@import url("https://fonts.googleapis.com/css2?family=Space+Grotesk:wght@400;500;600;700&family=Inter:wght@300;400;500;600;700&family=Fira+Code:wght@400;500;600&display=swap");

:root {
  --honey-bronze: #d4940a;
  --hyper-magenta: #9333ea;
  --neon-violet: #a855f7;
  --cool-horizon: #3b82f6;
  --blue-energy: #2563eb;
  --bg-deep: #fafafa;
  --bg-surface: #ffffff;
  --bg-elevated: #f5f5f5;
  --text-primary: #1a1a1a;
  --text-secondary: #4a4a4a;
  --text-muted: #7a7a7a;
  --border-subtle: rgba(0, 0, 0, 0.06);
  --border-light: rgba(0, 0, 0, 0.1);
  --gradient-full: linear-gradient(135deg, var(--honey-bronze) 0%, var(--neon-violet) 42%, var(--blue-energy) 100%);
  --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.06);
  --shadow-md: 0 8px 24px rgba(0, 0, 0, 0.08);
  --shadow-lg: 0 16px 48px rgba(0, 0, 0, 0.1);
  --radius-lg: 24px;
  --radius-md: 16px;
  --radius-sm: 12px;
  --font-sans: "Inter", -apple-system, BlinkMacSystemFont, sans-serif;
  --font-heading: "Space Grotesk", -apple-system, BlinkMacSystemFont, sans-serif;
  --font-code: "Fira Code", ui-monospace, SFMono-Regular, Menlo, monospace;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
  scroll-padding-top: 1rem;
}

body {
  min-height: 100vh;
  margin: 0;
  padding: 24px 28px 48px;
  color: var(--text-primary);
  background:
    radial-gradient(ellipse 120% 60% at 50% -20%, rgba(212, 148, 10, 0.05), transparent 60%),
    radial-gradient(ellipse 80% 50% at 100% 50%, rgba(147, 51, 234, 0.03), transparent 50%),
    var(--bg-deep);
  font-family: var(--font-sans);
  font-size: clamp(12px, 2.5vw, 15px);
  line-height: 1.55;
  -webkit-font-smoothing: antialiased;
}

a {
  color: inherit;
  transition: color 0.2s ease;
}

a:hover:not(.cta) {
  color: var(--honey-bronze);
}

button,
a {
  outline-color: var(--honey-bronze);
  outline-offset: 3px;
}

.skip-link {
  position: fixed;
  z-index: 1001;
  top: 12px;
  left: 12px;
  padding: 0.5rem 0.75rem;
  border-radius: 8px;
  color: #fff;
  background: var(--text-primary);
  transform: translateY(-150%);
}

.skip-link:focus-visible {
  transform: translateY(0);
}

.progress-sidebar {
  position: fixed;
  z-index: 1000;
  top: 50%;
  left: 32px;
  display: none;
  transform: translateY(-50%);
}

@media (min-width: 1400px) {
  .progress-sidebar {
    display: flex;
  }
}

.progress-track {
  position: relative;
  display: flex;
  flex-direction: column;
  align-items: flex-start;
}

.progress-line,
.progress-line-fill {
  position: absolute;
  top: 22px;
  left: 7px;
  width: 2px;
}

.progress-line {
  bottom: 22px;
  background: var(--border-light);
}

.progress-line-fill {
  height: 0;
  background: var(--honey-bronze);
  transition: height 0.3s ease, top 0.3s ease;
}

.progress-item {
  position: relative;
  z-index: 1;
  padding: 14px 0;
}

.progress-item a {
  display: flex;
  align-items: center;
  gap: 12px;
  text-decoration: none;
}

.progress-dot {
  width: 16px;
  height: 16px;
  flex: 0 0 auto;
  border: 2px solid var(--border-light);
  border-radius: 50%;
  background: var(--bg-surface);
  transition: 0.3s ease;
}

.progress-item.active .progress-dot,
.progress-item.passed .progress-dot {
  border-color: var(--honey-bronze);
  background: var(--honey-bronze);
}

.progress-item.active .progress-dot {
  box-shadow: 0 0 0 5px rgba(212, 148, 10, 0.2);
}

.progress-label {
  max-width: 320px;
  overflow: visible;
  color: var(--text-muted);
  font-family: var(--font-code);
  font-size: 12px;
  font-weight: 500;
  letter-spacing: 0.05em;
  opacity: 1;
  text-transform: uppercase;
  transition: color 0.2s ease, opacity 0.22s ease, max-width 0.32s ease;
  white-space: nowrap;
}

.progress-item.active .progress-label {
  max-width: 320px;
  color: var(--honey-bronze);
  opacity: 1;
}

