:root {
  --bg: #f7f8fa;
  --panel-bg: #ffffff;
  --border: #e1e4e8;
  --text: #1c2128;
  --text-muted: #6a737d;
  --accent: #b45309;
  --accent-bg: #fef3c7;
  color-scheme: light;
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  height: 100%;
  font-family: "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  color: var(--text);
  background: var(--bg);
}

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

/* Top bar ------------------------------------------------------------ */
.topbar {
  display: flex;
  align-items: center;
  gap: 24px;
  padding: 0 20px;
  height: 56px;
  background: var(--panel-bg);
  border-bottom: 1px solid var(--border);
  flex-shrink: 0;
}
.brand { display: flex; align-items: center; gap: 8px; font-weight: 700; white-space: nowrap; }
.brand-mark { color: var(--accent); font-size: 20px; }

.tab-bar { display: flex; gap: 4px; flex: 1; overflow-x: auto; }
.tab-btn {
  border: none;
  background: transparent;
  padding: 8px 14px;
  border-radius: 6px;
  font-size: 13px;
  font-weight: 500;
  color: var(--text-muted);
  cursor: pointer;
  white-space: nowrap;
}
.tab-btn:hover { background: #f1f2f4; color: var(--text); }
.tab-btn.active { background: var(--accent-bg); color: var(--accent); }

.topbar-meta { display: flex; align-items: center; gap: 10px; margin-left: auto; }
.badge {
  font-size: 11px;
  padding: 3px 8px;
  border-radius: 999px;
  background: #e6f4ea;
  color: #1a7f37;
  font-weight: 600;
}
.muted { color: var(--text-muted); font-size: 12px; }

/* Tabs ----------------------------------------------------------------- */
#tab-panels { flex: 1; min-height: 0; }
.tab-panel { height: 100%; }

.placeholder-tab {
  max-width: 560px;
  margin: 60px auto;
  text-align: center;
  color: var(--text-muted);
}
.placeholder-tab h2 { color: var(--text); }

.tab-layout { display: flex; height: 100%; }

/* Sidebar --------------------------------------------------------------- */
.sidebar {
  width: 280px;
  flex-shrink: 0;
  background: var(--panel-bg);
  border-right: 1px solid var(--border);
  overflow-y: auto;
  padding: 16px;
}
.control-group { margin-bottom: 22px; }
.control-group h3 {
  font-size: 11px;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  color: var(--text-muted);
  margin: 0 0 10px;
}
.field { display: block; margin-bottom: 10px; font-size: 13px; }
.field span { display: block; margin-bottom: 4px; color: var(--text-muted); }
.field select {
  width: 100%;
  padding: 6px 8px;
  border: 1px solid var(--border);
  border-radius: 6px;
  background: #fff;
  font-size: 13px;
}
.field.checkbox { display: flex; align-items: center; gap: 8px; }
.field.checkbox span { margin: 0; color: var(--text); }
.hint { font-size: 11.5px; color: var(--text-muted); line-height: 1.4; margin: 6px 0 0; }

#legend-swatches { display: flex; flex-direction: column; gap: 4px; }
.legend-row { display: flex; align-items: center; gap: 8px; font-size: 12px; }
.swatch { width: 14px; height: 14px; border-radius: 3px; border: 1px solid rgba(0,0,0,0.15); display: inline-block; }

.stats p { margin: 4px 0; font-size: 13px; }
.stats span { font-weight: 700; }

/* Map -------------------------------------------------------------------- */
.map-area { flex: 1; position: relative; }
.map-canvas { position: absolute; inset: 0; }

.station-popup h4 { margin: 0 0 8px; font-size: 13px; }
.station-popup dl { margin: 0; font-size: 12px; display: grid; grid-template-columns: auto 1fr; gap: 2px 8px; }
.station-popup dt { color: var(--text-muted); }
.station-popup dd { margin: 0; text-align: right; }
.btn-detail {
  margin-top: 10px;
  width: 100%;
  padding: 6px 8px;
  border: none;
  border-radius: 6px;
  background: var(--accent);
  color: #fff;
  font-size: 12px;
  font-weight: 600;
  cursor: pointer;
}
.btn-detail:hover { background: #92400e; }

/* Detail slide-over ------------------------------------------------------ */
.detail-overlay {
  position: fixed;
  inset: 0;
  background: rgba(0,0,0,0.25);
  z-index: 900;
}
.detail-panel {
  position: fixed;
  top: 0;
  right: 0;
  bottom: 0;
  width: min(560px, 92vw);
  background: var(--panel-bg);
  box-shadow: -8px 0 24px rgba(0,0,0,0.15);
  z-index: 901;
  padding: 20px;
  overflow-y: auto;
  transform: translateX(100%);
  transition: transform 0.22s ease;
}
.detail-panel.open { transform: translateX(0); }

.icon-btn {
  position: absolute;
  top: 14px;
  right: 14px;
  border: none;
  background: transparent;
  font-size: 22px;
  line-height: 1;
  cursor: pointer;
  color: var(--text-muted);
}
.icon-btn:hover { color: var(--text); }

.detail-section { margin-top: 20px; }
.detail-section h4 { margin: 0 0 8px; font-size: 14px; }
.chart-wrap { height: 220px; }
.chart-wrap-tall { height: 320px; }
.loading, .error { font-size: 13px; }
.error { color: #cf222e; }