/* ===================================================
   AWESOME BCI — Clean Modern Design
   Light, spacious, refined. Stripe/Linear inspired.
   =================================================== */

:root {
  --white: #ffffff;
  --gray-50: #f8fafc;
  --gray-100: #f1f5f9;
  --gray-200: #e2e8f0;
  --gray-300: #cbd5e1;
  --gray-400: #94a3b8;
  --gray-500: #64748b;
  --gray-600: #475569;
  --gray-700: #334155;
  --gray-800: #1e293b;
  --gray-900: #0f172a;
  --gray-950: #020617;

  --indigo-50: #eef2ff;
  --indigo-100: #e0e7ff;
  --indigo-200: #c7d2fe;
  --indigo-400: #818cf8;
  --indigo-500: #6366f1;
  --indigo-600: #4f46e5;
  --indigo-700: #4338ca;

  --violet-500: #8b5cf6;
  --sky-400: #38bdf8;
  --emerald-500: #10b981;
  --amber-500: #f59e0b;
  --rose-500: #f43f5e;

  --shadow-xs: 0 1px 2px rgba(0,0,0,0.05);
  --shadow-sm: 0 1px 3px rgba(0,0,0,0.08), 0 1px 2px rgba(0,0,0,0.04);
  --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 15px -3px rgba(0,0,0,0.08), 0 4px 6px -4px rgba(0,0,0,0.04);
  --shadow-xl: 0 20px 25px -5px rgba(0,0,0,0.08), 0 8px 10px -6px rgba(0,0,0,0.04);
  --shadow-indigo: 0 4px 14px rgba(79, 70, 229, 0.25);

  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 16px;
  --radius-xl: 20px;
  --radius-2xl: 24px;
  --radius-full: 9999px;

  --ease: cubic-bezier(0.4, 0, 0.2, 1);
  --ease-out: cubic-bezier(0, 0, 0.2, 1);
  --transition: all 0.2s var(--ease);
  --transition-slow: all 0.4s var(--ease-out);
}

/* ——— Reset ——— */
*, *::before, *::after { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; }

body {
  font-family: 'Plus Jakarta Sans', sans-serif;
  line-height: 1.6;
  color: var(--gray-800);
  background: var(--white);
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}

.container { width: 100%; max-width: 1200px; margin: 0 auto; padding: 0 2rem; }

a { color: var(--indigo-600); text-decoration: none; transition: var(--transition); }
a:hover { color: var(--indigo-700); }
ul { list-style: none; }
img { max-width: 100%; height: auto; }

/* ——— Typography ——— */
h1, h2, h3, h4, h5, h6 {
  font-family: 'Plus Jakarta Sans', sans-serif;
  font-weight: 700;
  line-height: 1.2;
  margin-bottom: 1rem;
  color: var(--gray-900);
  letter-spacing: -0.02em;
}

h1 { font-size: 2.5rem; }
h2 { font-size: 2rem; }
h3 { font-size: 1.35rem; }
p { margin-bottom: 1rem; color: var(--gray-500); }

/* ——— Buttons ——— */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  padding: 0.7rem 1.5rem;
  font-family: 'Plus Jakarta Sans', sans-serif;
  font-weight: 600;
  font-size: 0.875rem;
  border: none;
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: var(--transition);
  text-decoration: none;
}

.btn-primary {
  background: var(--indigo-600);
  color: var(--white);
  box-shadow: var(--shadow-indigo);
}

.btn-primary:hover {
  background: var(--indigo-700);
  color: var(--white);
  transform: translateY(-1px);
  box-shadow: 0 6px 20px rgba(79, 70, 229, 0.35);
}

.btn-secondary { background: var(--indigo-50); color: var(--indigo-600); }
.btn-secondary:hover { background: var(--indigo-100); color: var(--indigo-700); }

.btn-outline {
  background: var(--white);
  border: 1.5px solid var(--gray-200);
  color: var(--gray-700);
}

.btn-outline:hover {
  border-color: var(--indigo-200);
  background: var(--indigo-50);
  color: var(--indigo-600);
  transform: translateY(-1px);
}

/* ——— Navigation ——— */
.navbar {
  position: sticky;
  top: 0;
  z-index: 1000;
  background: rgba(255, 255, 255, 0.85);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--gray-100);
}

.glass-effect {
  background: rgba(255, 255, 255, 0.85);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--gray-100);
  box-shadow: none;
}

.navbar .container {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 0.75rem 2rem;
}

.logo {
  display: flex;
  align-items: center;
  gap: 0.4rem;
  font-size: 1.25rem;
  font-weight: 800;
  color: var(--gray-900);
  letter-spacing: -0.02em;
}

