:root {
  --bg: #f4f6f8;
  --card: #ffffff;
  --line: #dde3e8;
  --ink: #1c252d;
  --muted: #6b7a86;
  --accent: #1f7a6b;
  --accent-2: #c8811a;
  --danger: #b23a2f;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font: 14px/1.55 "Segoe UI", "Microsoft YaHei", system-ui, sans-serif;
}

.topbar {
  display: flex;
  align-items: flex-end;
  justify-content: space-between;
  gap: 24px;
  padding: 18px 28px;
  background: #16202a;
  color: #eef3f5;
}
.brand h1 { margin: 0; font-size: 20px; letter-spacing: .5px; }
.brand .sub { margin: 4px 0 0; font-size: 12.5px; color: #98a9b6; }

.api-box { display: flex; align-items: center; gap: 8px; }
.api-box label { font-size: 12px; color: #98a9b6; }
.api-box input {
  width: 240px;
  padding: 7px 9px;
  border-radius: 6px;
  border: 1px solid #3a4a57;
  background: #0f1820;
  color: #dfe8ec;
  font-size: 13px;
}
.status { font-size: 12px; padding: 3px 8px; border-radius: 999px; }
.status.on { background: #1f7a6b33; color: #7fd8c0; border: 1px solid #2f9b86; }
.status.off { background: #b23a2f22; color: #ffb3aa; border: 1px solid #8f4038; }

main { max-width: 1320px; margin: 0 auto; padding: 20px 24px 60px; display: grid; gap: 20px; }

.card {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 12px;
  padding: 18px 20px 20px;
}
.card-head {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 18px;
  margin-bottom: 14px;
}
.card-head h2 { display: flex; align-items: center; gap: 10px; margin: 0; font-size: 16px; }
.idx {
  display: inline-flex;
  width: 22px; height: 22px;
  align-items: center; justify-content: center;
  border-radius: 6px;
  background: var(--accent);
  color: #fff;
  font-size: 12px;
}
.hint { margin: 6px 0 0; font-size: 12.5px; color: var(--muted); }
.head-actions { display: flex; align-items: center; gap: 10px; flex-wrap: wrap; }

.btn {
  border: 1px solid var(--accent);
  background: var(--accent);
  color: #fff;
  padding: 7px 14px;
  border-radius: 7px;
  font-size: 13px;
  cursor: pointer;
}
.btn:hover { filter: brightness(1.06); }
.btn.ghost { background: #fff; color: var(--accent); }
.btn.primary { background: #16202a; border-color: #16202a; }
.btn:disabled { opacity: .45; cursor: not-allowed; filter: none; }

.sel { display: inline-flex; align-items: center; gap: 6px; font-size: 12.5px; color: var(--muted); }
.sel select, .sel input {
  padding: 5px 8px;
  border: 1px solid var(--line);
  border-radius: 6px;
  background: #fff;
  color: var(--ink);
  font-size: 13px;
}
.sel input[type=number] { width: 74px; }

/* import */
.import-grid { display: grid; grid-template-columns: 1.1fr 40px 1fr; gap: 14px; align-items: start; }
.import-or { text-align: center; color: var(--muted); font-size: 12px; padding-top: 46px; }
.dropzone {
  border: 2px dashed #c3d0d8;
  border-radius: 10px;
  padding: 26px 18px;
  text-align: center;
  background: #fbfcfd;
  cursor: pointer;
  transition: border-color .15s, background .15s;
}
.dropzone.over { border-color: var(--accent); background: #f0f7f5; }
.dz-title { margin: 0 0 4px; font-weight: 600; }
.dz-sub { margin: 0 0 12px; font-size: 12.5px; color: var(--muted); }

.import-side { display: grid; gap: 10px; }
.row { display: flex; gap: 10px; flex-wrap: wrap; }
.paste-label { font-size: 12.5px; color: var(--muted); }
#paste-json {
  width: 100%;
  height: 110px;
  resize: vertical;
  padding: 9px;
  border: 1px solid var(--line);
  border-radius: 8px;
  font: 12px/1.5 ui-monospace, Consolas, monospace;
  color: var(--ink);
  background: #fcfdfe;
}
.preset-panel {
  display: grid;
  gap: 8px;
  padding: 10px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #fafcfc;
}
.preset-panel .preset-row { display: flex; gap: 8px; align-items: center; flex-wrap: wrap; }
.preset-panel select { padding: 5px 8px; border: 1px solid var(--line); border-radius: 6px; font-size: 13px; }

