:root {
  color-scheme: light;
  --navy: #071150;
  --ink: #101815;
  --muted: #64706b;
  --green: #1f8f61;
  --gold: #f7b733;
  --paper: #f7f3eb;
  --white: #fff;
  --line: rgba(16, 24, 21, 0.14);
}

* { box-sizing: border-box; }

html,
body {
  margin: 0;
  overflow-x: hidden;
  font-family: Inter, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  color: var(--ink);
  background: var(--paper);
}

a { color: inherit; }

button,
input {
  font: inherit;
}

.topbar {
  position: sticky;
  top: 0;
  z-index: 10;
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 16px;
  padding: 12px clamp(14px, 4vw, 54px);
  background: rgba(7, 17, 80, 0.97);
  color: white;
}

.brand {
  display: flex;
  align-items: center;
  gap: 12px;
  text-decoration: none;
}

.brand-mark {
  width: 42px;
  height: 42px;
  display: grid;
  place-items: center;
  border: 1px solid rgba(255,255,255,0.35);
  font-weight: 900;
}

.brand strong,
.brand small {
  display: block;
}

.brand small {
  color: var(--gold);
  font-size: 0.7rem;
  font-weight: 900;
  text-transform: uppercase;
}

.version-badge {
  min-height: 28px;
  display: inline-flex;
  align-items: center;
  border: 1px solid rgba(255,255,255,0.28);
  background: rgba(255,255,255,0.08);
  padding: 0 9px;
  color: rgba(255,255,255,0.86);
  font-size: 0.72rem;
  font-weight: 900;
}

.top-link,
.primary-link,
.secondary-link,
.primary-btn {
  min-height: 44px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border: 1px solid transparent;
  padding: 0 16px;
  font-weight: 900;
  text-decoration: none;
}

.top-link,
.secondary-link {
  border-color: rgba(255,255,255,0.22);
  background: rgba(255,255,255,0.08);
  color: white;
}

.secondary-link {
  border-color: var(--line);
  background: white;
  color: var(--navy);
}

.as-button {
  cursor: pointer;
}

.primary-link,
.primary-btn {
  background: var(--green);
  color: white;
}

.hero {
  min-height: 620px;
  display: grid;
  align-items: end;
  padding: clamp(26px, 6vw, 78px);
  background:
    linear-gradient(180deg, rgba(7,17,80,0.72), rgba(7,17,80,0.42), rgba(31,143,97,0.55)),
    url("https://images.unsplash.com/photo-1560518883-ce09059eeffa?auto=format&fit=crop&w=1800&q=82") center/cover;
  color: white;
}

.hero-copy {
  width: min(760px, 100%);
}

.eyebrow {
  margin: 0 0 12px;
  color: var(--gold);
  font-size: 0.78rem;
  font-weight: 900;
  letter-spacing: 0.05em;
  text-transform: uppercase;
}

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

h1 {
  margin-bottom: 18px;
  font-size: clamp(2.4rem, 7vw, 5.5rem);
  line-height: 0.95;
}

h2 {
  color: var(--navy);
  font-size: clamp(2rem, 4vw, 3.8rem);
  line-height: 1;
}

.hero p {
  max-width: 660px;
  color: rgba(255,255,255,0.84);
  font-size: 1.08rem;
  line-height: 1.65;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 26px;
}

.course-band,
.curriculum,
.welcome-video,
.checkout-section,
.student-shell,
.access-shell {
  padding: clamp(28px, 5vw, 70px) clamp(14px, 5vw, 72px);
}

.course-band {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1px;
  background: var(--line);
}

.course-band article,
.module-grid article,
.student-module-card,
.checkout-form,
.access-card,
.lesson-player {
  border: 1px solid var(--line);
  background: white;
}

.course-band article {
  padding: 24px;
}

.course-band strong,
.course-band span {
  display: block;
}

.course-band span,
.module-grid p,
.checkout-copy p,
.access-card p,
.lesson-copy p {
  color: var(--muted);
  line-height: 1.6;
}

.section-head {
  width: min(820px, 100%);
}

.module-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 14px;
}

.module-grid article,
.student-module-card {
  padding: 24px;
}

.student-module-card {
  width: 100%;
  min-height: 184px;
  display: block;
  border-radius: 0;
  color: var(--ink);
  cursor: pointer;
  font: inherit;
  text-align: left;
  transition: border-color 0.18s ease, box-shadow 0.18s ease, transform 0.18s ease;
}

