:root {
  --color-cybersecurity: #e74c3c;
  --color-ai-ml: #9b59b6;
  --color-software-engineering: #3498db;
  --color-open-source: #27ae60;
  --color-cloud-devops: #e67e22;
  --color-design-ux: #e91e8c;
  --color-startup: #1abc9c;
  --color-blockchain-web3: #f1c40f;
  --color-vendor-platform: #7f8c8d;
  --accent: #6c63ff;
  --radius: 8px;
}

/* Dark theme (default fallback in :root + explicit selector) */
:root, [data-theme="dark"] {
  --bg: #0f1117;
  --bg-card: #1a1d27;
  --bg-input: #252836;
  --text: #e4e6eb;
  --text-muted: #8b8fa3;
  --border: #2d3041;
  --shadow-dropdown: rgba(0, 0, 0, 0.4);
  --popup-heading: #1a1d27;
  --popup-text: #555;
  --popup-desc: #444;
  --popup-price: #333;
  --badge-text: #fff;
  --badge-blockchain-text: #333;
  color-scheme: dark;
}

/* Light theme -- higher specificity via html[data-theme] */
html[data-theme="light"] {
  --bg: #f0f2f5;
  --bg-card: #ffffff;
  --bg-input: #e9ecf0;
  --text: #1a1d27;
  --text-muted: #5f6578;
  --border: #d1d5db;
  --shadow-dropdown: rgba(0, 0, 0, 0.12);
  --popup-heading: #1a1d27;
  --popup-text: #444;
  --popup-desc: #555;
  --popup-price: #1a1d27;
  --badge-text: #fff;
  --badge-blockchain-text: #333;
  color-scheme: light;
}

* { margin: 0; padding: 0; box-sizing: border-box; }

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Oxygen, Ubuntu, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.5;
  min-height: 100vh;
}

a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }

/* Header */
.header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 16px 24px;
  background: var(--bg-card);
  border-bottom: 1px solid var(--border);
  flex-wrap: wrap;
  gap: 12px;
}

.header h1 {
  font-size: 1.35rem;
  font-weight: 700;
  letter-spacing: -0.02em;
}

.header-right {
  display: flex;
  gap: 16px;
  align-items: center;
}

.stat {
  font-size: 0.82rem;
  color: var(--text-muted);
  background: var(--bg-input);
  padding: 4px 12px;
  border-radius: 999px;
  white-space: nowrap;
}

/* Filter bar */
.filter-bar {
  display: flex;
  gap: 12px;
  padding: 14px 24px;
  background: var(--bg-card);
  border-bottom: 1px solid var(--border);
  flex-wrap: wrap;
  align-items: flex-end;
}

.filter-group {
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.filter-group label {
  font-size: 0.7rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--text-muted);
  font-weight: 600;
}

.filter-group input,
.filter-group select {
  background: var(--bg-input);
  border: 1px solid var(--border);
  color: var(--text);
  padding: 6px 10px;
  border-radius: var(--radius);
  font-size: 0.85rem;
  font-family: inherit;
  outline: none;
  transition: border-color 0.15s;
}

.filter-group input:focus,
.filter-group select:focus {
  border-color: var(--accent);
}

#filter-search { min-width: 200px; }
#filter-continent { min-width: 130px; }

/* Category dropdown */
.dropdown {
  position: relative;
  min-width: 180px;
}

.dropdown-toggle {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 8px;
  width: 100%;
  background: var(--bg-input);
  border: 1px solid var(--border);
  color: var(--text);
  padding: 6px 10px;
  border-radius: var(--radius);
  font-size: 0.85rem;
  font-family: inherit;
  cursor: pointer;
  outline: none;
  transition: border-color 0.15s;
  text-align: left;
}

.dropdown-toggle:focus,
.dropdown.open .dropdown-toggle {
  border-color: var(--accent);
}

.dropdown-label {
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
  flex: 1;
}

.dropdown-arrow {
  font-size: 0.7rem;
  color: var(--text-muted);
  flex-shrink: 0;
  transition: transform 0.15s;
}