.logo:hover { color: var(--gray-900); }

.logo i {
  color: var(--indigo-600);
}
.logo i { font-size: 1.2rem; }

.nav-links { display: flex; align-items: center; gap: 0.25rem; }
.nav-links li { margin-left: 0; }

.nav-links a {
  color: var(--gray-500);
  font-weight: 500;
  font-size: 0.9rem;
  padding: 0.4rem 0.85rem;
  border-radius: var(--radius-sm);
  transition: var(--transition);
}

.nav-links a:hover { color: var(--gray-900); background: var(--gray-50); }
.nav-links a.active { color: var(--indigo-600); background: var(--indigo-50); }

.menu-toggle {
  display: none;
  font-size: 1.2rem;
  cursor: pointer;
  color: var(--gray-600);
  padding: 0.4rem;
  border-radius: var(--radius-sm);
}

/* ——— Gradient text ——— */
.gradient-text {
  background: linear-gradient(135deg, var(--indigo-700) 0%, var(--indigo-500) 100%);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
  display: inline-block;
}

.gradient-text2 {
  background: linear-gradient(135deg, #fbbf24 0%, #f97316 100%);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
  display: inline-block;
}

/* ============================================
   HERO
   ============================================ */

.hero {
  position: relative;
  padding: 8rem 0 6rem;
  min-height: 85vh;
  display: flex;
  align-items: center;
  text-align: left;
  overflow: hidden;
  background:
    radial-gradient(ellipse 80% 70% at 70% 20%, rgba(99, 102, 241, 0.06) 0%, transparent 60%),
    radial-gradient(ellipse 60% 50% at 20% 80%, rgba(139, 92, 246, 0.04) 0%, transparent 50%),
    var(--gray-50);
}

/* Subtle dot pattern */
.hero::before {
  content: '';
  position: absolute;
  inset: 0;
  background-image: radial-gradient(circle, var(--gray-200) 1px, transparent 1px);
  background-size: 32px 32px;
  opacity: 0.4;
  mask-image: radial-gradient(ellipse 70% 60% at 50% 40%, black 20%, transparent 70%);
  -webkit-mask-image: radial-gradient(ellipse 70% 60% at 50% 40%, black 20%, transparent 70%);
}

.hero-particles {
  position: absolute;
  inset: 0;
  z-index: 1;
}

.hero-content {
  position: relative;
  z-index: 2;
  display: flex;
  align-items: center;
}

.hero-text { max-width: 720px; }

.animated-title {
  font-size: 4.5rem;
  font-weight: 800;
  letter-spacing: -0.04em;
  margin-bottom: 0.5rem;
  line-height: 1.05;
  color: var(--gray-900);
  animation: fadeUp 0.8s var(--ease-out) forwards;
  opacity: 0;
}

@keyframes fadeUp {
  from { opacity: 0; transform: translateY(20px); }
  to   { opacity: 1; transform: translateY(0); }
}

.subtitle-container { position: relative; margin-bottom: 2.5rem; }

.animated-subtitle {
  font-size: 1.2rem;
  color: var(--gray-500);
  margin-bottom: 0;
  opacity: 0;
  animation: fadeUp 0.8s var(--ease-out) 0.15s forwards;
  max-width: 480px;
  font-weight: 400;
  line-height: 1.65;
}

/* ——— Hero Buttons ——— */
.hero-buttons {
  display: flex;
  gap: 0.75rem;
  margin-top: 0;
  opacity: 0;
  animation: fadeUp 0.8s var(--ease-out) 0.3s forwards;
}

.btn-with-count {
  display: flex;
  align-items: center;
  padding: 1rem 1.25rem;
  gap: 0.85rem;
  text-align: left;
  position: relative;
  overflow: hidden;
  min-width: 180px;
  background: var(--white);
  border: 1px solid var(--gray-200);
  border-radius: var(--radius-lg);
  transition: var(--transition);
  box-shadow: var(--shadow-sm);
}

.btn-with-count:hover {
  transform: translateY(-3px);
  box-shadow: var(--shadow-lg);
  border-color: var(--gray-300);
}

.btn-with-count .btn-icon {
  font-size: 1rem;
  flex-shrink: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
  border-radius: var(--radius-md);
  transition: var(--transition);
}

.btn-primary.btn-with-count {
  background: var(--indigo-600);
  border-color: var(--indigo-600);
  box-shadow: var(--shadow-indigo);
}

.btn-primary.btn-with-count .btn-icon {
  background: rgba(255, 255, 255, 0.2);
  color: var(--white);
}

.btn-primary.btn-with-count .btn-title {
  color: rgba(255, 255, 255, 0.85);
}

.btn-primary.btn-with-count:hover {
  background: var(--indigo-700);
  border-color: var(--indigo-700);
  box-shadow: 0 8px 24px rgba(79, 70, 229, 0.4);
}

