:root {
  color-scheme: light;
  color-scheme: only light;
  --page: #ffffff;
  --surface: #fafafa;
  --section: #f5f5f5;
  --raised: #ededed;
  --text: #151515;
  --muted: #484848;
  --dim: #626262;
  --accent: #252525;
  --accent-strong: #101010;
  --rule: #cfcfcf;
  --mono: ui-monospace, "SFMono-Regular", Menlo, Consolas, monospace;
  --sans: "Arial Black", Arial, sans-serif;
  --columns: 1120px;
  --masthead: 60px;
  --fine-grid: radial-gradient(circle at 1px 1px, #666666 0.7px, transparent 1px);
  font-family: var(--mono);
  font-size: 16px;
  background: var(--page);
  color: var(--text);
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body { margin: 0; min-width: 0; }
body::selection { background: var(--accent); color: var(--page); }
a { color: inherit; }
a, button, summary { -webkit-tap-highlight-color: transparent; }
:focus-visible { outline: 3px solid var(--accent-strong); outline-offset: 5px; }
[hidden] { display: none !important; }

.shell { width: min(var(--columns), calc(100% - 56px)); margin-inline: auto; }
.skip-link {
  position: fixed;
  z-index: 10;
  inset: 10px auto auto 10px;
  transform: translateY(-160%);
  padding: 12px 16px;
  background: var(--text);
  color: var(--page);
}
.skip-link:focus { transform: translateY(0); }

.site-header, .hero {
  --page: #101010;
  --text: #f5f5f5;
  --muted: #c7c7c7;
  --dim: #a3a3a3;
  --accent: #dedede;
  --accent-strong: #ffffff;
  --rule: #353535;
  background: var(--page);
  color: var(--text);
}
.site-header {
  position: relative;
  z-index: 1;
  border-bottom: 1px solid var(--rule);
}
.site-header::before, .site-footer::before {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background: var(--fine-grid) 0 0 / 6px 6px;
  opacity: 0.22;
  mask-image: linear-gradient(90deg, black, transparent 30%, transparent 70%, black);
}
.nav, .footer-inner, .nav-end { display: flex; align-items: center; }
.nav, .footer-inner { position: relative; min-height: var(--masthead); justify-content: space-between; gap: 18px; }
.nav-end { gap: clamp(12px, 4vw, 32px); }
.wordmark {
  display: inline-flex;
  align-items: center;
  gap: 7px;
  min-height: 44px;
  color: var(--text);
  font-size: 1.13rem;
  font-weight: 900;
  line-height: 1;
  text-decoration: none;
  white-space: nowrap;
}
.wordmark-nxt { color: var(--accent); }
.wordmark-year { color: var(--dim); font-size: .67rem; font-weight: 500; }
.brand-signal { width: 14px; height: 14px; background: var(--fine-grid) 0 0 / 4px 4px; }
.nav-link, .back-top {
  display: inline-flex;
  align-items: center;
  min-height: 44px;
  gap: 6px;
  color: var(--text);
  font-size: .72rem;
  text-decoration: none;
  text-transform: uppercase;
}
.nav-link:hover, .back-top:hover { color: var(--accent-strong); text-decoration: underline; text-underline-offset: 4px; }
.draft { color: var(--muted); font-size: .66rem; letter-spacing: .04em; white-space: nowrap; text-transform: uppercase; }
.draft span { color: var(--accent); }

