/* ==========================================================================
   EBBC OPENDATA - MONOCHROMATIC APPLE-MINIMALIST DESIGN SYSTEM
   ========================================================================== */

:root {
  /* Pure Monochromatic iOS/macOS Dark Palette */
  --bg-primary: #000000;          /* Deep pitch black background */
  --bg-secondary: #0a0a0c;        /* Secondary panel background */
  --bg-surface: #16161a;          /* Cards & UI elements surface */
  --bg-surface-hover: #222227;    /* Subtle hover state */
  
  --border-color: rgba(255, 255, 255, 0.08);
  --border-color-focus: rgba(255, 255, 255, 0.25);
  
  --text-primary: #ffffff;        /* Pure white */
  --text-secondary: #8e8e93;      /* SF Gray secondary */
  --text-muted: #48484a;          /* SF Gray tertiary */
  
  --color-accent: #ffffff;
  --color-accent-dim: rgba(255, 255, 255, 0.08);
  
  /* Apple System Fonts */
  --font-display: -apple-system, BlinkMacSystemFont, "SF Pro Display", "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  --font-sans: -apple-system, BlinkMacSystemFont, "SF Pro Text", "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  
  /* Layout Metrics */
  --max-width: 1200px;
  --border-radius-lg: 12px;
  --border-radius-md: 8px;
  --border-radius-sm: 5px;
  --transition-smooth: all 0.2s ease-in-out;
}

* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  background-color: var(--bg-primary);
  color: var(--text-primary);
  font-family: var(--font-sans);
  min-height: 100vh;
  position: relative;
  overflow-x: hidden;
  line-height: 1.5;
}

/* Scrollbar (Minimalist) */
::-webkit-scrollbar {
  width: 5px;
  height: 5px;
}
::-webkit-scrollbar-track {
  background: var(--bg-primary);
}
::-webkit-scrollbar-thumb {
  background: rgba(255, 255, 255, 0.15);
  border-radius: 10px;
}
::-webkit-scrollbar-thumb:hover {
  background: rgba(255, 255, 255, 0.3);
}

/* Disable Background Orbs completely for pure monochromatic look */
.glow-orb {
  display: none !important;
}

/* Glass panel redesigned as solid macOS style panel */
.glass-panel {
  background: var(--bg-surface);
  border: 1px solid var(--border-color);
  border-radius: var(--border-radius-lg);
  box-shadow: 0 4px 24px rgba(0, 0, 0, 0.4);
  transition: var(--transition-smooth);
}

/* ==========================================================================
   LAYOUT CONTAINER
   ========================================================================== */

.app-container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 3rem 2rem;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  gap: 2rem;
}

/* ==========================================================================
   HEADER
   ========================================================================== */

.app-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding-bottom: 2rem;
  border-bottom: 1px solid var(--border-color);
  flex-wrap: wrap;
  gap: 1.5rem;
}

.logo-area {
  display: flex;
  align-items: center;
  gap: 1rem;
}

.logo-icon {
  width: 42px;
  height: 42px;
  background: #ffffff;
  color: #000000;
  border-radius: var(--border-radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.25rem;
  font-weight: 700;
}

.logo-text h1 {
  font-family: var(--font-display);
  font-size: 1.5rem;
  font-weight: 700;
  letter-spacing: -0.5px;
  color: var(--text-primary);
}
.logo-text h1 span {
  background: none;
  -webkit-background-clip: unset;
  background-clip: unset;
  -webkit-text-fill-color: initial;
  color: var(--text-primary);
}
.logo-text p {
  color: var(--text-secondary);
  font-size: 0.85rem;
  font-weight: 400;
}

.header-badges {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  flex-wrap: wrap;
}

.badge-link img {
  height: 18px;
  filter: grayscale(1) brightness(0.9);
  transition: var(--transition-smooth);
}
.badge-link img:hover {
  filter: none;
}

.badge-pill {
  background: rgba(255, 255, 255, 0.04);
  border: 1px solid var(--border-color);
  padding: 0.3rem 0.6rem;
  border-radius: 40px;
  font-size: 0.75rem;
  font-weight: 500;
  display: flex;
  align-items: center;
  gap: 0.4rem;
  color: var(--text-secondary);
}

