:root {
  --bg: #0b1020;
  --bg-card: #131a2c;
  --bg-elevated: #1b243d;
  --bg-deep: #060912;
  --border: #28324f;
  --border-strong: #3b4870;
  --text: #e6ecf5;
  --text-muted: #8c97b3;
  --accent: #38bdf8;
  --accent-2: #a78bfa;
  --warn: #f59e0b;
  --danger: #f43f5e;
  --good: #22c55e;
  --path: #f43f5e;
  --highlight: #fbbf24;
}

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

html, body {
  height: 100%;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "Helvetica Neue",
    "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  background: var(--bg);
  color: var(--text);
  font-size: 14px;
  overflow: hidden;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

#app {
  display: flex;
  flex-direction: column;
  height: 100vh;
}

/* ====== Header ====== */
.app-header {
  padding: 10px 18px;
  background: linear-gradient(180deg, var(--bg-card) 0%, #101729 100%);
  border-bottom: 1px solid var(--border);
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-shrink: 0;
  z-index: 5;
}
.brand { display: flex; align-items: center; gap: 10px; }
.brand-mark {
  width: 28px; height: 28px;
  display: inline-flex; align-items: center; justify-content: center;
  background: linear-gradient(135deg, #38bdf8 0%, #a78bfa 100%);
  border-radius: 8px;
  font-size: 16px;
  box-shadow: 0 4px 14px rgba(56, 189, 248, 0.25);
}
.app-header h1 {
  font-size: 16px;
  font-weight: 600;
  letter-spacing: 0.2px;
}
.header-meta { display: flex; gap: 8px; }
.meta-pill {
  background: var(--bg-elevated);
  border: 1px solid var(--border);
  color: var(--text-muted);
  padding: 4px 10px;
  border-radius: 999px;
  font-size: 12px;
  font-variant-numeric: tabular-nums;
}

/* ====== Main layout ====== */
.app-main {
  flex: 1;
  display: grid;
  grid-template-columns: 1fr 380px;
  overflow: hidden;
  min-height: 0;
}

.graph-section {
  display: flex;
  flex-direction: column;
  border-right: 1px solid var(--border);
  overflow: hidden;
  min-height: 0;
}

.info-section {
  background: var(--bg-card);
  overflow-y: auto;
  padding: 14px;
  display: flex;
  flex-direction: column;
  gap: 12px;
  min-height: 0;
}

.info-section::-webkit-scrollbar { width: 8px; }
.info-section::-webkit-scrollbar-track { background: var(--bg-card); }
.info-section::-webkit-scrollbar-thumb { background: var(--border-strong); border-radius: 4px; }

/* ====== Toolbar ====== */
.graph-toolbar {
  display: flex;
  gap: 12px;
  padding: 10px 14px;
  background: var(--bg-card);
  border-bottom: 1px solid var(--border);
  flex-wrap: wrap;
  align-items: center;
  flex-shrink: 0;
}
.tool-group { display: flex; gap: 6px; align-items: center; flex-wrap: wrap; }
.tool-search { flex: 1; min-width: 240px; }
.tool-actions { margin-left: auto; }

.tool-label {
  font-size: 12px;
  color: var(--text-muted);
  margin-right: 4px;
}

input[type="text"] {
  background: var(--bg-deep);
  border: 1px solid var(--border);
  color: var(--text);
  padding: 6px 10px;
  border-radius: 6px;
  font-size: 13px;
  outline: none;
  font-family: inherit;
  min-width: 0;
}
input[type="text"]::placeholder { color: #5b6783; }
input[type="text"]:focus { border-color: var(--accent); box-shadow: 0 0 0 2px rgba(56, 189, 248, 0.15); }

button { font-family: inherit; }

.btn {
  background: var(--bg-elevated);
  border: 1px solid var(--border);
  color: var(--text);
  padding: 6px 12px;
  border-radius: 6px;
  cursor: pointer;
  font-size: 13px;
  transition: all 0.15s ease;
  white-space: nowrap;
}
.btn:hover { background: #243156; border-color: var(--border-strong); }
.btn:active { transform: translateY(1px); }
.btn-ghost { background: transparent; }
.btn-primary {
  background: linear-gradient(135deg, #38bdf8 0%, #818cf8 100%);
  border: none;
  color: #060912;
  font-weight: 600;
}
.btn-primary:hover { filter: brightness(1.08); background: linear-gradient(135deg, #38bdf8 0%, #818cf8 100%); }
.btn-icon {
  width: 30px; padding: 6px 0;
  text-align: center; font-weight: 600;
  font-size: 14px;
}