.hero { isolation: isolate; overflow: hidden; position: relative; border-bottom: 1px solid var(--rule); }
.hero-art { position: absolute; z-index: -1; inset: 0; overflow: hidden; pointer-events: none; }
.hero-art canvas, .field-fallback { position: absolute; inset: 0; width: 100%; height: 100%; }
.hero-art::after {
  content: "";
  position: absolute;
  inset: 0;
  background:
    linear-gradient(180deg, var(--page) 0%, transparent 10%, transparent 83%, var(--page) 100%),
    radial-gradient(ellipse at 50% 49%, #101010f5 0%, #101010eb 26%, #10101042 52%, transparent 73%);
}
.field-fallback {
  background: var(--fine-grid) 0 0 / 5px 6px;
  mask-image: radial-gradient(ellipse at center, transparent 28%, #0007 34%, black 44%, black 51%, transparent 68%);
}
.has-canvas .field-fallback { opacity: .37; }
.hero-shell {
  position: relative;
  min-height: max(660px, calc(100svh - var(--masthead)));
  display: grid;
  grid-template-rows: minmax(0, 1fr) auto;
}
.hero-copy {
  width: min(100%, 720px);
  align-self: center;
  justify-self: center;
  text-align: center;
  padding: 70px 0 82px;
}
.field-coordinate, .field-sweep {
  position: absolute;
  color: var(--dim);
  font-size: .68rem;
  line-height: 1.55;
  letter-spacing: .05em;
  pointer-events: none;
}
.field-coordinate span { color: var(--accent); }
.field-coordinate-top { top: 26px; left: 0; }
.field-coordinate-right { top: 26px; right: 0; text-align: right; }
.field-sweep { bottom: 112px; left: 0; font-size: .61rem; white-space: nowrap; }
.brand-lockup {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 12px;
  width: max-content;
  max-width: 100%;
  margin: 0 auto 24px;
}
.brand-mark {
  display: flex;
  width: clamp(106px, 29vw, 195px);
  height: clamp(68px, 13vw, 98px);
  align-items: center;
  justify-content: center;
}
.brand-mark img { display: block; width: 100%; height: 100%; object-fit: contain; transform: scale(1.17); }
.brand-mark-kd img { transform: scale(1.62); }
.partnership-cross { color: var(--accent); font-size: 1.25rem; }
.eyebrow { margin: 0; color: var(--accent-strong); font-size: .75rem; font-weight: 650; letter-spacing: .09em; line-height: 1.5; text-transform: uppercase; }
.hero-eyebrow { color: var(--muted); }
.hero-eyebrow > span:not(.signal-pip) { color: var(--accent); }
.signal-pip { display: inline-block; width: 7px; height: 7px; margin-right: 5px; background: var(--accent); vertical-align: 1px; }
.hero h1 {
  position: relative;
  display: grid;
  place-items: center;
  min-height: clamp(54px, 9.63vw, 130px);
  margin: 8px 0 9px;
}
.hero-title-text, .queue-simulator-live {
  position: absolute;
  width: 1px;
  height: 1px;
  overflow: hidden;
  clip-path: inset(50%);
  white-space: nowrap;
}
.hero-wordmark {
  display: block;
  width: min(100%, clamp(13.2rem, 42vw, 33rem));
  height: auto;
  fill: var(--text);
}
.hero-wordmark-event { fill: var(--accent); }
.hero-description { width: min(100%, 40ch); margin: 22px auto 18px; color: var(--text); font-size: clamp(.83rem, 1.4vw, 1rem); line-height: 1.65; }
.hero-cta {
  display: inline-flex;
  align-items: center;
  min-height: 47px;
  padding: 0 15px;
  gap: 13px;
  border: 1px solid var(--accent);
  background: var(--accent);
  color: var(--page);
  font-size: .77rem;
  font-weight: 700;
  text-decoration: none;
}
.hero-cta:hover { background: var(--text); border-color: var(--text); }
.hero-cta span { font-size: 1.08rem; }

.field-controls { position: absolute; z-index: 2; right: 0; bottom: 102px; display: flex; align-items: center; gap: 10px; }
.field-caption { color: var(--dim); font-size: .62rem; }
.motion-button {
  display: inline-flex;
  align-items: center;
  min-height: 44px;
  gap: 6px;
  padding: 0 9px;
  border: 1px solid var(--rule);
  background: var(--page);
  color: var(--muted);
  font: 600 .65rem var(--mono);
  text-transform: uppercase;
  cursor: pointer;
}
.motion-button:hover { color: var(--text); border-color: var(--accent); }
.play-icon, .is-paused .pause-icon { display: none; }
.is-paused .play-icon { display: inline; }
.event-strip {
  display: grid;
  grid-template-columns: 1fr 1fr 1fr;
  margin: 0;
  border: 1px solid var(--rule);
  border-bottom: 0;
  background: var(--page);
}
.event-strip > div { min-height: 82px; padding: 15px 18px; display: grid; align-content: center; gap: 4px; }
.event-strip > div + div { border-left: 1px solid var(--rule); }
.event-strip dt { color: var(--accent-strong); font-size: .67rem; font-weight: 650; text-transform: uppercase; letter-spacing: .05em; }
.event-strip dd { margin: 0; color: var(--text); font-size: .94rem; font-weight: 700; }

