:root {
  --bg: #f6f8fb;
  --panel: #ffffff;
  --panel-2: #f1f5f9;
  --border: #e2e8f0;
  --border-strong: #cbd5e1;
  --text: #0f172a;
  --text-muted: #64748b;
  --accent: #2563eb;
  --accent-soft: #dbeafe;
  --danger: #dc2626;
  --danger-soft: #fee2e2;
  --shadow-sm: 0 1px 2px rgba(15, 23, 42, 0.06);
  --shadow-md: 0 4px 12px rgba(15, 23, 42, 0.08);
  --shadow-lg: 0 10px 30px rgba(15, 23, 42, 0.12);
  --radius: 10px;
  --radius-sm: 6px;
  --font: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  padding: 0;
  height: 100%;
  font-family: var(--font);
  color: var(--text);
  background: var(--bg);
  overflow: hidden;
  -webkit-font-smoothing: antialiased;
}

body { display: flex; flex-direction: column; }

/* ----------- Top bar ----------- */
.topbar {
  display: flex;
  align-items: center;
  gap: 18px;
  padding: 10px 18px;
  background: var(--panel);
  border-bottom: 1px solid var(--border);
  box-shadow: var(--shadow-sm);
  z-index: 10;
  flex-shrink: 0;
}

.brand {
  display: flex;
  align-items: center;
  gap: 9px;
  font-weight: 700;
  font-size: 15px;
  letter-spacing: -0.01em;
  color: var(--text);
  padding-right: 8px;
}
.brand svg { color: var(--accent); }

.toolbar {
  display: flex;
  align-items: center;
  gap: 14px;
  flex: 1;
}

.tool-group {
  display: inline-flex;
  background: var(--panel-2);
  border-radius: 10px;
  padding: 4px;
  gap: 2px;
}

.add-shape-wrap { position: relative; }
.add-shape-btn {
  font-weight: 600;
  padding: 7px 12px 7px 10px;
  gap: 6px;
}
.add-shape-btn svg { color: currentColor; }
.shape-popover {
  position: absolute;
  top: calc(100% + 6px);
  left: 0;
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 12px;
  box-shadow: var(--shadow-lg);
  padding: 8px;
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 4px;
  z-index: 20;
  min-width: 280px;
}
.shape-tile {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 4px;
  padding: 8px 6px;
  background: transparent;
  border: 1px solid transparent;
  border-radius: 8px;
  cursor: pointer;
  color: var(--text-muted);
  font-family: var(--font);
  font-size: 11.5px;
  transition: background 0.1s, color 0.1s, border-color 0.1s;
}
.shape-tile:hover {
  background: var(--panel-2);
  color: var(--text);
  border-color: var(--border);
}
.shape-tile svg {
  width: 36px;
  height: 24px;
}

.tool-btn {
  width: 38px;
  height: 32px;
  border: none;
  background: transparent;
  border-radius: 7px;
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  color: var(--text-muted);
  transition: background 0.12s, color 0.12s, transform 0.06s;
}
.tool-btn svg { width: 22px; height: 18px; }
.tool-btn:hover { background: #fff; color: var(--text); box-shadow: var(--shadow-sm); }
.tool-btn:active { transform: scale(0.96); }
.tool-btn.active {
  background: var(--accent);
  color: #fff;
  box-shadow: 0 1px 3px rgba(37, 99, 235, 0.4);
}

.divider {
  width: 1px;
  height: 26px;
  background: var(--border);
}

.select-label {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-size: 12.5px;
  color: var(--text-muted);
}
.select-label span { white-space: nowrap; }

select, input[type="text"], input[type="number"], textarea {
  font-family: var(--font);
  font-size: 13px;
  color: var(--text);
  background: var(--panel);
  border: 1px solid var(--border-strong);
  border-radius: var(--radius-sm);
  padding: 6px 10px;
  outline: none;
  transition: border-color 0.12s, box-shadow 0.12s;
}
select { padding-right: 28px; cursor: pointer; }
select:focus, input:focus, textarea:focus {
  border-color: var(--accent);
  box-shadow: 0 0 0 3px var(--accent-soft);
}
textarea { resize: vertical; min-height: 60px; }

.zoom-group {
  display: inline-flex;
  background: var(--panel-2);
  border-radius: 8px;
  padding: 3px;
  gap: 2px;
}
.zoom-group button {
  min-width: 36px;
  height: 28px;
  padding: 0 8px;
  border: none;
  background: transparent;
  color: var(--text-muted);
  font-weight: 600;
  font-size: 13px;
  font-family: var(--font);
  border-radius: 6px;
  cursor: pointer;
  transition: background 0.12s, color 0.12s;
}
.zoom-group button:hover { background: #fff; color: var(--text); }

