:root {
  color-scheme: dark;
  --bg: #07111a;
  --panel: #0b1721;
  --panel-2: #10212d;
  --line: #213744;
  --muted: #91a6b3;
  --text: #eef8fb;
  --accent: #72e4ff;
  --accent-ink: #031116;
  --danger: #ff8f8f;
  --shadow: 0 18px 60px rgba(0, 0, 0, 0.38);
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
}

* { box-sizing: border-box; }
html, body { width: 100%; height: 100%; margin: 0; overflow: hidden; background: var(--bg); color: var(--text); }
button, input, select { font: inherit; }
button, select, input { color: inherit; }

.app-shell { position: relative; display: grid; grid-template-columns: 328px minmax(0, 1fr); width: 100%; height: 100%; height: 100dvh; }
.controls {
  overflow-y: auto;
  overscroll-behavior: contain;
  padding: 22px 20px 28px;
  background: linear-gradient(180deg, #0d1a24 0%, #09141d 100%);
  border-right: 1px solid var(--line);
  scrollbar-width: thin;
  z-index: 5;
}
.brand { display: flex; align-items: flex-start; justify-content: space-between; gap: 16px; }
.eyebrow { margin: 0 0 5px; color: var(--accent); font-size: 0.68rem; font-weight: 800; letter-spacing: 0.15em; }
h1 { margin: 0; font-size: 2rem; line-height: 1; letter-spacing: -0.045em; }
.lede { margin: 14px 0 18px; color: var(--muted); line-height: 1.45; font-size: 0.91rem; }
section { padding: 17px 0 13px; border-top: 1px solid var(--line); }
section h2 { margin: 0 0 12px; color: #cfe2e9; font-size: 0.74rem; text-transform: uppercase; letter-spacing: 0.11em; }
.section-title { display: flex; align-items: center; justify-content: space-between; gap: 10px; }

button {
  min-height: 36px;
  padding: 7px 10px;
  border: 1px solid #2b4655;
  border-radius: 8px;
  background: #132632;
  cursor: pointer;
  transition: border-color 120ms ease, background 120ms ease, transform 80ms ease;
}
button:hover { background: #19313f; border-color: #477083; }
button:active { transform: translateY(1px); }
button.primary { background: var(--accent); border-color: var(--accent); color: var(--accent-ink); font-weight: 800; }
button.primary:hover { filter: brightness(1.08); }
button.running { background: #ffcf66; border-color: #ffcf66; color: #241802; }
button.compact { min-height: 34px; padding-inline: 11px; white-space: nowrap; }
button:disabled { opacity: 0.45; cursor: not-allowed; }
.info-button {
  width: 28px;
  min-height: 28px;
  padding: 0;
  border-radius: 50%;
  color: var(--accent);
  font-size: 0.88rem;
  font-weight: 800;
  line-height: 1;
  text-transform: none;
  letter-spacing: 0;
}

.button-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 8px; }
.wide-button { width: 100%; margin-bottom: 9px; }
.about-button { width: 100%; min-height: 44px; margin-top: 8px; }
.discovery-actions { margin-bottom: 9px; }
.discovery-note { margin: 0; color: var(--muted); font-size: 0.8rem; line-height: 1.45; }
.discovery-provenance { margin: 8px 0 0; color: var(--muted); font-size: 0.76rem; line-height: 1.45; overflow-wrap: anywhere; }
.discovery-provenance strong { font-weight: 600; }
.discovery-source-links { display: block; margin-top: 4px; }
.discovery-source-links a { color: var(--accent); text-underline-offset: 2px; }
.discovery-source-links a:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; }
.primary-actions { margin: 5px 0 18px; }
.field { display: grid; gap: 6px; margin: 0 0 11px; font-size: 0.86rem; }
.field > span, .range-field > span { display: flex; justify-content: space-between; gap: 12px; color: #d5e4e9; }
.field small { color: var(--muted); line-height: 1.35; }
.inline-control { display: grid; grid-template-columns: minmax(0, 1fr) auto; gap: 7px; }
input[type="text"], input[type="search"], input[type="number"], select {
  width: 100%;
  min-height: 35px;
  padding: 7px 9px;
  border: 1px solid #294352;
  border-radius: 7px;
  outline: none;
  background: #091721;
}
input[type="text"]:focus, input[type="search"]:focus, input[type="number"]:focus, select:focus { border-color: var(--accent); box-shadow: 0 0 0 2px rgba(114, 228, 255, 0.12); }
#snapshotStatus.error { color: var(--danger); }
input.invalid { border-color: var(--danger); box-shadow: 0 0 0 2px rgba(255, 143, 143, 0.12); }
input[type="range"] { width: 100%; accent-color: var(--accent); }
output { color: var(--accent); font-variant-numeric: tabular-nums; }
.check-field { display: flex; align-items: center; gap: 9px; margin: 0 0 12px; color: #d5e4e9; font-size: 0.86rem; }
.check-field input { accent-color: var(--accent); }