.sprint-countdown {
  position: relative;
  isolation: isolate;
  padding: clamp(28px, 6vw, 72px) 0;
  border-bottom: 1px solid var(--rule);
  background: var(--section);
}
.sprint-countdown::before {
  content: "";
  position: absolute;
  z-index: -1;
  inset: 0;
  pointer-events: none;
  background: var(--fine-grid) 0 0 / 6px 6px;
  opacity: .34;
  mask-image: linear-gradient(100deg, black, transparent 25%, transparent 75%, black);
}
.countdown-header {
  display: flex;
  flex-wrap: wrap;
  align-items: flex-end;
  justify-content: space-between;
  gap: 12px 22px;
}
.countdown-header h2 {
  margin: 6px 0 0;
  font-family: var(--sans);
  font-size: clamp(2rem, 4.4vw, 4.4rem);
  font-weight: 900;
  letter-spacing: -.065em;
  line-height: .98;
}
.countdown-date { color: var(--muted); font-size: .82rem; }
.countdown-clock {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 1px;
  margin: clamp(15px, 3vw, 28px) 0 0;
  border: 1px solid var(--rule);
  background: var(--rule);
  text-align: center;
}
.countdown-clock > div {
  display: flex;
  flex-direction: column-reverse;
  gap: clamp(3px, 1vw, 9px);
  min-width: 0;
  padding: clamp(10px, 2vw, 23px) 3px;
  background: var(--surface);
}
.countdown-clock dt {
  color: var(--muted);
  font-size: clamp(.58rem, 1vw, .82rem);
  font-weight: 650;
  letter-spacing: .06em;
  text-transform: uppercase;
}
.countdown-clock dd {
  margin: 0;
  color: var(--accent-strong);
  font-size: clamp(1.65rem, 7.7vw, 6rem);
  font-variant-numeric: tabular-nums;
  font-weight: 800;
  line-height: .98;
}
.countdown-complete { margin: 14px 0 0; color: var(--accent-strong); font-size: .82rem; }

.challenges {
  position: relative;
  isolation: isolate;
  padding: clamp(60px, 9vw, 112px) 0 clamp(56px, 7vw, 90px);
  overflow: hidden;
  background: var(--page);
  scroll-margin-top: 0;
}
.challenges::before {
  content: "";
  position: absolute;
  z-index: -1;
  inset: 0;
  background: var(--fine-grid) 0 0 / 5px 5px;
  opacity: .46;
  mask-image: linear-gradient(116deg, black, transparent 29%, transparent 71%, black);
}
.challenges::after {
  content: ". : + * # % @ # * + : .";
  position: absolute;
  top: 20px;
  right: max(28px, calc((100% - var(--columns)) / 2));
  color: var(--dim);
  font: .65rem var(--mono);
  letter-spacing: .18em;
}
.section-head { display: grid; grid-template-columns: 1.45fr 1fr; align-items: end; gap: 24px; margin-bottom: 32px; }
.section-head h2 {
  margin: 6px 0 0;
  font-family: var(--sans);
  font-size: clamp(2.5rem, 6vw, 5.4rem);
  line-height: .93;
  font-weight: 900;
  letter-spacing: -.085em;
}
.section-aside { width: min(100%, 40ch); }
.section-aside p { margin: 0; color: var(--muted); font-size: .83rem; line-height: 1.7; }
.briefs { display: grid; gap: 9px; }
.brief {
  display: grid;
  grid-template-columns: 32px 82px minmax(0, 1fr) auto;
  align-items: center;
  gap: clamp(10px, 2vw, 21px);
  min-height: 110px;
  padding: 14px clamp(12px, 3vw, 30px);
  border: 1px solid var(--rule);
  background: var(--surface);
  text-decoration: none;
}
.brief:hover { border-color: var(--accent); background: var(--raised); }
.brief:focus-visible { outline-offset: -4px; }
.brief-index { align-self: start; color: var(--accent); font-size: .83rem; font-weight: 700; }
.brief-index span { color: var(--dim); }
.brief-ascii { color: var(--accent); font-size: .62rem; line-height: 1.11; white-space: pre; }
.brief-ascii span { display: block; }
.brief-labels { display: grid; gap: 5px; }
.brief-tag { color: var(--accent-strong); font-size: .65rem; letter-spacing: .025em; text-transform: uppercase; }
.brief-title { font-family: var(--sans); font-size: clamp(1.33rem, 3vw, 2.3rem); font-weight: 900; line-height: 1.02; letter-spacing: -.045em; }
.brief-teaser { color: var(--muted); font-size: .78rem; line-height: 1.5; }
.brief-toggle { display: flex; align-items: center; gap: 8px; color: var(--text); }
.toggle-copy { font-size: .67rem; text-transform: uppercase; white-space: nowrap; }
.brief-arrow {
  display: grid;
  width: 33px;
  height: 33px;
  place-items: center;
  border: 1px solid var(--rule);
  color: var(--accent);
  font: 700 1rem var(--mono);
}
.brief:hover .brief-arrow { border-color: var(--accent); }
.deliverable {
  display: flex;
  gap: 12px;
  margin-top: 28px;
  padding: 17px 18px;
  border-left: 3px solid var(--accent);
  background: var(--raised);
}
.deliverable-glyph { flex: none; color: var(--accent-strong); font-weight: 700; }
.deliverable p { margin: 0; color: var(--muted); font-size: .81rem; line-height: 1.6; }
.deliverable strong { color: var(--text); }

