:root {
  --primary: #1a56db;
  --primary-dark: #1e40af;
  --background: #ffffff;
  --text-color: #111827;
  --secondary-text: #374151;
  --accent-background: #f9fafb;
  --border-color: #e5e7eb;
  --dark-bg: #1f2937;
  --light-text: #f3f4f6;
  --success-color: #059669;
  /* New color for annotations */
  --annotation-primary: #5c6bc0;
  --annotation-primary-gradient-start: #7c8ae6;
  --annotation-primary-gradient-end: #5c6bc0;
}

* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

body {
  font-family: "Source Sans 3", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  line-height: 1.75;
  color: var(--text-color);
  background: var(--background);
  font-size: 17px;
}

/* Container styles */
.container {
  width: 95%;
  max-width: 1800px;
  margin: 0 auto;
  padding: 0 40px;
}

.container-wide {
  width: 98%;
  max-width: 1900px;
  margin: 0 auto;
  padding: 0 40px;
}

/* Header Styles */
.header {
  background: linear-gradient(135deg, #f8fafc 0%, #f1f5f9 100%);
  padding: 30px 20px 20px;
  text-align: center;
  border-bottom: 1px solid var(--border-color);
  width: 98%;
  max-width: 1900px;
  margin: 0 auto;
}

.org-logos {
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 80px;
  margin-bottom: 15px;
  flex-wrap: wrap;
}

.org-logos img {
  height: 100px;
  width: auto;
  object-fit: contain;
}

/* Second row of logos - larger size */
.org-logos-secondary {
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 60px;
  margin-bottom: 25px;
  flex-wrap: wrap;
}

.org-logos-secondary img {
  height: 130px;
  width: auto;
  object-fit: contain;
}

.paper-title {
  font-family: "Playfair Display", Georgia, serif;
  font-size: 3.8em;
  font-weight: 700;
  color: var(--text-color);
  margin-bottom: 25px;
  line-height: 1.15;
  max-width: none;
  width: 100%;
  margin-left: auto;
  margin-right: auto;
  letter-spacing: -0.02em;
}

.authors {
  font-size: 1.25em;
  margin: 18px 0 8px;
  color: var(--text-color);
  font-weight: 500;
}

.authors a {
  color: var(--primary);
  text-decoration: none;
  transition: color 0.2s;
}

.authors a:hover {
  color: var(--primary-dark);
  text-decoration: underline;
}

.author-equal {
  font-size: 1.05em;
  color: #6b7280;
  margin-top: 6px;
}

.affiliations {
  font-size: 1.1em;
  color: var(--secondary-text);
  margin: 15px 0 25px;
  line-height: 1.9;
}

.links {
  display: flex;
  justify-content: center;
  gap: 20px;
  flex-wrap: wrap;
}

.btn {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 16px 34px;
  background: var(--primary);
  color: white;
  text-decoration: none;
  border-radius: 8px;
  font-weight: 600;
  font-size: 1.15em;
  transition: all 0.2s ease;
  border: 2px solid transparent;
}

.btn:hover {
  background: var(--primary-dark);
  transform: translateY(-2px);
  box-shadow: 0 4px 12px rgba(26, 86, 219, 0.3);
}

.btn-outline {
  background: var(--background);
  color: var(--primary);
  border: 2px solid var(--primary);
}

.btn-outline:hover {
  background: var(--primary);
  color: white;
}

.btn svg {
  width: 24px;
  height: 24px;
}

/* Sections */
section {
  padding: 70px 0;
}

/* Abstract section styling */
#abstract {
  padding: 25px 0 20px;
}

#abstract h2 {
  margin-bottom: 12px;
  font-size: 1.5em;
}

#abstract .abstract-content {
  max-width: 100%;
  margin: 0 auto;
  text-align: justify;
  font-size: 1.15rem !important;
  line-height: 1.65 !important;
}

#abstract + .section-sep {
  margin-top: 20px;
  margin-bottom: 30px;
}

/* Typography - Section headings */
h2 {
  font-size: 1.75em;
  font-weight: 600;
  color: var(--text-color);
  margin-bottom: 20px;
  text-align: center;
  font-family: "Playfair Display", Georgia, serif;
}

h3 {
  font-size: 1.35em;
  font-weight: 600;
  color: var(--text-color);
  margin-bottom: 15px;
  font-family: "Playfair Display", Georgia, serif;
}

h4 {
  font-size: 1.15em;
  font-weight: 600;
  color: var(--text-color);
  margin-bottom: 12px;
  font-family: "Playfair Display", Georgia, serif;
}

p {
  font-size: 1.1em;
  line-height: 1.85;
  color: var(--secondary-text);
}

/* Teaser/Hero */
.teaser {
  margin: 50px auto;
  text-align: center;
  width: 100%;
}

