/* ==========================================================================
   Apple UI Design System - 4D Vision Project Page
   Based on Apple Human Interface Guidelines & SKILL.md principles
   ========================================================================== */

/* Apple Design System Tokens */
:root {
  /* Colors - Light Mode */
  --bg-primary: #ffffff;
  --bg-secondary: #f5f5f7;
  --bg-tertiary: #e8e8ed;
  --glass-bg: rgba(255, 255, 255, 0.75);
  --glass-border: rgba(0, 0, 0, 0.08);
  --glass-shadow: 0 8px 32px 0 rgba(0, 0, 0, 0.06);

  --text-primary: #1d1d1f;
  --text-secondary: #86868b;
  --text-tertiary: #6e6e73;
  --text-light: #94a3b8;

  --accent: #0071e3;
  --accent-hover: #0077ed;
  --accent-soft: rgba(0, 113, 227, 0.08);
  
  --border-color: rgba(0, 0, 0, 0.08);

  /* Typography Scale */
  --font-family: -apple-system, BlinkMacSystemFont, 'SF Pro Display', 'SF Pro Text', 'Inter', 'Segoe UI', sans-serif;
  --font-mono: 'SF Mono', 'Monaco', 'Cascadia Code', 'Roboto Mono', monospace;

  --text-hero: 600 48px/1.1 var(--font-family);
  --text-title: 600 32px/1.2 var(--font-family);
  --text-body: 400 17px/1.5 var(--font-family);
  --text-caption: 400 13px/1.4 var(--font-family);

  /* Spacing System */
  --space-xs: 4px;
  --space-sm: 8px;
  --space-md: 16px;
  --space-lg: 24px;
  --space-xl: 48px;
  --space-2xl: 96px;

  /* Components & Micro-interactions */
  --radius-sm: 8px;
  --radius-md: 14px;
  --radius-lg: 20px;
  --radius-pill: 980px;

  --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.04);
  --shadow-md: 0 4px 20px rgba(0, 0, 0, 0.06);
  --shadow-lg: 0 12px 40px rgba(0, 0, 0, 0.08);

  --transition-fast: all 0.2s cubic-bezier(0.25, 0.1, 0.25, 1);
  --transition-smooth: all 0.3s cubic-bezier(0.25, 0.1, 0.25, 1);
  --transition-spring: all 0.4s cubic-bezier(0.175, 0.885, 0.32, 1.275);
}


/* Global Baseline */
html {
  scroll-behavior: smooth;
  background-color: var(--bg-primary);
}

body {
  font-family: var(--font-family);
  color: var(--text-primary);
  background-color: var(--bg-primary);
  line-height: 1.5;
  font-size: 17px;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  margin: 0;
  padding: 0;
}

/* Apple Key Pattern: Glassmorphic Card */
.apple-card,
.card {
  background: var(--glass-bg);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-radius: var(--radius-lg);
  border: 1px solid var(--glass-border);
  box-shadow: var(--glass-shadow);
  transition: var(--transition-smooth);
  padding: var(--space-xl);
  margin-bottom: var(--space-xl);
}

.apple-card:hover {
  box-shadow: 0 12px 48px rgba(0, 0, 0, 0.09);
}

/* Hero Section */
.hero {
  position: relative;
  overflow: hidden;
  padding-top: var(--space-xl);
  padding-bottom: var(--space-xl);
}

.publication-header .hero-body {
  padding: var(--space-xl) var(--space-md) var(--space-lg);
}

.publication-title {
  font-family: var(--font-family) !important;
  font-size: 48px !important;
  font-weight: 600 !important;
  line-height: 1.1 !important;
  letter-spacing: -0.015em;
  color: var(--text-primary) !important;
  margin-bottom: var(--space-lg) !important;
  max-width: 900px;
  margin-left: auto;
  margin-right: auto;
}

.publication-authors {
  font-family: var(--font-family) !important;
  font-size: 17px;
  color: var(--text-secondary);
  line-height: 1.6;
  margin-bottom: var(--space-md);
}

.publication-authors a {
  color: var(--text-primary) !important;
  text-decoration: none;
  font-weight: 500;
  transition: var(--transition-fast);
  border-bottom: 1px solid transparent;
}

.publication-authors a:hover {
  color: var(--accent) !important;
  border-bottom-color: var(--accent);
}

.author-block {
  display: inline-block;
  margin-right: var(--space-xs);
}

.publication-venue {
  display: inline-block;
  margin-top: var(--space-md);
  padding: var(--space-xs) var(--space-md);
  background: var(--accent-soft);
  color: var(--accent);
  border-radius: var(--radius-pill);
  font-weight: 600;
  font-size: 14px;
  letter-spacing: 0.02em;
}

.eql-cntrb {
  font-size: 13px;
  color: var(--text-secondary);
  font-style: normal;
  margin-top: var(--space-sm);
}