.summary { margin-top: 16px; }
.summary .empty { margin: 0; color: var(--muted); font-size: 13px; }
.summary table { width: 100%; border-collapse: collapse; font-size: 13px; }
.summary th, .summary td { border-bottom: 1px solid var(--line); padding: 6px 8px; text-align: left; }
.summary th { color: var(--muted); font-weight: 500; width: 190px; }
.pill { display: inline-block; padding: 2px 8px; border-radius: 999px; font-size: 12px; }
.pill.ok { background: #eaf5f2; color: var(--accent); border: 1px solid #bfe0d7; }
.pill.warn { background: #fdf3e3; color: var(--accent-2); border: 1px solid #ecd2a8; }
.pill.miss { background: #fdecea; color: var(--danger); border: 1px solid #f2c2bb; }

/* visualisation */
.viz { display: grid; gap: 14px; }
/* keep in sync: every element the JS toggles with .hidden must actually collapse */
.hidden { display: none !important; }

.viz-toolbar {
  display: flex;
  align-items: center;
  gap: 10px;
  flex-wrap: wrap;
  padding: 10px 12px;
  background: #f7f9fa;
  border: 1px solid var(--line);
  border-radius: 9px;
}
.step-label { margin-left: auto; font-size: 12.5px; color: var(--muted); font-variant-numeric: tabular-nums; }

.viz-body { display: grid; grid-template-columns: minmax(0, 1.55fr) minmax(280px, 1fr); gap: 16px; }
.canvas-wrap { position: relative; }
#room-canvas, #batch-canvas {
  width: 100%;
  height: auto;
  background: #fbfdfe;
  border: 1px solid var(--line);
  border-radius: 10px;
  display: block;
}
.legend { display: flex; gap: 14px; flex-wrap: wrap; margin-top: 8px; font-size: 12px; color: var(--muted); }
.legend .sw { display: inline-block; width: 12px; height: 12px; border-radius: 3px; margin-right: 5px; vertical-align: -2px; border: 1px solid #0001; }

.side { display: grid; gap: 12px; align-content: start; }
.kpis { display: grid; grid-template-columns: repeat(3, 1fr); gap: 8px; }
.kpi {
  padding: 8px 10px;
  border: 1px solid var(--line);
  border-radius: 9px;
  background: #fbfcfd;
}
.kpi .k { font-size: 11.5px; color: var(--muted); }
.kpi .v { font-size: 16px; font-weight: 600; font-variant-numeric: tabular-nums; }

.panel { border: 1px solid var(--line); border-radius: 9px; padding: 10px 12px; }
.panel h3 { margin: 0 0 8px; font-size: 13px; display: flex; align-items: center; gap: 8px; }
.tag {
  font-size: 11px;
  padding: 1px 7px;
  border-radius: 999px;
  background: #eef2f5;
  color: var(--muted);
  border: 1px solid var(--line);
}
.arrival-panel, .event-panel { font-size: 12.5px; color: #2c3944; }
.arrival-panel .big { font-size: 15px; font-weight: 600; }
.event-row {
  display: grid;
  grid-template-columns: auto 1fr auto;
  gap: 8px;
  padding: 4px 0;
  border-bottom: 1px dashed #e6ecf0;
  font-variant-numeric: tabular-nums;
}
.event-row:last-child { border-bottom: 0; }
.event-row .delta.down { color: var(--danger); }
.event-row .delta.up { color: var(--accent); }
.type-badge { font-size: 11px; padding: 1px 6px; border-radius: 4px; background: #eef2f5; color: var(--muted); }

.chart-wrap { border: 1px solid var(--line); border-radius: 10px; padding: 10px 12px; background: #fff; }
.chart-head { display: flex; align-items: baseline; gap: 12px; }
.chart-head h3 { margin: 0; font-size: 13px; }
#spark { width: 100%; height: auto; display: block; }

.viz-foot { display: flex; align-items: center; gap: 12px; }
.muted { font-size: 12px; color: var(--muted); }
.placeholder { margin: 4px 0 0; color: var(--muted); font-size: 13px; }

/* batch */
.batch-progress { margin: 0 0 14px; }
.bar { height: 8px; border-radius: 999px; background: #e8eef2; overflow: hidden; }
.fill { height: 100%; width: 0%; background: var(--accent); transition: width .2s; }
.batch-progress p { margin: 6px 0 0; }