.btn-outline.btn-with-count {
  background: var(--white);
  border-color: var(--gray-200);
}

.btn-outline.btn-with-count .btn-icon {
  background: var(--gray-50);
  color: var(--gray-500);
}

.btn-outline.btn-with-count:hover .btn-icon {
  background: var(--indigo-50);
  color: var(--indigo-600);
}

.btn-with-count .btn-content {
  display: flex;
  flex-direction: column;
  gap: 0.1rem;
  flex-grow: 1;
  min-width: 0;
}

.btn-with-count .btn-title {
  font-weight: 600;
  font-size: 0.85rem;
  line-height: 1.3;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  color: var(--gray-700);
}

.btn-with-count .btn-count {
  font-size: 1.75rem;
  font-weight: 800;
  line-height: 1;
  letter-spacing: -0.03em;
  color: var(--gray-900);
}

.btn-primary.btn-with-count .btn-count { color: var(--white); }

.btn-with-count:hover .btn-icon { transform: scale(1.05); }

/* ——— Page Header (subpages) ——— */
.page-header {
  padding: 4rem 0 3rem;
  text-align: center;
  position: relative;
  overflow: hidden;
  background:
    radial-gradient(ellipse 60% 80% at 50% 0%, rgba(99, 102, 241, 0.06) 0%, transparent 60%),
    var(--gray-50);
  border-bottom: 1px solid var(--gray-100);
}

.page-header h1 {
  font-size: 2.5rem;
  margin-bottom: 0.5rem;
  position: relative;
  z-index: 2;
}

.page-header p {
  font-size: 1.05rem;
  color: var(--gray-500);
  max-width: 550px;
  margin: 0 auto;
  position: relative;
  z-index: 2;
}

/* ——— Content Section ——— */
.content-section { padding: 2.5rem 0; }

/* ——— Controls ——— */
.controls {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 1.5rem;
  flex-wrap: wrap;
  gap: 1rem;
}

.search-box { position: relative; width: 100%; max-width: 380px; }

.search-box input {
  width: 100%;
  padding: 0.65rem 1rem 0.65rem 2.5rem;
  border: 1.5px solid var(--gray-200);
  border-radius: var(--radius-full);
  font-family: 'Plus Jakarta Sans', sans-serif;
  font-size: 0.9rem;
  color: var(--gray-800);
  background: var(--white);
  transition: var(--transition);
}

.search-box input::placeholder { color: var(--gray-400); }

.search-box input:focus {
  outline: none;
  border-color: var(--indigo-400);
  box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.1);
}

.search-box i {
  position: absolute;
  left: 0.9rem;
  top: 50%;
  transform: translateY(-50%);
  color: var(--gray-400);
  font-size: 0.8rem;
}

.sort-options { display: flex; align-items: center; gap: 0.5rem; }
.sort-options label { color: var(--gray-500); font-size: 0.875rem; font-weight: 500; }

.sort-options select {
  padding: 0.55rem 0.9rem;
  border: 1.5px solid var(--gray-200);
  border-radius: var(--radius-sm);
  font-family: 'Plus Jakarta Sans', sans-serif;
  font-size: 0.875rem;
  background: var(--white);
  color: var(--gray-700);
  cursor: pointer;
  transition: var(--transition);
}

.sort-options select:focus { outline: none; border-color: var(--indigo-400); }

/* ============================================
   DATA TABLE
   ============================================ */

.data-table {
  width: 100%;
  border-collapse: separate;
  border-spacing: 0;
  border-radius: var(--radius-lg);
  overflow: hidden;
  margin-bottom: 2rem;
  background: var(--white);
  border: 1px solid var(--gray-200);
  box-shadow: var(--shadow-sm);
}

.data-table th,
.data-table td {
  padding: 0.8rem 1rem;
  text-align: left;
  border-bottom: 1px solid var(--gray-100);
}

.data-table th {
  background: var(--gray-50);
  color: var(--gray-500);
  font-weight: 600;
  font-size: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  position: sticky;
  top: 0;
  z-index: 10;
}

.data-table tr:last-child td { border-bottom: none; }
.data-table tr { transition: background 0.15s var(--ease); }
.data-table tr:hover { background: var(--gray-50); }
.data-table tr:nth-child(even) { background: rgba(248, 250, 252, 0.5); }
.data-table tr:nth-child(even):hover { background: var(--gray-50); }

.data-table .paper-title,
.data-table .dataset-title {
  font-weight: 600;
  font-size: 0.9rem;
  display: block;
  margin-bottom: 0;
  line-height: 1.45;
  color: var(--gray-800);
}