.actions { display: flex; gap: 8px; align-items: center; }
#chart-name {
  width: 150px;
  font-size: 13px;
  padding: 7px 10px;
}
#dirty-dot {
  display: inline-block;
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: transparent;
  margin-right: -4px;
  transition: background 0.15s;
  flex-shrink: 0;
}
#dirty-dot.dirty {
  background: #fb923c;
  box-shadow: 0 0 0 2px rgba(251, 146, 60, 0.18);
}

.btn {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  border: 1px solid transparent;
  font-family: var(--font);
  font-size: 13px;
  font-weight: 600;
  padding: 7px 14px;
  border-radius: 8px;
  cursor: pointer;
  transition: background 0.12s, border-color 0.12s, color 0.12s, transform 0.06s;
}
.btn:active { transform: translateY(1px); }
.btn.primary {
  background: var(--accent);
  color: #fff;
  box-shadow: 0 1px 2px rgba(37, 99, 235, 0.3);
}
.btn.primary:hover { background: #1d4ed8; }
.btn.ghost {
  background: transparent;
  color: var(--text-muted);
  border-color: var(--border);
}
.btn.ghost:hover { background: var(--panel-2); color: var(--text); }
.btn.danger {
  background: var(--danger-soft);
  color: var(--danger);
}
.btn.danger:hover { background: #fecaca; }

/* ----------- Workspace ----------- */
.workspace {
  position: relative;
  flex: 1;
  overflow: hidden;
}

#canvas {
  width: 100%;
  height: 100%;
  display: block;
  cursor: default;
  user-select: none;
  -webkit-user-select: none;
  background: var(--bg);
}
#canvas.panning { cursor: grabbing; }
#canvas.adding { cursor: crosshair; }
#canvas.connecting { cursor: crosshair; }

/* SVG node styles */
.node-shape {
  fill: #ffffff;
  stroke: #cbd5e1;
  stroke-width: 1.5;
  transition: stroke 0.1s, filter 0.1s;
  filter: url(#node-shadow);
}
.node.selected .node-shape {
  stroke: var(--accent);
  stroke-width: 2;
  filter: url(#node-shadow-strong);
}
.node.hovered .node-shape {
  stroke: #94a3b8;
  filter: url(#node-shadow-strong);
}
.node-title {
  font-family: var(--font);
  font-weight: 600;
  font-size: 14px;
  fill: #0f172a;
  text-anchor: middle;
  dominant-baseline: middle;
  pointer-events: none;
}
.node-desc {
  font-family: var(--font);
  font-weight: 400;
  font-size: 11.5px;
  fill: #475569;
  text-anchor: middle;
  pointer-events: none;
}
.node { cursor: move; }

/* Group nodes */
.node.group .group-title-bar {
  cursor: move;
}
.node.group .group-border {
  pointer-events: stroke;
  cursor: move;
}
.node.group .group-tinted-body {
  cursor: move;
}
.node.group.selected .group-border {
  stroke: var(--accent) !important;
  stroke-width: 2 !important;
}
.node.group.drop-target .group-border {
  stroke: var(--accent) !important;
  stroke-width: 2.4 !important;
  stroke-dasharray: 6 4 !important;
}
.node.group.drop-target .group-title-bar {
  filter: brightness(0.94);
}
.node.group.drop-target .group-tinted-body {
  fill-opacity: 0.75 !important;
}
.group-label { pointer-events: none; }

/* Resize handles */
.resize-handle {
  fill: #ffffff;
  stroke: var(--accent);
  stroke-width: 1.5;
  vector-effect: non-scaling-stroke;
}
.resize-handle:hover {
  fill: var(--accent);
}

/* Edges */
.edge-path {
  fill: none;
  stroke: #475569;
  stroke-width: 1.8;
  marker-end: url(#arrowhead);
  transition: stroke 0.1s, stroke-width 0.1s;
}
.edge.selected .edge-path {
  stroke: var(--accent);
  stroke-width: 2.4;
  marker-end: url(#arrowhead-active);
}
.edge-hit {
  fill: none;
  stroke: transparent;
  stroke-width: 14;
  cursor: pointer;
}

