/* ==========================================================================
   STAND Academic Project Page - Modern Design System
   ========================================================================== */

:root {
  --primary: #2563eb;
  --primary-light: #3b82f6;
  --primary-dark: #1d4ed8;
  --primary-glow: rgba(37, 99, 235, 0.18);
  
  --accent-cyan: #06b6d4;
  --accent-indigo: #6366f1;
  --accent-rose: #f43f5e;
  --accent-amber: #f59e0b;
  --accent-emerald: #10b981;
  
  --bg-main: #f8fafc;
  --bg-card: #ffffff;
  --bg-card-subtle: #f1f5f9;
  --bg-dark: #0f172a;
  --bg-dark-card: #1e293b;
  
  --text-main: #0f172a;
  --text-muted: #64748b;
  --text-light: #94a3b8;
  --text-white: #f8fafc;
  
  --border-light: #e2e8f0;
  --border-focus: #93c5fd;
  
  --radius-sm: 6px;
  --radius-md: 12px;
  --radius-lg: 18px;
  --radius-xl: 24px;
  
  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.07), 0 2px 4px -2px rgba(0, 0, 0, 0.05);
  --shadow-lg: 0 10px 25px -3px rgba(15, 23, 42, 0.08), 0 4px 6px -4px rgba(15, 23, 42, 0.04);
  --shadow-xl: 0 20px 35px -5px rgba(15, 23, 42, 0.12), 0 8px 10px -6px rgba(15, 23, 42, 0.06);
  --shadow-glow: 0 0 30px rgba(37, 99, 235, 0.2);
}

/* Global Reset & Base Typography */
* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  scroll-behavior: smooth;
  font-size: 16px;
}

body {
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  color: var(--text-main);
  background-color: var(--bg-main);
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
}

h1, h2, h3, h4, h5, h6 {
  font-family: 'Outfit', 'Inter', sans-serif;
  color: var(--text-main);
  font-weight: 700;
  line-height: 1.25;
}

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

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

/* Container */
.page-container {
  max-width: 1180px;
  margin: 0 auto;
  padding: 0 1.5rem;
}

/* Navbar */
.top-navbar {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(255, 255, 255, 0.85);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border-bottom: 1px solid rgba(226, 232, 240, 0.8);
  transition: all 0.3s ease;
}

.nav-wrapper {
  display: flex;
  justify-content: space-between;
  align-items: center;
  height: 64px;
}

.nav-logo {
  font-family: 'Outfit', sans-serif;
  font-weight: 800;
  font-size: 1.35rem;
  display: flex;
  align-items: center;
  gap: 0.5rem;
  color: var(--text-main);
  letter-spacing: -0.5px;
}

.nav-logo-badge {
  font-size: 0.72rem;
  font-weight: 700;
  padding: 2px 8px;
  background: linear-gradient(135deg, var(--primary), var(--accent-indigo));
  color: white;
  border-radius: 999px;
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.nav-links {
  display: flex;
  gap: 1.5rem;
  list-style: none;
  align-items: center;
}

.nav-links a {
  font-size: 0.92rem;
  font-weight: 500;
  color: var(--text-muted);
  transition: color 0.2s ease;
}

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

.nav-btn {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  padding: 0.45rem 1rem;
  font-size: 0.88rem;
  font-weight: 600;
  border-radius: 999px;
  background: var(--bg-dark);
  color: white !important;
  transition: all 0.2s ease;
}

.nav-btn:hover {
  background: var(--primary);
  transform: translateY(-1px);
  box-shadow: var(--shadow-md);
}

/* Hero Section */
.hero-section {
  position: relative;
  padding: 3.5rem 0 3rem 0;
  background: radial-gradient(circle at 50% 10%, rgba(37, 99, 235, 0.08) 0%, transparent 60%);
  text-align: center;
}

/* Accepted Banner */
.accepted-badge-wrapper {
  display: inline-flex;
  align-items: center;
  gap: 0.6rem;
  background: rgba(255, 255, 255, 0.9);
  padding: 0.4rem 1.1rem;
  border-radius: 999px;
  border: 1px solid rgba(37, 99, 235, 0.25);
  box-shadow: 0 4px 15px rgba(37, 99, 235, 0.08);
  margin-bottom: 1.75rem;
  font-size: 0.88rem;
  font-weight: 600;
  color: #1e40af;
  animation: pulse-border 2.5s infinite;
}

