:root {
  --bg: #071019;
  --surface: rgba(10, 24, 36, 0.78);
  --surface-strong: rgba(13, 30, 45, 0.92);
  --panel: rgba(16, 35, 52, 0.84);
  --border: rgba(129, 170, 199, 0.16);
  --text: #eff8ff;
  --muted: #8fb0c5;
  --accent: #ff9d4d;
  --accent-2: #ffd166;
  --shadow: 0 20px 60px rgba(0, 0, 0, 0.32);
}

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

html,
body {
  margin: 0;
  min-height: 100%;
}

body {
  font-family: "Space Grotesk", sans-serif;
  color: var(--text);
  background:
    radial-gradient(circle at top left, rgba(255, 157, 77, 0.18), transparent 24%),
    radial-gradient(circle at 80% 0%, rgba(83, 176, 255, 0.18), transparent 22%),
    linear-gradient(180deg, #071019 0%, #091520 45%, #061018 100%);
}

a {
  color: inherit;
}

.topbar,
.hero,
.viewer-shell,
.sidebar,
.gallery-header,
.source-header,
.source-card {
  -webkit-backdrop-filter: blur(14px);
  backdrop-filter: blur(14px);
}

.topbar {
  position: sticky;
  top: 0;
  z-index: 3;
  display: flex;
  justify-content: space-between;
  gap: 16px;
  align-items: center;
  padding: 18px 24px;
  background: rgba(7, 16, 25, 0.86);
  border-bottom: 1px solid var(--border);
}

.topbar h1 {
  margin: 0;
  font-size: clamp(1.6rem, 2vw, 2.2rem);
}

.eyebrow {
  margin: 0 0 4px;
  color: var(--accent-2);
  text-transform: uppercase;
  letter-spacing: 0.18em;
  font-size: 0.72rem;
}

.tab-nav {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
}

.tab,
button,
select,
input[type="number"] {
  font: inherit;
  color: var(--text);
  background: rgba(19, 39, 57, 0.88);
  border: 1px solid var(--border);
  border-radius: 999px;
}

.tab,
button,
select {
  cursor: pointer;
  padding: 10px 14px;
}

.tab.active,
.accent-btn {
  background: linear-gradient(135deg, #9e4d19, #ff9d4d);
  border-color: rgba(255, 209, 102, 0.6);
  color: #fff9f1;
}

main {
  padding: 18px;
}

.hero {
  margin-bottom: 18px;
  padding: 18px 20px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 24px;
  box-shadow: var(--shadow);
}

.hero p {
  margin: 0;
}

.hero-note {
  margin-top: 8px !important;
  color: var(--muted);
}

.panel-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 320px;
  gap: 18px;
}

.viewer-shell,
.sidebar,
.gallery-panel,
.source-panel {
  border: 1px solid var(--border);
  border-radius: 24px;
  box-shadow: var(--shadow);
}

.viewer-shell {
  background: var(--surface);
  overflow: hidden;
}

.sidebar,
.gallery-panel,
.source-panel {
  background: var(--surface-strong);
}

.rule-bar,
.actions,
.gallery-header,
.source-header {
  padding: 16px 18px;
  border-bottom: 1px solid var(--border);
}

.actions {
  border-top: 1px solid var(--border);
  border-bottom: 0;
  display: flex;
  gap: 10px;
  flex-wrap: wrap;
}

.rule-bar {
  display: flex;
  align-items: center;
  gap: 10px;
  flex-wrap: wrap;
}

.rule-label,
.ctrl-title,
.muted,
.rule-class {
  color: var(--muted);
}

.rule-number {
  min-width: 44px;
  font-size: 2rem;
  font-weight: 700;
  color: var(--accent-2);
}

#rule-slider {
  flex: 1;
  min-width: 140px;
  accent-color: var(--accent);
}

#rule-number {
  width: 74px;
  padding: 10px 12px;
}

.rule-class {
  margin-left: auto;
}

.rule-diagram {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  justify-content: center;
  padding: 18px;
  border-bottom: 1px solid var(--border);
}

.pattern-block {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 6px;
}

.pattern-label {
  font-family: "IBM Plex Mono", monospace;
  font-size: 0.72rem;
  color: var(--muted);
}

.neighborhood {
  display: flex;
  gap: 2px;
}

.diagram-cell {
  width: 16px;
  height: 16px;
  border-radius: 4px;
  background: rgba(255, 255, 255, 0.1);
}

.diagram-cell.alive {
  background: var(--accent-2);
}

.diagram-cell.dead {
  background: rgba(59, 91, 116, 0.42);
  border: 1px solid rgba(255, 255, 255, 0.08);
}

.output-cell {
  cursor: pointer;
}

.canvas-card {
  padding: 18px;
}

#main-canvas {
  display: block;
  width: 100%;
  aspect-ratio: 5 / 3;
  border-radius: 20px;
  background: #04080c;
  image-rendering: pixelated;
}

