/* ==========================================================================
   CAIR Lab Project Page - Custom Premium CSS Style (100% JS-Free)
   ========================================================================== */

/* Import Google Font */
@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700;800&display=swap');

/* Color Variables and Design Tokens */
:root {
  --font-primary: 'Inter', system-ui, -apple-system, sans-serif;
  
  /* Color Palette (Deep Blue/Slate Premium Theme) */
  --color-bg-primary: hsl(210, 40%, 98%);
  --color-bg-secondary: hsl(0, 0%, 100%);
  --color-bg-accent: hsl(220, 100%, 97%);
  
  --color-text-primary: hsl(224, 71.4%, 4.1%);
  --color-text-secondary: hsl(215.4, 16.3%, 46.9%);
  --color-text-muted: hsl(215.4, 16.3%, 56.9%);
  
  --color-primary: hsl(221.2, 83.2%, 53.3%);
  --color-primary-hover: hsl(221.2, 83.2%, 45%);
  --color-primary-light: hsl(221.2, 83.2%, 93%);
  
  --color-border: hsl(214.3, 31.8%, 91.4%);
  --color-shadow: rgba(15, 23, 42, 0.06);
  
  --radius-sm: 8px;
  --radius-md: 16px;
  --radius-lg: 24px;
  --radius-full: 9999px;
  
  --transition-smooth: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  --max-width-content: 1100px;
}

/* Reset and Global Styles */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-primary);
  background-color: var(--color-bg-primary);
  color: var(--color-text-primary);
  line-height: 1.6;
  padding-top: 75px;
  -webkit-font-smoothing: antialiased;
}

/* Typography */
h1, h2, h3, h4 {
  font-weight: 700;
  color: var(--color-text-primary);
  letter-spacing: -0.02em;
}

h1 {
  font-size: 2.75rem;
  line-height: 1.15;
}

h2 {
  font-size: 2rem;
  text-align: center;
  margin-bottom: 2rem;
  position: relative;
  display: inline-block;
  left: 50%;
  transform: translateX(-50%);
}

h2::after {
  content: '';
  position: absolute;
  bottom: -8px;
  left: 30%;
  width: 40%;
  height: 3px;
  background: var(--color-primary);
  border-radius: var(--radius-full);
}

p {
  color: var(--color-text-secondary);
}

/* Glassmorphism Navigation */
nav {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  background: rgba(255, 255, 255, 0.85);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid rgba(226, 232, 240, 0.8);
  padding: 16px 8%;
  display: flex;
  justify-content: space-between;
  align-items: center;
  z-index: 1000;
}

nav .brand {
  font-weight: 700;
  font-size: 1.1rem;
  color: var(--color-text-primary);
  display: flex;
  align-items: center;
  gap: 10px;
  text-decoration: none;
}

nav .brand-logo {
  height: 32px;
  width: auto;
}

nav .nav-links {
  display: flex;
  gap: 24px;
}

nav a {
  color: var(--color-text-secondary);
  text-decoration: none;
  font-weight: 500;
  font-size: 0.95rem;
  transition: var(--transition-smooth);
}

nav a:hover {
  color: var(--color-primary);
}

/* Header & Hero Section */
header {
  background-color: var(--color-bg-secondary);
  padding: 80px 8% 60px;
  border-bottom: 1px solid var(--color-border);
  display: flex;
  justify-content: center;
}

.hero {
  max-width: var(--max-width-content);
  text-align: center;
}

.hero-logo {
  height: 90px;
  width: auto;
  margin-bottom: 24px;
  filter: drop-shadow(0 4px 6px rgba(0, 0, 0, 0.05));
}

.hero h1 {
  max-width: 900px;
  margin: 0 auto 24px;
}

.author-block {
  margin-top: 16px;
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.authors {
  font-size: 1.1rem;
  font-weight: 500;
  color: var(--color-text-primary);
}

.affiliation {
  font-size: 0.95rem;
  color: var(--color-text-secondary);
}

/* Buttons */
.hero-actions {
  display: flex;
  justify-content: center;
  gap: 16px;
  flex-wrap: wrap;
  margin-top: 32px;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 12px 24px;
  border-radius: var(--radius-full);
  font-weight: 600;
  text-decoration: none;
  font-size: 0.95rem;
  transition: var(--transition-smooth);
  border: 1px solid transparent;
}