@keyframes pulse-border {
  0% { box-shadow: 0 0 0 0 rgba(37, 99, 235, 0.2); }
  70% { box-shadow: 0 0 0 8px rgba(37, 99, 235, 0); }
  100% { box-shadow: 0 0 0 0 rgba(37, 99, 235, 0); }
}

.accepted-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: #2563eb;
  box-shadow: 0 0 8px #2563eb;
}

.hero-title {
  font-size: clamp(2rem, 4.5vw, 3.1rem);
  font-weight: 800;
  letter-spacing: -0.03em;
  color: #0f172a;
  max-width: 1000px;
  margin: 0 auto 1.25rem auto;
  line-height: 1.2;
}

.hero-title .highlight {
  background: linear-gradient(135deg, #1d4ed8 0%, #4338ca 50%, #0284c7 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.hero-subtitle {
  font-size: clamp(1.1rem, 2vw, 1.4rem);
  font-weight: 500;
  color: #475569;
  max-width: 850px;
  margin: 0 auto 2rem auto;
  letter-spacing: -0.01em;
}

/* Authors Block */
.authors-container {
  margin-bottom: 1.5rem;
}

.authors-list {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 0.6rem 1.2rem;
  font-size: 1.1rem;
  font-weight: 600;
  margin-bottom: 0.75rem;
}

.author-item a {
  color: #1e293b;
  border-bottom: 1px dotted transparent;
}

.author-item a:hover {
  color: var(--primary);
  border-bottom-color: var(--primary);
}

.author-item sup {
  color: var(--primary);
  font-weight: 700;
  margin-left: 2px;
}

.affiliations-list {
  font-size: 0.95rem;
  color: #64748b;
  margin-bottom: 0.4rem;
}

.affiliations-list span {
  margin: 0 0.5rem;
}

.corresponding-note {
  font-size: 0.85rem;
  color: #94a3b8;
  font-style: italic;
}

/* Action Links Button Row */
.action-links {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 0.85rem;
  margin: 2.25rem 0 1rem 0;
}

.action-btn {
  display: inline-flex;
  align-items: center;
  gap: 0.55rem;
  padding: 0.65rem 1.4rem;
  font-size: 0.95rem;
  font-weight: 600;
  border-radius: 999px;
  transition: all 0.25s cubic-bezier(0.16, 1, 0.3, 1);
  box-shadow: var(--shadow-sm);
}

.btn-primary {
  background: linear-gradient(135deg, #1e40af, #2563eb);
  color: white !important;
  box-shadow: 0 4px 14px rgba(37, 99, 235, 0.25);
}

.btn-primary:hover {
  background: linear-gradient(135deg, #1d4ed8, #1e40af);
  transform: translateY(-2px);
  box-shadow: 0 6px 20px rgba(37, 99, 235, 0.35);
}

.btn-dark {
  background: #1e293b;
  color: white !important;
}

.btn-dark:hover {
  background: #0f172a;
  transform: translateY(-2px);
  box-shadow: 0 6px 18px rgba(15, 23, 42, 0.25);
}

.btn-outline {
  background: white;
  color: #334155 !important;
  border: 1px solid #cbd5e1;
}

.btn-outline:hover {
  background: #f8fafc;
  border-color: #94a3b8;
  color: #0f172a !important;
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

/* Key Highlights Cards (TL;DR) */
.highlights-section {
  padding: 1.5rem 0 3.5rem 0;
}

.highlights-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 1.25rem;
  margin-top: 1rem;
}

.highlight-card {
  background: white;
  border: 1px solid rgba(226, 232, 240, 0.9);
  border-radius: var(--radius-lg);
  padding: 1.5rem;
  box-shadow: var(--shadow-md);
  transition: all 0.3s ease;
  position: relative;
  overflow: hidden;
}

.highlight-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 4px;
  background: linear-gradient(90deg, var(--primary), var(--accent-cyan));
  opacity: 0;
  transition: opacity 0.3s ease;
}

.highlight-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-lg);
  border-color: var(--border-focus);
}

.highlight-card:hover::before {
  opacity: 1;
}

.card-icon {
  width: 44px;
  height: 44px;
  border-radius: 12px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.3rem;
  margin-bottom: 1rem;
  background: rgba(37, 99, 235, 0.08);
  color: var(--primary);
}

