:root {
  --ink: #101014;
  --paper: #f8f3ea;
  --muted: #706b63;
  --line: rgba(16, 16, 20, 0.14);
  --green: #33c481;
  --blue: #2367d8;
  --coral: #ff6b5f;
  --amber: #f2b84b;
  --white: #ffffff;
  --shadow: 0 24px 70px rgba(16, 16, 20, 0.18);
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  color: var(--ink);
  background: var(--paper);
  font-family:
    Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI",
    sans-serif;
  line-height: 1.5;
}

body::before {
  position: fixed;
  inset: 0;
  z-index: -1;
  pointer-events: none;
  content: "";
  background-image:
    linear-gradient(rgba(16, 16, 20, 0.035) 1px, transparent 1px),
    linear-gradient(90deg, rgba(16, 16, 20, 0.035) 1px, transparent 1px);
  background-size: 42px 42px;
}

a {
  color: inherit;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 10;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  padding: 12px clamp(18px, 4vw, 56px);
  border-bottom: 1px solid var(--line);
  background: rgba(248, 243, 234, 0.92);
  backdrop-filter: blur(18px);
}

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

.brand-mark {
  width: 36px;
  height: 36px;
  border-radius: 8px;
  background: var(--ink);
}

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

.brand strong {
  font-size: 0.95rem;
  line-height: 1.1;
}

.brand small {
  color: var(--muted);
  font-size: 0.78rem;
}

.nav-links {
  display: flex;
  flex-wrap: wrap;
  justify-content: flex-end;
  gap: 6px;
}

.nav-links a {
  padding: 8px 10px;
  border-radius: 8px;
  color: #34322e;
  font-size: 0.9rem;
  text-decoration: none;
}

.nav-links a:hover {
  background: rgba(16, 16, 20, 0.07);
}

.hero {
  display: grid;
  grid-template-columns: minmax(0, 0.98fr) minmax(340px, 0.78fr);
  gap: clamp(24px, 4vw, 56px);
  align-items: stretch;
  min-height: calc(100vh - 82px);
  padding: clamp(28px, 6vw, 76px) clamp(18px, 4vw, 56px) 36px;
}

.hero-copy {
  display: flex;
  flex-direction: column;
  justify-content: center;
}

.eyebrow,
.section-kicker {
  margin: 0 0 16px;
  color: var(--blue);
  font-size: 0.78rem;
  font-weight: 850;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

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

h1 {
  max-width: 920px;
  margin-bottom: 22px;
  font-size: clamp(3.6rem, 8.8vw, 8.2rem);
  font-weight: 950;
  letter-spacing: 0;
  line-height: 0.93;
  overflow-wrap: break-word;
}

h2 {
  margin-bottom: 18px;
  font-size: clamp(2.1rem, 4.7vw, 5.3rem);
  font-weight: 950;
  letter-spacing: 0;
  line-height: 0.98;
}

h3 {
  margin-bottom: 10px;
  font-size: 1.04rem;
  line-height: 1.2;
}

.hero-lede {
  max-width: 760px;
  color: #2f2c27;
  font-size: clamp(1.1rem, 1.75vw, 1.4rem);
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin: 12px 0 32px;
}

.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 48px;
  padding: 13px 18px;
  border: 2px solid var(--ink);
  border-radius: 8px;
  font-weight: 850;
  text-decoration: none;
  transition:
    transform 160ms ease,
    box-shadow 160ms ease,
    background 160ms ease;
}

.button:hover {
  transform: translateY(-2px);
}

.button.primary {
  color: var(--ink);
  background: var(--green);
  box-shadow: 6px 6px 0 var(--ink);
}

.button.secondary {
  background: transparent;
}

.hero-facts {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 1px;
  max-width: 740px;
  margin: auto 0 0;
  overflow: hidden;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--line);
}

.hero-facts div {
  min-width: 0;
  padding: 18px;
  background: rgba(255, 255, 255, 0.46);
}

.hero-facts dt {
  color: var(--muted);
  font-size: 0.76rem;
  font-weight: 850;
  text-transform: uppercase;
}

.hero-facts dd {
  margin: 6px 0 0;
  font-size: clamp(1.3rem, 2vw, 1.9rem);
  font-weight: 950;
}

.hero-visual {
  position: relative;
  display: grid;
  place-items: center;
  min-height: 540px;
  overflow: hidden;
  border: 2px solid var(--ink);
  border-radius: 8px;
  background:
    linear-gradient(135deg, rgba(51, 196, 129, 0.2), transparent 38%),
    linear-gradient(45deg, rgba(35, 103, 216, 0.18), transparent 42%),
    #ffffff;
  box-shadow: var(--shadow);
}

#product-canvas {
  width: min(100%, 620px);
  aspect-ratio: 1;
}

.visual-caption {
  position: absolute;
  right: 18px;
  bottom: 18px;
  left: 18px;
  display: grid;
  gap: 4px;
  padding: 16px;
  border: 1px solid rgba(16, 16, 20, 0.14);
  border-radius: 8px;
  background: rgba(248, 243, 234, 0.82);
  backdrop-filter: blur(12px);
}

.visual-caption span {
  color: var(--blue);
  font-size: 0.76rem;
  font-weight: 950;
  text-transform: uppercase;
}