.progress-item a:hover .progress-label {
  color: var(--honey-bronze);
}

@media (hover: hover) {
  .progress-label {
    max-width: 0;
    overflow: hidden;
    opacity: 0;
  }

  .progress-item.active .progress-label {
    max-width: 320px;
    overflow: visible;
    opacity: 1;
  }

  .progress-sidebar:hover .progress-label,
  .progress-sidebar:focus-within .progress-label {
    max-width: 320px;
    opacity: 1;
  }
}

.main-content {
  position: relative;
  z-index: 1;
  max-width: 1060px;
  margin: 0 auto;
}

.hero-flow {
  position: relative;
  isolation: isolate;
  overflow: hidden;
  margin-bottom: 4px;
  padding: 24px 48px 40px;
  border: 1px solid var(--border-subtle);
  border-radius: 28px;
  background: var(--bg-surface);
  box-shadow: var(--shadow-lg);
}

.hero-flow::before,
.hero-flow::after,
.hero-orb {
  position: absolute;
  z-index: 0;
  content: "";
  pointer-events: none;
}

.hero-flow::before {
  width: 600px;
  height: 600px;
  top: -250px;
  left: -150px;
  border-radius: 50%;
  background: radial-gradient(circle, rgba(212, 148, 10, 0.12), transparent 70%);
  animation: orb-flow-one 25s ease-in-out infinite;
}

.hero-flow::after {
  width: 500px;
  height: 500px;
  right: -100px;
  bottom: -200px;
  border-radius: 50%;
  background: radial-gradient(circle, rgba(147, 51, 234, 0.08), transparent 70%);
  animation: orb-flow-two 30s ease-in-out infinite;
}

.hero-orb {
  width: 450px;
  height: 450px;
  top: 40%;
  right: 10%;
  border-radius: 50%;
  background: radial-gradient(circle, rgba(37, 99, 235, 0.06), transparent 70%);
  animation: orb-flow-three 28s ease-in-out infinite;
}

.hero-flow > * {
  position: relative;
  z-index: 1;
}

.hero-flow > .hero-orb {
  position: absolute;
  z-index: 0;
  transform: translateY(-50%);
}

@keyframes orb-flow-one {
  0%, 100% { transform: translate(0, 0); }
  25% { transform: translate(80px, 40px); }
  50% { transform: translate(120px, -20px); }
  75% { transform: translate(40px, 60px); }
}

@keyframes orb-flow-two {
  0%, 100% { transform: translate(0, 0); }
  25% { transform: translate(-60px, -50px); }
  50% { transform: translate(-100px, 30px); }
  75% { transform: translate(-30px, -40px); }
}

@keyframes orb-flow-three {
  0%, 100% { transform: translateY(-50%) translate(0, 0); }
  33% { transform: translateY(-50%) translate(-50px, 70px); }
  66% { transform: translateY(-50%) translate(40px, -50px); }
}

.eyebrow {
  margin: 0 0 0.35rem;
  color: var(--honey-bronze);
  font-family: var(--font-code);
  font-size: 0.75rem;
  font-weight: 600;
  letter-spacing: 0.12em;
  text-align: center;
  text-transform: uppercase;
}

.hero-text,
.section-head h2,
.tagline,
.media-card figcaption,
.result-card h3 {
  font-family: var(--font-heading);
}

.hero-text {
  margin: 0 0 8px;
  color: var(--text-primary);
  font-size: clamp(24px, 3.8vw, 36px);
  font-weight: 500;
  letter-spacing: -0.03em;
  line-height: 1.08;
  text-align: center;
  text-wrap: balance;
}

.sub-hero-text {
  max-width: 600px;
  margin: 0 auto 16px;
  color: var(--text-secondary);
  font-family: var(--font-heading);
  font-size: clamp(17px, 2.5vw, 26px);
  line-height: 1.5;
  text-align: center;
}

.hero-video-wrap {
  width: 100%;
  max-width: 960px;
  margin: 0 auto 20px;
  overflow: hidden;
  border-radius: 14px;
  box-shadow: 0 4px 24px rgba(0, 0, 0, 0.1);
}

video {
  display: block;
  width: 100%;
  border: 0;
  border-radius: 11px;
  background: var(--bg-elevated);
}

.hero-video-wrap video {
  border-radius: 14px;
}

.authors {
  min-height: 100px;
  margin: 0 0 32px;
  color: var(--text-secondary);
  font-size: 14px;
  line-height: 2;
  text-align: center;
}

.authors span {
  display: block;
}

.authors a {
  color: inherit;
  text-decoration: underline;
  text-underline-offset: 0.14em;
}

.authors .affiliation {
  margin-top: 12px;
  color: var(--text-muted);
  font-size: 13px;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 14px;
  margin-bottom: 28px;
}