/* Apple Buttons - Modern Pill Shapes */
.publication-links {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: var(--space-md);
  margin-top: var(--space-lg);
}

.button,
.btn-primary {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-sm);
  background: var(--accent) !important;
  color: #ffffff !important;
  padding: 12px 24px !important;
  border-radius: var(--radius-pill) !important;
  font-size: 15px !important;
  font-weight: 500 !important;
  border: none !important;
  cursor: pointer;
  text-decoration: none !important;
  box-shadow: var(--shadow-sm);
  transition: var(--transition-fast) !important;
  min-height: 44px;
}

.button:hover,
.btn-primary:hover {
  transform: scale(1.02);
  filter: brightness(1.05);
  box-shadow: var(--shadow-md);
  background: var(--accent-hover) !important;
  color: #ffffff !important;
}

.button:active,
.btn-primary:active {
  transform: scale(0.98);
}

.button.is-dark {
  background: var(--text-primary) !important;
  color: var(--bg-primary) !important;
}

.button.is-dark:hover {
  background: var(--accent) !important;
  color: #ffffff !important;
}

.btn-coming-soon,
.btn-coming-soon[disabled] {
  background: var(--bg-tertiary) !important;
  color: var(--text-secondary) !important;
  cursor: not-allowed;
  opacity: 0.7;
  box-shadow: none;
  pointer-events: auto;
}

.btn-coming-soon:hover,
.btn-coming-soon[disabled]:hover {
  transform: none;
  filter: none;
  box-shadow: none;
  background: var(--bg-tertiary) !important;
  color: var(--text-secondary) !important;
}

.button .icon {
  font-size: 16px;
  display: inline-flex;
  align-items: center;
}

/* Teaser Section */
.teaser .hero-body {
  padding: 0;
}

.teaser-card {
  background: var(--glass-bg);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-radius: var(--radius-lg);
  border: 1px solid var(--glass-border);
  box-shadow: var(--glass-shadow);
  padding: var(--space-lg);
  margin-bottom: var(--space-2xl);
  overflow: hidden;
}

.teaser-card img {
  width: 100%;
  height: auto;
  border-radius: var(--radius-md);
  display: block;
  box-shadow: var(--shadow-sm);
}

.teaser-caption {
  font-size: 15px;
  color: var(--text-secondary);
  line-height: 1.5;
  margin-top: var(--space-md);
  text-align: left;
}

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

/* Sections & Typography */
.section {
  padding: var(--space-xl) var(--space-md);
}

.container.is-max-desktop {
  max-width: 980px;
}

.title.is-3 {
  font-family: var(--font-family) !important;
  font-size: 32px !important;
  font-weight: 600 !important;
  line-height: 1.2 !important;
  letter-spacing: -0.01em;
  color: var(--text-primary) !important;
  margin-bottom: var(--space-lg) !important;
  position: relative;
  padding-bottom: 0;
  text-align: left;
}

/* Remove old underline bar */
.title.is-3::after {
  display: none;
}

.title.is-4 {
  font-family: var(--font-family) !important;
  font-size: 22px !important;
  font-weight: 600 !important;
  color: var(--text-primary) !important;
  margin-top: var(--space-lg) !important;
  margin-bottom: var(--space-md) !important;
}

.subtitle.is-6 {
  font-size: 14px !important;
  color: var(--text-secondary) !important;
  font-weight: 400 !important;
  margin-top: var(--space-sm) !important;
}

.content {
  font-size: 17px;
  line-height: 1.6;
  color: var(--text-secondary);
}

.content strong {
  color: var(--text-primary);
  font-weight: 600;
}

.content p {
  margin-bottom: var(--space-md);
}

.content ul, .content ol {
  margin-top: var(--space-sm);
  margin-bottom: var(--space-md);
  padding-left: var(--space-lg);
}

.content li {
  margin-bottom: var(--space-xs);
}

/* Section Background Alternation */
.hero.is-light {
  background: var(--bg-secondary);
  border-top: 1px solid var(--border-color);
  border-bottom: 1px solid var(--border-color);
  padding-top: var(--space-2xl);
  padding-bottom: var(--space-2xl);
}

/* Media Figures Styling */
.media-box {
  background: var(--bg-secondary);
  border-radius: var(--radius-lg);
  padding: var(--space-md);
  border: 1px solid var(--border-color);
  box-shadow: var(--shadow-sm);
  margin-top: var(--space-md);
  margin-bottom: var(--space-md);
  transition: var(--transition-smooth);
}

.media-box:hover {
  transform: scale(1.005);
  box-shadow: var(--shadow-md);
}

.media-box img {
  border-radius: var(--radius-md);
  width: 100%;
  height: auto;
  display: block;
}

