:root {
  --bg: #0c0e14;
  --panel: #161a26;
  --panel-2: #1e2434;
  --border: #2a3146;
  --text: #e6e9f0;
  --muted: #8b93a7;
  --accent: #4ade80;
  --accent-dim: #16653480;
  --danger: #f87171;
  --cell-alive: #4ade80;
  --cell-ghost: #2a3146;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  font-family: ui-sans-serif, system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  background: radial-gradient(1200px 600px at 50% -10%, #141a2b 0%, var(--bg) 60%);
  color: var(--text);
  min-height: 100vh;
}

.app {
  max-width: 780px;
  margin: 0 auto;
  padding: 32px 20px 64px;
}

header { text-align: center; margin-bottom: 28px; }

h1 {
  font-size: 2.6rem;
  margin: 0;
  letter-spacing: -1px;
  font-weight: 800;
}
h1 span { color: var(--accent); }

.tagline {
  color: var(--muted);
  margin: 8px auto 0;
  max-width: 44ch;
  line-height: 1.5;
}

.controls-panel {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 14px;
  padding: 20px;
}

.field-label {
  display: block;
  font-size: 0.8rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--muted);
  margin-bottom: 8px;
}

.input-row { display: flex; gap: 10px; }

input[type="text"] {
  flex: 1;
  background: var(--panel-2);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 12px 14px;
  color: var(--text);
  font-size: 1rem;
  outline: none;
  transition: border-color 0.15s;
}
input[type="text"]:focus { border-color: var(--accent); }

.btn {
  background: var(--panel-2);
  border: 1px solid var(--border);
  color: var(--text);
  border-radius: 10px;
  padding: 12px 16px;
  font-size: 0.95rem;
  cursor: pointer;
  transition: background 0.15s, border-color 0.15s, transform 0.05s;
  white-space: nowrap;
}
.btn:hover { border-color: var(--accent); }
.btn:active { transform: translateY(1px); }

.btn.primary {
  background: var(--accent);
  border-color: var(--accent);
  color: #06210f;
  font-weight: 700;
}
.btn.primary:hover { background: #5eed94; }

.error {
  color: var(--danger);
  margin: 12px 0 0;
  font-size: 0.9rem;
}

.stage { margin-top: 28px; }

.canvas-wrap {
  position: relative;
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 14px;
  padding: 16px;
  display: flex;
  justify-content: center;
}

canvas {
  width: 100%;
  max-width: 560px;
  height: auto;
  image-rendering: pixelated;
  border-radius: 6px;
  background: #fff;
}

.badge {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-bottom: 12px;
  font-size: 0.75rem;
  font-variant-numeric: tabular-nums;
}
.badge span {
  background: #0c0e14cc;
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: 4px 8px;
  color: var(--accent);
  backdrop-filter: blur(4px);
}
.status { color: var(--muted) !important; }
.status.stable {
  color: #06210f !important;
  background: var(--accent) !important;
  border-color: var(--accent) !important;
  font-weight: 700;
}
.status.dead {
  color: #fff !important;
  background: #7f1d1d !important;
  border-color: var(--danger) !important;
  font-weight: 700;
}

.playbar {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 12px;
  margin-top: 16px;
}

.speed, .toggle {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 0.85rem;
  color: var(--muted);
}
.speed input[type="range"] { accent-color: var(--accent); }
.toggle input { accent-color: var(--accent); }

.hint {
  color: var(--muted);
  font-size: 0.85rem;
  line-height: 1.5;
  margin-top: 16px;
}

@media (max-width: 520px) {
  .input-row { flex-direction: column; }
  h1 { font-size: 2.1rem; }
}