.site-footer { position: relative; border-top: 1px solid var(--rule); }
.footer-inner { min-height: 84px; }
.footer-inner p { margin: 0; color: var(--muted); font-size: .72rem; text-align: center; }

@media (max-width: 700px) {
  .shell { width: calc(100% - 36px); }
  .field-coordinate, .field-sweep, .field-caption { display: none; }
  .hero-shell { min-height: max(600px, calc(100svh - var(--masthead))); }
  .hero-copy { padding: 65px 0 93px; }
  .hero-art::after {
    background:
      linear-gradient(180deg, var(--page) 0%, transparent 16%, transparent 81%, var(--page) 100%),
      radial-gradient(ellipse at 50% 43%, #101010ea 0%, #101010e0 24%, #10101046 49%, transparent 72%);
  }
  .section-head { grid-template-columns: 1fr; gap: 12px; }
  .brief { grid-template-columns: 24px minmax(0, 1fr) auto; padding: 14px 12px; }
  .brief-ascii, .toggle-copy { display: none; }
}

@media (max-width: 455px) {
  :root { --masthead: 52px; }
  .shell { width: calc(100% - 28px); }
  .nav-end { gap: 10px; }
  .wordmark { gap: 5px; font-size: 1rem; }
  .wordmark-year { display: none; }
  .nav-link, .back-top, .draft { font-size: .59rem; }
  .brand-lockup { gap: 9px; margin-bottom: 20px; }
  .eyebrow { font-size: .66rem; }
  .hero h1 { margin-top: 11px; }
  .field-controls { bottom: 94px; }
  .event-strip > div { padding: 8px 6px; min-height: 77px; }
  .event-strip dt { font-size: .57rem; line-height: 1.35; }
  .event-strip dd { font-size: .69rem; }
  .section-head { margin-bottom: 23px; }
  .footer-inner { flex-wrap: wrap; gap: 0 12px; min-height: 78px; padding: 7px 0; }
  .footer-inner p { order: 3; flex-basis: 100%; text-align: left; padding-bottom: 6px; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
}

.challenge-hero {
  position: relative;
  isolation: isolate;
  padding: clamp(40px, 6vw, 90px) 0;
  border-bottom: 1px solid var(--rule);
}
.challenge-hero::before, .challenge-scenario::before {
  content: "";
  position: absolute;
  z-index: -1;
  inset: 0;
  pointer-events: none;
  background: var(--fine-grid) 0 0 / 6px 6px;
  opacity: .4;
  mask-image: linear-gradient(130deg, black, transparent 29%, transparent 80%, black);
}
.challenge-hero-grid {
  display: grid;
  grid-template-columns: minmax(0, .80fr) minmax(0, 1.20fr);
  align-items: center;
  gap: clamp(24px, 4vw, 56px);
}
.challenge-heading { min-width: 0; }
.challenge-heading h1, .challenge-section-head h2 {
  margin: 10px 0 0;
  font-family: var(--sans);
  font-size: clamp(2.7rem, 5.3vw, 5.6rem);
  font-weight: 900;
  line-height: .96;
  letter-spacing: -.072em;
  overflow-wrap: break-word;
}
.challenge-heading h1 { text-wrap: balance; }
.challenge-heading-long h1 { font-size: clamp(2.55rem, 4.55vw, 4.75rem); }
.challenge-question {
  margin: 23px 0 0;
  color: var(--text);
  font-size: clamp(.91rem, 1.4vw, 1.06rem);
  font-weight: 650;
  line-height: 1.6;
}
.challenge-intro {
  margin: 13px 0 0;
  color: var(--muted);
  font-size: .89rem;
  line-height: 1.7;
}
.challenge-status {
  margin: 20px 0 0;
  color: var(--accent-strong);
  font-size: .72rem;
  line-height: 1.5;
}
.challenge-status span { margin-right: 3px; }