/* ==========================================================================
   NAVIGATION (Segmented Control style)
   ========================================================================== */

.nav-tabs {
  display: flex;
  gap: 0.25rem;
  background: #121214;
  padding: 3px;
  border-radius: 9px;
  border: 1px solid var(--border-color);
  align-self: flex-start;
}

.tab-btn {
  background: transparent;
  border: none;
  color: var(--text-secondary);
  font-family: var(--font-display);
  font-size: 0.85rem;
  font-weight: 500;
  padding: 0.5rem 1rem;
  border-radius: 7px;
  cursor: pointer;
  display: flex;
  align-items: center;
  gap: 0.5rem;
  transition: var(--transition-smooth);
}

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

.tab-btn.active {
  color: #000000;
  background: #ffffff;
  font-weight: 600;
  box-shadow: 0 1px 4px rgba(0, 0, 0, 0.15);
}

/* Tab Panels */
.tab-panel {
  display: none;
  animation: none;
}
.tab-panel.active {
  display: block;
}

/* ==========================================================================
   1. DASHBOARD PANEL
   ========================================================================== */

/* Stats Grid */
.stats-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 1.25rem;
  margin-bottom: 2rem;
}

.stat-card {
  background: var(--bg-surface);
  border: 1px solid var(--border-color);
  border-radius: var(--border-radius-lg);
  padding: 1.25rem;
  display: flex;
  flex-direction: column;
  position: relative;
  transition: var(--transition-smooth);
}
.stat-card::before {
  display: none; /* remove gradient line */
}
.stat-card:hover {
  background: var(--bg-surface-hover);
  border-color: rgba(255, 255, 255, 0.15);
}

.stat-card .stat-icon {
  position: absolute;
  right: 1.25rem;
  top: 1.25rem;
  font-size: 1.5rem;
  opacity: 0.25;
  color: var(--text-secondary);
}

.stat-info h3 {
  font-size: 0.8rem;
  color: var(--text-secondary);
  font-weight: 500;
  text-transform: uppercase;
  letter-spacing: 0.5px;
  margin-bottom: 0.5rem;
}
.stat-value {
  font-family: var(--font-display);
  font-size: 1.8rem;
  font-weight: 700;
  margin-bottom: 0.2rem;
  color: var(--text-primary);
  letter-spacing: -0.5px;
}
.stat-footer {
  font-size: 0.75rem;
  color: var(--text-secondary);
  font-weight: 400;
}

/* Charts Grid */
.charts-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(450px, 1fr));
  gap: 1.25rem;
}

@media (max-width: 768px) {
  .charts-grid {
    grid-template-columns: 1fr;
  }
}

.chart-card {
  background: var(--bg-surface);
  border: 1px solid var(--border-color);
  border-radius: var(--border-radius-lg);
  padding: 1.5rem;
}
.chart-card .chart-header {
  margin-bottom: 1.25rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
}
.chart-card h3 {
  font-family: var(--font-display);
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--text-primary);
  display: flex;
  align-items: center;
  gap: 0.5rem;
}
.chart-card h3 i {
  color: var(--text-secondary);
}
.chart-container {
  position: relative;
  height: 260px;
}

/* ==========================================================================
   2. DATA EXPLORER PANEL
   ========================================================================== */

.explorer-layout {
  display: grid;
  grid-template-columns: 280px 1fr;
  gap: 1.5rem;
}

@media (max-width: 992px) {
  .explorer-layout {
    grid-template-columns: 1fr;
  }
}

/* Filters Sidebar */
.filters-sidebar {
  padding: 1.25rem;
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
}

.sidebar-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
}
.sidebar-header h3 {
  font-family: var(--font-display);
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--text-primary);
}

.btn-text {
  background: transparent;
  border: none;
  color: var(--text-secondary);
  font-weight: 500;
  font-size: 0.8rem;
  cursor: pointer;
  transition: var(--transition-smooth);
}
.btn-text:hover {
  color: var(--text-primary);
  text-decoration: none;
}

.filter-group {
  display: flex;
  flex-direction: column;
  gap: 0.4rem;
}
.filter-group label {
  font-size: 0.8rem;
  font-weight: 500;
  color: var(--text-secondary);
}