.cta {
  display: inline-flex;
  align-items: center;
  gap: 0.55rem;
  padding: 14px 28px;
  border: 1px solid var(--border-light);
  border-radius: 12px;
  font-size: 14px;
  font-weight: 600;
  text-decoration: none;
  transition: transform 0.25s ease, box-shadow 0.25s ease, background-color 0.25s ease;
}

.cta .link-icon {
  display: block;
  width: 1rem;
  height: 1rem;
  flex: 0 0 auto;
}

.cta .link-icon--arxiv {
  width: 0.86rem;
  height: 1rem;
}

.cta .link-icon--fill {
  fill: currentColor;
}

.cta:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-sm);
}

.cta.primary {
  border-color: var(--honey-bronze);
  color: #000;
  background: var(--honey-bronze);
}

.cta.primary:hover {
  border-color: #e2a51d;
  color: #000;
  background: #e2a51d;
}

.cta.dark {
  border-color: var(--text-primary);
  color: #fff;
  background: var(--text-primary);
}

.hero-conference-badge {
  display: flex;
  justify-content: center;
  margin: 2px 0 10px;
}

.interactive-badge {
  display: inline-block;
  margin-left: 8px;
  padding: 4px 10px;
  border: 1px solid rgba(212, 148, 10, 0.3);
  border-radius: 100px;
  position: relative;
  top: -3px;
  color: var(--honey-bronze);
  background: rgba(212, 148, 10, 0.1);
  font-size: 11.5px;
  font-weight: 600;
  letter-spacing: 0.05em;
  text-transform: uppercase;
  vertical-align: middle;
}

.interactive-badge--conference {
  margin-left: 0;
  padding: 7px 18px;
  top: 0;
  border-color: rgba(212, 148, 10, 0.5);
  color: #8a4f00;
  background:
    linear-gradient(135deg, rgba(255, 246, 214, 0.96), rgba(255, 184, 74, 0.28)),
    rgba(212, 148, 10, 0.16);
  box-shadow:
    0 10px 28px rgba(212, 148, 10, 0.18),
    inset 0 1px 0 rgba(255, 255, 255, 0.8);
  font-size: 12px;
  letter-spacing: 0.08em;
  text-transform: none;
}

.hero-waves {
  width: 100%;
  height: 70px;
  margin-top: 24px;
  overflow: hidden;
  opacity: 0.7;
}

.waves-svg {
  display: block;
  width: 100%;
  height: 100%;
}

.wave-parallax use {
  animation: wave-shift 16s cubic-bezier(0.55, 0.5, 0.45, 0.5) infinite;
}

.wave-parallax use:nth-child(1) { animation-delay: -2s; animation-duration: 16s; }
.wave-parallax use:nth-child(2) { animation-delay: -4s; animation-duration: 14s; }
.wave-parallax use:nth-child(3) { animation-delay: -6s; animation-duration: 20s; }
.wave-parallax use:nth-child(4) { animation-delay: -8s; animation-duration: 18s; }

@keyframes wave-shift {
  0%, 100% { transform: translate3d(-90px, 0, 0); }
  50% { transform: translate3d(20px, 0, 0); }
}

.tagline {
  margin: 24px 0 20px;
  padding: 48px 0 0;
  color: var(--text-primary);
  font-size: 28px;
  font-weight: 500;
  letter-spacing: -0.02em;
}

.tagline::after {
  display: block;
  width: 100%;
  height: 3px;
  margin-top: 24px;
  border-radius: 2px;
  background: linear-gradient(90deg, var(--honey-bronze), rgba(212, 148, 10, 0.15) 40%, transparent);
  content: "";
}

.section-card {
  margin: 0 0 24px;
  padding: 32px;
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg);
  background: var(--bg-surface);
  box-shadow: var(--shadow-md);
  color: var(--text-secondary);
  text-align: center;
  transition: box-shadow 0.3s ease;
}

.section-card:hover {
  box-shadow: var(--shadow-lg);
}

.section-head {
  display: grid;
  justify-items: center;
  gap: 0.75rem;
  margin: 0 0 1.5rem;
  text-align: center;
}

.section-head h2 {
  margin: 0;
  font-size: 18px;
  font-weight: 600;
  letter-spacing: -0.02em;
  line-height: 1.05;
}

.section-head p,
.result-card p {
  margin: 0;
  color: var(--text-secondary);
}

.section-head p {
  max-width: none;
  font-size: 15px;
  line-height: 1.7;
  text-align: justify;
  text-wrap: pretty;
}

.section-head .method-features {
  justify-self: stretch;
  width: 100%;
  margin: 0;
  padding-left: 1.5rem;
  text-align: justify;
}

.challenges-grid,
.results-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 24px;
}

