:root {
  color-scheme: dark;
  --ink: #edf8ff;
  --muted: #91a8bb;
  --line: rgba(133, 199, 233, 0.2);
  --panel: #091624;
  --deep: #03080e;
  --cyan: #63e6e2;
  --focus: #fff36d;
  font-family:
    Inter,
    ui-sans-serif,
    system-ui,
    -apple-system,
    BlinkMacSystemFont,
    "Segoe UI",
    sans-serif;
}
* {
  box-sizing: border-box;
}
html {
  background: var(--deep);
  scroll-behavior: smooth;
}
body {
  margin: 0;
  color: var(--ink);
  background:
    radial-gradient(circle at 65% -10%, #12304c 0, transparent 42%), var(--deep);
  min-height: 100vh;
}
button,
input {
  font: inherit;
}
.skip-link {
  position: fixed;
  left: 1rem;
  top: 1rem;
  z-index: 10;
  transform: translateY(-180%);
  background: #fff;
  color: #000;
  padding: 0.7rem 1rem;
}
.skip-link:focus {
  transform: none;
}
.app-shell {
  width: min(1440px, 100%);
  margin: auto;
  padding: 0 clamp(1rem, 3vw, 3rem);
}
.topbar {
  min-height: 104px;
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  align-items: center;
  border-bottom: 1px solid var(--line);
}
.wordmark {
  justify-self: start;
  color: #f5f4f0;
  font-size: 1.02rem;
  font-weight: 350;
  letter-spacing: 0.17em;
  text-decoration: none;
  text-transform: uppercase;
  white-space: nowrap;
}
.wordmark span {
  font-weight: 800;
}
.title-lockup {
  text-align: center;
}
.eyebrow {
  margin: 0 0 0.4rem;
  color: var(--cyan);
  font:
    700 0.68rem/1.2 ui-monospace,
    SFMono-Regular,
    Consolas,
    monospace;
  letter-spacing: 0.18em;
}
.title-lockup h1 {
  margin: 0;
  font:
    500 clamp(1.35rem, 3vw, 2rem) / 1 Georgia,
    serif;
}
.icon-link {
  justify-self: end;
  display: grid;
  place-items: center;
  width: 42px;
  height: 42px;
  border: 1px solid var(--line);
  color: var(--ink);
  font-size: 1.55rem;
  text-decoration: none;
}
.intro {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 2rem;
  align-items: end;
  padding: clamp(2.5rem, 6vw, 5rem) 0;
}
.intro h2,
.about-grid h2 {
  margin: 0;
  font:
    500 clamp(1.8rem, 4vw, 3.5rem) / 1.02 Georgia,
    serif;
}
.intro > p {
  max-width: 38rem;
  margin: 0;
  color: var(--muted);
  font-size: clamp(1rem, 1.6vw, 1.25rem);
  line-height: 1.6;
}
.simulation-panel {
  border: 1px solid var(--line);
  background: rgba(9, 22, 36, 0.82);
  padding: clamp(1rem, 2vw, 1.6rem);
  box-shadow: 0 30px 80px rgba(0, 0, 0, 0.3);
}
.panel-heading {
  display: flex;
  justify-content: space-between;
  align-items: end;
  gap: 1rem;
  padding: 0.25rem 0 1rem;
}
.panel-heading h2 {
  margin: 0;
  font:
    500 1.35rem Georgia,
    serif;
}
.readout {
  display: flex;
  gap: 1.5rem;
  color: var(--muted);
  font:
    600 0.67rem ui-monospace,
    monospace;
  text-transform: uppercase;
  letter-spacing: 0.1em;
}
.readout b {
  display: block;
  color: var(--ink);
  font-size: 1rem;
  text-align: right;
}
.canvas-frame {
  position: relative;
  width: min(100%, 960px);
  aspect-ratio: 1;
  margin-inline: auto;
  background: #02070c;
  overflow: hidden;
  border: 1px solid var(--line);
  touch-action: pinch-zoom;
}
.canvas-frame::before {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background: radial-gradient(
    circle at center,
    rgba(35, 94, 122, 0.16),
    transparent 60%
  );
  z-index: 1;
}
canvas {
  display: block;
  width: 100%;
  height: 100%;
  position: relative;
  z-index: 2;
  cursor: crosshair;