/* Form Controls */
input[type="text"], 
input[type="number"],
select {
  background: #000000;
  border: 1px solid var(--border-color);
  padding: 0.6rem 0.75rem;
  border-radius: var(--border-radius-md);
  color: var(--text-primary);
  font-family: var(--font-sans);
  font-size: 0.85rem;
  outline: none;
  transition: var(--transition-smooth);
}
input[type="text"]:focus,
input[type="number"]:focus,
select:focus {
  border-color: var(--border-color-focus);
}

select option {
  background: #000000;
  color: var(--text-primary);
}

/* Checkboxes style */
.checkbox-group {
  display: flex;
  flex-direction: column;
  gap: 0.4rem;
}
.checkbox-container {
  display: block;
  position: relative;
  padding-left: 24px;
  cursor: pointer;
  font-size: 0.8rem !important;
  color: var(--text-secondary) !important;
  user-select: none;
}
.checkbox-container input {
  position: absolute;
  opacity: 0;
  cursor: pointer;
}
.checkmark {
  position: absolute;
  top: 1px;
  left: 0;
  height: 14px;
  width: 14px;
  background-color: #000000;
  border: 1px solid var(--border-color);
  border-radius: 3px;
  transition: var(--transition-smooth);
}
.checkbox-container:hover input ~ .checkmark {
  border-color: rgba(255, 255, 255, 0.2);
}
.checkbox-container input:checked ~ .checkmark {
  background-color: #ffffff;
  border-color: #ffffff;
}
.checkmark:after {
  content: "";
  position: absolute;
  display: none;
}
.checkbox-container input:checked ~ .checkmark:after {
  display: block;
}
.checkbox-container .checkmark:after {
  left: 4px;
  top: 1px;
  width: 3px;
  height: 7px;
  border: solid #000000;
  border-width: 0 1.5px 1.5px 0;
  transform: rotate(45deg);
}
.checkbox-container input:checked ~ span {
  color: var(--text-primary);
}

.sort-controls {
  display: flex;
  gap: 0.4rem;
}
.sort-controls select {
  flex-grow: 1;
}
.btn-icon-toggle {
  background: #000000;
  border: 1px solid var(--border-color);
  color: var(--text-secondary);
  width: 34px;
  height: 34px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: var(--border-radius-md);
  cursor: pointer;
  transition: var(--transition-smooth);
}
.btn-icon-toggle:hover {
  color: var(--text-primary);
  border-color: rgba(255, 255, 255, 0.2);
}

.export-actions {
  border-top: 1px solid var(--border-color);
  padding-top: 1rem;
}
.export-actions h4 {
  font-size: 0.75rem;
  color: var(--text-secondary);
  font-weight: 500;
  margin-bottom: 0.5rem;
}
.btn-row {
  display: flex;
  gap: 0.4rem;
}

/* Minimalist Buttons */
.btn {
  font-family: var(--font-display);
  font-weight: 500;
  border: none;
  border-radius: var(--border-radius-md);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0.4rem;
  transition: var(--transition-smooth);
}
.btn-sm {
  padding: 0.4rem 0.75rem;
  font-size: 0.8rem;
}
.btn-primary {
  background: #ffffff;
  color: #000000;
}
.btn-primary:hover {
  background: rgba(255, 255, 255, 0.9);
}
.btn-secondary {
  background: transparent;
  border: 1px solid var(--border-color);
  color: var(--text-primary);
}
.btn-secondary:hover {
  background: rgba(255, 255, 255, 0.05);
  border-color: rgba(255, 255, 255, 0.15);
}

/* Results Content */
.results-container {
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.results-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  background: #0a0a0c;
  padding: 0.6rem 1rem;
  border-radius: var(--border-radius-md);
  border: 1px solid var(--border-color);
  flex-wrap: wrap;
  gap: 0.5rem;
}
.results-count {
  font-size: 0.8rem;
  color: var(--text-secondary);
}
.results-count span {
  font-weight: 600;
  color: var(--text-primary);
}

.pagination-controls {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  font-size: 0.8rem;
}
.btn-icon {
  background: #000000;
  border: 1px solid var(--border-color);
  color: var(--text-secondary);
  width: 26px;
  height: 26px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: var(--border-radius-sm);
  cursor: pointer;
  transition: var(--transition-smooth);
}
.btn-icon:hover:not(:disabled) {
  color: var(--text-primary);
  border-color: rgba(255, 255, 255, 0.2);
}
.btn-icon:disabled {
  opacity: 0.25;
  cursor: not-allowed;
}

