:root {
  --bg: #0b1020;
  --surface: #121a2e;
  --surface-2: #1a2440;
  --border: #26324f;
  --text: #e2e8f0;
  --muted: #94a3b8;
  --accent: #facc15;
  --pos: #ff4d5e;
  --neg: #3b82f6;
  --error: #f87171;
  color-scheme: dark;
}
:root[data-theme="light"] {
  --bg: #f1f5f9;
  --surface: #ffffff;
  --surface-2: #f1f5f9;
  --border: #d5dce6;
  --text: #0f172a;
  --muted: #64748b;
  --accent: #ca8a04;
  --pos: #e11d48;
  --neg: #2563eb;
  --error: #dc2626;
  color-scheme: light;
}

* { box-sizing: border-box; }
html, body { height: 100%; margin: 0; }
body {
  background: var(--bg);
  color: var(--text);
  font: 14px/1.5 system-ui, -apple-system, "Segoe UI", "Microsoft YaHei", "PingFang SC", sans-serif;
  display: grid;
  grid-template-rows: auto 1fr auto;
  overflow: hidden;
}
button, select, input, textarea { font: inherit; color: inherit; }
button {
  background: var(--surface-2);
  border: 1px solid var(--border);
  border-radius: 7px;
  padding: 5px 11px;
  cursor: pointer;
}
button:hover { border-color: var(--muted); }
button:focus-visible, select:focus-visible, input:focus-visible { outline: 2px solid var(--accent); outline-offset: 1px; }
button.primary { background: var(--accent); color: #111; border-color: transparent; font-weight: 600; }
select, input[type="number"], input[type="text"] {
  background: var(--surface-2);
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: 4px 6px;
}
.sr-only { position: absolute; width: 1px; height: 1px; overflow: hidden; clip: rect(0 0 0 0); }
.muted { color: var(--muted); }
.spacer { flex: 1; }

/* Top bar */
.topbar {
  display: flex; align-items: center; gap: 8px;
  padding: 8px 12px;
  background: var(--surface);
  border-bottom: 1px solid var(--border);
}
.brand { font-weight: 700; font-size: 16px; display: flex; align-items: center; gap: 8px; margin-right: 8px; white-space: nowrap; }
.site-nav { display: flex; align-items: center; gap: 12px; white-space: nowrap; font-size: 12px; }
.site-nav a { color: var(--muted); text-underline-offset: 3px; }
.site-nav a:hover { color: var(--text); }
.logo {
  width: 22px; height: 14px; display: inline-block;
  background: radial-gradient(circle at 25% 50%, var(--pos) 0 5px, transparent 6px),
              radial-gradient(circle at 75% 50%, var(--neg) 0 5px, transparent 6px);
}
#scene-select { min-width: 230px; max-width: 46vw; }

/* Main layout */
.layout {
  display: grid;
  grid-template-columns: 64px 1fr 300px;
  min-height: 0;
}
.tools {
  display: flex; flex-direction: column; gap: 4px;
  padding: 8px 6px;
  background: var(--surface);
  border-right: 1px solid var(--border);
  overflow-y: auto;
}
.tools button {
  display: flex; flex-direction: column; align-items: center; gap: 2px;
  padding: 6px 2px; font-size: 11px; background: transparent; border-color: transparent;
}
.tools button svg { width: 22px; height: 22px; fill: currentColor; stroke: currentColor; }
.tools button.active { background: var(--surface-2); border-color: var(--accent); color: var(--accent); }
.tools .tool-sep { height: 1px; background: var(--border); margin: 4px 2px; }
.tools .sign b { font-size: 20px; line-height: 22px; }
.tools .sign.pos b { color: var(--pos); }
.tools .sign.neg b { color: var(--neg); }

.stage { position: relative; min-width: 0; min-height: 0; overflow: hidden; }
#canvas { display: block; width: 100%; height: 100%; touch-action: none; cursor: crosshair; }
#canvas.grab { cursor: grab; }
#canvas.grabbing { cursor: grabbing; }
#canvas.move { cursor: move; }

.legend {
  position: absolute; left: 10px; bottom: 26px;
  background: color-mix(in srgb, var(--surface) 88%, transparent);
  border: 1px solid var(--border); border-radius: 8px;
  padding: 6px 9px; font-size: 12px; pointer-events: none;
  display: flex; flex-direction: column; gap: 4px; max-width: 280px;
}
.legend:empty { display: none; }
.legend .bar { height: 9px; border-radius: 3px; }
.legend .ends { display: flex; justify-content: space-between; color: var(--muted); font-size: 11px; }
.legend .swatch { display: inline-block; width: 18px; height: 0; border-top: 2px solid; vertical-align: middle; margin-right: 6px; }
.hint {
  position: absolute; top: 40%; left: 50%; transform: translate(-50%, -50%);
  background: var(--surface); border: 1px solid var(--border); border-radius: 10px;
  padding: 14px 18px; text-align: center; color: var(--muted); pointer-events: none; max-width: 340px;
}