/* Column widths */
.data-table.papers-table th:nth-child(1), .data-table.papers-table td:nth-child(1) { width: 33%; white-space: normal; }
.data-table.datasets-table th:nth-child(1), .data-table.datasets-table td:nth-child(1) { width: 25%; white-space: normal; }

.data-table.papers-table th:nth-child(2), .data-table.papers-table td:nth-child(2),
.data-table.datasets-table th:nth-child(2), .data-table.datasets-table td:nth-child(2) {
  width: 15%; color: var(--gray-500); font-size: 0.85rem;
}

.data-table.papers-table th:nth-child(3), .data-table.papers-table td:nth-child(3),
.data-table.datasets-table th:nth-child(3), .data-table.datasets-table td:nth-child(3) {
  width: 7%; color: var(--gray-400); font-size: 0.85rem; font-variant-numeric: tabular-nums;
}

.data-table.papers-table th:nth-child(4), .data-table.papers-table td:nth-child(4) {
  width: 20%; color: var(--gray-500); font-size: 0.85rem;
}

.data-table.datasets-table th:nth-child(4), .data-table.datasets-table td:nth-child(4) {
  width: 30%; color: var(--gray-500); font-size: 0.85rem;
}

.data-table.papers-table th:nth-child(5), .data-table.papers-table td:nth-child(5),
.data-table.datasets-table th:nth-child(5), .data-table.datasets-table td:nth-child(5) {
  width: 10%;
}

/* Link pills */
.data-table .links { gap: 0.35rem; }

.data-table .link-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  height: 28px;
  padding: 0 0.6rem;
  border-radius: var(--radius-full);
  background: var(--indigo-50);
  color: var(--indigo-600);
  transition: var(--transition);
  font-size: 0.75rem;
  font-weight: 600;
}

.data-table .link-btn:hover {
  background: var(--indigo-600);
  color: var(--white);
  transform: translateY(-1px);
  box-shadow: var(--shadow-indigo);
}

/* ——— Resource List ——— */
.list-container { margin-bottom: 2rem; }
.resource-list { display: flex; flex-direction: column; gap: 0.65rem; }

.resource-item {
  background: var(--white);
  border: 1px solid var(--gray-200);
  border-radius: var(--radius-lg);
  padding: 1.25rem 1.5rem;
  transition: var(--transition);
  box-shadow: var(--shadow-xs);
}

.resource-item:hover {
  border-color: var(--indigo-200);
  box-shadow: var(--shadow-md);
  transform: translateY(-2px);
}

.resource-item h3 {
  font-size: 1rem;
  margin-bottom: 0.3rem;
  color: var(--gray-800);
}

.resource-item .meta { color: var(--gray-400); font-size: 0.85rem; margin-bottom: 0.5rem; }

.resource-item .links { display: flex; gap: 1rem; margin-top: 0.6rem; }

.resource-item .links a {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  font-weight: 600;
  font-size: 0.85rem;
}

/* ——— Groups Grid ——— */
.groups-description {
  color: var(--gray-500);
  font-size: 0.92rem;
  margin-bottom: 1.5rem;
  line-height: 1.6;
}

.groups-description .groups-ref {
  display: block;
  margin-top: 0.35rem;
  font-size: 0.82rem;
  color: var(--gray-400);
}

.groups-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: 0.75rem;
  margin-bottom: 2.5rem;
}

.group-card {
  background: var(--white);
  border: 1px solid var(--gray-200);
  border-radius: var(--radius-lg);
  padding: 1.25rem;
  transition: var(--transition);
  box-shadow: var(--shadow-xs);
  position: relative;
  display: flex;
  flex-direction: column;
}

.group-card:hover {
  border-color: var(--indigo-200);
  box-shadow: var(--shadow-md);
  transform: translateY(-2px);
}

.group-type {
  display: inline-block;
  font-size: 0.68rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  padding: 0.2rem 0.55rem;
  border-radius: var(--radius-full);
  margin-bottom: 0.75rem;
  width: fit-content;
}

.group-type.academic {
  background: var(--indigo-50);
  color: var(--indigo-600);
}

.group-type.industry {
  background: #fef3c7;
  color: #92400e;
}

.group-card h3 {
  font-size: 0.95rem;
  font-weight: 700;
  margin-bottom: 0.2rem;
  color: var(--gray-800);
  line-height: 1.35;
}

.group-affiliation {
  font-size: 0.82rem;
  color: var(--gray-400);
  margin-bottom: 0.85rem;
  flex-grow: 1;
}

.group-links {
  display: flex;
  gap: 0.75rem;
  padding-top: 0.75rem;
  border-top: 1px solid var(--gray-100);
}