/* Articles List */
.articles-list {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

.loading-state {
  text-align: center;
  padding: 3rem;
  color: var(--text-secondary);
  font-size: 0.95rem;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
}

.article-card {
  background: var(--bg-surface);
  border: 1px solid var(--border-color);
  border-radius: var(--border-radius-lg);
  padding: 1.25rem;
  cursor: pointer;
  position: relative;
  transition: var(--transition-smooth);
}
.article-card::after {
  display: none !important; /* remove color line */
}
.article-card:hover {
  background: var(--bg-surface-hover);
  border-color: rgba(255, 255, 255, 0.15);
}

.card-header-row {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 0.5rem;
  gap: 1rem;
}
.card-year-badge {
  background: rgba(255, 255, 255, 0.06);
  border: 1px solid var(--border-color);
  color: var(--text-primary);
  font-size: 0.7rem;
  font-weight: 600;
  padding: 0.1rem 0.4rem;
  border-radius: 3px;
  font-family: var(--font-display);
}
.card-doi {
  font-size: 0.7rem;
  color: var(--text-secondary);
  font-family: monospace;
}

.article-card h3 {
  font-family: var(--font-display);
  font-size: 1rem;
  font-weight: 600;
  margin-bottom: 0.25rem;
  line-height: 1.35;
  color: var(--text-primary);
}

.card-authors {
  font-size: 0.8rem;
  color: var(--text-secondary);
  margin-bottom: 0.75rem;
}

.card-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem;
  align-items: center;
}

/* Main content flex layout to push footer */
.main-content {
  flex: 1;
  display: flex;
  flex-direction: column;
}

/* Colorful Apple-style Badges */
.badge-tag {
  font-size: 0.7rem;
  padding: 0.15rem 0.45rem;
  border-radius: 4px;
  font-weight: 500;
  display: inline-flex;
  align-items: center;
  gap: 0.3rem;
  transition: var(--transition-smooth);
}
.badge-tag.tool {
  background: rgba(10, 132, 255, 0.08);
  border: 1px solid rgba(10, 132, 255, 0.2);
  color: #0a84ff;
}
.badge-tag.source {
  background: rgba(48, 209, 88, 0.08);
  border: 1px solid rgba(48, 209, 88, 0.2);
  color: #30d158;
}
.badge-tag.stage {
  background: rgba(255, 159, 10, 0.08);
  border: 1px solid rgba(255, 159, 10, 0.2);
  color: #ff9f0a;
}

/* Empty State */
.empty-state {
  text-align: center;
  padding: 3rem;
  color: var(--text-secondary);
  font-size: 0.95rem;
}
.empty-state i {
  font-size: 2rem;
  opacity: 0.2;
  margin-bottom: 0.75rem;
  display: block;
}

/* ==========================================================================
   3. API DOCUMENTATION PANEL
   ========================================================================== */

.docs-layout {
  display: grid;
  grid-template-columns: 240px 1fr;
  gap: 1.5rem;
}

@media (max-width: 992px) {
  .docs-layout {
    grid-template-columns: 1fr;
  }
}

.docs-sidebar {
  padding: 1rem 0;
}
.docs-sidebar h3 {
  font-family: var(--font-display);
  font-size: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.5px;
  color: var(--text-muted);
  margin-bottom: 0.75rem;
  padding-bottom: 0.25rem;
  border-bottom: 1px solid var(--border-color);
}
.docs-sidebar ul {
  list-style: none;
}
.docs-sidebar li {
  margin-bottom: 0.25rem;
}
.docs-sidebar a {
  color: var(--text-secondary);
  text-decoration: none;
  font-size: 0.8rem;
  font-weight: 500;
  display: flex;
  align-items: center;
  gap: 0.4rem;
  padding: 0.4rem 0.5rem;
  border-radius: var(--border-radius-sm);
  transition: var(--transition-smooth);
}
.docs-sidebar a:hover, 
.docs-sidebar a.active {
  color: var(--text-primary);
  background: rgba(255, 255, 255, 0.04);
}