.btn-primary {
  background-color: var(--color-primary);
  color: #fff;
  box-shadow: 0 4px 12px rgba(37, 99, 235, 0.15);
}

.btn-primary:hover {
  background-color: var(--color-primary-hover);
  transform: translateY(-2px);
  box-shadow: 0 6px 16px rgba(37, 99, 235, 0.25);
}

.btn-secondary {
  background-color: var(--color-bg-secondary);
  color: var(--color-text-primary);
  border-color: var(--color-border);
}

.btn-secondary:hover {
  background-color: var(--color-bg-accent);
  color: var(--color-primary);
  border-color: var(--color-primary);
  transform: translateY(-2px);
}

.hero-note {
  margin-top: 16px;
  font-size: 0.85rem;
  color: var(--color-text-muted);
}

/* Sections */
section {
  padding: 80px 8%;
  background-color: var(--color-bg-secondary);
  border-bottom: 1px solid var(--color-border);
  overflow: hidden;
}

section:nth-child(even) {
  background-color: var(--color-bg-primary);
}

/* Abstract */
#abstract .abstract-content {
  max-width: 850px;
  margin: 0 auto;
  text-align: justify;
  font-size: 1.05rem;
  line-height: 1.8;
}

/* Two Column Layouts (Overview & Training) */
.split-layout {
  display: flex;
  align-items: center;
  gap: 60px;
  max-width: var(--max-width-content);
  margin: 0 auto;
}

.split-text {
  flex: 1;
}

.split-text p {
  margin-bottom: 16px;
  font-size: 1.02rem;
  line-height: 1.7;
}

.split-visual {
  flex: 1.2;
}

.split-visual img,
.split-visual svg {
  width: 100%;
  height: auto;
  border-radius: var(--radius-md);
  box-shadow: 0 12px 30px var(--color-shadow);
  display: block;
}

/* ==========================================================================
   CSS Translation Slideshow (100% JS-Free & Page Jump Free Carousel)
   ========================================================================== */
.carousel-wrapper {
  position: relative;
  max-width: 850px;
  margin: 0 auto;
}

.scroll-container-wrapper {
  overflow: hidden;
  width: 100%;
  border-radius: var(--radius-md);
  box-shadow: 0 20px 40px var(--color-shadow);
  background-color: #000;
}

.scroll-container-inner {
  display: flex;
  width: 600%; /* 6 slides, each 100% of parent wrapper width */
  transition: transform 0.6s cubic-bezier(0.4, 0, 0.2, 1);
}

.scroll-slide-custom {
  width: 16.666%; /* 100% / 6 slides */
  flex-shrink: 0;
  position: relative;
}

.scroll-slide-custom img {
  width: 100%;
  height: auto;
  max-height: 50vh;
  object-fit: contain;
  display: block;
}

/* Radio translation mapping */
#slide-radio-1:checked ~ .scroll-container-wrapper > .scroll-container-inner {
  transform: translateX(0%);
}
#slide-radio-2:checked ~ .scroll-container-wrapper > .scroll-container-inner {
  transform: translateX(-16.666%);
}
#slide-radio-3:checked ~ .scroll-container-wrapper > .scroll-container-inner {
  transform: translateX(-33.333%);
}
#slide-radio-4:checked ~ .scroll-container-wrapper > .scroll-container-inner {
  transform: translateX(-50%);
}
#slide-radio-5:checked ~ .scroll-container-wrapper > .scroll-container-inner {
  transform: translateX(-66.666%);
}
#slide-radio-6:checked ~ .scroll-container-wrapper > .scroll-container-inner {
  transform: translateX(-83.333%);
}