.card-title {
  font-size: 1.1rem;
  font-weight: 700;
  margin-bottom: 0.5rem;
  color: var(--text-main);
}

.card-desc {
  font-size: 0.92rem;
  color: var(--text-muted);
  line-height: 1.55;
}

/* Main Section Blocks */
.content-section {
  padding: 4rem 0;
  border-top: 1px solid var(--border-light);
}

.section-header {
  text-align: center;
  max-width: 800px;
  margin: 0 auto 2.5rem auto;
}

.section-tag {
  display: inline-block;
  font-size: 0.8rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 1px;
  color: var(--primary);
  background: rgba(37, 99, 235, 0.08);
  padding: 4px 12px;
  border-radius: 999px;
  margin-bottom: 0.75rem;
}

.section-title {
  font-size: clamp(1.75rem, 3vw, 2.35rem);
  font-weight: 800;
  letter-spacing: -0.02em;
  margin-bottom: 0.75rem;
}

.section-subtitle {
  font-size: 1.05rem;
  color: var(--text-muted);
}

/* Glassmorphism Card Style */
.content-card {
  background: white;
  border: 1px solid var(--border-light);
  border-radius: var(--radius-xl);
  padding: 2.25rem;
  box-shadow: var(--shadow-md);
  margin-bottom: 2rem;
}

/* Two Column Layout */
.grid-2col {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 2.5rem;
  align-items: center;
}

@media (max-width: 900px) {
  .grid-2col {
    grid-template-columns: 1fr;
    gap: 1.75rem;
  }
}

/* Image Frames */
.figure-container {
  background: #ffffff;
  border: 1px solid var(--border-light);
  border-radius: var(--radius-lg);
  padding: 1.25rem;
  box-shadow: var(--shadow-sm);
  text-align: center;
  transition: all 0.3s ease;
}

.figure-container:hover {
  box-shadow: var(--shadow-md);
}

.figure-container img {
  max-width: 100%;
  height: auto;
  border-radius: var(--radius-md);
  display: block;
  margin: 0 auto;
}

.figure-caption {
  margin-top: 1rem;
  font-size: 0.88rem;
  color: var(--text-muted);
  text-align: center;
  line-height: 1.5;
}

/* Architecture Component Steps */
.arch-steps {
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
}

.step-card {
  display: flex;
  gap: 1.2rem;
  padding: 1.25rem;
  background: var(--bg-main);
  border-radius: var(--radius-md);
  border-left: 4px solid var(--primary);
  transition: transform 0.2s ease;
}

.step-card:hover {
  transform: translateX(4px);
  background: #f1f5f9;
}

.step-num {
  font-family: 'Outfit', sans-serif;
  font-size: 1.4rem;
  font-weight: 800;
  color: var(--primary);
  line-height: 1;
}

.step-body h4 {
  font-size: 1.05rem;
  font-weight: 700;
  margin-bottom: 0.3rem;
}

.step-body p {
  font-size: 0.9rem;
  color: var(--text-muted);
}

/* Mathematical Formulation Callout */
.math-callout {
  background: linear-gradient(135deg, rgba(37, 99, 235, 0.04) 0%, rgba(99, 102, 241, 0.04) 100%);
  border: 1px solid rgba(147, 197, 253, 0.5);
  border-radius: var(--radius-lg);
  padding: 1.5rem 1.75rem;
  margin: 1.5rem 0;
}

.math-callout h4 {
  font-size: 1rem;
  font-weight: 700;
  color: #1e3a8a;
  margin-bottom: 0.5rem;
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

/* Interactive Tabs */
.tabs-nav {
  display: flex;
  justify-content: center;
  gap: 0.5rem;
  margin-bottom: 2rem;
  flex-wrap: wrap;
}

.tab-btn {
  padding: 0.65rem 1.35rem;
  font-size: 0.92rem;
  font-weight: 600;
  border-radius: 999px;
  border: 1px solid var(--border-light);
  background: white;
  color: var(--text-muted);
  cursor: pointer;
  transition: all 0.2s ease;
}