.group-links a {
  display: inline-flex;
  align-items: center;
  gap: 0.3rem;
  font-size: 0.78rem;
  font-weight: 600;
  color: var(--indigo-600);
  transition: var(--transition);
}

.group-links a:hover {
  color: var(--indigo-700);
}

.group-links a i {
  font-size: 0.72rem;
}

/* Groups — See Also */
.groups-also {
  background: var(--gray-50);
  border: 1px solid var(--gray-200);
  border-radius: var(--radius-lg);
  padding: 1.5rem;
}

.groups-also h3 {
  font-size: 0.95rem;
  font-weight: 700;
  margin-bottom: 0.75rem;
  color: var(--gray-700);
}

.groups-also ul {
  display: flex;
  flex-direction: column;
  gap: 0.45rem;
}

.groups-also li {
  font-size: 0.85rem;
  color: var(--gray-500);
}

.groups-also li a {
  font-weight: 600;
}

/* ——— Tabs ——— */
.tabs {
  display: flex;
  gap: 0.25rem;
  margin-bottom: 1.5rem;
  border-bottom: 1px solid var(--gray-200);
}

.tab-btn {
  padding: 0.65rem 1.25rem;
  background: none;
  border: none;
  border-bottom: 2px solid transparent;
  font-family: 'Plus Jakarta Sans', sans-serif;
  font-weight: 600;
  font-size: 0.9rem;
  color: var(--gray-400);
  cursor: pointer;
  transition: var(--transition);
  white-space: nowrap;
}

.tab-btn.active, .tab-btn:hover { color: var(--indigo-600); border-bottom-color: var(--indigo-600); }
.tab-content { display: none; }
.tab-content.active { display: block; }

/* ——— Loading / No Results ——— */
.loading:not(.btn-count), .no-results { text-align: center; padding: 4rem 0; }

.spinner {
  display: inline-block;
  width: 36px; height: 36px;
  border: 3px solid var(--gray-200);
  border-top: 3px solid var(--indigo-600);
  border-radius: 50%;
  animation: spin 0.7s linear infinite;
  margin-bottom: 1rem;
}

@keyframes spin { 0% { transform: rotate(0deg); } 100% { transform: rotate(360deg); } }

.no-results i { font-size: 2.5rem; color: var(--gray-300); margin-bottom: 1rem; }
.no-results p { color: var(--gray-400); }
.hidden { display: none; }

/* ——— Pagination ——— */
.pagination { display: flex; justify-content: center; align-items: center; margin-top: 2rem; gap: 0.25rem; }

.pagination-btn {
  display: inline-flex; align-items: center; justify-content: center;
  width: 36px; height: 36px;
  border-radius: var(--radius-sm);
  background: var(--white);
  border: 1px solid var(--gray-200);
  color: var(--gray-600);
  font-weight: 600;
  font-size: 0.82rem;
  transition: var(--transition);
  cursor: pointer;
}

.pagination-btn:hover { background: var(--gray-50); border-color: var(--indigo-200); color: var(--indigo-600); }

.pagination-btn.active {
  background: var(--indigo-600);
  border-color: var(--indigo-600);
  color: var(--white);
  box-shadow: var(--shadow-indigo);
}

.pagination-btn.disabled { opacity: 0.4; cursor: not-allowed; }
.pagination-btn.prev, .pagination-btn.next { width: auto; padding: 0 0.85rem; }

.pagination-ellipsis {
  display: inline-flex; align-items: center; justify-content: center;
  width: 36px; height: 36px; color: var(--gray-400); font-weight: 600;
}

/* ============================================
   CONTRIBUTE SECTION
   ============================================ */

.contribute {
  padding: 5rem 0;
  position: relative;
  overflow: hidden;
  text-align: left;
  background: linear-gradient(135deg, var(--indigo-600) 0%, var(--violet-500) 100%);
  color: var(--white);
}

.contribute::before {
  content: '';
  position: absolute;
  inset: 0;
  background-image: radial-gradient(circle, rgba(255,255,255,0.08) 1px, transparent 1px);
  background-size: 28px 28px;
  opacity: 0.5;
}

.contribute-content {
  display: flex; align-items: center; justify-content: space-between;
  position: relative; z-index: 2;
}

.contribute-text { flex: 0 0 58%; }

.contribute-text h2 {
  font-size: 2.5rem;
  margin-bottom: 1rem;
  color: var(--white);
}

.contribute-text p {
  font-size: 1.05rem;
  margin-bottom: 2rem;
  color: rgba(255,255,255,0.8);
  max-width: 480px;
  line-height: 1.7;
}