/* Navigation arrows inside slides */
.scroll-slide-custom .arrow-btn {
  position: absolute;
  top: 50%;
  transform: translateY(-50%);
  width: 44px;
  height: 44px;
  background-color: rgba(255, 255, 255, 0.85);
  color: var(--color-text-primary);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.5rem;
  font-weight: 700;
  cursor: pointer;
  user-select: none;
  transition: var(--transition-smooth);
  z-index: 10;
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15);
  border: 1px solid rgba(255, 255, 255, 0.2);
  backdrop-filter: blur(4px);
  -webkit-backdrop-filter: blur(4px);
}

.scroll-slide-custom .arrow-btn:hover {
  background-color: #fff;
  color: var(--color-primary);
  transform: translateY(-50%) scale(1.08);
}

.scroll-slide-custom .prev-btn {
  left: 20px;
}

.scroll-slide-custom .next-btn {
  right: 20px;
}

/* Indicators */
.carousel-indicators-custom {
  display: flex;
  justify-content: center;
  gap: 10px;
  margin-top: 20px;
}

.indicator-dot-custom {
  width: 10px;
  height: 10px;
  border-radius: var(--radius-full);
  background-color: var(--color-border);
  transition: var(--transition-smooth);
  display: inline-block;
  cursor: pointer;
}

.indicator-dot-custom:hover {
  background-color: var(--color-primary-hover);
}

/* Active State indicator dots mapping */
#slide-radio-1:checked ~ .carousel-indicators-custom #dot-1,
#slide-radio-2:checked ~ .carousel-indicators-custom #dot-2,
#slide-radio-3:checked ~ .carousel-indicators-custom #dot-3,
#slide-radio-4:checked ~ .carousel-indicators-custom #dot-4,
#slide-radio-5:checked ~ .carousel-indicators-custom #dot-5,
#slide-radio-6:checked ~ .carousel-indicators-custom #dot-6 {
  background-color: var(--color-primary);
  transform: scale(1.2);
}

/* ==========================================================================
   CSS Scroll Snapping Results Grid (JS-Free Algorithm Carousel)
   ========================================================================== */
.results-carousel-container {
  max-width: var(--max-width-content);
  margin: 0 auto;
}

.results-nav {
  display: flex;
  justify-content: center;
  gap: 12px;
  margin-bottom: 30px;
  flex-wrap: wrap;
}

.results-nav-btn {
  padding: 10px 20px;
  border-radius: var(--radius-full);
  background-color: var(--color-bg-secondary);
  border: 1px solid var(--color-border);
  color: var(--color-text-secondary);
  text-decoration: none;
  font-weight: 600;
  font-size: 0.9rem;
  transition: var(--transition-smooth);
}

.results-nav-btn:hover {
  background-color: var(--color-bg-accent);
  color: var(--color-primary);
  border-color: var(--color-primary);
}

/* Scroll snap container for Algo Slides */
.algo-scroll-container {
  display: flex;
  overflow-x: auto;
  scroll-snap-type: x mandatory;
  scroll-behavior: smooth;
  padding: 10px 0 24px;
}

/* Hide scrollbars but allow swiping */
.algo-scroll-container::-webkit-scrollbar {
  display: none;
}
.algo-scroll-container {
  -ms-overflow-style: none;
  scrollbar-width: none;
}

.algo-card {
  flex: 0 0 100%;
  scroll-snap-align: start;
  scroll-snap-stop: always;
  background-color: var(--color-bg-secondary);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: 30px;
  box-shadow: 0 10px 30px var(--color-shadow);
  display: flex;
  flex-direction: column;
  gap: 20px;
}

.algo-info-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 16px;
  border-bottom: 1px solid var(--color-border);
  padding-bottom: 16px;
}

.algo-tag {
  background-color: var(--color-primary-light);
  color: var(--color-primary);
  font-weight: 700;
  font-size: 1rem;
  padding: 8px 16px;
  border-radius: var(--radius-full);
  text-transform: uppercase;
}

.algo-desc {
  max-width: 800px;
  color: var(--color-text-secondary);
  line-height: 1.6;
}

/* 2x2 Grid of Metrics inside each Algorithm Slide */
.algo-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 20px;
}

.metric-panel {
  background-color: var(--color-bg-primary);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: 16px;
  text-align: center;
  transition: var(--transition-smooth);
}