.tab-btn:hover {
  background: #f1f5f9;
  color: var(--text-main);
}

.tab-btn.active {
  background: var(--primary);
  color: white;
  border-color: var(--primary);
  box-shadow: 0 4px 12px rgba(37, 99, 235, 0.25);
}

.tab-pane {
  display: none;
  animation: fadeIn 0.3s ease-in-out;
}

.tab-pane.active {
  display: block;
}

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(6px); }
  to { opacity: 1; transform: translateY(0); }
}

/* Data Tables */
.table-responsive {
  overflow-x: auto;
  border-radius: var(--radius-lg);
  border: 1px solid var(--border-light);
  box-shadow: var(--shadow-sm);
  background: white;
  margin: 1.5rem 0;
}

.data-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.87rem;
  text-align: center;
  white-space: nowrap;
}

.data-table thead th {
  background: #f8fafc;
  color: #334155;
  font-weight: 700;
  padding: 10px 12px;
  border-bottom: 1px solid var(--border-light);
  border-right: 1px solid var(--border-light);
}

.data-table tbody td {
  padding: 8px 10px;
  border-bottom: 1px solid #f1f5f9;
  border-right: 1px solid #f1f5f9;
  color: #1e293b;
}

.data-table tbody tr:hover {
  background-color: #f8fafc;
}

.data-table .model-name {
  font-weight: 600;
  text-align: left;
  padding-left: 14px;
}

/* Method Category Badges in Table */
.tag-utad1 {
  background: #f1f5f9;
  color: #475569;
  font-size: 0.72rem;
  font-weight: 700;
  padding: 2px 6px;
  border-radius: 4px;
}

.tag-utad2 {
  background: #ecfdf5;
  color: #047857;
  font-size: 0.72rem;
  font-weight: 700;
  padding: 2px 6px;
  border-radius: 4px;
}

.tag-stad {
  background: #fff7ed;
  color: #c2410c;
  font-size: 0.72rem;
  font-weight: 700;
  padding: 2px 6px;
  border-radius: 4px;
}

.tag-ours {
  background: #eff6ff;
  color: #1d4ed8;
  font-size: 0.72rem;
  font-weight: 800;
  padding: 2px 8px;
  border-radius: 4px;
  border: 1px solid #bfdbfe;
}

.best-val {
  font-weight: 800;
  color: #1e40af;
  background: rgba(37, 99, 235, 0.06);
}

.second-val {
  text-decoration: underline;
  font-weight: 600;
  color: #0f172a;
}

/* BibTeX Box */
.bibtex-box {
  background: #0f172a;
  border-radius: var(--radius-lg);
  padding: 1.75rem;
  position: relative;
  box-shadow: var(--shadow-lg);
  color: #e2e8f0;
}

.bibtex-box pre {
  margin: 0;
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.86rem;
  line-height: 1.6;
  overflow-x: auto;
  color: #93c5fd;
}

.copy-bibtex-btn {
  position: absolute;
  top: 1rem;
  right: 1rem;
  background: rgba(255, 255, 255, 0.12);
  color: white;
  border: 1px solid rgba(255, 255, 255, 0.2);
  border-radius: var(--radius-sm);
  padding: 0.4rem 0.85rem;
  font-size: 0.82rem;
  font-weight: 600;
  cursor: pointer;
  display: flex;
  align-items: center;
  gap: 0.4rem;
  transition: all 0.2s ease;
}

.copy-bibtex-btn:hover {
  background: rgba(255, 255, 255, 0.22);
}

.copy-bibtex-btn.copied {
  background: #059669;
  border-color: #10b981;
}

/* Footer */
.page-footer {
  background: #0f172a;
  color: #94a3b8;
  padding: 3rem 0;
  font-size: 0.9rem;
  border-top: 1px solid #1e293b;
}

.footer-content {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 1.5rem;
}

.footer-links a {
  color: #cbd5e1;
  margin-left: 1.5rem;
  font-weight: 500;
}

.footer-links a:hover {
  color: var(--primary-light);
}

/* Responsive adjustments */
@media (max-width: 768px) {
  .nav-links {
    display: none;
  }
  
  .hero-title {
    font-size: 1.85rem;
  }
  
  .hero-subtitle {
    font-size: 1.05rem;
  }
  
  .action-links {
    flex-direction: column;
  }
  
  .action-btn {
    width: 100%;
    justify-content: center;
  }
}