.contribute .btn-primary {
  background: var(--white);
  color: var(--indigo-600);
  box-shadow: 0 4px 14px rgba(0,0,0,0.15);
  padding: 0.85rem 2rem;
  font-size: 0.95rem;
  font-weight: 700;
}

.contribute .btn-primary:hover {
  background: var(--gray-50);
  color: var(--indigo-700);
  transform: translateY(-2px);
  box-shadow: 0 8px 24px rgba(0,0,0,0.2);
}

.contribute-graphic { flex: 0 0 35%; position: relative; height: 280px; }
.connect-animation { position: relative; width: 100%; height: 100%; }

.node {
  position: absolute;
  width: 12px; height: 12px;
  border-radius: 50%;
  animation: nodeFloat 5s ease-in-out infinite;
}

.node-1 { top: 20%; left: 15%; background: rgba(255,255,255,0.9); box-shadow: 0 0 16px rgba(255,255,255,0.4); }
.node-2 { top: 50%; left: 55%; background: rgba(255,255,255,0.7); box-shadow: 0 0 16px rgba(255,255,255,0.3); animation-delay: 1.5s; }
.node-3 { top: 78%; left: 35%; background: rgba(255,255,255,0.8); box-shadow: 0 0 16px rgba(255,255,255,0.35); animation-delay: 3s; }

.connector {
  position: absolute;
  height: 1px;
  background: linear-gradient(90deg, transparent 0%, rgba(255,255,255,0.25) 50%, transparent 100%);
  animation: pulse 3s ease-in-out infinite;
}

.connector-1-2 { width: 42%; top: 35%; left: 22%; transform: rotate(28deg); }
.connector-2-3 { width: 30%; top: 65%; left: 42%; transform: rotate(-28deg); animation-delay: 0.8s; }
.connector-3-1 { width: 28%; top: 50%; left: 18%; transform: rotate(-55deg); animation-delay: 1.6s; }

@keyframes nodeFloat { 0%, 100% { transform: translateY(0) scale(1); } 50% { transform: translateY(-10px) scale(1.3); } }
@keyframes pulse { 0%, 100% { opacity: 0.3; } 50% { opacity: 0.7; } }
@keyframes float { 0%, 100% { transform: translateY(0); } 50% { transform: translateY(-15px); } }

/* ============================================
   FOOTER
   ============================================ */

footer {
  background: var(--gray-900);
  color: var(--gray-300);
  padding: 3.5rem 0 2rem;
}

.footer-content {
  display: grid;
  grid-template-columns: 1.5fr repeat(3, 1fr);
  gap: 2.5rem;
  margin-bottom: 2.5rem;
}

.footer-info { display: flex; flex-direction: column; gap: 0.75rem; }

.footer-logo {
  font-size: 1.25rem;
  font-weight: 800;
  display: flex;
  align-items: center;
  color: var(--white);
  gap: 0.4rem;
  letter-spacing: -0.02em;
}

.footer-logo i { font-size: 1.3rem; color: var(--indigo-400); }
.footer-info p { color: var(--gray-400); font-size: 0.85rem; line-height: 1.65; }

.footer-nav h3, .footer-docs h3, .footer-contact h3 {
  margin-bottom: 1rem;
  font-size: 0.75rem;
  font-weight: 700;
  color: var(--gray-300);
  text-transform: uppercase;
  letter-spacing: 0.1em;
  position: relative;
  padding-bottom: 0.6rem;
}

.footer-nav h3::after, .footer-docs h3::after, .footer-contact h3::after {
  content: '';
  position: absolute;
  bottom: 0; left: 0;
  width: 20px; height: 2px;
  background: var(--indigo-500);
  border-radius: 1px;
}

.footer-nav ul, .footer-docs ul, .footer-contact ul { display: flex; flex-direction: column; gap: 0.45rem; }

.footer-nav a, .footer-docs a, .footer-contact a {
  color: var(--gray-400); font-size: 0.85rem;
  transition: var(--transition);
  display: inline-flex; align-items: center;
}

.footer-nav a:hover, .footer-docs a:hover, .footer-contact a:hover { color: var(--white); transform: translateX(2px); }

.footer-contact a i { margin-right: 0.4rem; font-size: 0.85rem; width: 16px; text-align: center; }

.footer-bottom {
  padding-top: 1.5rem;
  border-top: 1px solid rgba(255, 255, 255, 0.08);
  text-align: center;
}

.footer-bottom p { color: var(--gray-500); font-size: 0.8rem; }

/* ============================================
   MODERN THEME — index.html-only enhancements
   ============================================ */

.modern-theme .btn {
  padding: 0.8rem 1.75rem;
  font-size: 0.9rem;
  border-radius: var(--radius-md);
}