.stats { display: grid; grid-template-columns: 1fr 1fr; gap: 7px 14px; margin: 0; }
.stats div { min-width: 0; }
.stats dt { color: var(--muted); font-size: 0.72rem; }
.stats dd { margin: 2px 0 0; font-size: 0.9rem; font-variant-numeric: tabular-nums; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.footer-note { margin: 12px 0 0; color: #6f8794; font-size: 0.72rem; line-height: 1.5; }

.stage { position: relative; min-width: 0; min-height: 0; overflow: hidden; background: var(--bg); }
#lifeCanvas { display: block; width: 100%; height: 100%; touch-action: none; cursor: crosshair; }
#lifeCanvas:focus-visible { outline: 2px solid var(--accent); outline-offset: -3px; }
.sr-only { position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px; overflow: hidden; clip-path: inset(50%); white-space: nowrap; border: 0; }
#lifeCanvas.pan-tool { cursor: grab; }
#lifeCanvas.dragging { cursor: grabbing; }
.busy {
  position: absolute;
  left: 50%; top: 50%;
  transform: translate(-50%, -50%);
  display: grid;
  justify-items: center;
  gap: 9px;
  width: min(310px, calc(100% - 40px));
  padding: 24px;
  border: 1px solid #274453;
  border-radius: 14px;
  background: rgba(9, 23, 33, 0.94);
  box-shadow: var(--shadow);
  text-align: center;
  z-index: 4;
}
.busy[hidden], .toast[hidden] { display: none; }
.busy span { color: var(--muted); font-size: 0.86rem; }
.spinner { width: 28px; height: 28px; border: 3px solid #23404f; border-top-color: var(--accent); border-radius: 50%; animation: spin 0.8s linear infinite; }
@keyframes spin { to { transform: rotate(360deg); } }
.toast {
  position: absolute;
  left: 50%; bottom: 34px;
  transform: translateX(-50%);
  max-width: min(420px, calc(100% - 32px));
  padding: 10px 14px;
  border: 1px solid #315062;
  border-radius: 9px;
  background: rgba(11, 27, 38, 0.95);
  box-shadow: var(--shadow);
  color: #eaf8fb;
  font-size: 0.84rem;
  text-align: center;
  z-index: 6;
}
.canvas-hint { position: absolute; right: 14px; bottom: 10px; color: rgba(195, 218, 225, 0.5); font-size: 0.72rem; pointer-events: none; }

.icon-button { min-width: 36px; padding: 0; font-size: 1.5rem; line-height: 1; }
.stage-actions {
  position: absolute;
  top: calc(12px + env(safe-area-inset-top, 0px));
  left: calc(12px + env(safe-area-inset-left, 0px));
  right: calc(12px + env(safe-area-inset-right, 0px));
  display: flex;
  align-items: center;
  justify-content: flex-end;
  gap: 12px;
  z-index: 7;
  pointer-events: none;
}
.stage-actions button { min-height: 44px; box-shadow: var(--shadow); pointer-events: auto; touch-action: manipulation; }
.menu-button { margin-right: auto; }
.viewport-run { min-width: 100px; font-weight: 800; }
.mobile-only { display: none; }

