:root {
  --bg: #e8e4dc;
  --panel: #faf8f4;
  --panel-border: #d4cfc4;
  --text: #2a2724;
  --text-soft: #5c574f;
  --muted: #8a847a;
  --accent: #3d6b5e;
  --alive: #4f9a82;
  --alive-bright: #6ec4a8;
  --shadow: rgba(42, 39, 36, 0.1);
  --font-ui: 'Source Sans 3', system-ui, sans-serif;
  --font-display: 'Libre Baskerville', Georgia, serif;
  --font-mono: 'IBM Plex Mono', ui-monospace, monospace;
  --radius: 10px;
}

* {
  box-sizing: border-box;
}

html,
body {
  margin: 0;
  min-height: 100%;
  background: var(--bg);
  color: var(--text);
  font-family: var(--font-ui);
  font-size: 15px;
  line-height: 1.5;
}

body {
  padding: 1.5rem 1.25rem 2.5rem;
}

.sim-ambient {
  position: fixed;
  inset: 0;
  pointer-events: none;
  background:
    radial-gradient(ellipse 70% 55% at 12% 8%, rgba(79, 154, 130, 0.16), transparent 55%),
    radial-gradient(ellipse 60% 50% at 90% 20%, rgba(123, 95, 174, 0.1), transparent 50%),
    linear-gradient(165deg, #f2efe8 0%, #e6e1d8 100%);
  z-index: 0;
}

.sim-app {
  position: relative;
  z-index: 1;
  width: min(100%, 1180px);
  margin: 0 auto;
}

.sim-header {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  gap: 1rem;
  margin-bottom: 1.25rem;
}

.sim-eyebrow {
  margin: 0 0 0.35rem;
  font-size: 0.82rem;
}

.sim-eyebrow a {
  color: var(--accent);
  text-decoration: none;
  font-weight: 600;
}

.sim-eyebrow a:hover {
  text-decoration: underline;
}

.sim-title-block h1 {
  margin: 0;
  font-family: var(--font-display);
  font-size: clamp(1.6rem, 3vw, 2.1rem);
}

.sim-tagline {
  margin: 0.35rem 0 0;
  color: var(--text-soft);
  font-size: 0.92rem;
}

.sim-rules-badge {
  flex-shrink: 0;
  padding: 0.45rem 0.75rem;
  border-radius: 999px;
  border: 1px solid var(--panel-border);
  background: var(--panel);
  font-family: var(--font-mono);
  font-size: 0.78rem;
  font-weight: 600;
  color: var(--accent);
  box-shadow: 0 2px 10px var(--shadow);
}

.sim-stage {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 260px;
  gap: 1rem;
  align-items: start;
}

.sim-canvas-wrap {
  position: relative;
  border-radius: var(--radius);
  border: 1px solid #2a2824;
  background: #141210;
  overflow: hidden;
  box-shadow:
    0 8px 28px var(--shadow),
    inset 0 0 0 1px rgba(255, 255, 255, 0.04);
}

#sim-canvas {
  display: block;
  width: 100%;
  height: auto;
  max-height: min(72vh, 640px);
  image-rendering: pixelated;
  image-rendering: crisp-edges;
  cursor: crosshair;
}

.sim-canvas-glow {
  position: absolute;
  inset: 0;
  pointer-events: none;
  background: radial-gradient(ellipse at center, transparent 40%, rgba(79, 154, 130, 0.12) 100%);
  mix-blend-mode: screen;
}

.sim-panel {
  display: flex;
  flex-direction: column;
  gap: 0.85rem;
  padding: 1rem 1.1rem;
  border-radius: var(--radius);
  border: 1px solid var(--panel-border);
  background: var(--panel);
  box-shadow: 0 2px 12px var(--shadow);
}

.sim-stats {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0.5rem;
}

.sim-stat {
  padding: 0.55rem 0.65rem;
  border-radius: 8px;
  background: #f3f0ea;
  border: 1px solid #e4dfd4;
}

.sim-stat-label {
  display: block;
  font-size: 0.72rem;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  color: var(--muted);
}

.sim-stat-value {
  display: block;
  margin-top: 0.15rem;
  font-family: var(--font-mono);
  font-size: 1.15rem;
  font-weight: 600;
  color: var(--accent);
}

.sim-controls {
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem;
}

.sim-btn {
  flex: 1 1 auto;
  min-width: 4.5rem;
  padding: 0.5rem 0.7rem;
  border-radius: 8px;
  border: 1px solid var(--panel-border);
  background: #fff;
  color: var(--text);
  font-family: var(--font-ui);
  font-size: 0.85rem;
  font-weight: 600;
  cursor: pointer;
  transition: background 0.12s ease, border-color 0.12s ease;
}

.sim-btn:hover {
  border-color: #a8a196;
  background: #fffdf9;
}

.sim-btn-primary {
  background: var(--accent);
  border-color: var(--accent);
  color: #f5faf8;
}

.sim-btn-primary:hover {
  background: #356055;
  border-color: #356055;
}

.sim-btn-primary.is-playing {
  background: #7b5fae;
  border-color: #7b5fae;
}

.sim-btn-ghost {
  background: transparent;
}

.sim-field {
  display: flex;
  flex-direction: column;
  gap: 0.35rem;
  font-size: 0.82rem;
  font-weight: 600;
  color: var(--text-soft);
}

.sim-field input[type='range'] {
  width: 100%;
  accent-color: var(--accent);
}

.sim-field-hint {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--muted);
  font-weight: 500;
}

.sim-select {
  width: 100%;
  padding: 0.45rem 0.55rem;
  border-radius: 8px;
  border: 1px solid var(--panel-border);
  background: #fff;
  font-family: var(--font-ui);
  font-size: 0.85rem;
  color: var(--text);
}

.sim-check {
  display: flex;
  align-items: center;
  gap: 0.45rem;
  font-size: 0.82rem;
  color: var(--text-soft);
  cursor: pointer;
}

.sim-check input {
  accent-color: var(--accent);
}

.sim-hint {
  margin: 0;
  font-size: 0.78rem;
  color: var(--muted);
  line-height: 1.45;
}

.sim-hint kbd {
  padding: 0.1rem 0.35rem;
  border-radius: 4px;
  border: 1px solid #d4cfc4;
  background: #f3f0ea;
  font-family: var(--font-mono);
  font-size: 0.72rem;
}

.sim-legend {
  display: flex;
  flex-wrap: wrap;
  gap: 0.55rem 0.85rem;
  padding-top: 0.35rem;
  border-top: 1px solid #ebe6dc;
  font-size: 0.75rem;
  color: var(--muted);
}

.sim-legend .dot {
  display: inline-block;
  width: 0.65rem;
  height: 0.65rem;
  margin-right: 0.25rem;
  border-radius: 2px;
  vertical-align: middle;
}

.dot-alive {
  background: var(--alive);
}

.dot-born {
  background: #f4ecd2;
}

.dot-died {
  background: #5a302a;
}

@media (max-width: 900px) {
  .sim-stage {
    grid-template-columns: 1fr;
  }

  .sim-header {
    flex-direction: column;
  }
}