/* Anchor handles */
.anchor {
  fill: #ffffff;
  stroke: var(--accent);
  stroke-width: 1.8;
  cursor: crosshair;
  opacity: 0;
  transition: opacity 0.12s, r 0.12s;
  pointer-events: all;
}
.node:hover .anchor,
.node.selected .anchor,
.node.connect-source .anchor {
  opacity: 1;
}
.anchor:hover {
  fill: var(--accent);
  r: 6;
}

/* Temporary connecting line */
.temp-edge {
  fill: none;
  stroke: var(--accent);
  stroke-width: 2;
  stroke-dasharray: 4 4;
  marker-end: url(#arrowhead-active);
  pointer-events: none;
}

/* ----------- Inspector ----------- */
.inspector {
  position: absolute;
  top: 16px;
  right: 16px;
  width: 280px;
  background: var(--panel);
  border-radius: 12px;
  box-shadow: var(--shadow-lg);
  padding: 16px;
  z-index: 5;
  border: 1px solid var(--border);
  transition: transform 0.18s ease, opacity 0.18s ease;
}
.inspector.hidden {
  transform: translateX(20px);
  opacity: 0;
  pointer-events: none;
}
.inspector header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 14px;
}
.inspector h2 {
  margin: 0;
  font-size: 14px;
  font-weight: 700;
  letter-spacing: -0.01em;
}
#inspector-close {
  background: transparent;
  border: none;
  font-size: 22px;
  line-height: 1;
  color: var(--text-muted);
  cursor: pointer;
  padding: 0 4px;
  border-radius: 4px;
}
#inspector-close:hover { color: var(--text); background: var(--panel-2); }

.field {
  margin-bottom: 12px;
  display: flex;
  flex-direction: column;
  gap: 5px;
}
.field.row {
  flex-direction: row;
  gap: 8px;
}
.field.row > div {
  flex: 1;
  display: flex;
  flex-direction: column;
  gap: 5px;
}
.field label {
  font-size: 11.5px;
  font-weight: 600;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.04em;
}

.color-row { display: flex; gap: 6px; flex-wrap: wrap; }
.swatch {
  width: 26px;
  height: 26px;
  border-radius: 6px;
  border: 1px solid var(--border-strong);
  cursor: pointer;
  padding: 0;
  transition: transform 0.08s, box-shadow 0.12s;
}
.swatch:hover { transform: scale(1.08); }
.swatch.active { box-shadow: 0 0 0 2px var(--accent); }

.inspector-actions {
  display: flex;
  gap: 8px;
  margin-top: 8px;
}
.inspector-actions .btn { flex: 1; justify-content: center; }

.checkbox-line {
  display: inline-flex;
  align-items: center;
  gap: 7px;
  font-size: 12.5px;
  color: var(--text);
  cursor: pointer;
  user-select: none;
}
.checkbox-line input[type="checkbox"] {
  width: 14px;
  height: 14px;
  margin: 0;
  accent-color: var(--accent);
}
.btn.small {
  padding: 5px 10px;
  font-size: 12px;
}
.btn.icon {
  width: 30px;
  padding: 5px 0;
  justify-content: center;
  font-size: 15px;
  line-height: 1;
}

/* Modal */
.modal-overlay {
  position: fixed;
  inset: 0;
  background: rgba(15, 23, 42, 0.45);
  backdrop-filter: blur(2px);
  -webkit-backdrop-filter: blur(2px);
  z-index: 50;
  display: flex;
  align-items: center;
  justify-content: center;
}
.modal {
  background: var(--panel);
  border-radius: 14px;
  box-shadow: var(--shadow-lg);
  width: min(460px, 92vw);
  max-height: 80vh;
  display: flex;
  flex-direction: column;
  overflow: hidden;
  border: 1px solid var(--border);
}
.modal-wide { width: min(640px, 94vw); }
.modal header {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 12px 16px;
  border-bottom: 1px solid var(--border);
}
.modal header h2 {
  margin: 0;
  font-size: 14px;
  font-weight: 700;
  letter-spacing: -0.01em;
  flex: 1;
}
.modal header button {
  background: transparent;
  border: none;
  font-size: 22px;
  line-height: 1;
  color: var(--text-muted);
  cursor: pointer;
  padding: 0 4px;
  border-radius: 4px;
}
.modal header button:hover { color: var(--text); background: var(--panel-2); }
.modal-body { padding: 8px 0; overflow: auto; }
.modal-empty {
  padding: 24px;
  text-align: center;
  font-size: 13px;
  color: var(--text-muted);
}
.modal-pad { padding: 16px 18px; }
.modal-label {
  display: block;
  font-size: 11.5px;
  font-weight: 600;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.04em;
  margin-bottom: 6px;
}
#save-as-name {
  width: 100%;
  font-size: 14px;
  padding: 8px 10px;
}
.modal-hint {
  font-size: 12px;
  color: var(--text-muted);
  margin: 8px 0 0 0;
}
.modal-footer {
  display: flex;
  justify-content: flex-end;
  gap: 8px;
  padding: 12px 18px;
  border-top: 1px solid var(--border);
}