/* Side panel */
.panel {
  background: var(--surface);
  border-left: 1px solid var(--border);
  overflow-y: auto;
  padding: 8px;
  display: flex; flex-direction: column; gap: 8px;
}
.card { background: var(--surface-2); border: 1px solid var(--border); border-radius: 10px; padding: 9px 11px; }
.card h2 { font-size: 12px; text-transform: uppercase; letter-spacing: .06em; color: var(--muted); margin: 0 0 6px; }
.card p { margin: 0; }
.row { display: flex; align-items: center; gap: 8px; margin: 5px 0; justify-content: space-between; }
.row:has(input[type="checkbox"]) { justify-content: flex-start; }
.row.slider { flex-wrap: wrap; }
.row.slider input { width: 100%; }
.row output { margin-left: auto; color: var(--accent); font-variant-numeric: tabular-nums; }
input[type="range"] { accent-color: var(--accent); }
input[type="checkbox"] { accent-color: var(--accent); }

.props { display: grid; grid-template-columns: auto 1fr; gap: 5px 8px; align-items: center; }
.props label { color: var(--muted); font-size: 12px; }
.props input[type="number"], .props input[type="text"] { width: 100%; min-width: 0; }
.props .wide { grid-column: 1 / -1; }
.props .type { grid-column: 1 / -1; font-weight: 600; display: flex; align-items: center; gap: 8px; }
.props .chip { width: 10px; height: 10px; border-radius: 50%; display: inline-block; }
.prop-buttons { display: flex; gap: 6px; margin-top: 8px; flex-wrap: wrap; }
.prop-buttons button { flex: 1; padding: 4px 6px; font-size: 12px; }
.prop-buttons .danger { color: var(--error); }

/* Status bar */
.status {
  display: flex; gap: 16px; justify-content: space-between; align-items: center;
  padding: 5px 12px;
  background: var(--surface);
  border-top: 1px solid var(--border);
  font-size: 12.5px; font-variant-numeric: tabular-nums;
  white-space: nowrap; overflow: hidden;
}
#status-probe { overflow: hidden; text-overflow: ellipsis; }
.status .warn { color: var(--error); }

/* Dialogs */
dialog {
  background: var(--surface); color: var(--text);
  border: 1px solid var(--border); border-radius: 12px;
  padding: 0; width: min(760px, calc(100vw - 32px));
}
dialog::backdrop { background: rgba(0, 0, 0, .5); }
.dlg { padding: 16px 18px; display: flex; flex-direction: column; gap: 10px; }
.dlg h2 { margin: 0; font-size: 17px; }
.dlg p { margin: 0; }
#json-text {
  width: 100%; resize: vertical;
  font: 12.5px/1.45 ui-monospace, "Cascadia Code", Consolas, monospace;
  background: var(--bg); border: 1px solid var(--border); border-radius: 8px; padding: 10px;
}
.error { color: var(--error); min-height: 1.2em; white-space: pre-wrap; }
.dlg-buttons { display: flex; gap: 8px; align-items: center; flex-wrap: wrap; }
code, kbd {
  font: 12px ui-monospace, Consolas, monospace;
  background: var(--surface-2); border: 1px solid var(--border); border-radius: 4px; padding: 0 4px;
}
.help { margin: 0; padding-left: 18px; display: flex; flex-direction: column; gap: 6px; }
.keys { border-collapse: collapse; font-size: 13px; }
.keys td { padding: 3px 10px 3px 0; vertical-align: top; }

/* Narrow screens: tools on top, panel below the canvas */
@media (max-width: 860px) {
  body { height: auto; min-height: 100dvh; display: block; overflow-x: hidden; overflow-y: auto; }
  .layout { grid-template-columns: 1fr; grid-template-rows: auto 62vh auto; }
  .tools { min-height: 72px; flex-direction: row; border-right: 0; border-bottom: 1px solid var(--border); overflow-x: auto; overflow-y: hidden; }
  .tools .tool-sep { width: 1px; height: auto; margin: 2px 4px; }
  .tools button { min-width: 50px; }
  .panel { border-left: 0; border-top: 1px solid var(--border); overflow: visible; }
  .topbar { flex-wrap: wrap; }
  .topbar .site-nav { order: 2; width: 100%; padding-top: 3px; }
  .topbar > .spacer { display: none; }
  #scene-select { min-width: 0; max-width: 60vw; }
  .status { flex-direction: column; align-items: flex-start; gap: 2px; white-space: normal; }
}
@media (max-width: 480px) {
  .topbar { gap: 6px; padding: 8px; }
  .brand { margin-right: 0; }
  .scene-pick { flex: 1 1 150px; min-width: 140px; }
  #scene-select { width: 100%; max-width: 100%; }
  .topbar button { padding: 5px 8px; }
  .legend { font-size: 11px; left: 7px; bottom: 10px; max-width: calc(100% - 14px); }
  .dlg { padding: 14px; }
  #json-text { min-height: 180px; }
}