.dropdown.open .dropdown-arrow {
  transform: rotate(180deg);
}

.dropdown-menu {
  display: none;
  position: absolute;
  top: calc(100% + 4px);
  left: 0;
  min-width: 100%;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 6px 0;
  z-index: 1000;
  max-height: 260px;
  overflow-y: auto;
  box-shadow: 0 8px 24px var(--shadow-dropdown);
}

.dropdown.open .dropdown-menu {
  display: block;
}

.dropdown-item {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 6px 14px;
  font-size: 0.84rem;
  color: var(--text);
  cursor: pointer;
  transition: background 0.1s;
  white-space: nowrap;
}

.dropdown-item:hover {
  background: var(--bg-input);
}

.dropdown-item input[type="checkbox"] {
  accent-color: var(--accent);
  width: 15px;
  height: 15px;
  cursor: pointer;
  flex-shrink: 0;
}
#filter-date-from,
#filter-date-to { width: 140px; }

.filter-actions {
  justify-content: flex-end;
}

#filter-reset {
  background: var(--bg-input);
  border: 1px solid var(--border);
  color: var(--text-muted);
  padding: 6px 16px;
  border-radius: var(--radius);
  cursor: pointer;
  font-size: 0.85rem;
  font-family: inherit;
  transition: background 0.15s, color 0.15s;
}

#filter-reset:hover {
  background: var(--accent);
  color: #fff;
  border-color: var(--accent);
}

/* Map */
.map-container {
  position: relative;
  padding: 0 24px;
  margin-top: 16px;
}

#map {
  height: 55vh;
  min-height: 350px;
  border-radius: var(--radius);
  border: 1px solid var(--border);
  z-index: 1;
}

.legend {
  position: absolute;
  bottom: 16px;
  right: 40px;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 10px 14px;
  z-index: 500;
  font-size: 0.75rem;
  display: flex;
  flex-wrap: wrap;
  gap: 8px 16px;
  max-width: 500px;
}

.legend-item {
  display: flex;
  align-items: center;
  gap: 5px;
  white-space: nowrap;
}

.legend-dot {
  width: 10px;
  height: 10px;
  border-radius: 50%;
  display: inline-block;
  flex-shrink: 0;
}

/* Table */
.table-container {
  padding: 16px 24px 24px;
}

.table-header {
  margin-bottom: 10px;
}

.table-header h2 {
  font-size: 1.1rem;
  font-weight: 600;
}

.table-header h2 span {
  font-weight: 400;
  color: var(--text-muted);
  font-size: 0.85rem;
}

.table-scroll {
  overflow-x: auto;
  border: 1px solid var(--border);
  border-radius: var(--radius);
}

#conference-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.85rem;
}

#conference-table th {
  background: var(--bg-input);
  padding: 10px 14px;
  text-align: left;
  font-weight: 600;
  font-size: 0.78rem;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  color: var(--text-muted);
  cursor: pointer;
  user-select: none;
  white-space: nowrap;
  border-bottom: 2px solid var(--border);
  position: sticky;
  top: 0;
}

#conference-table th:hover {
  color: var(--text);
}

.sort-arrow { font-size: 0.65rem; }
.sort-asc .sort-arrow::after { content: " ▲"; }
.sort-desc .sort-arrow::after { content: " ▼"; }

#conference-table td {
  padding: 9px 14px;
  border-bottom: 1px solid var(--border);
  vertical-align: top;
}

#conference-table tbody tr {
  transition: background 0.12s;
}

#conference-table tbody tr:hover {
  background: var(--bg-input);
}

.row-past {
  opacity: 0.45;
}

.conf-name-link {
  font-weight: 600;
  color: var(--text);
}

.conf-name-link:hover {
  color: var(--accent);
}

/* Category badge */
.cat-badge {
  display: inline-block;
  padding: 2px 8px;
  border-radius: 999px;
  font-size: 0.72rem;
  font-weight: 600;
  color: var(--badge-text);
  white-space: nowrap;
}