.challenge-scene {
  display: grid;
  min-width: 0;
  margin: 0;
  border: 1px solid var(--rule);
  background: var(--surface);
}
.challenge-scene-top {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 12px;
  min-height: 44px;
  padding: 8px 13px;
}
.challenge-scene-top .eyebrow { font-size: .67rem; }
.scene-mode { color: var(--dim); white-space: nowrap; font-size: .64rem; }
.challenge-scene-viewport {
  position: relative;
  min-width: 0;
  border-top: 1px solid var(--rule);
  border-bottom: 1px solid var(--rule);
  background: var(--section);
}
.challenge-canvas {
  display: block;
  width: 100%;
  height: clamp(250px, 35vw, 430px);
}
.challenge-scene-fallback {
  display: grid;
  align-items: center;
  min-height: clamp(160px, 23vw, 270px);
  margin: 0;
  padding: 28px;
  color: var(--muted);
  background: linear-gradient(#f5f5f59f, #f5f5f5ee), var(--fine-grid) 0 0 / 6px 6px;
  font-size: .88rem;
  line-height: 1.7;
}

#queue-simulator { scroll-margin-top: 12px; }
.queue-simulator {
  min-inline-size: 0;
  margin: 0;
  padding: 11px 13px;
  border: 0;
  border-bottom: 1px solid var(--rule);
  background: var(--page);
}
.queue-simulator legend {
  float: left;
  width: 100%;
  margin: 0 0 4px;
  padding: 0;
  color: var(--text);
  font-size: .93rem;
  font-weight: 750;
  line-height: 1.4;
}
.queue-simulator legend span {
  display: inline-block;
  margin-left: 6px;
  color: var(--dim);
  font-size: .65rem;
  font-weight: 600;
  text-transform: uppercase;
}
.queue-simulator-note {
  clear: both;
  margin: 0;
  color: var(--muted);
  font-size: .72rem;
  line-height: 1.45;
}
.queue-simulator-inputs {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  gap: 4px 12px;
  align-items: end;
  margin: 9px 0 8px;
}
.queue-simulator-rate { min-width: 0; }
.queue-simulator-rate > div {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  align-items: baseline;
  gap: 3px 9px;
  color: var(--text);
  font-size: .72rem;
  font-weight: 750;
}
.queue-simulator-rate output { white-space: nowrap; }
.queue-simulator-rate input {
  display: block;
  width: 100%;
  height: 44px;
  margin: 0;
  accent-color: var(--accent);
  cursor: pointer;
}
.queue-simulator-rate input:focus-visible { outline-offset: -3px; }
.queue-simulator-actions { display: flex; flex-wrap: wrap; align-items: center; gap: 4px 7px; }
.queue-simulator-checkout, .queue-simulator-reset {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  min-height: 44px;
  padding: 4px 8px;
  border: 1px solid var(--rule);
  color: var(--text);
  background: var(--surface);
  font: 650 .68rem/1.4 var(--mono);
  cursor: pointer;
}
.queue-simulator-checkout:hover, .queue-simulator-reset:hover { background: var(--raised); border-color: var(--dim); }
.queue-simulator-checkout input {
  flex: none;
  width: 17px;
  height: 17px;
  margin: 0;
  accent-color: var(--accent);
}
@supports selector(label:has(input:focus-visible)) {
  .queue-simulator-checkout:has(input:focus-visible) {
    outline: 3px solid var(--accent-strong);
    outline-offset: 2px;
  }
  .queue-simulator-checkout input:focus-visible { outline: none; }
}
.queue-simulator-reset:focus-visible { outline-offset: 2px; }
.queue-simulator-metrics {
  display: grid;
  grid-template-columns: minmax(0, .8fr) minmax(0, .9fr) minmax(0, 1.3fr);
  margin: 0;
  border: 1px solid var(--rule);
}
.queue-simulator-metrics > div { min-width: 0; padding: 6px 8px; }
.queue-simulator-metrics > div + div { border-left: 1px solid var(--rule); }
.queue-simulator-metrics dt { color: var(--muted); font-size: .65rem; line-height: 1.35; }
.queue-simulator-metrics dd {
  margin: 4px 0 0;
  color: var(--text);
  font-size: .78rem;
  font-weight: 750;
  line-height: 1.35;
  font-variant-numeric: tabular-nums;
  overflow-wrap: break-word;
}
.queue-simulator[data-queue-overflow="true"] .queue-simulator-metrics > div:last-child { background: var(--accent); }
.queue-simulator[data-queue-overflow="true"] .queue-simulator-metrics > div:last-child :is(dt, dd) { color: var(--page); }
.queue-simulator-model { margin-top: 7px; }
@media (max-width: 560px) {
  .queue-simulator-inputs { grid-template-columns: 1fr; }
}