/* Type filter chips */
.type-chip {
  display: inline-flex;
  align-items: center;
  gap: 5px;
  padding: 4px 10px;
  border: 1px solid var(--border-strong);
  border-radius: 999px;
  cursor: pointer;
  font-size: 12px;
  user-select: none;
  background: var(--bg-elevated);
  transition: all 0.15s;
}
.type-chip:hover { border-color: var(--accent); }
.type-chip.off {
  opacity: 0.4;
  background: transparent;
  text-decoration: line-through;
}
.type-chip .dot {
  width: 8px; height: 8px; border-radius: 50%;
}

/* ====== Graph ====== */
.graph-container {
  flex: 1;
  position: relative;
  background: radial-gradient(ellipse at center, #0c1326 0%, #060912 100%);
  overflow: hidden;
  min-height: 0;
}

#graph-svg {
  width: 100%;
  height: 100%;
  display: block;
  cursor: grab;
  user-select: none;
}
#graph-svg.dragging { cursor: grabbing; }

/* Nodes */
.node circle {
  cursor: pointer;
  transition: stroke-width 0.12s, filter 0.12s;
  filter: drop-shadow(0 1px 2px rgba(0,0,0,0.5));
}
.node:hover circle {
  stroke-width: 3;
  filter: drop-shadow(0 0 6px rgba(56, 189, 248, 0.6));
}
.node.selected circle {
  stroke: var(--danger);
  stroke-width: 4;
  filter: drop-shadow(0 0 8px rgba(244, 63, 94, 0.7));
}
.node.path-node circle {
  stroke: var(--path);
  stroke-width: 3.5;
  filter: drop-shadow(0 0 6px rgba(244, 63, 94, 0.6));
}

/* Edges */
.edge {
  stroke-opacity: 0.5;
  pointer-events: none;
  transition: stroke-opacity 0.15s;
}
.edge.path-edge {
  stroke: var(--path);
  stroke-opacity: 1;
  stroke-width: 3;
  filter: drop-shadow(0 0 4px rgba(244, 63, 94, 0.5));
}
.edge.dimmed { stroke-opacity: 0.05; }

/* Labels */
.node-label {
  fill: #cbd5e1;
  font-size: 10px;
  pointer-events: none;
  text-anchor: middle;
  user-select: none;
  paint-order: stroke;
  stroke: #060912;
  stroke-width: 3px;
  stroke-linejoin: round;
}
.node.selected .node-label { fill: #fff8e1; }
.node.path-node .node-label { fill: #ffe4e6; }

/* Loading */
.loading {
  position: absolute;
  top: 50%; left: 50%;
  transform: translate(-50%, -50%);
  color: var(--text-muted);
  font-size: 13px;
  pointer-events: none;
  z-index: 10;
  text-align: center;
}
.loading-spinner {
  width: 32px; height: 32px;
  margin: 0 auto 10px;
  border: 3px solid var(--border);
  border-top-color: var(--accent);
  border-radius: 50%;
  animation: spin 0.9s linear infinite;
}
@keyframes spin { to { transform: rotate(360deg); } }
.loading.hidden { display: none; }

.legend {
  position: absolute;
  top: 12px; left: 12px;
  display: flex; flex-direction: column;
  gap: 4px;
  background: rgba(11, 16, 32, 0.7);
  backdrop-filter: blur(6px);
  padding: 8px 10px;
  border-radius: 6px;
  border: 1px solid var(--border);
  font-size: 11px;
  color: var(--text-muted);
  pointer-events: none;
}
.legend-item { display: flex; align-items: center; gap: 6px; }
.legend .dot { width: 8px; height: 8px; border-radius: 50%; }

.hint {
  position: absolute;
  bottom: 12px; left: 50%;
  transform: translateX(-50%);
  background: rgba(11, 16, 32, 0.7);
  backdrop-filter: blur(6px);
  padding: 6px 12px;
  border-radius: 999px;
  border: 1px solid var(--border);
  font-size: 11px;
  color: var(--text-muted);
  pointer-events: none;
  white-space: nowrap;
}
.hint.hidden { display: none; }

/* ====== Path section ====== */
.path-section {
  padding: 12px 14px;
  background: var(--bg-card);
  border-top: 1px solid var(--border);
  flex-shrink: 0;
}
.path-controls {
  display: flex;
  gap: 6px;
  align-items: center;
  flex-wrap: wrap;
  margin-bottom: 8px;
}
.path-label {
  font-size: 12px;
  color: var(--text-muted);
  margin-right: 4px;
}
.arrow-sep {
  color: var(--text-muted);
  font-size: 14px;
}
.path-result {
  min-height: 36px;
  padding: 8px 10px;
  background: var(--bg-deep);
  border-radius: 6px;
  border: 1px solid var(--border);
  font-size: 13px;
  line-height: 1.9;
  word-break: break-word;
}
.path-result .path-status-ok { color: var(--good); font-weight: 500; }
.path-result .path-status-unreachable { color: var(--danger); }
.path-result .path-status-same { color: var(--warn); }
.path-result .path-status-invalid { color: var(--text-muted); }

