:root {
  color-scheme: dark;
  --ink: #f5f7f8;
  --muted: #b9c4ca;
  --canvas: #071013;
  --panel: #0e1b20;
  --panel-soft: #14262c;
  --line: #294047;
  --accent: #69d1c5;
  --accent-strong: #93eee3;
  --warm: #f1c77d;
  --radius: 22px;
}

* { box-sizing: border-box; }

html { background: var(--canvas); }

body {
  margin: 0;
  min-width: 320px;
  overflow-x: hidden;
  color: var(--ink);
  background:
    radial-gradient(circle at 12% -10%, rgba(105, 209, 197, .18), transparent 34rem),
    linear-gradient(180deg, #081115 0%, #071013 100%);
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  line-height: 1.55;
}

button, video { font: inherit; }

.shell {
  width: min(1120px, calc(100% - 40px));
  margin: 0 auto;
  padding: 28px 0 48px;
}

.masthead,
.response,
footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
}

.masthead > *,
.hero,
.video-card,
.lesson,
.response,
.clue-grid > * {
  min-width: 0;
}

.masthead {
  padding-bottom: 26px;
  border-bottom: 1px solid var(--line);
}

.wordmark {
  display: flex;
  align-items: center;
  gap: 12px;
  font-size: .82rem;
  font-weight: 750;
  letter-spacing: .14em;
}

.mark {
  display: grid;
  width: 34px;
  height: 34px;
  place-items: center;
  border: 1px solid var(--accent);
  border-radius: 50%;
  color: var(--accent-strong);
  font-family: Georgia, serif;
  font-size: 1.15rem;
}

.program-label,
.eyebrow {
  color: var(--accent-strong);
  font-size: .76rem;
  font-weight: 750;
  letter-spacing: .14em;
  text-transform: uppercase;
}

.hero {
  max-width: 900px;
  padding: 74px 0 48px;
}

.eyebrow { margin: 0 0 12px; }

h1, h2, h3, p { margin-top: 0; }

h1 {
  max-width: 820px;
  margin-bottom: 22px;
  font-size: clamp(3rem, 8vw, 6.8rem);
  font-weight: 780;
  letter-spacing: -.065em;
  line-height: .92;
}

h2 {
  margin-bottom: 12px;
  font-size: clamp(1.65rem, 4vw, 2.8rem);
  letter-spacing: -.035em;
  line-height: 1.05;
}

h3 {
  margin-bottom: 8px;
  font-size: 1.08rem;
}

.lede {
  max-width: 760px;
  margin-bottom: 0;
  color: var(--muted);
  font-size: clamp(1.05rem, 2vw, 1.3rem);
  overflow-wrap: anywhere;
}

.video-card,
.lesson,
.response {
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: rgba(14, 27, 32, .9);
  box-shadow: 0 24px 80px rgba(0, 0, 0, .25);
}

.video-card { overflow: hidden; }
.video-copy { padding: 28px 30px 18px; }
.video-copy h2 { margin-bottom: 0; }

video {
  display: block;
  width: 100%;
  max-height: 630px;
  min-width: 0;
  background: #020405;
  aspect-ratio: 16 / 9;
}

.lesson {
  margin-top: 24px;
  padding: 34px 30px 30px;
}

.clue-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 14px;
  margin-top: 28px;
}

.clue-grid article {
  min-height: 210px;
  padding: 22px;
  border: 1px solid var(--line);
  border-radius: 16px;
  background: var(--panel-soft);
}

.clue-grid p,
.response p,
footer { color: var(--muted); }

.number {
  display: block;
  margin-bottom: 32px;
  color: var(--warm);
  font-family: ui-monospace, SFMono-Regular, Menlo, monospace;
  font-size: .82rem;
}

.response {
  align-items: flex-end;
  margin-top: 24px;
  padding: 32px 30px;
}

.response > div { max-width: 720px; }
.response p { margin-bottom: 0; }

button {
  flex: 0 0 auto;
  padding: 13px 20px;
  border: 1px solid var(--accent);
  border-radius: 999px;
  color: #05201e;
  background: var(--accent-strong);
  font-weight: 780;
  cursor: pointer;
}

button:hover { background: white; }
button:focus-visible { outline: 3px solid var(--warm); outline-offset: 4px; }
button[disabled] { cursor: default; opacity: .75; }

.acknowledgement {
  flex-basis: 100%;
  color: var(--accent-strong) !important;
  font-weight: 700;
}

footer {
  align-items: flex-start;
  padding: 30px 4px 0;
  font-size: .78rem;
}

footer p { max-width: 48%; margin-bottom: 0; }

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

@media (max-width: 760px) {
  .shell { width: min(100% - 24px, 1120px); padding-top: 18px; }
  .masthead { align-items: flex-start; flex-direction: column; gap: 14px; }
  .wordmark { font-size: .72rem; letter-spacing: .11em; }
  .program-label { text-align: left; }
  .hero { padding: 52px 2px 34px; }
  h1 { font-size: clamp(2.65rem, 15vw, 4.6rem); }
  .video-copy, .lesson, .response { padding-left: 20px; padding-right: 20px; }
  .clue-grid { grid-template-columns: 1fr; }
  .clue-grid article { min-height: auto; }
  .number { margin-bottom: 18px; }
  .response { align-items: stretch; flex-direction: column; }
  button { width: 100%; }
  footer { display: block; }
  footer p { max-width: none; }
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { scroll-behavior: auto !important; }
}