.challenge-scene-caption {
  display: flex;
  align-items: center;
  min-height: 57px;
  margin: 0;
  padding: 10px 13px;
  color: var(--muted);
  font-size: .75rem;
  line-height: 1.55;
}
.challenge-scene-controls {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  border-top: 1px solid var(--rule);
}
.challenge-scene-controls button {
  display: flex;
  align-items: center;
  gap: 6px;
  min-height: 46px;
  padding: 8px 10px;
  border: 0;
  border-right: 1px solid var(--rule);
  background: var(--surface);
  color: var(--muted);
  font: 600 .72rem/1.4 var(--mono);
  text-align: left;
  cursor: pointer;
}
.challenge-scene-controls button:last-of-type,
.challenge-scene-controls button[data-scene-stage="2"] { border-right: 0; }
.challenge-scene-controls button span { color: var(--dim); }
.challenge-scene-controls button:hover { background: var(--raised); color: var(--text); }
.challenge-scene-controls button[aria-pressed="true"] { background: var(--accent); color: var(--page); }
.challenge-scene-controls button[aria-pressed="true"] span { color: inherit; }
.challenge-scene-controls button:focus-visible { outline-offset: -3px; }
.challenge-scene-controls button.challenge-scene-pause {
  grid-column: 1 / -1;
  justify-content: end;
  border-top: 1px solid var(--rule);
}


.challenge-scene-readouts {
  border-top: 1px solid var(--rule);
  background: var(--page);
}
.challenge-scene-readouts > .eyebrow { padding: 9px 13px 0; font-size: .63rem; }
.challenge-scene-readout {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  margin: 0;
}
.challenge-scene-readout > div { min-width: 0; padding: 9px 12px 13px; }
.challenge-scene-readout > div + div { border-left: 1px solid var(--rule); }
.challenge-scene-readout dt {
  color: var(--text);
  font-size: .72rem;
  font-weight: 750;
  line-height: 1.35;
}
.challenge-scene-readout dt span { color: var(--dim); }
.challenge-scene-readout dd {
  margin: 4px 0 0;
  color: var(--muted);
  font-size: .72rem;
  line-height: 1.45;
}

