: var(--brand);
  color: #fff;
  font-size: 1.05rem;
  cursor: pointer;
  opacity: 0;
  visibility: hidden;
  transform: translateY(10px);
  transition: opacity 0.2s ease, transform 0.2s ease, visibility 0.2s ease;
}

.scroll-to-top.visible {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}

.scroll-to-top:hover {
  background: var(--brand-dark);
}

@media screen and (max-width: 940px) {
  .authors-line {
    font-size: 1.02rem;
  }
}

@media screen and (max-width: 768px) {
  .hero-section {
    padding-top: 3.2rem;
  }

  .project-title .title-line {
    white-space: normal;
  }

  .compare-grid {
    grid-template-columns: 1fr;
  }

  .failure-card-head,
  .failure-card-body {
    padding: 0.8rem;
  }

  .section-block {
    padding: 2rem 0.95rem;
  }
}