/* Endpoint Badges */
.badge {
  font-size: 0.65rem;
  font-weight: 600;
  padding: 0.1rem 0.3rem;
  border-radius: 3px;
}
.badge.get {
  background: rgba(255, 255, 255, 0.08);
  border: 1px solid rgba(255, 255, 255, 0.15);
  color: var(--text-primary);
}
.badge.large {
  font-size: 0.8rem;
  padding: 0.2rem 0.5rem;
}

/* Docs Content */
.docs-content {
  padding: 1.5rem;
  display: flex;
  flex-direction: column;
  gap: 2rem;
  max-height: 75vh;
  overflow-y: auto;
}

.doc-section {
  display: none;
  flex-direction: column;
  gap: 1rem;
}
.doc-section.active {
  display: flex;
}

.doc-section h2 {
  font-family: var(--font-display);
  font-size: 1.3rem;
  font-weight: 700;
}
.doc-section p {
  color: var(--text-secondary);
  font-size: 0.9rem;
}

.endpoint-header {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  padding-bottom: 0.75rem;
  border-bottom: 1px solid var(--border-color);
}

.info-box {
  padding: 0.75rem 1rem;
  border-radius: var(--border-radius-md);
  font-size: 0.85rem;
}
.info-box h4 {
  font-weight: 600;
  margin-bottom: 0.15rem;
}
.info-box.note {
  background: rgba(255, 255, 255, 0.03);
  border: 1px solid var(--border-color);
  color: var(--text-secondary);
}
.info-box.note h4 { color: var(--text-primary); }
.info-box.tip {
  background: rgba(255, 255, 255, 0.03);
  border: 1px solid var(--border-color);
  color: var(--text-secondary);
}
.info-box.tip h4 { color: var(--text-primary); }

/* Parameters Table */
.params-table {
  width: 100%;
  border-collapse: collapse;
  margin: 0.5rem 0;
  font-size: 0.85rem;
}
.params-table th, 
.params-table td {
  padding: 0.6rem 0.8rem;
  text-align: left;
  border-bottom: 1px solid var(--border-color);
}
.params-table th {
  color: var(--text-secondary);
  font-weight: 500;
  background: rgba(255, 255, 255, 0.01);
}
.params-table td code {
  background: rgba(255, 255, 255, 0.05);
  padding: 0.1rem 0.25rem;
  border-radius: 3px;
  font-size: 0.8rem;
  color: var(--text-primary);
}

/* Sandbox Box */
.sandbox-box {
  background: #000000;
  border: 1px solid var(--border-color);
  border-radius: var(--border-radius-lg);
  padding: 1rem;
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}
.sandbox-controls {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
  background: rgba(255,255,255,0.01);
  padding: 0.6rem;
  border-radius: var(--border-radius-md);
  border: 1px solid var(--border-color);
}
.sandbox-control-row {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  flex-wrap: wrap;
}
.sandbox-control-row label {
  font-size: 0.75rem;
  font-weight: 500;
  color: var(--text-secondary);
  min-width: 70px;
}
.sandbox-control-row input {
  padding: 0.35rem 0.5rem;
  font-size: 0.8rem;
  border-radius: var(--border-radius-sm);
  background: #0a0a0c;
  border: 1px solid var(--border-color);
  color: var(--text-primary);
  max-width: 120px;
}

.sandbox-url-bar {
  background: #0a0a0c;
  padding: 0.5rem 0.75rem;
  border-radius: var(--border-radius-sm);
  font-family: monospace;
  font-size: 0.75rem;
  word-break: break-all;
  border: 1px dashed var(--border-color);
}
.sandbox-url-bar span {
  color: var(--text-primary);
  font-weight: 600;
}

.sandbox-response {
  max-height: 220px;
  overflow-y: auto;
  background: #0a0a0c;
  padding: 0.75rem;
  border-radius: var(--border-radius-md);
  border: 1px solid var(--border-color);
}
.sandbox-response pre {
  margin: 0;
  font-family: monospace;
  font-size: 0.8rem;
}
.sandbox-response code {
  color: var(--text-primary);
  white-space: pre-wrap;
  word-break: break-all;
}