.sidebar {
  padding: 8px 0;
}

.ctrl-section {
  padding: 16px 18px;
  border-bottom: 1px solid var(--border);
}

.ctrl-section:last-child {
  border-bottom: 0;
}

.ctrl-title {
  margin: 0 0 12px;
  font-size: 0.78rem;
  text-transform: uppercase;
  letter-spacing: 0.14em;
}

.ctrl-row,
.checkbox-row,
.stack label {
  display: flex;
  align-items: center;
  gap: 10px;
}

.ctrl-row {
  margin-bottom: 10px;
}

.ctrl-row:last-child {
  margin-bottom: 0;
}

.stack {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.stack.compact {
  gap: 8px;
}

.pill-group {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.pill-group label,
.checkbox-row {
  padding: 9px 12px;
  border-radius: 999px;
  border: 1px solid var(--border);
  background: var(--panel);
}

.pill-group input[type="radio"] {
  display: none;
}

.pill-group label:has(input:checked) {
  background: rgba(140, 71, 22, 0.75);
  border-color: rgba(255, 209, 102, 0.48);
}

input[type="range"] {
  flex: 1;
  accent-color: var(--accent);
}

input[type="color"] {
  width: 46px;
  height: 34px;
  padding: 2px;
  border-radius: 10px;
  border: 1px solid var(--border);
  background: rgba(18, 38, 55, 0.9);
}

.value-badge {
  min-width: 42px;
  text-align: right;
  color: var(--accent-2);
  font-weight: 700;
}

.ghost-btn {
  background: rgba(18, 38, 55, 0.9);
}

.color-stop {
  display: flex;
  align-items: center;
  gap: 8px;
}

.gallery-panel,
.source-panel {
  overflow: hidden;
}

.gallery-header p,
.source-header p {
  margin: 0;
  color: var(--muted);
}

.gallery-grid,
.source-list {
  display: grid;
  gap: 12px;
  padding: 18px;
}

.gallery-grid {
  grid-template-columns: repeat(auto-fill, minmax(150px, 1fr));
}

.gallery-item,
.source-card {
  border: 1px solid var(--border);
  border-radius: 18px;
  background: rgba(13, 30, 45, 0.88);
}

.gallery-item {
  overflow: hidden;
  cursor: pointer;
}

.gallery-thumb {
  display: block;
  width: 100%;
  aspect-ratio: 1;
  background: #061018;
}

.gallery-label {
  padding: 10px 12px 12px;
}

.gallery-label strong {
  display: block;
  margin-bottom: 4px;
}

.gallery-label span {
  color: var(--muted);
  font-size: 0.86rem;
}

.source-stack {
  display: grid;
  gap: 18px;
  padding: 18px;
}

.source-group {
  display: grid;
  gap: 12px;
}

.source-group-title {
  margin: 0;
  padding: 0 2px;
  color: var(--accent-2);
  font-size: 0.92rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.source-list {
  padding: 0;
}

.source-card {
  padding: 16px 18px;
  min-width: 0;
}

.source-card h4 {
  margin: 0 0 8px;
  min-width: 0;
}

.source-card p {
  margin: 0;
  color: var(--muted);
}

.filename-pill {
  display: inline-flex;
  max-width: 100%;
  padding: 6px 10px;
  border-radius: 14px;
  font-family: "IBM Plex Mono", monospace;
  font-size: 0.92rem;
  line-height: 1.45;
  color: var(--accent-2);
  background: rgba(140, 71, 22, 0.28);
  border: 1px solid rgba(255, 209, 102, 0.34);
  white-space: normal;
  overflow-wrap: anywhere;
  word-break: break-word;
}

.source-card-link {
  padding: 0;
}

.source-card-link h4 {
  margin: 0;
}

.source-card-link a {
  display: block;
  padding: 16px 18px;
  color: var(--text);
  text-decoration: underline;
  text-decoration-color: rgba(255, 209, 102, 0.7);
  text-underline-offset: 3px;
  transition: color 120ms ease, background 120ms ease, border-color 120ms ease;
}

.source-card-link a::after {
  content: " ->";
  color: var(--accent-2);
}

.source-card-link p {
  padding: 0 18px 16px;
}

.source-card-link:hover,
.source-card-link:focus-within {
  border-color: rgba(255, 209, 102, 0.42);
  background: rgba(20, 42, 62, 0.95);
}

.source-card-link a:hover,
.source-card-link a:focus-visible {
  color: var(--accent-2);
}

@media (min-width: 900px) {
  .source-list {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

[hidden] {
  display: none !important;
}

@media (max-width: 940px) {
  .panel-grid {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 640px) {
  .topbar {
    flex-direction: column;
    align-items: flex-start;
  }

  main {
    padding: 12px;
  }

  .rule-bar {
    padding: 14px;
  }
}