:root {
  --paper: #f3f0e9;
  --ink: #111110;
  --coral: #eaa28e;
  --sage: #aeb79a;
  --blue: #b8ccd3;
  --lilac: #c7c1d6;
  --serif: Georgia, "Times New Roman", serif;
  --sans: Inter, ui-sans-serif, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
}

* { box-sizing: border-box; }

html { background: var(--paper); color: var(--ink); }

body {
  margin: 0;
  background:
    linear-gradient(rgba(17, 17, 16, 0.035) 1px, transparent 1px),
    var(--paper);
  background-size: 100% 2rem;
  font-family: var(--sans);
  font-size: 1rem;
  line-height: 1.55;
}

a { color: inherit; }

.page {
  width: min(100% - 2rem, 78rem);
  min-height: 100vh;
  margin: 0 auto;
  padding: 1.25rem 0 1.5rem;
  display: grid;
  grid-template-rows: auto 1fr auto;
}

header,
footer {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 1.5rem;
  padding-bottom: 1rem;
  border-bottom: 2px solid var(--ink);
}

footer {
  padding: 1rem 0 0;
  border-top: 2px solid var(--ink);
  border-bottom: 0;
  font-size: 0.76rem;
  font-weight: 750;
  letter-spacing: 0.1em;
  text-transform: uppercase;
}

.wordmark {
  font-family: var(--serif);
  font-size: 1.22rem;
  font-weight: 700;
  line-height: 0.83;
  letter-spacing: -0.06em;
  text-decoration: none;
}

.top-links {
  display: flex;
  gap: 1.1rem;
  font-size: 0.76rem;
  font-weight: 750;
  letter-spacing: 0.12em;
  text-transform: uppercase;
}

.top-links a { text-underline-offset: 0.24rem; }

main { padding: clamp(3rem, 7vw, 6.5rem) 0; }

.lesson-heading {
  display: grid;
  grid-template-columns: minmax(0, 1.2fr) minmax(16rem, 0.5fr);
  gap: clamp(2rem, 8vw, 8rem);
  align-items: end;
  padding-bottom: clamp(2.5rem, 5vw, 4.5rem);
  border-bottom: 2px solid var(--ink);
}

.eyebrow,
.kicker {
  margin: 0 0 1.2rem;
  font-size: 0.75rem;
  font-weight: 800;
  letter-spacing: 0.22em;
  text-transform: uppercase;
}

h1,
h2,
h3 { font-family: var(--serif); }

h1 {
  max-width: 9ch;
  margin: 0;
  font-size: clamp(4rem, 10vw, 8.4rem);
  line-height: 0.8;
  letter-spacing: -0.075em;
}

.deck {
  margin: 0;
  font-family: var(--serif);
  font-size: clamp(1.55rem, 3vw, 2.45rem);
  line-height: 1.05;
  letter-spacing: -0.035em;
}

.content-grid {
  display: grid;
  grid-template-columns: minmax(0, 0.72fr) minmax(0, 1fr);
  gap: clamp(2.5rem, 7vw, 7rem);
  padding-top: clamp(2.5rem, 5vw, 4.5rem);
}

.method {
  align-self: start;
  border: 2px solid var(--ink);
  box-shadow: 0.55rem 0.55rem 0 var(--ink);
}

.method-title {
  margin: 0;
  padding: 1rem 1.2rem;
  border-bottom: 2px solid var(--ink);
  background: var(--accent, var(--coral));
  font-family: var(--sans);
  font-size: 0.75rem;
  font-weight: 850;
  letter-spacing: 0.18em;
  text-transform: uppercase;
}

.method ol { margin: 0; padding: 0; list-style: none; counter-reset: method; }

.method li {
  counter-increment: method;
  display: grid;
  grid-template-columns: 2.5rem 1fr;
  gap: 0.75rem;
  padding: 1rem 1.2rem;
  border-bottom: 1px solid rgba(17, 17, 16, 0.45);
}

.method li:last-child { border-bottom: 0; }

.method li::before {
  content: counter(method, decimal-leading-zero);
  font-size: 0.75rem;
  font-weight: 850;
  letter-spacing: 0.1em;
}

.explanation { max-width: 45rem; }

.explanation p {
  margin: 0 0 1.25rem;
  font-size: clamp(1.05rem, 1.8vw, 1.25rem);
}

.explanation h2 {
  margin: 2.5rem 0 1rem;
  font-size: clamp(2rem, 4vw, 3.4rem);
  line-height: 0.95;
  letter-spacing: -0.055em;
}

.move {
  margin-top: 2.5rem;
  padding: 1.4rem;
  border: 2px solid var(--ink);
  background: var(--accent-soft, var(--blue));
}

.move h3 {
  margin: 0 0 0.7rem;
  font-family: var(--sans);
  font-size: 0.75rem;
  letter-spacing: 0.18em;
  text-transform: uppercase;
}

.move p { margin: 0; }

.next {
  display: inline-flex;
  margin-top: 2rem;
  padding-bottom: 0.15rem;
  font-weight: 800;
  text-decoration-thickness: 2px;
  text-underline-offset: 0.28rem;
}

.lesson-nav {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: 0.75rem 1.5rem;
}

a:focus-visible { outline: 3px solid var(--blue); outline-offset: 4px; }

@media (max-width: 760px) {
  .page { width: min(100% - 1.5rem, 46rem); }
  .lesson-heading,
  .content-grid { grid-template-columns: 1fr; }
  h1 { font-size: clamp(3.7rem, 18vw, 6rem); }
  .deck { max-width: 22ch; }
  footer { flex-direction: column; gap: 0.4rem; }
}