.link-buttons {
  display: flex;
  gap: 0.75rem;
  flex-wrap: wrap;
}
.link-buttons a {
  text-decoration: none;
}

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

.app-footer {
  margin-top: auto;
  border-top: 1px solid var(--border-color);
  padding: 2.5rem 0 1.5rem 0;
  display: flex;
  flex-direction: column;
  gap: 2rem;
  width: 100%;
}

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

.footer-brand {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
  max-width: 450px;
}

.footer-logo {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  color: var(--text-primary);
  font-family: var(--font-display);
  font-size: 1.1rem;
  font-weight: 600;
}

.footer-logo i {
  font-size: 1rem;
  opacity: 0.9;
}

.footer-logo strong {
  font-weight: 800;
}

.footer-tagline {
  color: var(--text-secondary);
  font-size: 0.825rem;
  line-height: 1.4;
}

.footer-links-group {
  display: flex;
  gap: 1rem;
  flex-wrap: wrap;
}

.footer-action-link {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  background: rgba(255, 255, 255, 0.03);
  border: 1px solid var(--border-color);
  padding: 0.6rem 1rem;
  border-radius: var(--border-radius-md);
  color: var(--text-secondary);
  text-decoration: none;
  font-size: 0.8rem;
  font-weight: 500;
  transition: var(--transition-smooth);
}

.footer-action-link:hover {
  color: var(--text-primary);
  background: rgba(255, 255, 255, 0.08);
  border-color: rgba(255, 255, 255, 0.15);
  transform: translateY(-2px);
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.2);
}

.footer-bottom {
  display: flex;
  justify-content: space-between;
  align-items: center;
  border-top: 1px solid rgba(255, 255, 255, 0.03);
  padding-top: 1.25rem;
  flex-wrap: wrap;
  gap: 1rem;
  font-size: 0.775rem;
  color: var(--text-muted);
}

.footer-copyright {
  font-weight: 400;
}

.footer-credit {
  display: flex;
  align-items: center;
  gap: 0.35rem;
}

.credit-heart {
  color: #ef4444;
  animation: heartBeat 1.5s infinite ease-in-out;
}

@keyframes heartBeat {
  0%, 100% { transform: scale(1); }
  50% { transform: scale(1.15); }
}

@media (max-width: 768px) {
  .app-footer {
    padding: 2rem 1rem 1.5rem 1rem;
    gap: 1.5rem;
  }
  .footer-main {
    flex-direction: column;
    align-items: center;
    text-align: center;
    gap: 1.5rem;
  }
  .footer-brand {
    align-items: center;
  }
  .footer-links-group {
    justify-content: center;
    width: 100%;
  }
  .footer-action-link {
    width: 100%;
    justify-content: center;
  }
  .footer-bottom {
    flex-direction: column;
    text-align: center;
    gap: 0.75rem;
    padding-top: 1rem;
  }
}

/* ==========================================================================
   ARTICLE DETAIL MODAL (Minimal macOS Sheet style)
   ========================================================================== */

.modal-overlay {
  position: fixed;
  top: 0;
  left: 0;
  width: 100vw;
  height: 100vh;
  background: rgba(0, 0, 0, 0.75);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  z-index: 100;
  display: none;
  align-items: center;
  justify-content: center;
  padding: 1.5rem;
}
.modal-overlay.active {
  display: flex;
}

.modal-content {
  background: #1c1c1e;
  border: 1px solid rgba(255, 255, 255, 0.12);
  border-radius: var(--border-radius-lg);
  max-width: 700px;
  width: 100%;
  max-height: 85vh;
  overflow-y: auto;
  position: relative;
  padding: 2rem;
  box-shadow: 0 10px 40px rgba(0,0,0,0.6);
}
.modal-close {
  position: absolute;
  top: 1rem;
  right: 1rem;
  background: rgba(255,255,255,0.06);
  border: 1px solid var(--border-color);
  color: var(--text-secondary);
  width: 28px;
  height: 28px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: var(--transition-smooth);
}
.modal-close:hover {
  color: var(--text-primary);
  background: rgba(255,255,255,0.12);
}