.signal-strip {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  margin: 0 clamp(18px, 4vw, 56px);
  border: 2px solid var(--ink);
  border-radius: 8px;
  background: var(--ink);
  color: var(--white);
}

.signal-strip article {
  min-width: 0;
  padding: 20px;
  border-right: 1px solid rgba(255, 255, 255, 0.18);
}

.signal-strip article:last-child {
  border-right: 0;
}

.signal-strip span {
  display: block;
  color: rgba(255, 255, 255, 0.66);
  font-size: 0.78rem;
  font-weight: 850;
  text-transform: uppercase;
}

.signal-strip strong {
  display: block;
  margin-top: 6px;
  font-size: clamp(1.05rem, 1.5vw, 1.4rem);
}

.section {
  padding: clamp(60px, 9vw, 118px) clamp(18px, 4vw, 56px);
}

.two-column {
  display: grid;
  grid-template-columns: minmax(0, 0.9fr) minmax(320px, 1fr);
  gap: clamp(28px, 6vw, 78px);
  align-items: start;
}

.prose,
.panel-copy,
.feedback-copy p,
.language-section p {
  color: #302d29;
  font-size: clamp(1.04rem, 1.4vw, 1.2rem);
}

.prose p:last-child,
.panel-copy:last-child,
.feedback-copy p:last-child,
.language-section p:last-child {
  margin-bottom: 0;
}

.details-grid {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 14px;
  padding-top: 0;
}

.details-grid article,
.steps article {
  min-width: 0;
  padding: 20px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: rgba(255, 255, 255, 0.46);
}

.card-number,
.steps span {
  display: inline-block;
  margin-bottom: 34px;
  color: var(--coral);
  font-size: 0.82rem;
  font-weight: 950;
}

.lesson-panel {
  display: grid;
  grid-template-columns: minmax(280px, 0.8fr) minmax(320px, 1fr);
  gap: clamp(28px, 6vw, 72px);
  align-items: center;
  background: #ffffff;
}

.lesson-board {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 12px;
}

.lesson-board span,
.language-grid span {
  min-width: 0;
  padding: 14px 16px;
  border: 2px solid var(--ink);
  border-radius: 8px;
  background: var(--paper);
  font-weight: 850;
}

.lesson-board span:nth-child(3n + 1) {
  background: rgba(51, 196, 129, 0.22);
}

.lesson-board span:nth-child(3n + 2) {
  background: rgba(35, 103, 216, 0.18);
}

.lesson-board span:nth-child(3n + 3) {
  background: rgba(242, 184, 75, 0.28);
}

.feedback-panel {
  display: grid;
  grid-template-columns: minmax(280px, 0.8fr) minmax(320px, 1fr);
  gap: clamp(28px, 6vw, 72px);
  align-items: start;
}

.steps {
  display: grid;
  gap: 14px;
}

.language-section {
  background: #ffffff;
}

.language-section h2,
.language-section p {
  max-width: 980px;
}

.language-grid {
  display: grid;
  grid-template-columns: repeat(6, minmax(0, 1fr));
  gap: 10px;
  margin-top: 28px;
}

.language-grid span {
  border-color: var(--line);
  background: rgba(248, 243, 234, 0.78);
  text-align: center;
}

.faq {
  padding-top: clamp(60px, 9vw, 118px);
}

.faq h2 {
  max-width: 900px;
}

details {
  border-top: 1px solid var(--line);
  background: rgba(255, 255, 255, 0.28);
}

details:last-child {
  border-bottom: 1px solid var(--line);
}

summary {
  cursor: pointer;
  padding: 22px 0;
  font-size: clamp(1.05rem, 1.6vw, 1.28rem);
  font-weight: 900;
}

details p {
  max-width: 820px;
  padding-bottom: 22px;
  color: #34322e;
}

.site-footer {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: 16px;
  padding: 28px clamp(18px, 4vw, 56px);
  border-top: 1px solid var(--line);
  color: #403c36;
  font-size: 0.9rem;
}

.site-footer p {
  margin: 0;
}

#favicon-canvas {
  position: fixed;
  left: -9999px;
  width: 1px;
  height: 1px;
}

@media (max-width: 1000px) {
  .hero,
  .two-column,
  .lesson-panel,
  .feedback-panel {
    grid-template-columns: 1fr;
  }

  .hero {
    min-height: auto;
  }

  .hero-visual {
    min-height: 460px;
  }

  .signal-strip,
  .details-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .signal-strip article:nth-child(2) {
    border-right: 0;
  }

  .language-grid {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
}

@media (max-width: 700px) {
  .site-header {
    position: static;
    align-items: flex-start;
    flex-direction: column;
  }

  .nav-links {
    justify-content: flex-start;
  }

  h1 {
    font-size: clamp(3rem, 14vw, 5.5rem);
  }

  .hero-facts,
  .signal-strip,
  .details-grid,
  .lesson-board,
  .language-grid {
    grid-template-columns: 1fr;
  }

  .signal-strip article {
    border-right: 0;
    border-bottom: 1px solid rgba(255, 255, 255, 0.18);
  }

  .signal-strip article:last-child {
    border-bottom: 0;
  }

  .button {
    width: 100%;
  }
}