/* Data Tables - Apple Aesthetic */
.table-container {
  overflow-x: auto;
  margin-top: var(--space-md);
  margin-bottom: var(--space-xl);
  border-radius: var(--radius-md);
  border: 1px solid var(--border-color);
  box-shadow: var(--shadow-sm);
  background: var(--bg-primary);
}

.table {
  width: 100%;
  border-collapse: separate;
  border-spacing: 0;
  background-color: transparent !important;
  color: var(--text-primary) !important;
  font-size: 14px;
}

.table th {
  background-color: var(--bg-secondary) !important;
  color: var(--text-primary) !important;
  font-weight: 600;
  padding: 12px 16px;
  border-bottom: 1px solid var(--border-color);
  font-size: 13px;
  text-transform: uppercase;
  letter-spacing: 0.03em;
}

.table td {
  padding: 12px 16px;
  border-bottom: 1px solid var(--border-color);
  color: var(--text-secondary);
}

.table tbody tr {
  transition: var(--transition-fast);
}

.table tbody tr:hover {
  background-color: var(--bg-secondary) !important;
}

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

/* Highlighted "Ours" Row in Table */
.table tr.highlight-row,
.table tr[style*="font-weight: bold"] {
  background-color: var(--accent-soft) !important;
  color: var(--text-primary) !important;
  font-weight: 600;
}

.table tr.highlight-row td,
.table tr[style*="font-weight: bold"] td {
  color: var(--accent) !important;
}

/* Chart Visualization Section */
.chart-section {
  background: var(--bg-secondary);
  border-radius: var(--radius-lg);
  padding: var(--space-lg);
  border: 1px solid var(--border-color);
  box-shadow: var(--shadow-sm);
  margin-top: var(--space-lg);
  margin-bottom: var(--space-xl);
  transition: var(--transition-smooth);
}

.chart-section:hover {
  box-shadow: var(--shadow-md);
}

.chart-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: var(--space-lg);
  flex-wrap: wrap;
  gap: var(--space-md);
}

.chart-title {
  font-family: var(--font-family);
  font-size: 18px;
  font-weight: 600;
  color: var(--text-primary);
  letter-spacing: -0.01em;
  margin: 0;
}

.chart-toggle-group {
  display: flex;
  gap: var(--space-xs);
  background: var(--bg-primary);
  border-radius: var(--radius-pill);
  padding: 3px;
  border: 1px solid var(--border-color);
  box-shadow: var(--shadow-sm);
}

.chart-toggle-btn {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 8px 16px;
  border: none;
  border-radius: var(--radius-pill);
  background: transparent;
  color: var(--text-secondary);
  font-family: var(--font-family);
  font-size: 13px;
  font-weight: 500;
  cursor: pointer;
  transition: var(--transition-fast);
  min-height: 36px;
  white-space: nowrap;
}

.chart-toggle-btn:hover {
  color: var(--text-primary);
}

.chart-toggle-btn.active {
  background: var(--accent);
  color: #ffffff;
  box-shadow: var(--shadow-sm);
}

.toggle-dot {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: currentColor;
  opacity: 0.5;
  transition: var(--transition-fast);
}

.chart-toggle-btn.active .toggle-dot {
  opacity: 1;
  background: #ffffff;
}

.chart-canvas-wrapper {
  position: relative;
  width: 100%;
  max-height: 520px;
  min-height: 480px;
  background: var(--bg-primary);
  border-radius: var(--radius-md);
  padding: var(--space-md) var(--space-sm) var(--space-sm);
  border: 1px solid var(--border-color);
}

.chart-legend {
  display: flex;
  justify-content: center;
  gap: var(--space-lg);
  margin-top: var(--space-md);
  flex-wrap: wrap;
}

.chart-legend-item {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-family: var(--font-family);
  font-size: 13px;
  font-weight: 500;
  color: var(--text-secondary);
  cursor: default;
  transition: var(--transition-fast);
}

.chart-legend-item:hover {
  color: var(--text-primary);
}

.chart-legend-swatch {
  width: 12px;
  height: 12px;
  border-radius: 3px;
  flex-shrink: 0;
}

.chart-legend-item.is-ours .chart-legend-swatch {
  box-shadow: 0 0 0 2px rgba(118, 171, 47, 0.25);
}

.chart-legend-item.is-ours {
  color: var(--text-primary);
  font-weight: 600;
}

@media screen and (max-width: 768px) {
  .chart-header {
    flex-direction: column;
    align-items: flex-start;
  }

  .chart-canvas-wrapper {
    max-height: 350px;
    padding: var(--space-sm) var(--space-xs) var(--space-xs);
  }

  .chart-toggle-group {
    align-self: stretch;
  }

  .chart-toggle-btn {
    flex: 1;
    justify-content: center;
    padding: 8px 12px;
  }