.modal-header-area {
  margin-bottom: 1.25rem;
  padding-bottom: 1.25rem;
  border-bottom: 1px solid var(--border-color);
}
.modal-year-badge {
  background: rgba(255, 255, 255, 0.08);
  border: 1px solid var(--border-color);
  color: var(--text-primary);
  font-size: 0.75rem;
  font-weight: 600;
  padding: 0.2rem 0.5rem;
  border-radius: 3px;
  display: inline-block;
  margin-bottom: 0.75rem;
  font-family: var(--font-display);
}
.modal-header-area h2 {
  font-family: var(--font-display);
  font-size: 1.3rem;
  font-weight: 700;
  line-height: 1.35;
  margin-bottom: 0.5rem;
  color: var(--text-primary);
}
.modal-authors {
  color: var(--text-secondary);
  font-size: 0.85rem;
  font-weight: 400;
}

.modal-body-area {
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
}

.modal-section h4 {
  font-family: var(--font-display);
  font-size: 0.8rem;
  color: var(--text-muted);
  margin-bottom: 0.4rem;
  text-transform: uppercase;
  letter-spacing: 0.5px;
}
.abstract-text {
  color: var(--text-primary);
  font-size: 0.9rem;
  line-height: 1.6;
  text-align: justify;
}

.modal-meta-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1.25rem;
}
@media (max-width: 576px) {
  .modal-meta-grid {
    grid-template-columns: 1fr;
  }
}

.meta-column h4 {
  font-family: var(--font-display);
  font-size: 0.75rem;
  color: var(--text-muted);
  margin-bottom: 0.4rem;
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.badge-list {
  display: flex;
  flex-wrap: wrap;
  gap: 0.35rem;
}
.badge-list .badge-tag {
  font-size: 0.75rem;
  padding: 0.15rem 0.45rem;
}

.mt-4 { margin-top: 0.75rem; }

.modal-footer-area {
  margin-top: 0.75rem;
  padding-top: 1.25rem;
  border-top: 1px solid var(--border-color);
  font-size: 0.8rem;
  display: flex;
  align-items: center;
  gap: 0.4rem;
}
.doi-label {
  color: var(--text-muted);
}
.doi-link {
  color: var(--text-primary);
  text-decoration: underline;
  font-family: monospace;
}
.doi-link:hover {
  color: var(--text-secondary);
}

/* ==========================================================================
   LANDING PAGE STYLES (Apple-Minimalist Hero Screen)
   ========================================================================== */

.landing-container {
  max-width: 800px;
  margin: 0 auto;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  padding: 4rem 2rem;
  text-align: center;
  gap: 3rem;
  animation: fadeIn 0.4s ease-out;
}

.landing-hero {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 1.5rem;
}

.landing-logo {
  width: 64px;
  height: 64px;
  background: #ffffff;
  color: #000000;
  border-radius: 16px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 2rem;
  box-shadow: 0 10px 30px rgba(255, 255, 255, 0.1);
  margin-bottom: 0.5rem;
}

.landing-hero h1 {
  font-family: var(--font-display);
  font-size: 3rem;
  font-weight: 800;
  letter-spacing: -1.5px;
  color: var(--text-primary);
}
.landing-hero h1 span {
  color: var(--text-secondary);
}

.landing-subtitle {
  font-size: 1.15rem;
  color: var(--text-secondary);
  max-width: 600px;
  line-height: 1.5;
}

.landing-author-badge {
  background: rgba(255, 255, 255, 0.05);
  border: 1px solid var(--border-color);
  padding: 0.4rem 1rem;
  border-radius: 40px;
  font-size: 0.8rem;
  font-weight: 500;
  color: var(--text-secondary);
  display: flex;
  align-items: center;
  gap: 0.5rem;
  margin-top: 0.5rem;
}
.landing-author-badge i {
  color: #0a84ff; /* Accent Blue icon */
}

/* Feature grid */
.landing-features {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 1.5rem;
  width: 100%;
}

.landing-feat-card {
  background: var(--bg-surface);
  border: 1px solid var(--border-color);
  border-radius: var(--border-radius-lg);
  padding: 1.5rem;
  text-align: left;
  transition: var(--transition-smooth);
}
.landing-feat-card:hover {
  background: var(--bg-surface-hover);
  border-color: rgba(255, 255, 255, 0.15);
}