.media-card,
.result-card {
  min-width: 0;
  margin: 0;
  padding: 20px;
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  background: var(--bg-elevated);
  box-shadow: var(--shadow-sm);
  transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.media-card:hover,
.result-card:hover {
  transform: translateY(-3px);
  box-shadow: var(--shadow-md);
}

.media-card figcaption,
.result-card h3 {
  margin: 0 0 12px;
  font-size: 1rem;
  font-weight: 600;
}

.media-card video,
.result-card video {
  aspect-ratio: 16 / 9;
  margin: 18px 0;
  border-radius: 16px;
  object-fit: contain;
  box-shadow: var(--shadow-sm);
}

.challenge-video {
  width: calc((100% - 24px) / 2 - 42px);
  aspect-ratio: 16 / 9;
  margin: 18px auto;
  border-radius: 16px;
  object-fit: contain;
  box-shadow: var(--shadow-sm);
}

.results-video {
  width: 100%;
  aspect-ratio: 16 / 9;
  margin: 18px 0 0;
  border-radius: 16px;
  object-fit: contain;
  box-shadow: var(--shadow-sm);
}

.results-image {
  display: block;
  width: 100%;
  height: auto;
  margin: 18px 0 0;
  border-radius: 16px;
}

.result-card p {
  font-size: 14px;
  line-height: 1.6;
}

#experiment-setup .result-card p {
  text-align: justify;
}

.method-figure {
  margin: 0;
  overflow: hidden;
  border-radius: var(--radius-md);
  background: var(--bg-surface);
  border: 0;
  box-shadow: none;
}

.method-image {
  display: block;
  width: 100%;
  height: auto;
}

.site-footer {
  margin: 0 0 24px;
  padding: 0;
  border: 0;
  background: transparent;
  color: var(--text-muted);
  text-align: center;
}

.bibtex-code {
  margin: 0;
  padding: 32px;
  border: 1px solid var(--border-subtle);
  border-radius: 20px;
  background: var(--bg-elevated);
  box-shadow: var(--shadow-sm);
  text-align: left;
}

.citation-block {
  max-width: 100%;
  margin: 0;
  padding: 0;
  overflow-x: auto;
  border: 0;
  color: var(--text-secondary);
  background: var(--bg-elevated);
  font-family: var(--font-code);
  font-size: 12px;
  line-height: 1.7;
  text-align: left;
}

.acknowledgement {
  max-width: 980px;
  margin: 0 auto 24px;
  color: var(--text-muted);
  font-size: 13px;
  line-height: 1.7;
  text-align: center;
}

.acknowledgement p {
  margin: 0;
}

.footer {
  margin-top: 36px;
  padding-top: 40px;
  border-top: 1px solid var(--border-subtle);
  color: var(--text-muted);
  font-size: 13px;
  text-align: center;
}

::-webkit-scrollbar {
  width: 8px;
  height: 8px;
}

::-webkit-scrollbar-track {
  background: var(--bg-elevated);
}

::-webkit-scrollbar-thumb {
  border-radius: 4px;
  background: var(--border-light);
}

::-webkit-scrollbar-thumb:hover {
  background: var(--text-muted);
}

[data-reveal] {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity 560ms ease, transform 560ms ease;
}

[data-reveal].is-visible {
  opacity: 1;
  transform: translateY(0);
}

::selection {
  color: var(--text-primary);
  background: rgba(255, 184, 74, 0.25);
}

:focus-visible {
  outline: 2px solid var(--honey-bronze);
  outline-offset: 3px;
}

@media (max-width: 768px) {
  body {
    padding: 16px 10px;
    font-size: 14px;
  }

  .hero-flow {
    padding: 32px 16px 28px;
    border-radius: 20px;
  }

  .hero-text {
    font-size: 28px;
  }

  .sub-hero-text {
    font-size: 17px;
  }

  .authors {
    min-height: 184px;
    font-size: 13px;
  }

  .tagline {
    font-size: 22px;
  }

  .section-card {
    padding: 16px;
    border-radius: 16px;
  }

  .challenges-grid,
  .results-grid {
    grid-template-columns: 1fr;
    gap: 16px;
  }

  .media-card,
  .result-card {
    padding: 18px;
  }

  .challenge-video {
    width: calc(100% - 38px);
  }

  .site-footer {
    padding: 0;
  }
}

@media (max-width: 480px) {
  .hero-flow {
    padding: 24px 12px;
  }

  .hero-text {
    font-size: 24px;
  }

  .sub-hero-text {
    font-size: 15px;
  }

  .cta {
    padding: 10px 16px;
    font-size: 13px;
  }

  .tagline {
    font-size: 20px;
  }
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }

  *,
  *::before,
  *::after {
    animation: none !important;
    transition: none !important;
  }

  [data-reveal] {
    opacity: 1;
    transform: none;
  }
}