:root {
  --bg: #f2f4f8;
  --panel: #ffffff;
  --panel-muted: #f8fafc;
  --text: #10203a;
  --muted: #5d6b82;
  --primary: #0f62fe;
  --primary-hover: #054ada;
  --border: #d7deea;
  --canvas-bg: #ffffff;
  --cell: #2c73ff;
  --cell-glow: rgba(44, 115, 255, 0.3);
  --danger: #d92d20;
  --focus: #7aa3ff;
  --shadow: 0 10px 30px rgba(16, 32, 58, 0.08);
}

[data-theme="dark"] {
  --bg: #0d1420;
  --panel: #111c2d;
  --panel-muted: #182538;
  --text: #e6eefc;
  --muted: #a8b6ce;
  --primary: #6aa8ff;
  --primary-hover: #82b7ff;
  --border: #24354f;
  --canvas-bg: #0b1220;
  --cell: #7fb0ff;
  --cell-glow: rgba(127, 176, 255, 0.35);
  --danger: #ff6b6b;
  --focus: #9fc0ff;
  --shadow: 0 12px 30px rgba(0, 0, 0, 0.35);
}

*,
*::before,
*::after {
  box-sizing: border-box;
}

body {
  margin: 0;
  background: radial-gradient(circle at 20% 0%, #dbe8ff33 0%, transparent 35%), var(--bg);
  color: var(--text);
  font-family:
    Inter,
    system-ui,
    -apple-system,
    "Segoe UI",
    Roboto,
    "Helvetica Neue",
    Arial,
    sans-serif;
  line-height: 1.5;
}

.app-header,
.app-footer {
  width: min(1280px, 94vw);
  margin-inline: auto;
}

.app-header {
  padding: 1.2rem 0 0.6rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
}

.app-header h1 {
  margin: 0;
  font-size: clamp(1.5rem, 2.2vw, 2rem);
  letter-spacing: -0.02em;
}

.subtitle {
  margin: 0.25rem 0 0;
  color: var(--muted);
  font-size: 0.95rem;
}

.app-layout {
  width: min(1280px, 94vw);
  margin: 0 auto;
  display: grid;
  grid-template-columns: 280px 1fr 320px;
  gap: 1rem;
  align-items: start;
}

.panel {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 14px;
  box-shadow: var(--shadow);
  padding: 1rem;
}

.panel h2 {
  margin: 0 0 0.75rem;
  font-size: 1rem;
  letter-spacing: 0.01em;
}

.canvas-panel {
  min-width: 0;
}

.canvas-header {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 0.75rem;
}

.canvas-container {
  background: var(--canvas-bg);
  border: 1px solid var(--border);
  border-radius: 12px;
  overflow: hidden;
  margin-top: 0.75rem;
}

#life-canvas {
  display: block;
  width: 100%;
  height: auto;
  touch-action: none;
  image-rendering: pixelated;
  image-rendering: crisp-edges;
}

.row {
  display: flex;
  gap: 0.5rem;
}

.row.wrap {
  flex-wrap: wrap;
}

.field {
  margin-top: 0.85rem;
}

.field label {
  display: block;
  margin-bottom: 0.35rem;
  font-size: 0.92rem;
  color: var(--muted);
}

input[type="range"],
select,
textarea {
  width: 100%;
}

button,
select,
textarea,
input {
  font: inherit;
}

button {
  border: 1px solid transparent;
  background: var(--primary);
  color: #fff;
  border-radius: 10px;
  padding: 0.45rem 0.75rem;
  cursor: pointer;
  transition: 140ms ease;
}

button:hover {
  background: var(--primary-hover);
}

button.ghost {
  background: transparent;
  color: var(--text);
  border-color: var(--border);
}

button.ghost:hover {
  background: var(--panel-muted);
}

textarea,
select,
input[type="range"] {
  border: 1px solid var(--border);
  border-radius: 10px;
  background: var(--panel-muted);
  color: var(--text);
}

textarea {
  padding: 0.6rem;
  resize: vertical;
  min-height: 7rem;
}

.toggle {
  display: inline-flex;
  align-items: center;
  gap: 0.45rem;
  color: var(--text);
  font-size: 0.92rem;
}

.toggles {
  margin-top: 0.75rem;
}

.status-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 0.65rem;
  margin: 0;
}

.status-grid div {
  background: var(--panel-muted);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 0.55rem 0.65rem;
}

.status-grid dt {
  margin: 0;
  color: var(--muted);
  font-size: 0.8rem;
}

.status-grid dd {
  margin: 0.15rem 0 0;
  font-weight: 600;
}

.muted {
  margin: 0.6rem 0 0;
  color: var(--muted);
  font-size: 0.87rem;
}

details {
  background: var(--panel-muted);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 0.55rem 0.7rem;
  margin-bottom: 0.6rem;
}

summary {
  cursor: pointer;
  font-weight: 600;
}

ol {
  padding-left: 1.2rem;
}

.app-footer {
  padding: 1rem 0 1.5rem;
  color: var(--muted);
}

button:focus-visible,
select:focus-visible,
textarea:focus-visible,
input:focus-visible,
summary:focus-visible {
  outline: 2px solid var(--focus);
  outline-offset: 2px;
}

@media (max-width: 1120px) {
  .app-layout {
    grid-template-columns: 1fr;
  }

  .controls-panel {
    order: 1;
  }

  .canvas-panel {
    order: 2;
  }

  .side-panel {
    order: 3;
  }
}