.challenge-section { padding: clamp(46px, 7vw, 88px) 0; }
.challenge-scenario {
  position: relative;
  isolation: isolate;
  background: var(--section);
  border-bottom: 1px solid var(--rule);
}
.challenge-section-head { max-width: 73ch; margin-bottom: clamp(24px, 3vw, 36px); }
.challenge-section-head h2 { font-size: clamp(2.1rem, 4.5vw, 4.55rem); }
.challenge-section-head > p:last-child {
  max-width: 64ch;
  margin: 15px 0 0;
  color: var(--muted);
  font-size: .9rem;
  line-height: 1.7;
}
.challenge-flow, .challenge-design-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 1px;
  margin: 0;
  padding: 0;
  border: 1px solid var(--rule);
  background: var(--rule);
  list-style: none;
}
.challenge-flow > li, .challenge-design-grid > div {
  min-width: 0;
  padding: clamp(15px, 3vw, 27px);
  background: var(--surface);
}
.challenge-step-id {
  display: inline-block;
  margin-bottom: 11px;
  padding: 3px 7px;
  border: 1px solid var(--rule);
  color: var(--accent-strong);
  font-size: .74rem;
}
.challenge-flow h3, .challenge-design-grid h3, .challenge-workbench-block h3 {
  margin: 0;
  color: var(--text);
  font-family: Arial, sans-serif;
  font-size: clamp(1.05rem, 2vw, 1.45rem);
  font-weight: 800;
  letter-spacing: -.018em;
}
.challenge-flow p, .challenge-design-grid p {
  margin: 7px 0 0;
  color: var(--muted);
  font-size: .83rem;
  line-height: 1.68;
}
.challenge-stage-notes { margin: 14px 0 0; border-top: 1px solid var(--rule); }
.challenge-stage-notes > div { margin: 11px 0 0; }
.challenge-stage-notes dt {
  color: var(--text);
  font-size: .72rem;
  font-weight: 750;
}
.challenge-stage-notes dd {
  margin: 4px 0 0;
  color: var(--muted);
  font-size: .82rem;
  line-height: 1.6;
}
.challenge-design-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
.challenge-workbench-block { margin-top: clamp(24px, 4vw, 46px); }
.challenge-checklist, .challenge-demo-sequence {
  margin: 12px 0 0;
  color: var(--muted);
  font-size: .82rem;
  line-height: 1.6;
}
.challenge-checklist {
  padding: 0;
  border: 1px solid var(--rule);
  list-style: none;
}
.challenge-checklist li {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(0, 2fr);
  gap: 7px 16px;
  padding: 11px 15px;
  background: var(--surface);
}
.challenge-checklist li + li { border-top: 1px solid var(--rule); }
.challenge-checklist strong, .challenge-demo-sequence strong { color: var(--text); }
.challenge-checklist p, .challenge-demo-sequence p { margin: 0; }
.challenge-demo-sequence {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 12px 26px;
  padding-left: 22px;
}
.challenge-demo-sequence li::marker { color: var(--text); font-weight: 750; }
.challenge-demo-sequence li { padding-left: 2px; }
.challenge-demo-sequence p { margin-top: 2px; }
.challenge-deliverable { margin-top: 18px; }
.challenge-next {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 12px;
  margin-top: 30px;
}
.challenge-next a {
  display: grid;
  gap: 5px;
  min-height: 69px;
  padding: 11px 15px;
  border: 1px solid var(--rule);
  text-decoration: none;
}
.challenge-next a:last-child { text-align: right; }
.challenge-next a:hover { border-color: var(--accent); background: var(--raised); }
.challenge-next a strong { font-size: .9rem; line-height: 1.4; }

@media (max-width: 820px) {
  .challenge-hero-grid { grid-template-columns: 1fr; }
  .challenge-heading { max-width: 64ch; }
  .challenge-hero-grid h1 { font-size: clamp(2.7rem, 8vw, 4.4rem); }
  .challenge-canvas { height: clamp(230px, 56vw, 390px); }
  .challenge-flow { grid-template-columns: 1fr; }
}

@media (max-width: 455px) {
  .challenge-hero { padding-top: 32px; }
  .challenge-hero-grid h1 { font-size: clamp(2.35rem, 9vw, 3.15rem); }
  .challenge-scene-top { padding-inline: 10px; }
  .scene-mode { display: none; }
  .challenge-scene-controls button { flex-direction: column; align-items: flex-start; gap: 3px; padding-inline: 7px; font-size: .65rem; }
  .challenge-scene-controls button.challenge-scene-pause { align-items: flex-end; }
  .challenge-scene-readout { grid-template-columns: 1fr; }
  .challenge-scene-readout > div {
    display: grid;
    grid-template-columns: minmax(0, 108px) minmax(0, 1fr);
    gap: 6px;
    padding: 7px 10px;
  }
  .challenge-scene-readout > div + div { border-left: 0; border-top: 1px solid var(--rule); }
  .challenge-scene-readout dd { margin: 0; }
  .challenge-design-grid, .challenge-demo-sequence, .challenge-checklist li { grid-template-columns: 1fr; }
  .challenge-next { gap: 7px; }
  .challenge-next a { padding-inline: 9px; }
  .challenge-next a strong { font-size: .79rem; }
}