.landing-feat-card .feat-icon {
  font-size: 1.5rem;
  color: var(--text-primary);
  margin-bottom: 1rem;
}
.landing-feat-card h3 {
  font-family: var(--font-display);
  font-size: 1rem;
  font-weight: 600;
  margin-bottom: 0.5rem;
  color: var(--text-primary);
}
.landing-feat-card p {
  font-size: 0.8rem;
  color: var(--text-secondary);
  line-height: 1.5;
}

/* About description block */
.landing-about-section {
  max-width: 680px;
  border-top: 1px solid var(--border-color);
  border-bottom: 1px solid var(--border-color);
  padding: 1.75rem 0;
}
.landing-about-section p {
  font-size: 0.9rem;
  color: var(--text-secondary);
  line-height: 1.7;
  text-align: justify;
}
.landing-about-section strong {
  color: var(--text-primary);
}

/* Call to action */
.landing-cta {
  margin-top: 1rem;
}
.btn-enter {
  padding: 0.9rem 2.2rem;
  font-size: 1rem;
  border-radius: 99px; /* Pill shape */
  font-weight: 600;
  box-shadow: 0 4px 15px rgba(255, 255, 255, 0.1);
  letter-spacing: -0.2px;
}

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

@media (max-width: 576px) {
  .landing-hero h1 {
    font-size: 2.25rem;
  }
  .landing-subtitle {
    font-size: 1rem;
  }
}

/* Sandbox Code Snippets */
.sandbox-snippets {
  margin-top: 1rem;
  border-top: 1px solid var(--border-color);
  padding-top: 1rem;
}
.snippet-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 0.5rem;
  font-size: 0.85rem;
  font-weight: 500;
  color: var(--text-secondary);
}
.snippet-tabs {
  display: flex;
  gap: 0.35rem;
}
.snippet-tab {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  color: var(--text-secondary);
  padding: 0.2rem 0.55rem;
  border-radius: 4px;
  font-size: 0.72rem;
  font-family: inherit;
  font-weight: 500;
  cursor: pointer;
  transition: all 0.2s ease;
}
.snippet-tab:hover {
  background: var(--bg-card-hover);
  color: var(--text-primary);
}
.snippet-tab.active {
  background: var(--text-primary);
  color: var(--bg-card);
  border-color: var(--text-primary);
}
.snippet-code-box {
  margin: 0;
  background: rgba(0, 0, 0, 0.2);
  border-radius: 6px;
  padding: 0.75rem;
  font-size: 0.8rem;
  border: 1px solid var(--border-color);
  overflow-x: auto;
}
.snippet-code-box code {
  color: #a9b2c3;
  font-family: var(--font-mono);
  white-space: pre;
}

/* Charts Customizer Toolbar */
.charts-toolbar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 0.85rem 1.25rem;
  margin-bottom: 1.5rem;
  border-radius: var(--border-radius-md);
  background: var(--bg-card);
  border: 1px solid var(--border-color);
}
.toolbar-title {
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--text-primary);
  display: flex;
  align-items: center;
  gap: 0.5rem;
}
.toolbar-controls {
  display: flex;
  gap: 1.25rem;
}
.toolbar-control {
  display: flex;
  align-items: center;
  gap: 0.5rem;
}
.toolbar-control label {
  font-size: 0.8rem;
  color: var(--text-secondary);
  font-weight: 500;
  display: flex;
  align-items: center;
  gap: 0.35rem;
}
.toolbar-select {
  background: rgba(255, 255, 255, 0.04);
  border: 1px solid var(--border-color);
  color: var(--text-primary);
  padding: 0.3rem 0.65rem;
  border-radius: 6px;
  font-size: 0.78rem;
  outline: none;
  cursor: pointer;
  transition: all 0.2s ease;
}
.toolbar-select:hover {
  background: rgba(255, 255, 255, 0.08);
  border-color: rgba(255, 255, 255, 0.2);
}
.toolbar-select:focus {
  border-color: var(--text-primary);
}

@media (max-width: 768px) {
  .charts-toolbar {
    flex-direction: column;
    align-items: stretch;
    gap: 1rem;
  }
  .toolbar-controls {
    flex-direction: column;
    gap: 0.75rem;
  }
  .toolbar-control {
    justify-content: space-between;
  }
}