.path-result .path-node {
  display: inline-block;
  padding: 2px 8px;
  background: var(--bg-elevated);
  border: 1px solid var(--border-strong);
  border-radius: 4px;
  margin: 0 1px;
  cursor: pointer;
  font-size: 12px;
  transition: all 0.12s;
}
.path-result .path-node:hover {
  background: var(--accent);
  color: #060912;
  border-color: var(--accent);
  transform: translateY(-1px);
}
.path-result .arrow {
  color: var(--text-muted);
  margin: 0 4px;
  font-size: 11px;
}
.path-result .placeholder { color: var(--text-muted); font-style: italic; }

/* ====== Info cards ====== */
.card {
  background: var(--bg-elevated);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 12px;
}
.card h3 {
  font-size: 12px;
  font-weight: 600;
  color: var(--text-muted);
  margin-bottom: 10px;
  text-transform: uppercase;
  letter-spacing: 0.6px;
  display: flex;
  align-items: center;
  gap: 6px;
}
.card-sub {
  font-size: 10px;
  color: #5b6783;
  font-weight: 400;
  text-transform: none;
  letter-spacing: 0;
}

.stats-list {
  display: flex;
  flex-direction: column;
  gap: 2px;
}

.stat-row {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 6px 8px;
  border-radius: 4px;
  cursor: pointer;
  font-size: 13px;
  transition: background 0.12s;
  border: 1px solid transparent;
}
.stat-row:hover {
  background: var(--bg-card);
  border-color: var(--border);
}
.stat-row .stat-name {
  display: flex;
  align-items: center;
  gap: 8px;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
  flex: 1;
  min-width: 0;
}
.stat-row .stat-name .name-text {
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}
.stat-row .stat-name .dot {
  width: 9px; height: 9px;
  border-radius: 50%;
  flex-shrink: 0;
}
.stat-row .stat-count {
  color: var(--text-muted);
  font-variant-numeric: tabular-nums;
  font-size: 12px;
  padding-left: 8px;
}

/* ====== Node details ====== */
.placeholder {
  color: var(--text-muted);
  font-size: 12px;
  font-style: italic;
}

.detail-row {
  margin-bottom: 10px;
  font-size: 13px;
}
.detail-label {
  color: var(--text-muted);
  font-size: 10px;
  text-transform: uppercase;
  letter-spacing: 0.5px;
  margin-bottom: 2px;
}
.detail-value {
  color: var(--text);
  word-break: break-word;
}
.detail-value .id-mono {
  font-family: ui-monospace, "SF Mono", Menlo, Consolas, monospace;
  font-size: 12px;
  background: var(--bg-deep);
  padding: 1px 6px;
  border-radius: 3px;
  border: 1px solid var(--border);
}
.detail-value .type-badge {
  display: inline-block;
  padding: 1px 8px;
  border-radius: 999px;
  font-size: 11px;
  font-weight: 500;
  background: var(--bg-deep);
  border: 1px solid var(--border);
}
.detail-value .meta-line {
  display: flex; gap: 12px; flex-wrap: wrap;
  color: var(--text-muted);
  font-size: 12px;
}
.detail-value .meta-line .stat {
  display: inline-flex;
  gap: 4px;
  font-variant-numeric: tabular-nums;
}
.detail-value .meta-line .stat strong {
  color: var(--text);
  font-weight: 600;
}

.neighbors-list {
  display: flex;
  flex-wrap: wrap;
  gap: 4px;
  margin-top: 4px;
}
.neighbor-chip {
  padding: 3px 8px;
  background: var(--bg-deep);
  border: 1px solid var(--border-strong);
  border-radius: 999px;
  font-size: 11px;
  cursor: pointer;
  transition: all 0.12s;
  display: inline-flex;
  align-items: center;
  gap: 4px;
}
.neighbor-chip:hover {
  background: var(--accent);
  color: #060912;
  border-color: var(--accent);
  transform: translateY(-1px);
}
.neighbor-chip .dot {
  width: 6px; height: 6px; border-radius: 50%;
}
.neighbor-empty { color: var(--text-muted); font-size: 12px; }

.neighbors-group {
  margin-top: 8px;
}
.neighbors-group-label {
  font-size: 10px;
  color: var(--text-muted);
  margin-bottom: 4px;
  text-transform: uppercase;
  letter-spacing: 0.4px;
}