.metric-panel:hover {
  transform: translateY(-3px);
  box-shadow: 0 8px 20px var(--color-shadow);
  border-color: var(--color-primary-light);
}

.metric-panel img,
.metric-panel svg {
  width: 100%;
  height: auto;
  border-radius: var(--radius-sm);
  display: block;
}

.metric-panel span {
  display: block;
  margin-top: 12px;
  font-weight: 600;
  color: var(--color-text-primary);
  font-size: 0.9rem;
}

/* Results Navigation Arrows */
.results-carousel-wrapper {
  position: relative;
}

.results-nav-arrows {
  position: absolute;
  top: 50%;
  left: -20px;
  right: -20px;
  transform: translateY(-50%);
  display: flex;
  justify-content: space-between;
  pointer-events: none;
  z-index: 10;
}

/* Results Table Style */
.results-table-container {
  width: 100%;
  margin-top: 20px;
  overflow-x: auto;
  border-radius: var(--radius-md);
  border: 1px solid var(--color-border);
  box-shadow: 0 4px 12px var(--color-shadow);
}

.results-table {
  width: 100%;
  border-collapse: collapse;
  text-align: left;
  background-color: var(--color-bg-secondary);
  font-size: 0.95rem;
}

.results-table th, 
.results-table td {
  padding: 14px 20px;
  border-bottom: 1px solid var(--color-border);
}

.results-table th {
  background-color: var(--color-bg-primary);
  font-weight: 700;
  color: var(--color-text-primary);
}

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

.results-table tr.highlight-row {
  background-color: var(--color-primary-light);
}

.results-table tr.highlight-row td {
  color: var(--color-primary);
  font-weight: 700;
}

/* Video demo section */
.video-section-container {
  max-width: 850px;
  margin: 0 auto;
}

.video-container {
  position: relative;
  width: 100%;
  padding-bottom: 56.25%; /* 16:9 Aspect Ratio */
  height: 0;
  border-radius: var(--radius-md);
  overflow: hidden;
  box-shadow: 0 20px 40px var(--color-shadow);
  background: #000;
}

.video-container video {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  border: none;
}

/* BibTeX Section */
#citation .citation-container {
  max-width: 850px;
  margin: 0 auto;
}

.bibtex-box {
  background-color: hsl(222.2, 47.4%, 11.2%);
  color: hsl(210, 40%, 98%);
  padding: 24px;
  border-radius: var(--radius-md);
  font-family: 'Courier New', Courier, monospace;
  font-size: 0.9rem;
  line-height: 1.5;
  overflow-x: auto;
  border: 1px solid hsl(217.2, 32.6%, 17.5%);
  box-shadow: inset 0 2px 4px rgba(0, 0, 0, 0.3);
}

/* Footer styling */
footer {
  text-align: center;
  padding: 40px 20px;
  background-color: hsl(222.2, 47.4%, 11.2%);
  color: hsl(215, 20.2%, 65.1%);
  font-size: 0.9rem;
  border-top: 1px solid hsl(217.2, 32.6%, 17.5%);
}

footer a {
  color: #fff;
  text-decoration: none;
  font-weight: 500;
}

footer a:hover {
  text-decoration: underline;
}

/* ==========================================================================
   Responsive Media Queries
   ========================================================================== */
@media (max-width: 992px) {
  h1 {
    font-size: 2.25rem;
  }
  .split-layout {
    flex-direction: column;
    gap: 30px;
  }
  .split-text, .split-visual {
    width: 100%;
  }
}

@media (max-width: 768px) {
  nav {
    padding: 16px 4%;
  }
  nav .nav-links {
    gap: 14px;
  }
  body {
    padding-top: 70px;
  }
  header {
    padding: 60px 4% 40px;
  }
  h1 {
    font-size: 1.85rem;
  }
  section {
    padding: 60px 4%;
  }
  .algo-card {
    padding: 20px;
  }
  .algo-grid {
    grid-template-columns: 1fr;
  }
  .arrow-btn {
    width: 36px;
    height: 36px;
    font-size: 1.2rem;
  }
  .results-nav-arrows {
    left: 5px;
    right: 5px;
  }
}