.teaser video {
  width: 100%;
  max-width: 100%;
  border-radius: 12px;
  box-shadow: 0 12px 50px rgba(0, 0, 0, 0.12);
}

.teaser img {
  max-width: 100%;
  border-radius: 12px;
}

.teaser-caption {
  display: none;
}

/* Abstract */
.abstract-content {
  max-width: 100%;
  margin: 0 auto;
  text-align: justify;
}

.abstract-content p {
  margin-bottom: 22px;
  font-size: 1.15em;
}

.highlight {
  color: var(--primary);
  font-weight: 600;
}

/* Figures */
.figure {
  margin: 50px 0;
  text-align: center;
  width: 100%;
}

.figure img {
  width: 100%;
  max-width: none;
  border-radius: 10px;
}

.figure-caption {
  margin-top: 20px;
  color: var(--secondary-text);
  font-size: 1em;
  max-width: 900px;
  margin-left: auto;
  margin-right: auto;
  line-height: 1.75;
}

.figure-caption strong {
  color: var(--text-color);
}

/* Two Column */
.two-col {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 45px;
  margin: 50px 0;
  align-items: start;
}

.two-col .figure {
  margin: 0;
}

.two-col .figure img {
  width: 100%;
  height: 300px;
  object-fit: contain;
  background: #fafafa;
  border-radius: 10px;
}

/* Stats */
.stats {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
  margin: 55px 0;
}

.stat-card {
  text-align: center;
  padding: 35px 20px;
  background: linear-gradient(135deg, var(--primary) 0%, #3b82f6 100%);
  border-radius: 14px;
  color: white;
}

.stat-number {
  font-family: "Playfair Display", Georgia, serif;
  font-size: 2.5em;
  font-weight: 700;
  margin-bottom: 8px;
}

.stat-label {
  font-size: 0.95em;
  opacity: 0.95;
  font-weight: 500;
}

/* Pipeline */
.pipeline-section {
  background: var(--accent-background);
  padding: 70px 0;
  margin: 70px 0;
}

/* Pipeline Overview Section */
.pipeline-overview {
  margin-top: 70px;
  padding: 50px 0;
}

.pipeline-overview h2 {
  text-align: center;
  font-family: "Noto Serif", Georgia, serif;
  font-size: 2.2rem;
  margin-bottom: 35px;
  color: var(--primary);
}

.pipeline-intro {
  max-width: 100%;
  margin: 0 auto 25px;
  text-align: justify;
  color: var(--secondary-text);
  line-height: 1.85;
  font-size: 1.25rem;
}

.pipeline-image-container {
  margin: 50px auto;
  text-align: center;
  width: 100%;
}

.pipeline-img {
  width: 100%;
  max-width: 1600px;
  border-radius: 14px;
  box-shadow: 0 10px 40px rgba(0, 0, 0, 0.1);
}

.pipeline-stages {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 28px;
  max-width: 1200px;
  margin: 50px auto 0;
}

.pipeline-stage {
  background: #fff;
  border-radius: 14px;
  padding: 28px;
  box-shadow: 0 4px 24px rgba(0, 0, 0, 0.06);
  border: 1px solid var(--border-color);
  transition: transform 0.2s, box-shadow 0.2s;
}

.pipeline-stage:hover {
  transform: translateY(-4px);
  box-shadow: 0 10px 35px rgba(0, 0, 0, 0.1);
}

.stage-header {
  display: flex;
  align-items: center;
  gap: 14px;
  margin-bottom: 18px;
}

.stage-num {
  background: var(--primary);
  color: #fff;
  padding: 8px 14px;
  border-radius: 22px;
  font-size: 0.9rem;
  font-weight: 600;
}

.stage-header h3 {
  font-family: "Noto Serif", Georgia, serif;
  font-size: 1.15rem;
  color: var(--primary);
  margin: 0;
}

.pipeline-stage p {
  color: var(--secondary-text);
  line-height: 1.75;
  font-size: 1rem;
  margin: 0;
}

.pipeline-stage em {
  color: var(--primary);
  font-style: normal;
  font-weight: 500;
}

/* Method Cards */
.method-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 28px;
  margin: 50px 0;
}

.method-card {
  background: white;
  padding: 30px;
  border-radius: 14px;
  border: 1px solid var(--border-color);
  transition: all 0.2s ease;
}

.method-card:hover {
  box-shadow: 0 12px 35px rgba(0, 0, 0, 0.08);
  transform: translateY(-4px);
}

.method-number {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
  background: var(--primary);
  color: white;
  border-radius: 50%;
  font-weight: 700;
  font-size: 1.1em;
  margin-bottom: 18px;
}

