:root {
  --bg: #0a0a0a;
  --surface: #111111;
  --border: #1a1a1a;
  --text: #e8e6e3;
  --text-secondary: #999590;
  --text-dim: #666360;
  --font-sans: "Inter", system-ui, -apple-system, sans-serif;
  --font-serif: "Newsreader", Georgia, serif;
  --max-w: 1080px;
  --gap: clamp(1.5rem, 4vw, 3rem);
}

*,
*::before,
*::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  scroll-behavior: smooth;
  -webkit-font-smoothing: antialiased;
}

body {
  font-family: var(--font-sans);
  color: var(--text);
  background: var(--bg);
  line-height: 1.6;
  min-height: 100vh;
}

/* ---- NAV ---- */

nav {
  position: sticky;
  top: 0;
  z-index: 10;
  display: flex;
  align-items: center;
  justify-content: space-between;
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 1.25rem clamp(1.5rem, 4vw, 2rem);
  background: rgba(10, 10, 10, 0.85);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
}

.brand {
  font-weight: 700;
  font-size: 1.1rem;
  letter-spacing: 0.06em;
  color: var(--text);
  text-decoration: none;
}

.nav-links {
  display: flex;
  gap: 2rem;
}

.nav-links a {
  color: var(--text-secondary);
  text-decoration: none;
  font-size: 0.875rem;
  transition: color 0.2s;
}

.nav-links a:hover {
  color: var(--text);
}

/* ---- HERO ---- */

.hero {
  max-width: var(--max-w);
  margin: 0 auto;
  padding: clamp(4rem, 10vw, 8rem) clamp(1.5rem, 4vw, 2rem) clamp(3rem, 8vw, 6rem);
}

.hero h1 {
  font-family: var(--font-serif);
  font-weight: 500;
  font-size: clamp(2.2rem, 5.5vw, 4rem);
  line-height: 1.15;
  max-width: 20ch;
  letter-spacing: -0.02em;
}

.hero-sub {
  margin-top: 1.5rem;
  max-width: 58ch;
  color: var(--text-secondary);
  font-size: 1.05rem;
  line-height: 1.75;
}

/* ---- SECTIONS ---- */

.section {
  max-width: var(--max-w);
  margin: 0 auto;
  padding: clamp(3rem, 8vw, 6rem) clamp(1.5rem, 4vw, 2rem);
  border-top: 1px solid var(--border);
}

.section-label {
  font-size: 0.75rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--text-dim);
  margin-bottom: 1rem;
}

.section h2 {
  font-family: var(--font-serif);
  font-weight: 500;
  font-size: clamp(1.6rem, 4vw, 2.6rem);
  line-height: 1.2;
  letter-spacing: -0.01em;
  max-width: 28ch;
}

.section-intro {
  margin-top: 0.75rem;
  color: var(--text-secondary);
  max-width: 52ch;
}

/* ---- PROSE (thesis) ---- */

.prose {
  margin-top: 2rem;
  max-width: 60ch;
}

.prose p {
  color: var(--text-secondary);
  margin-bottom: 1.25rem;
  font-size: 1.05rem;
  line-height: 1.8;
}

.prose em {
  font-family: var(--font-serif);
  font-style: italic;
  color: var(--text);
}

/* ---- GRID (cards) ---- */

.grid {
  display: grid;
  gap: 1px;
  margin-top: 2.5rem;
  background: var(--border);
  border: 1px solid var(--border);
}

.card {
  background: var(--bg);
  padding: 2rem;
  opacity: 0;
  transform: translateY(12px);
  transition: opacity 0.5s ease, transform 0.5s ease;
}

.card.is-visible {
  opacity: 1;
  transform: translateY(0);
}

.card-num {
  display: block;
  font-size: 0.75rem;
  color: var(--text-dim);
  letter-spacing: 0.08em;
  margin-bottom: 1rem;
}

.card h3 {
  font-size: 1.15rem;
  font-weight: 600;
  margin-bottom: 0.75rem;
  line-height: 1.3;
}

.card p {
  color: var(--text-secondary);
  font-size: 0.95rem;
  line-height: 1.7;
}

/* ---- STEPS ---- */

.steps {
  margin-top: 2.5rem;
  display: grid;
  gap: 0;
}

.step {
  display: grid;
  grid-template-columns: 3.5rem 1fr;
  gap: 1rem;
  padding: 1.75rem 0;
  border-bottom: 1px solid var(--border);
  align-items: baseline;
}

.step:first-child {
  border-top: 1px solid var(--border);
}

.step-num {
  font-size: 0.75rem;
  color: var(--text-dim);
  letter-spacing: 0.08em;
  padding-top: 0.15rem;
}

.step h3 {
  font-size: 1.05rem;
  font-weight: 600;
  margin-bottom: 0.4rem;
}

.step p {
  color: var(--text-secondary);
  font-size: 0.95rem;
  line-height: 1.65;
}

/* ---- MODULES (academy) ---- */

.modules {
  margin-top: 2.5rem;
  display: grid;
  gap: 0;
}

.module {
  display: grid;
  grid-template-columns: 2.5rem 1fr;
  gap: 1rem;
  padding: 1.25rem 0;
  border-bottom: 1px solid var(--border);
  align-items: baseline;
}

.module:first-child {
  border-top: 1px solid var(--border);
}

.module span {
  font-size: 0.75rem;
  color: var(--text-dim);
  letter-spacing: 0.08em;
}

.module p {
  color: var(--text-secondary);
  font-size: 0.95rem;
  line-height: 1.65;
}

.module strong {
  color: var(--text);
}

/* ---- CTA ---- */

.section-cta {
  padding-top: clamp(4rem, 10vw, 8rem);
  padding-bottom: clamp(4rem, 10vw, 8rem);
}

.section-cta h2 {
  font-family: var(--font-serif);
  font-weight: 400;
  font-style: italic;
  max-width: 32ch;
  font-size: clamp(1.4rem, 3.5vw, 2.2rem);
  line-height: 1.4;
  color: var(--text-secondary);
}

.btn {
  display: inline-block;
  margin-top: 2rem;
  padding: 0.75rem 1.75rem;
  color: var(--bg);
  background: var(--text);
  text-decoration: none;
  font-weight: 600;
  font-size: 0.9rem;
  border-radius: 0;
  transition: opacity 0.2s;
}

.btn:hover {
  opacity: 0.85;
}

/* ---- FOOTER ---- */

footer {
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 2rem clamp(1.5rem, 4vw, 2rem);
  border-top: 1px solid var(--border);
  display: flex;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 1rem;
  font-size: 0.8rem;
  color: var(--text-dim);
}

/* ---- RESPONSIVE ---- */

@media (min-width: 768px) {
  .grid {
    grid-template-columns: 1fr 1fr;
  }
}

@media (max-width: 600px) {
  .nav-links {
    gap: 1.25rem;
  }

  .nav-links a {
    font-size: 0.8rem;
  }

  .step {
    grid-template-columns: 2.5rem 1fr;
  }
}