  touch-action: pinch-zoom;
}
canvas:focus-visible {
  outline: 4px solid var(--focus);
  outline-offset: -5px;
  box-shadow: inset 0 0 0 9px rgba(255, 243, 109, 0.18);
}
canvas.cell-cursor-active:focus-visible {
  outline: 0;
  box-shadow: none;
}
.controls {
  display: flex;
  align-items: center;
  gap: 0.65rem;
  padding-top: 1rem;
  flex-wrap: wrap;
}
.controls button {
  min-height: 44px;
  border: 1px solid var(--line);
  background: transparent;
  color: var(--ink);
  padding: 0.65rem 1rem;
  cursor: pointer;
  text-transform: uppercase;
  font:
    700 0.72rem ui-monospace,
    monospace;
  letter-spacing: 0.08em;
}
.controls button:hover {
  border-color: var(--cyan);
  color: var(--cyan);
}
.controls .primary {
  background: var(--cyan);
  border-color: var(--cyan);
  color: #031116;
  min-width: 110px;
}
.controls .primary:hover {
  color: #031116;
}
.controls label {
  margin-left: auto;
  display: flex;
  align-items: center;
  gap: 0.65rem;
  color: var(--muted);
  font:
    700 0.68rem ui-monospace,
    monospace;
  text-transform: uppercase;
  letter-spacing: 0.09em;
}
.controls input {
  accent-color: var(--cyan);
  width: min(220px, 26vw);
}
.controls output {
  min-width: 62px;
  color: var(--ink);
  text-transform: none;
}
.status,
.keyboard-help {
  color: var(--muted);
  font-size: 0.78rem;
}
.keyboard-help {
  margin-bottom: 0;
}
kbd {
  border: 1px solid var(--line);
  border-radius: 3px;
  padding: 0.12rem 0.28rem;
  color: var(--ink);
  background: #06101a;
}
.about-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
  margin: clamp(3rem, 7vw, 6rem) 0;
}
.about-grid article {
  background: var(--deep);
  padding: clamp(1.5rem, 4vw, 3.5rem);
}
.about-grid h2 {
  font-size: clamp(1.6rem, 3vw, 2.7rem);
  margin-bottom: 1.4rem;
}
.about-grid p,
.about-grid li {
  color: var(--muted);
  line-height: 1.65;
}
.about-grid ol {
  padding-left: 1.25rem;
  margin: 0;
}
.about-grid li + li {
  margin-top: 0.5rem;
}
footer {
  min-height: 100px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  border-top: 1px solid var(--line);
  color: var(--muted);
  font-size: 0.75rem;
}
footer nav {
  display: flex;
  gap: 1.2rem;
}
footer a {
  color: var(--ink);
}
:focus-visible {
  outline: 3px solid var(--focus);
  outline-offset: 3px;
}
@media (max-width: 720px) {
  .topbar {
    grid-template-columns: auto 1fr auto;
  }
  .title-lockup .eyebrow {
    display: none;
  }
  .intro,
  .about-grid {
    grid-template-columns: 1fr;
  }
  .intro {
    align-items: start;
  }
  .panel-heading {
    align-items: start;
  }
  .readout {
    gap: 0.7rem;
  }
  .title-lockup {
    display: none;
  }
  .topbar {
    grid-template-columns: 1fr auto;
  }
  .controls label {
    width: 100%;
    margin: 0.4rem 0 0;
  }
  .controls input {
    flex: 1;
    width: auto;
  }
  .keyboard-help {
    display: none;
  }
  footer {
    align-items: flex-start;
    padding: 1.5rem 0;
    gap: 1rem;
  }
  footer nav {
    flex-wrap: wrap;
    justify-content: flex-end;
  }
}
@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }
  * {
    animation: none !important;
    transition: none !important;
  }
}
@media (forced-colors: active) {
  .canvas-frame,
  button,
  .icon-link {
    border: 1px solid CanvasText;
  }
  .primary {
    forced-color-adjust: none;
  }
  canvas {
    border: 1px solid CanvasText;
  }
}