.method-title {
  font-size: 1.15em;
  color: var(--text-color);
  margin-bottom: 12px;
  font-weight: 600;
}

.method-desc {
  color: var(--secondary-text);
  font-size: 1em;
  line-height: 1.7;
}

/* Contributions */
.contributions-list {
  max-width: 1000px;
  margin: 40px auto 0;
}

.contribution-item {
  display: flex;
  gap: 18px;
  margin-bottom: 25px;
  padding: 22px 30px;
  background: var(--accent-background);
  border-radius: 12px;
  border-left: 5px solid var(--primary);
}

.contribution-num {
  flex-shrink: 0;
  width: 32px;
  height: 32px;
  background: var(--primary);
  color: white;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 600;
  font-size: 0.95em;
}

.contribution-text {
  color: var(--secondary-text);
  line-height: 1.75;
  font-size: 1.05em;
}

/* BibTeX */
.bibtex-wrapper {
  max-width: 900px;
  margin: 40px auto 0;
}

.bibtex {
  background: var(--dark-bg);
  color: var(--light-text);
  padding: 28px;
  border-radius: 12px;
  font-family: "Monaco", "Menlo", monospace;
  font-size: 0.9em;
  overflow-x: auto;
  position: relative;
  white-space: pre-wrap;
  word-break: break-all;
}

.copy-btn {
  position: absolute;
  top: 16px;
  right: 16px;
  padding: 10px 18px;
  background: #475569;
  color: white;
  border: none;
  border-radius: 6px;
  cursor: pointer;
  font-size: 0.9em;
  transition: background 0.2s;
}

.copy-btn:hover {
  background: #64748b;
}

/* Footer */
footer {
  text-align: center;
  padding: 60px 32px;
  background: var(--accent-background);
  color: var(--secondary-text);
  font-size: 1em;
}

footer .org-logos {
  margin-bottom: 30px;
}

footer .org-logos img {
  height: 45px;
  opacity: 0.7;
}

/* Annotation Examples Section */
.annotation-section {
  background: linear-gradient(135deg, #f8fafc 0%, #f0f4ff 100%);
  padding: 60px 0;
  margin: 50px 0;
}

.annotation-section .container {
  width: 75%;
  max-width: 1600px;
}

/* Scenario tabs - large cards */
.scenario-tabs {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
  margin-bottom: 35px;
  width: 100%;
}

.scenario-tab {
  padding: 28px 20px;
  background: white;
  border: 3px solid #e2e8f0;
  border-radius: 16px;
  cursor: pointer;
  font-family: "Source Sans 3", sans-serif;
  font-weight: 700;
  font-size: 1.4em;
  color: #3b5998;
  transition: all 0.3s ease;
  text-transform: uppercase;
  letter-spacing: 2px;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 12px;
  box-shadow: 0 4px 15px rgba(0, 0, 0, 0.05);
}

.scenario-tab::before {
  font-size: 2em;
  line-height: 1;
}

.scenario-tab[data-scenario="lab"]::before {
  content: "🔬";
}

.scenario-tab[data-scenario="factory"]::before {
  content: "🏭";
}

.scenario-tab[data-scenario="household"]::before {
  content: "🏠";
}

.scenario-tab:hover {
  background: rgba(59, 89, 152, 0.04);
  border-color: #3b5998;
  transform: translateY(-4px);
  box-shadow: 0 8px 25px rgba(59, 89, 152, 0.15);
}

.scenario-tab.active {
  background: linear-gradient(135deg, #3b5998 0%, #5c7cba 100%);
  border-color: transparent;
  color: white;
  box-shadow: 0 8px 30px rgba(59, 89, 152, 0.4);
}

/* Mode tabs - single row */
.mode-tabs-wrapper {
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 15px;
  margin-bottom: 30px;
  flex-wrap: nowrap;
  width: 100%;
}

.mode-tabs {
  display: flex;
  justify-content: center;
  gap: 12px;
  flex-wrap: nowrap;
  width: 100%;
  max-width: none;
}

.mode-tab {
  padding: 14px 28px;
  background: white;
  border: 2px solid var(--annotation-primary);
  border-radius: 50px;
  cursor: pointer;
  font-family: "Source Sans 3", sans-serif;
  font-weight: 600;
  font-size: 1.15em;
  color: var(--annotation-primary);
  transition: all 0.3s ease;
  white-space: nowrap;
}

.mode-tab:hover {
  background: rgba(92, 107, 192, 0.08);
}

.mode-tab.active {
  background: linear-gradient(
    135deg,
    var(--annotation-primary-gradient-start) 0%,
    var(--annotation-primary-gradient-end) 100%
  );
  border-color: transparent;
  color: white;
  box-shadow: 0 4px 12px rgba(92, 107, 192, 0.35);
}