.table-wrap { max-height: 420px; overflow: auto; }
.table-wrap table { width: 100%; border-collapse: collapse; font-size: 12px; font-variant-numeric: tabular-nums; }
.table-wrap thead th {
  position: sticky; top: 0;
  background: #f7f9fa;
  color: var(--muted);
  font-weight: 500;
  text-align: right;
  padding: 6px 8px;
  border-bottom: 1px solid var(--line);
}
.table-wrap tbody td { text-align: right; padding: 4px 8px; border-bottom: 1px solid #eef2f5; }
.table-wrap tbody td:first-child, .table-wrap thead th:first-child { text-align: left; }

.log {
  margin: 0;
  max-height: 220px;
  overflow: auto;
  padding: 10px 12px;
  background: #10181f;
  color: #c9d6dd;
  border-radius: 9px;
  font: 12px/1.6 ui-monospace, Consolas, monospace;
  white-space: pre-wrap;
}
.errors {
  margin-top: 12px;
  padding: 10px 12px;
  border: 1px solid #f2c2bb;
  background: #fdf6f5;
  border-radius: 9px;
  color: var(--danger);
  font-size: 12.5px;
  white-space: pre-wrap;
}

@media (max-width: 980px) {
  .viz-body { grid-template-columns: 1fr; }
  .import-grid { grid-template-columns: 1fr; }
  .import-or { padding: 0; }
}

/* ------------------------------- classroom form */
.form-block {
  border-top: 1px solid var(--line);
  padding: 14px 0 4px;
}
.form-block:first-of-type { border-top: 0; padding-top: 0; }
.form-block h3 { margin: 0 0 10px; font-size: 13.5px; }

.form-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
  gap: 10px 14px;
}
.form-grid.narrow { grid-template-columns: repeat(auto-fit, minmax(150px, 1fr)); }
.mix-grid { margin-top: 10px; }

.field { display: grid; gap: 4px; font-size: 12.5px; color: var(--muted); }
.field input,
.field select {
  padding: 7px 9px;
  border: 1px solid var(--line);
  border-radius: 7px;
  background: #fff;
  color: var(--ink);
  font-size: 13px;
}
.field input:focus,
.field select:focus { outline: 2px solid #b9d8cf; border-color: var(--accent); }
.field.check {
  display: flex;
  align-items: center;
  gap: 8px;
  align-self: end;
  padding-bottom: 8px;
  color: var(--ink);
  font-size: 13px;
}
.field.check input { width: 16px; height: 16px; }

.form-note { margin: 8px 0 0; font-size: 12.5px; color: var(--muted); }

.table-editor { display: grid; gap: 8px; justify-items: start; }
.table-editor table { width: 100%; border-collapse: collapse; font-size: 13px; }
.table-editor th {
  text-align: left;
  font-weight: 500;
  color: var(--muted);
  font-size: 12px;
  padding: 0 8px 6px;
}
.table-editor td { padding: 3px 8px 3px 0; }
.cell-input {
  width: 100%;
  max-width: 160px;
  padding: 6px 8px;
  border: 1px solid var(--line);
  border-radius: 6px;
  font-size: 13px;
  color: var(--ink);
}
.btn.small { padding: 4px 10px; font-size: 12px; }

.complexity-hint {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  margin-top: 16px;
  padding: 12px 14px;
  border: 1px dashed #c3d0d8;
  border-radius: 9px;
  background: #fbfcfd;
  font-size: 13px;
  flex-wrap: wrap;
}
.import-block { margin-top: 14px; }

/* ------------------------------- advanced block + preview */
.advanced {
  margin-top: 4px;
  border-top: 1px dashed #d6d0c4;
  padding-top: 10px;
}
.advanced > summary {
  cursor: pointer;
  font-size: 13px;
  color: var(--muted);
  padding: 4px 0 10px;
  list-style: none;
}
.advanced > summary::-webkit-details-marker { display: none; }
.advanced > summary::before { content: "▸ "; color: var(--muted); }
.advanced[open] > summary::before { content: "▾ "; }
.advanced .form-block { border-top: 1px solid var(--line); }
.advanced .form-block:first-of-type { border-top: 0; padding-top: 0; }

.preview-note {
  margin: -2px 0 12px;
  padding: 9px 12px;
  border-radius: 8px;
  background: #f4f7fa;
  border: 1px solid #dde6ef;
  font-size: 13px;
  color: var(--ink);
}
/* in preview mode only the room picture shows: no toolbar, KPIs, charts or download */
.viz.preview .viz-toolbar,
.viz.preview .side,
.viz.preview .chart-wrap,
.viz.preview .viz-foot,
.viz.preview .legend { display: none; }