dialog {
  width: min(560px, calc(100% - 32px));
  padding: 0;
  border: 1px solid #315061;
  border-radius: 14px;
  background: #0c1a24;
  color: var(--text);
  box-shadow: var(--shadow);
}
dialog::backdrop { background: rgba(0, 0, 0, 0.62); backdrop-filter: blur(3px); }
dialog form { position: relative; padding: 25px; }
dialog h2 { margin: 0 0 14px; font-size: 1.5rem; }
dialog p { color: #b9ccd4; line-height: 1.55; }
dialog code { color: var(--accent); }
.dialog-close { position: absolute; right: 14px; top: 14px; width: 36px; min-height: 36px; padding: 0; font-size: 1.4rem; }
.about-dialog { width: min(680px, calc(100% - 32px)); max-height: calc(100% - 32px); max-height: calc(100dvh - 32px); }
.about-dialog form { max-height: inherit; overflow-y: auto; overscroll-behavior: contain; }
.about-dialog h2 { padding-right: 40px; }
.about-dialog button { min-height: 44px; }
.about-dialog .dialog-close { width: 44px; min-height: 44px; }
.about-dialog a { color: var(--accent); text-underline-offset: 3px; }
.about-dialog a:focus-visible { outline: 2px solid var(--accent); outline-offset: 4px; }
.about-dialog .release-details { margin-top: -6px; color: var(--muted); font-size: 0.9rem; }
.about-catalogue { margin: 20px 0; padding: 18px; border: 1px solid #315061; border-radius: 9px; background: #10232f; }
.about-catalogue h3 { margin: 0 0 8px; font-size: 1.05rem; }
.about-catalogue p { margin: 0 0 12px; }
.about-catalogue p:last-child { margin-bottom: 0; }
.catalogue-links a { display: inline-block; padding: 7px 0; }
.catalogue-pdf-link { font-weight: 800; }
.about-catalogue .catalogue-offline-note { font-size: 0.85rem; }
.rules-dialog { width: min(680px, calc(100% - 32px)); max-height: min(820px, calc(100% - 32px)); }
.rules-dialog form { max-height: inherit; overflow-y: auto; overscroll-behavior: contain; }
.rules-dialog section { padding: 15px 0 4px; border-top: 1px solid var(--line); }
.rules-dialog h3 { margin: 0 0 8px; color: #dcecf1; font-size: 1rem; }
.rules-dialog p { margin: 0 0 13px; }
.state-transitions { display: grid; gap: 8px; margin: 0 0 13px; }
.state-transitions div { display: grid; grid-template-columns: 108px minmax(0, 1fr); gap: 12px; }
.state-transitions dt { color: #dcecf1; font-weight: 750; }
.state-transitions dd { margin: 0; color: #b9ccd4; line-height: 1.48; }
.rule-example { margin: 12px 0 20px; padding: 14px 15px 2px; border: 1px solid #315061; border-radius: 9px; background: #10232f; }

@media (max-width: 520px) {
  .state-transitions div { grid-template-columns: 1fr; gap: 3px; }
}

@media (max-width: 780px) {
  .app-shell { display: block; }
  .controls {
    position: absolute;
    /* Leave the playback strip accessible even with the drawer open. */
    inset: calc(68px + env(safe-area-inset-top, 0px)) auto 0 0;
    width: min(340px, calc(100% - 42px));
    padding-left: max(20px, env(safe-area-inset-left, 0px));
    padding-bottom: calc(28px + env(safe-area-inset-bottom, 0px));
    box-shadow: var(--shadow);
    transform: translateX(-105%);
    visibility: hidden;
    transition: transform 180ms ease;
  }
  .controls.open { transform: translateX(0); visibility: visible; }
  .mobile-only { display: inline-flex; align-items: center; justify-content: center; }
  .stage { width: 100%; height: 100%; }
  .canvas-hint { display: none; }
}