:root {
  --bg: #0e0f12;
  --panel: #151821;
  --panel-2: #1b2030;
  --text: #e7ecf3;
  --muted: #a8b0c0;
  --accent: #7cc5ff;
  --accent-2: #ffd166;
  --danger: #ff6b6b;
  --ok: #8cffc1;
}

* { box-sizing: border-box; }
html, body { height: 100%; overflow: hidden; }
body {
  margin: 0;
  background: radial-gradient(1200px 800px at 60% 40%, #0e0f12 20%, #0b0c10 100%);
  color: var(--text);
  font-family: ui-sans-serif, system-ui, -apple-system, Segoe UI, Roboto, Helvetica, Arial,
    "Apple Color Emoji", "Segoe UI Emoji";
}

#app {
  display: grid;
  grid-template-columns: 360px 1fr;
  height: 100vh;
}

#controls {
  padding: 16px 16px 24px 16px;
  background: linear-gradient(180deg, var(--panel) 0%, var(--panel-2) 100%);
  border-right: 1px solid #23283a;
  overflow-y: auto;
  height: 100vh;
  scrollbar-gutter: stable;
}

#controls, #stage { min-height: 0; }

#controls h2 { margin: 8px 0 16px; font-weight: 700; letter-spacing: 0.3px; }

.card {
  background: rgba(10,14,24,0.6);
  border: 1px solid #26304a;
  border-radius: 12px;
  padding: 12px;
  margin: 8px 0;
}

.card h3 {
  margin: 0 0 10px 0;
  font-size: 14px;
  color: #cbd6e9;
  letter-spacing: 0.2px;
}

.card:last-child { margin-bottom: 0; }

.field-group { margin-bottom: 12px; }
.field-group.two-col { display: grid; grid-template-columns: 1fr 1fr; gap: 8px; }
.field-group.three-col { display: grid; grid-template-columns: 1fr 1fr 1fr; gap: 8px; }

label { display: block; font-size: 12px; color: var(--muted); margin-bottom: 6px; }
small.help, .help { display:block; font-size: 11px; color: var(--muted); opacity: 0.85; margin-top: 4px; }

input, select {
  width: 100%;
  padding: 8px 10px;
  border-radius: 8px;
  border: 1px solid #2a3146;
  background: #0f1320;
  color: var(--text);
}

.checkbox { display: flex; align-items: center; gap: 8px; }
.checkbox input { width: auto; }

.buttons { display: grid; grid-template-columns: repeat(3, 1fr); gap: 8px; margin: 12px 0; width: 100%; }
.buttons button {
  background: #1a2234;
  color: var(--text);
  border: 1px solid #2a3146;
  border-radius: 8px;
  padding: 8px 10px;
  cursor: pointer;
  width: 100%;
}
.buttons button:hover { filter: brightness(1.15); }

/* Stronger specificity so these override the generic .buttons button rule */
.buttons .btn-start { background: #198754; border-color: #146c43; }
.buttons .btn-stop { background: #dc3545; border-color: #b02a37; }
.buttons .btn-reset { background: #2a3146; border-color: #20273a; }

/* Compact button row */
.buttons { gap: 8px; }

.sim-grid {
  display: grid;
  grid-template-columns: 1fr 132px;
  gap: 10px;
  align-items: center;
}

.stats { margin-top: 12px; display: grid; gap: 6px; }
.stat { display: grid; grid-template-columns: auto 1fr auto; align-items: center; gap: 8px; font-size: 14px; }
.stat span { color: var(--muted); }
.stat strong { color: var(--accent-2); font-variant-numeric: tabular-nums; }
.spark { width: 100%; height: 26px; border-left: 1px solid #2a3146; border-bottom: 1px solid #2a3146; }

#stage { position: relative; overflow: hidden; }
#canvas { display: block; width: 100%; height: 100%; background: #05070c; }
#overlay {
  position: absolute;
  left: 12px;
  bottom: 12px;
  padding: 6px 8px;
  border-radius: 6px;
  background: rgba(20, 25, 38, 0.85);
  border: 1px solid #2a3146;
  color: var(--muted);
  font-size: 12px;
}

.legend {
  position: absolute;
  right: 12px;
  bottom: 12px;
  font-size: 12px;
  color: var(--muted);
  background: rgba(20,25,38,0.85);
  border: 1px solid #2a3146;
  border-radius: 6px;
  padding: 6px 8px;
}

.chip {
  display: inline-block;
  padding: 2px 6px;
  border-radius: 999px;
  border: 1px solid #2a3146;
  background: #0f1320;
}