  .chart-legend {
    gap: var(--space-md);
  }
}

/* BibTeX Section */
pre {
  background: var(--bg-secondary) !important;
  border: 1px solid var(--border-color) !important;
  border-radius: var(--radius-md) !important;
  padding: var(--space-md) var(--space-lg) !important;
  font-size: 13px !important;
  line-height: 1.5;
  color: var(--text-primary) !important;
  font-family: var(--font-mono) !important;
  overflow-x: auto;
}

code {
  background: transparent !important;
  color: var(--text-primary) !important;
  font-family: var(--font-mono) !important;
}

.bibtex-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: var(--space-md);
}

.copy-bibtex-btn {
  background: var(--accent);
  color: #ffffff;
  border: none;
  border-radius: var(--radius-pill);
  padding: 8px 16px;
  font-size: 13px;
  font-weight: 500;
  cursor: pointer;
  transition: var(--transition-fast);
  display: inline-flex;
  align-items: center;
  gap: var(--space-xs);
  min-height: 36px;
}

.copy-bibtex-btn:hover {
  background: var(--accent-hover);
  transform: scale(1.02);
}

.copy-bibtex-btn.copied {
  background: #34c759; /* Apple green */
}

/* PDF Embed Frame */
.pdf-container {
  border-radius: var(--radius-lg);
  overflow: hidden;
  border: 1px solid var(--border-color);
  box-shadow: var(--shadow-md);
  margin-top: var(--space-md);
}

.pdf-container iframe {
  width: 100%;
  height: 750px;
  border: none;
  display: block;
}

/* Scroll to Top Floating Glass Button */
.scroll-to-top {
  position: fixed;
  bottom: 32px;
  right: 32px;
  width: 48px;
  height: 48px;
  background: var(--glass-bg);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  color: var(--text-primary);
  border: 1px solid var(--glass-border);
  border-radius: 50%;
  cursor: pointer;
  opacity: 0;
  visibility: hidden;
  transition: var(--transition-smooth);
  z-index: 999;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 16px;
  box-shadow: var(--glass-shadow);
}

.scroll-to-top:hover {
  transform: translateY(-2px) scale(1.05);
  background: var(--accent);
  color: #ffffff;
  border-color: var(--accent);
}

.scroll-to-top.visible {
  opacity: 1;
  visibility: visible;
}

/* Footer & Logo Row */
/* Footer & Single Line Logo Row */
.footer {
  background: var(--bg-secondary);
  border-top: 1px solid var(--border-color);
  padding: var(--space-xl) var(--space-md);
  margin-top: var(--space-2xl);
}

.footer-logos {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 36px;
  flex-wrap: nowrap;
  width: 100%;
  max-width: 1050px;
  margin: 0 auto;
}

.footer-logo-item {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
  transition: var(--transition-fast);
}

/* Baseline size for SMART */
.footer-logo-item img {
  height: 52px;
  width: auto;
  max-width: 170px;
  object-fit: contain;
  transition: var(--transition-fast);
  filter: drop-shadow(0 2px 6px rgba(0, 0, 0, 0.04));
}

/* ENTC and A*STAR logos slightly bigger */
.footer-logo-item.entc-logo img,
.footer-logo-item.astar-logo img {
  height: 66px;
  max-width: 200px;
}

/* UoM logo distinctly largest */
.footer-logo-item.uom-logo img {
  height: 94px;
  max-width: 250px;
}

.footer-logo-item:hover img {
  transform: scale(1.06);
}

/* Micro-Animations: Fade Up Entrance */
@keyframes fadeUp {
  from {
    opacity: 0;
    transform: translateY(20px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.fade-up {
  animation: fadeUp 0.6s cubic-bezier(0.25, 0.1, 0.25, 1) forwards;
}

/* Accessibility & Target Sizes */
a, button {
  min-height: 44px;
  touch-action: manipulation;
}

button.copy-bibtex-btn, button.close-btn {
  min-height: 36px;
}

/* Mobile Responsiveness */
@media screen and (max-width: 768px) {
  :root {
    --text-hero: 600 32px/1.15 var(--font-family);
    --text-title: 600 24px/1.2 var(--font-family);
  }

  .publication-title {
    font-size: 32px !important;
    margin-bottom: var(--space-md) !important;
  }

  .title.is-3 {
    font-size: 24px !important;
  }

  .publication-header .hero-body {
    padding: var(--space-lg) var(--space-xs);
  }

  .apple-card, .card {
    padding: var(--space-lg);
    border-radius: var(--radius-md);
  }

  .publication-links {
    flex-direction: column;
    width: 100%;
  }

  .button {
    width: 100%;
  }

  .scroll-to-top {
    bottom: 20px;
    right: 20px;
    width: 44px;
    height: 44px;
  }

  .pdf-container iframe {
    height: 500px;
  }
}