.annotation-content {
  display: none;
  animation: fadeIn 0.4s ease;
}

.annotation-content.active {
  display: block;
}

@keyframes fadeIn {
  from {
    opacity: 0;
    transform: translateY(10px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.example-card {
  background: white;
  border-radius: 16px;
  padding: 45px;
  max-width: 1400px;
  margin: 0 auto;
  box-shadow: 0 12px 45px rgba(0, 0, 0, 0.08);
}

/* Question styling */
.qa-question {
  font-family: "Source Serif 4", Georgia, serif;
  font-style: italic;
  font-size: 1.6em;
  font-weight: 600;
  color: #e07850;
  text-align: center;
  margin-bottom: 28px;
  line-height: 1.6;
}

/* Video container with side navigation arrows */
.example-video-container {
  margin-bottom: 28px;
  border-radius: 12px;
  overflow: hidden;
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.1);
  position: relative;
}

.example-video-container video {
  width: 100%;
  display: block;
}

/* Video navigation arrows on sides */
.video-nav-arrow {
  position: absolute;
  top: 50%;
  transform: translateY(-50%);
  width: 54px;
  height: 54px;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.95);
  border: 2px solid var(--annotation-primary);
  color: var(--annotation-primary);
  font-size: 1.6em;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all 0.3s ease;
  z-index: 10;
  box-shadow: 0 4px 15px rgba(0, 0, 0, 0.2);
}

.video-nav-arrow:hover {
  background: var(--annotation-primary);
  color: white;
  transform: translateY(-50%) scale(1.1);
}

.video-nav-arrow.prev {
  left: 20px;
}

.video-nav-arrow.next {
  right: 20px;
}

/* Answer styling */
.qa-answer {
  background: transparent;
  border-left: none;
  padding: 20px 40px;
  border-radius: 0;
  margin-bottom: 32px;
  text-align: center;
}

.qa-answer-label {
  display: none;
}

.qa-answer-text {
  font-family: "Source Serif 4", Georgia, serif;
  font-style: italic;
  font-weight: 500;
  font-size: 1.35em;
  line-height: 1.8;
  color: #4a5da8;
}

/* Frame sequence - larger images, no labels */
.frame-sequence {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 16px;
}

.frame-sequence img {
  width: 100%;
  aspect-ratio: 16 / 9;
  object-fit: cover;
  border-radius: 12px;
  border: 2px solid transparent;
  transition: all 0.2s ease;
  box-shadow: 0 3px 12px rgba(0, 0, 0, 0.1);
}

.frame-sequence img:hover {
  border-color: var(--annotation-primary);
  transform: scale(1.04);
  box-shadow: 0 6px 20px rgba(92, 107, 192, 0.3);
}

.frame-label {
  display: none;
}

/* Separator */
.section-sep {
  height: 1px;
  background: var(--border-color);
  max-width: 250px;
  margin: 0 auto 70px;
}

/* Responsive */
@media (max-width: 900px) {
  .stats {
    grid-template-columns: repeat(2, 1fr);
  }

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

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

  .pipeline-stages {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 768px) {
  .paper-title {
    font-size: 2.1em;
  }

  h2 {
    font-size: 1.7em;
  }

  .header {
    padding: 60px 20px 50px;
    width: 100%;
  }

  .org-logos {
    gap: 30px;
  }

  .org-logos img {
    height: 40px;
  }

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

  .scenario-tabs {
    gap: 8px;
    flex-wrap: wrap;
    grid-template-columns: 1fr;
  }

  .scenario-tab {
    padding: 12px 20px;
    font-size: 1.1em;
  }

  .scenario-tab::before {
    font-size: 1.5em;
  }

  .mode-tabs {
    gap: 8px;
    flex-wrap: wrap;
  }

  .mode-tab {
    padding: 10px 16px;
    font-size: 0.9em;
  }

  .example-card {
    padding: 25px 20px;
  }

  .frame-sequence {
    grid-template-columns: repeat(2, 1fr);
  }

  .video-nav-arrow {
    width: 44px;
    height: 44px;
    font-size: 1.4em;
  }

  .video-nav-arrow.prev {
    left: 10px;
  }

  .video-nav-arrow.next {
    right: 10px;
  }

  .pipeline-stages {
    grid-template-columns: 1fr;
  }

  .pipeline-overview h2 {
    font-size: 1.7rem;
  }
}

.section-title-mono {
    font-family: "Source Sans 3", system-ui, -apple-system, BlinkMacSystemFont, sans-serif;
    font-weight: 600;
    letter-spacing: 0.01em;
}