/* Marquee selection rectangle */
.marquee-rect {
  fill: rgba(37, 99, 235, 0.10);
  stroke: var(--accent);
  stroke-width: 1;
  stroke-dasharray: 4 3;
  pointer-events: none;
}
.chart-list { display: flex; flex-direction: column; }
.chart-row {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 9px 16px;
  border-bottom: 1px solid var(--border);
  cursor: pointer;
  transition: background 0.1s;
}
.chart-row:last-child { border-bottom: none; }
.chart-row:hover { background: var(--panel-2); }
.chart-row .chart-name {
  flex: 1;
  font-size: 13.5px;
  font-weight: 500;
  color: var(--text);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}
.chart-row .chart-meta {
  font-size: 11.5px;
  color: var(--text-muted);
  font-variant-numeric: tabular-nums;
  white-space: nowrap;
}
.chart-row .row-chevron {
  background: transparent;
  border: none;
  color: var(--text-muted);
  font-size: 11px;
  width: 18px;
  height: 18px;
  padding: 0;
  cursor: pointer;
  border-radius: 4px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  transition: transform 0.15s, background 0.1s;
  flex-shrink: 0;
}
.chart-row .row-chevron:hover { background: var(--panel); color: var(--text); }
.chart-row .row-chevron.open { transform: rotate(90deg); }
.chart-row .chart-version {
  font-size: 11px;
  font-weight: 600;
  color: var(--text-muted);
  background: var(--panel-2);
  padding: 2px 7px;
  border-radius: 999px;
  font-variant-numeric: tabular-nums;
  white-space: nowrap;
}
.chart-row .row-actions {
  display: flex;
  gap: 4px;
}
.chart-entry { display: block; }
.chart-entry + .chart-entry { border-top: 1px solid var(--border); }
.chart-entry .chart-row { border-bottom: none; }
.version-list {
  background: var(--panel-2);
  border-top: 1px solid var(--border);
  padding: 4px 0;
}
.version-loading {
  padding: 8px 16px 8px 48px;
  font-size: 12px;
  color: var(--text-muted);
}
.version-row {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 5px 16px 5px 48px;
  font-size: 12px;
}
.version-row + .version-row { border-top: 1px dashed var(--border); }
.version-row .version-rev {
  font-weight: 700;
  font-variant-numeric: tabular-nums;
  color: var(--text-muted);
  min-width: 32px;
}
.version-row .version-rev.current {
  color: var(--accent);
}
.version-row .version-when {
  flex: 1;
  color: var(--text-muted);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}
.row-btn {
  background: transparent;
  border: 1px solid transparent;
  color: var(--text-muted);
  padding: 4px 8px;
  font-size: 11.5px;
  border-radius: 5px;
  cursor: pointer;
  font-family: var(--font);
}
.row-btn:hover { background: #fff; color: var(--text); border-color: var(--border); }
.row-btn.danger:hover { background: var(--danger-soft); color: var(--danger); border-color: transparent; }
#group-autofit-field { align-items: center; }
#group-autofit-field > * { flex: none !important; }
#group-autofit-field > label { flex: 1 !important; }

/* ----------- Status bar ----------- */
.status {
  position: absolute;
  bottom: 12px;
  left: 16px;
  right: 16px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  pointer-events: none;
  font-size: 12px;
  color: var(--text-muted);
}
.status #status-text {
  background: rgba(255,255,255,0.85);
  backdrop-filter: blur(6px);
  -webkit-backdrop-filter: blur(6px);
  padding: 6px 10px;
  border-radius: 6px;
  border: 1px solid var(--border);
  box-shadow: var(--shadow-sm);
}
.status #status-text:empty {
  display: none;
}
.status .coords {
  background: rgba(255,255,255,0.85);
  backdrop-filter: blur(6px);
  -webkit-backdrop-filter: blur(6px);
  padding: 6px 10px;
  border-radius: 6px;
  border: 1px solid var(--border);
  font-variant-numeric: tabular-nums;
  box-shadow: var(--shadow-sm);
}