@import url('https://fonts.googleapis.com/css2?family=DM+Sans:ital,opsz,wght@0,9..40,400;0,9..40,500;0,9..40,600;0,9..40,700;1,9..40,400&family=JetBrains+Mono:wght@400;500&display=swap');

:root {
  --bg-app: #0f1117;
  --bg-panel: #161b26;
  --bg-panel-hover: #1c2333;
  --border: #2a3347;
  --text: #e8ecf4;
  --text-muted: #8b95a8;
  --accent: #3dd6c3;
  --accent-dim: #2a9d8f;
  --accent-glow: rgba(61, 214, 195, 0.15);
  --danger: #f07178;
  --radius: 10px;
  --sidebar-width: 320px;
  --font: 'DM Sans', system-ui, sans-serif;
  --mono: 'JetBrains Mono', monospace;
}

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

html, body {
  height: 100%;
  overflow: hidden;
}

body {
  font-family: var(--font);
  font-size: 15px;
  color: var(--text);
  background: var(--bg-app);
  background-image:
    radial-gradient(ellipse 80% 50% at 100% 0%, rgba(61, 214, 195, 0.06), transparent),
    radial-gradient(ellipse 60% 40% at 0% 100%, rgba(99, 102, 241, 0.05), transparent);
}

.app {
  display: flex;
  height: 100vh;
}

.sidebar {
  width: var(--sidebar-width);
  min-width: var(--sidebar-width);
  background: var(--bg-panel);
  border-right: 1px solid var(--border);
  display: flex;
  flex-direction: column;
  overflow: hidden;
}

.sidebar-header {
  padding: 1.25rem 1.25rem 1rem;
  border-bottom: 1px solid var(--border);
}

.logo {
  font-size: 1.35rem;
  font-weight: 700;
  letter-spacing: -0.02em;
  background: linear-gradient(135deg, var(--accent), #7c9eff);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.tagline {
  font-size: 0.8rem;
  color: var(--text-muted);
  margin-top: 0.25rem;
}

.sidebar-scroll {
  flex: 1;
  overflow-y: auto;
  padding: 1rem 1.25rem 1.5rem;
}

.sidebar-scroll::-webkit-scrollbar {
  width: 6px;
}

.sidebar-scroll::-webkit-scrollbar-thumb {
  background: var(--border);
  border-radius: 3px;
}

.panel-section {
  margin-bottom: 1.25rem;
}

.panel-section h2 {
  font-size: 0.7rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--text-muted);
  margin-bottom: 0.65rem;
}

.field label {
  display: block;
  font-size: 0.85rem;
  font-weight: 500;
  margin-bottom: 0.4rem;
  color: var(--text);
}

select {
  width: 100%;
  padding: 0.55rem 0.75rem;
  font-family: var(--font);
  font-size: 0.9rem;
  color: var(--text);
  background: var(--bg-app);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  cursor: pointer;
  appearance: none;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' fill='%238b95a8' viewBox='0 0 16 16'%3E%3Cpath d='M8 11L3 6h10l-5 5z'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 0.75rem center;
  padding-right: 2rem;
}

select:hover, select:focus {
  border-color: var(--accent-dim);
  outline: none;
  box-shadow: 0 0 0 3px var(--accent-glow);
}

.dataset-desc {
  font-size: 0.78rem;
  color: var(--text-muted);
  margin-top: 0.5rem;
  line-height: 1.4;
}

.stats {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0.5rem;
}

.stat-card {
  background: var(--bg-app);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 0.6rem 0.75rem;
}

.stat-card .value {
  font-family: var(--mono);
  font-size: 1.1rem;
  font-weight: 500;
  color: var(--accent);
}

.stat-card .label {
  font-size: 0.7rem;
  color: var(--text-muted);
  margin-top: 0.15rem;
}

.control {
  margin-bottom: 0.85rem;
}

.control-header {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  margin-bottom: 0.35rem;
}

.control-header label {
  font-size: 0.82rem;
  font-weight: 500;
}

.control-header output {
  font-family: var(--mono);
  font-size: 0.75rem;
  color: var(--accent);
  background: var(--accent-glow);
  padding: 0.15rem 0.45rem;
  border-radius: 4px;
}

input[type="range"] {
  width: 100%;
  height: 6px;
  -webkit-appearance: none;
  appearance: none;
  background: var(--border);
  border-radius: 3px;
  outline: none;
}

input[type="range"]::-webkit-slider-thumb {
  -webkit-appearance: none;
  width: 16px;
  height: 16px;
  border-radius: 50%;
  background: var(--accent);
  cursor: pointer;
  box-shadow: 0 0 0 3px var(--accent-glow);
  transition: transform 0.15s;
}

input[type="range"]::-webkit-slider-thumb:hover {
  transform: scale(1.1);
}

.checkbox-row {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.5rem 0;
  font-size: 0.85rem;
  cursor: pointer;
}

.checkbox-row input {
  width: 1rem;
  height: 1rem;
  accent-color: var(--accent);
  cursor: pointer;
}

.graph-area {
  flex: 1;
  position: relative;
  min-width: 0;
  background: var(--bg-app);
  overflow: hidden;
}

#networkGraph {
  width: 100%;
  height: 100%;
  cursor: grab;
  touch-action: none;
}

#networkGraph:active {
  cursor: grabbing;
}

#networkGraph svg {
  display: block;
  touch-action: none;
}

.zoom-toolbar {
  position: absolute;
  top: 1rem;
  right: 1rem;
  z-index: 5;
  display: flex;
  gap: 0.35rem;
}

.zoom-toolbar button {
  width: 2.25rem;
  height: 2.25rem;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: var(--bg-panel);
  color: var(--text);
  font-size: 1.1rem;
  font-family: var(--font);
  cursor: pointer;
  line-height: 1;
  transition: background 0.15s, border-color 0.15s;
}

.zoom-toolbar button:hover {
  background: var(--bg-panel-hover);
  border-color: var(--accent-dim);
}

#zoom-reset {
  width: auto;
  padding: 0 0.65rem;
  font-size: 0.8rem;
  font-weight: 600;
}

.zoom-hint {
  position: absolute;
  bottom: 0.75rem;
  left: 50%;
  transform: translateX(-50%);
  z-index: 5;
  font-size: 0.75rem;
  color: var(--text-muted);
  pointer-events: none;
  background: rgba(22, 27, 38, 0.85);
  padding: 0.35rem 0.75rem;
  border-radius: 999px;
  border: 1px solid var(--border);
}

.loading-overlay {
  position: absolute;
  inset: 0;
  background: rgba(15, 17, 23, 0.85);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 1rem;
  z-index: 10;
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.2s;
}

.loading-overlay.visible {
  opacity: 1;
  pointer-events: auto;
}

.spinner {
  width: 40px;
  height: 40px;
  border: 3px solid var(--border);
  border-top-color: var(--accent);
  border-radius: 50%;
  animation: spin 0.8s linear infinite;
}

@keyframes spin {
  to { transform: rotate(360deg); }
}

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

.tt {
  position: absolute;
  visibility: hidden;
  color: var(--text);
  padding: 0.5rem 0.75rem;
  background: var(--bg-panel);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  font-size: 0.8rem;
  line-height: 1.4;
  max-width: 280px;
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.4);
  pointer-events: none;
  z-index: 100;
}

.label {
  fill: var(--text);
  font-family: var(--font);
  font-weight: 500;
  paint-order: stroke fill;
  stroke: var(--bg-app);
  stroke-width: 4px;
  stroke-linejoin: round;
  pointer-events: none;
}