.student-module-card:hover,
.student-module-card:focus {
  border-color: rgba(31, 143, 97, 0.65);
  box-shadow: 0 14px 34px rgba(7, 17, 80, 0.12);
  outline: none;
  transform: translateY(-2px);
}

.student-module-card.is-active {
  border-color: var(--green);
  box-shadow: inset 0 0 0 2px rgba(31, 143, 97, 0.2);
}

.student-module-card.is-locked {
  cursor: default;
  opacity: 0.72;
}

.student-module-card.is-locked:hover,
.student-module-card.is-locked:focus {
  border-color: var(--line);
  box-shadow: none;
  transform: none;
}

.module-grid span,
.student-module-card span {
  color: var(--green);
  font-weight: 900;
  text-transform: uppercase;
}

.checkout-section {
  display: grid;
  grid-template-columns: minmax(0, 0.9fr) minmax(320px, 0.8fr);
  gap: 18px;
  align-items: start;
}

.checkout-form,
.access-card {
  display: grid;
  gap: 14px;
  padding: 24px;
}

label {
  display: grid;
  gap: 7px;
  color: var(--navy);
  font-weight: 900;
}

input {
  width: 100%;
  min-height: 52px;
  border: 1px solid var(--line);
  padding: 0 12px;
  color: var(--ink);
  font-weight: 800;
}

.form-note {
  margin: 0;
  color: var(--muted);
  font-size: 0.86rem;
}

.access-shell {
  min-height: calc(100vh - 66px);
  display: grid;
  place-items: center;
}

.access-card {
  width: min(520px, 100%);
}

.student-hero {
  padding: 30px;
  background: var(--navy);
  color: white;
}

.student-hero h1 {
  font-size: clamp(2rem, 5vw, 4rem);
}

.student-hero p {
  color: rgba(255,255,255,0.78);
}

.lesson-player {
  display: grid;
  grid-template-columns: minmax(0, 1.2fr) minmax(260px, 0.8fr);
  margin-top: 18px;
}

.video-frame {
  min-height: 320px;
  display: grid;
  place-items: center;
  align-content: center;
  gap: 8px;
  background: #101815;
  color: white;
  text-align: center;
}

.video-frame iframe {
  width: 100%;
  height: 100%;
  min-height: 320px;
  border: 0;
}

.public-video {
  width: min(980px, 100%);
  margin-top: 16px;
}

.test-mode-badge {
  display: inline-flex;
  width: fit-content;
  margin-bottom: 12px;
  border: 1px solid rgba(247, 183, 51, 0.5);
  background: #fff4d6;
  padding: 7px 10px;
  color: #8a5a00;
  font-size: 0.82rem;
  font-weight: 900;
  text-transform: uppercase;
}

.video-frame span {
  font-size: 1.25rem;
  font-weight: 900;
}

.video-frame small {
  color: rgba(255,255,255,0.7);
}

.lesson-copy {
  padding: 24px;
}

.student-shell .module-grid {
  margin-top: 18px;
}

.toast {
  position: fixed;
  left: 50%;
  bottom: 18px;
  z-index: 30;
  transform: translate(-50%, 20px);
  max-width: min(520px, calc(100% - 28px));
  border: 1px solid rgba(255,255,255,0.16);
  background: var(--navy);
  color: white;
  padding: 12px 14px;
  opacity: 0;
  pointer-events: none;
  transition: 0.2s ease;
  font-weight: 800;
}

.toast.is-visible {
  opacity: 1;
  transform: translate(-50%, 0);
}

@media (max-width: 760px) {
  .topbar,
  .hero-actions {
    align-items: stretch;
    flex-direction: column;
  }

  .top-link,
  .primary-link,
  .secondary-link,
  .primary-btn {
    width: 100%;
  }

  .hero {
    min-height: 560px;
    padding: 34px 14px;
  }

  .course-band,
  .module-grid,
  .checkout-section,
  .welcome-video,
  .lesson-player {
    grid-template-columns: 1fr;
  }

  .course-band,
  .curriculum,
  .checkout-section,
  .student-shell,
  .access-shell {
    padding: 34px 12px;
  }
}