.cat-badge.cybersecurity { background: var(--color-cybersecurity); }
.cat-badge.ai-ml { background: var(--color-ai-ml); }
.cat-badge.software-engineering { background: var(--color-software-engineering); }
.cat-badge.open-source { background: var(--color-open-source); }
.cat-badge.cloud-devops { background: var(--color-cloud-devops); }
.cat-badge.design-ux { background: var(--color-design-ux); }
.cat-badge.startup { background: var(--color-startup); }
.cat-badge.blockchain-web3 { background: var(--color-blockchain-web3); color: var(--badge-blockchain-text); }
.cat-badge.vendor-platform { background: var(--color-vendor-platform); }

/* CFP badge */
.cfp-badge {
  display: inline-block;
  padding: 2px 8px;
  border-radius: 999px;
  font-size: 0.72rem;
  font-weight: 600;
}

.cfp-badge.open {
  background: rgba(39, 174, 96, 0.2);
  color: #27ae60;
}

.cfp-badge.closed {
  background: rgba(231, 76, 60, 0.15);
  color: #e74c3c;
}

.cfp-badge.na {
  color: var(--text-muted);
}

/* Leaflet popup -- popups use Leaflet's own white bg so these stay fixed */
.conf-popup { min-width: 220px; }
.conf-popup h3 { font-size: 0.95rem; margin-bottom: 4px; color: var(--popup-heading); }
.conf-popup .popup-meta { font-size: 0.8rem; color: var(--popup-text); margin-bottom: 6px; }
.conf-popup .popup-desc { font-size: 0.78rem; color: var(--popup-desc); margin-bottom: 8px; }
.conf-popup .popup-links { font-size: 0.78rem; }
.conf-popup .popup-links a { margin-right: 12px; }
.conf-popup .popup-price { font-weight: 600; color: var(--popup-price); font-size: 0.8rem; }

/* Footer */
.footer {
  padding: 16px 24px;
  text-align: center;
  font-size: 0.78rem;
  color: var(--text-muted);
  border-top: 1px solid var(--border);
  margin-top: 8px;
}

.footer a { color: var(--accent); }

/* Theme toggle */
.theme-toggle {
  background: var(--bg-input);
  border: 1px solid var(--border);
  border-radius: 999px;
  width: 34px;
  height: 34px;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  padding: 0;
  transition: background 0.15s, border-color 0.15s;
  flex-shrink: 0;
}

.theme-toggle:hover {
  border-color: var(--accent);
}

.theme-icon {
  font-size: 1.1rem;
  line-height: 1;
}

[data-theme="dark"] .theme-icon-dark,
[data-theme="light"] .theme-icon-light {
  display: none;
}

[data-theme="dark"] .theme-icon-light,
[data-theme="light"] .theme-icon-dark {
  color: var(--text);
}

/* Leaflet tile theming -- invert tiles only in dark mode */
[data-theme="dark"] .leaflet-tile-pane {
  filter: invert(1) hue-rotate(180deg) brightness(0.85) contrast(1.1);
}

/* Cluster overrides */
.marker-cluster-small,
.marker-cluster-medium,
.marker-cluster-large {
  background: rgba(108, 99, 255, 0.25) !important;
}
.marker-cluster-small div,
.marker-cluster-medium div,
.marker-cluster-large div {
  background: var(--accent) !important;
  color: #fff !important;
  font-weight: 700;
}

/* Responsive */
@media (max-width: 768px) {
  .header { padding: 12px 16px; }
  .header h1 { font-size: 1.1rem; }
  .filter-bar { padding: 10px 16px; }
  .map-container { padding: 0 12px; margin-top: 10px; }
  #map { height: 40vh; min-height: 280px; }
  .table-container { padding: 12px; }
  .legend { right: 20px; bottom: 10px; max-width: 280px; }
  #filter-search { min-width: 140px; }
  .dropdown { min-width: 150px; }
}

@media (max-width: 480px) {
  .header { flex-direction: column; align-items: flex-start; }
  .filter-bar { flex-direction: column; }
  .filter-group input,
  .filter-group select { width: 100%; }
  #filter-search { min-width: unset; }
  .legend { position: static; margin: 8px 12px; max-width: 100%; }
}