.modern-theme .btn-primary {
  background: var(--indigo-600);
  box-shadow: var(--shadow-indigo);
}

.modern-theme .btn-primary:hover {
  background: var(--indigo-700);
  transform: translateY(-2px);
  box-shadow: 0 6px 20px rgba(79, 70, 229, 0.35);
}

.modern-theme .btn-outline {
  border: 1.5px solid var(--gray-200);
  color: var(--gray-700);
}

.modern-theme .btn-outline:hover {
  background: var(--indigo-50);
  border-color: var(--indigo-200);
  color: var(--indigo-600);
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

/* Override: contribute button must stay white even inside .modern-theme */
.contribute .btn-primary,
.modern-theme .contribute .btn-primary {
  background: var(--white);
  color: var(--indigo-600);
  box-shadow: 0 4px 14px rgba(0,0,0,0.15);
  padding: 0.85rem 2rem;
  font-size: 0.95rem;
  font-weight: 700;
}

.contribute .btn-primary:hover,
.modern-theme .contribute .btn-primary:hover {
  background: var(--gray-50);
  color: var(--indigo-700);
  transform: translateY(-2px);
  box-shadow: 0 8px 24px rgba(0,0,0,0.2);
}

/* ============================================
   RESPONSIVE
   ============================================ */

@media (max-width: 1024px) {
  .animated-title { font-size: 3.5rem; }
  .hero-content { flex-direction: column; }
  .hero-text { text-align: center; margin-bottom: 2rem; }
  .animated-subtitle { margin-left: auto; margin-right: auto; }
  .hero-buttons { justify-content: center; flex-wrap: wrap; }
  .contribute-content { flex-direction: column; }
  .contribute-text { flex: 0 0 100%; text-align: center; margin-bottom: 2rem; }
  .contribute-text p { margin: 0 auto 2rem; }
  .contribute-graphic { flex: 0 0 100%; }
  .footer-content { grid-template-columns: 1fr 1fr; }
}

@media (max-width: 768px) {
  /* ——— Global mobile spacing ——— */
  .container { padding: 0 1.25rem; }

  /* ——— Navigation ——— */
  .navbar .container { padding: 0.7rem 1.25rem; }
  .menu-toggle { display: block; }
  .logo { font-size: 1.1rem; }
  .logo i { font-size: 1.05rem; }

  .nav-links {
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    background: var(--white);
    flex-direction: column;
    align-items: stretch;
    padding: 0.5rem;
    gap: 0.15rem;
    z-index: 999;
    border-bottom: 1px solid var(--gray-200);
    box-shadow: 0 8px 24px rgba(0,0,0,0.08);
  }

  .nav-links.active {
    display: flex;
  }

  .nav-links li { margin: 0; }

  .nav-links a {
    display: block;
    text-align: left;
    font-size: 0.95rem;
    padding: 0.65rem 1rem;
    border-radius: var(--radius-sm);
  }

  .nav-links a:hover,
  .nav-links a.active {
    background: var(--gray-50);
  }

  /* ——— Hero ——— */
  .hero {
    padding: 6rem 0 4rem;
    min-height: auto;
  }

  .animated-title { font-size: 3.2rem; }
  .animated-subtitle { font-size: 1.05rem; line-height: 1.7; }
  .subtitle-container { margin-bottom: 2.5rem; }

  .hero-buttons {
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
    width: 100%;
    max-width: 340px;
    margin: 0 auto;
  }

  .btn-with-count {
    padding: 1rem 1.15rem;
    gap: 0.75rem;
    min-width: unset;
    width: 100%;
  }

  .btn-with-count .btn-icon { width: 38px; height: 38px; font-size: 0.95rem; }
  .btn-with-count .btn-title { font-size: 0.85rem; }
  .btn-with-count .btn-count { font-size: 1.5rem; }

  /* ——— Page Header ——— */
  .page-header { padding: 3rem 0 2rem; }
  .page-header h1 { font-size: 1.8rem; }
  .page-header p { font-size: 0.95rem; }

  /* ——— Controls ——— */
  .controls { flex-direction: column; align-items: stretch; gap: 0.75rem; }
  .search-box { max-width: 100%; }
  .sort-options { width: 100%; }
  .sort-options select { flex-grow: 1; }

  /* ——— Contribute ——— */
  .contribute { padding: 3.5rem 0; }
  .contribute-text h2 { font-size: 1.7rem; }
  .contribute-text p { font-size: 0.95rem; }
  .contribute-graphic { height: 200px; }

