:root {
  --bg: #ffffff;
  --text: #111111;
  --muted: #5f5f5f;
  --quiet: #8b8b8b;
  --line: #dddddd;
  --line-soft: #eeeeee;
  --panel: #f7f6f2;
  --accent: #6f5f45;
  --accent-soft: #efe9dc;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  min-height: 100vh;
  color: var(--text);
  background: var(--bg);
  font-family: "Libre Franklin", "Helvetica Neue", Arial, sans-serif;
  font-size: 16px;
  line-height: 1.72;
}

a {
  color: inherit;
}

.site-header,
.site-footer,
main {
  width: min(1060px, calc(100% - 48px));
  margin: 0 auto;
}

.site-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 34px 0 24px;
  border-bottom: 1px solid var(--line);
}

.brand,
.site-nav {
  display: flex;
  align-items: center;
}

.brand {
  gap: 12px;
  font-size: 1.08rem;
  font-weight: 500;
  letter-spacing: 0.01em;
  text-decoration: none;
}

.brand-mark {
  display: inline-grid;
  width: 34px;
  height: 34px;
  place-items: center;
  border: 1px solid var(--text);
  border-radius: 50%;
  font-size: 1.08rem;
  font-weight: 600;
}

.site-nav {
  gap: 28px;
}

.site-nav a {
  color: var(--text);
  font-size: 0.9rem;
  font-weight: 400;
  text-decoration: none;
}

.site-nav a:hover,
.text-link:hover {
  text-decoration: underline;
  text-underline-offset: 4px;
}

.hero {
  display: grid;
  grid-template-columns: minmax(0, 1.15fr) minmax(300px, 0.85fr);
  gap: 72px;
  align-items: start;
  padding: 82px 0 96px;
  border-bottom: 1px solid var(--line);
}

.eyebrow {
  margin: 0 0 18px;
  color: var(--accent);
  font-size: 0.78rem;
  font-weight: 600;
  letter-spacing: 0.14em;
  text-transform: uppercase;
}

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

h1,
h2,
h3,
blockquote {
  font-weight: 400;
  letter-spacing: -0.035em;
}

h1 {
  max-width: 790px;
  margin-bottom: 28px;
  font-size: clamp(3rem, 7vw, 5.8rem);
  line-height: 0.98;
}

h2 {
  margin-bottom: 0;
  font-size: clamp(2rem, 4vw, 3.45rem);
  line-height: 1.08;
}

h3 {
  margin-bottom: 12px;
  font-size: 1.12rem;
  line-height: 1.35;
}

.hero-lede {
  max-width: 650px;
  margin-bottom: 34px;
  color: var(--muted);
  font-size: clamp(1.02rem, 1.8vw, 1.18rem);
  font-weight: 300;
}

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

.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 42px;
  padding: 0 18px;
  border: 1px solid var(--text);
  font-size: 0.9rem;
  font-weight: 500;
  text-decoration: none;
}

.button.primary {
  background: var(--text);
  color: var(--bg);
}

.button.secondary {
  background: transparent;
  color: var(--text);
}

.claim-card,
.problem-card,
.method-panel,
.collaboration-card,
.thesis {
  border: 1px solid var(--line);
  background: var(--bg);
}

.claim-card {
  padding: 28px;
  background: var(--panel);
}

.claim-card-header,
.site-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 18px;
}

.claim-card-header {
  margin-bottom: 18px;
  padding-bottom: 14px;
  border-bottom: 1px solid var(--line);
  font-size: 0.78rem;
  font-weight: 600;
  letter-spacing: 0.12em;
  text-transform: uppercase;
}

.status-pill {
  padding: 4px 8px;
  border: 1px solid var(--accent);
  color: var(--accent);
  font-size: 0.68rem;
}

.claim-grid {
  display: grid;
  gap: 0;
  margin: 0;
}

.claim-grid div {
  padding: 18px 0;
  border-bottom: 1px solid var(--line);
}

.claim-grid div:last-child {
  border-bottom: 0;
}

dt {
  margin-bottom: 4px;
  font-weight: 600;
}

dd {
  margin: 0;
  color: var(--muted);
  font-weight: 300;
}

.section {
  padding: 86px 0;
  border-bottom: 1px solid var(--line);
}

.section-heading {
  display: grid;
  gap: 16px;
  max-width: 720px;
  margin-bottom: 38px;
}

.problem-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  border-top: 1px solid var(--line);
  border-left: 1px solid var(--line);
}

.problem-card {
  min-height: 285px;
  padding: 28px;
  border-top: 0;
  border-right: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
  border-left: 0;
}

.problem-card p,
.method-panel p,
.collaboration-card p {
  color: var(--muted);
  font-weight: 300;
}

.problem-index {
  display: block;
  margin-bottom: 54px;
  color: var(--quiet);
  font-size: 0.82rem;
  font-weight: 500;
}

.split {
  display: grid;
  grid-template-columns: 0.9fr 1.1fr;
  gap: 64px;
  align-items: start;
}

.method-panel,
.collaboration-card {
  padding: 0;
  border: 0;
  background: transparent;
}

.method-list {
  display: grid;
  gap: 14px;
  margin: 28px 0 0;
  padding-left: 22px;
  color: var(--text);
}

.method-list li::marker {
  color: var(--accent);
  font-weight: 600;
}

.thesis {
  padding: 64px;
  background: var(--accent-soft);
}

blockquote {
  max-width: 930px;
  margin: 0;
  font-size: clamp(1.7rem, 4.5vw, 3.6rem);
  line-height: 1.12;
}

.text-link {
  display: inline-flex;
  margin-top: 12px;
  color: var(--text);
  font-weight: 600;
  text-decoration: none;
}

.site-footer {
  padding: 28px 0 36px;
  color: var(--muted);
  font-size: 0.86rem;
}

@media (max-width: 880px) {
  .site-header {
    align-items: flex-start;
    flex-direction: column;
    gap: 18px;
  }

  .hero,
  .split,
  .problem-grid {
    grid-template-columns: 1fr;
  }

  .hero {
    gap: 42px;
    padding: 62px 0 72px;
  }

  .problem-grid {
    border-left: 0;
  }

  .problem-card {
    border-right: 0;
  }

  .claim-card {
    max-width: 540px;
  }
}

@media (max-width: 560px) {
  .site-header,
  .site-footer,
  main {
    width: min(100% - 30px, 1060px);
  }

  .site-nav {
    flex-wrap: wrap;
    gap: 14px 20px;
  }

  .section {
    padding: 58px 0;
  }

  .claim-card,
  .problem-card,
  .thesis {
    padding: 22px;
  }

  .site-footer {
    align-items: flex-start;
    flex-direction: column;
  }
}