  /* ——— Footer ——— */
  footer { padding: 3rem 0 1.5rem; }

  .footer-content {
    grid-template-columns: 1fr 1fr;
    gap: 2rem 1.5rem;
  }

  .footer-info { grid-column: 1 / -1; }

  .footer-logo { font-size: 1.1rem; }
  .footer-info p { font-size: 0.82rem; }

  .footer-nav h3, .footer-docs h3, .footer-contact h3 {
    font-size: 0.7rem;
    margin-bottom: 0.75rem;
    padding-bottom: 0.5rem;
  }

  .footer-nav a, .footer-docs a, .footer-contact a { font-size: 0.82rem; }

  .footer-bottom { padding-top: 1.25rem; }
  .footer-bottom p { font-size: 0.75rem; }

  /* ——— Mobile table ——— */
  .data-table.papers-table th:not(:first-child):not(:last-child),
  .data-table.papers-table td:not(:first-child):not(:last-child),
  .data-table.datasets-table th:not(:first-child):not(:last-child),
  .data-table.datasets-table td:not(:first-child):not(:last-child) { display: none; }

  .data-table.papers-table th:first-child, .data-table.papers-table td:first-child,
  .data-table.datasets-table th:first-child, .data-table.datasets-table td:first-child { width: 75%; padding-right: 0; }

  .data-table.papers-table th:last-child, .data-table.papers-table td:last-child,
  .data-table.datasets-table th:last-child, .data-table.datasets-table td:last-child { width: 25%; text-align: center; }

  .data-table tr.expandable-row { display: none; background: var(--gray-50); }
  .data-table tr.expandable-row.active { display: table-row; }
  .data-table tr.expandable-row td { padding: 1rem; border-top: none; }
  .data-table tr.expandable-row .paper-details, .data-table tr.expandable-row .dataset-details { display: flex; flex-direction: column; gap: 0.5rem; }
  .data-table tr.expandable-row .paper-detail-item, .data-table tr.expandable-row .dataset-detail-item { display: flex; flex-direction: column; }
  .data-table tr.expandable-row .paper-detail-label, .data-table tr.expandable-row .dataset-detail-label { font-weight: 600; color: var(--gray-400); font-size: 0.72rem; text-transform: uppercase; letter-spacing: 0.05em; }
  .data-table tr.expandable-row .paper-detail-value, .data-table tr.expandable-row .dataset-detail-value { font-size: 0.88rem; color: var(--gray-600); }
  .data-table tr.expandable-row .link-buttons { display: flex; gap: 0.5rem; margin-top: 0.75rem; }

  .data-table .paper-title, .data-table .dataset-title { cursor: pointer; display: flex; align-items: center; transition: var(--transition); }
  .data-table .paper-title:hover, .data-table .dataset-title:hover { color: var(--indigo-600); }

  .data-table .paper-title::after, .data-table .dataset-title::after {
    content: '\f078'; font-family: 'Font Awesome 5 Free'; font-weight: 900;
    margin-left: 0.5rem; font-size: 0.65rem; color: var(--gray-400); transition: var(--transition);
  }

  .data-table .paper-title.active::after, .data-table .dataset-title.active::after { transform: rotate(180deg); color: var(--indigo-600); }

  .data-table.papers-table td:last-child > a:not(:first-child),
  .data-table.datasets-table td:last-child > a:not(:first-child) { display: none; }

  .data-table th, .data-table td { padding: 0.7rem; }
  .data-table .link-btn { padding: 0 0.5rem; height: 26px; font-size: 0.72rem; }

  /* ——— Resource items ——— */
  .resource-item { padding: 1rem 1.15rem; }
  .resource-item h3 { font-size: 0.95rem; }

  /* ——— Tabs ——— */
  .tabs { gap: 0; }
  .tab-btn { padding: 0.6rem 1rem; font-size: 0.85rem; }
}

@media (max-width: 576px) {
  .animated-title { font-size: 2.6rem; }
  .animated-subtitle { font-size: 0.95rem; }
  .page-header h1 { font-size: 1.5rem; }
  .page-header p { font-size: 0.88rem; }

  .hero { padding: 5rem 0 3.5rem; }
  .subtitle-container { margin-bottom: 2.25rem; }
  .hero-buttons { max-width: 300px; gap: 0.65rem; }

  .btn-with-count .btn-title { font-size: 0.82rem; white-space: normal; }

  .contribute { padding: 3rem 0; }
  .contribute-text h2 { font-size: 1.4rem; }
  .contribute-text p { font-size: 0.88rem; }
  .contribute-graphic { height: 160px; }

  .groups-grid { grid-template-columns: 1fr; gap: 0.6rem; }
  .group-card { padding: 1rem; }
  .groups-also { padding: 1.15rem; }

  .footer-content {
    grid-template-columns: 1fr;
    gap: 1.5rem;
  }
}