:root {
  --bg: #f4f2ec;
  --surface: #fbfaf6;
  --text: #181817;
  --muted: #6d6a62;
  --line: #d9d4c9;
  --accent: #2c4a9a;
  --accent-soft: #e7eaf5;
  --shadow: 0 20px 60px rgba(40, 35, 25, 0.07);
  --serif: "Iowan Old Style", "Palatino Linotype", Palatino, "Book Antiqua", Georgia, serif;
  --sans: Inter, ui-sans-serif, -apple-system, BlinkMacSystemFont, "Segoe UI", Helvetica, Arial, sans-serif;
  --mono: "SFMono-Regular", Consolas, "Liberation Mono", Menlo, monospace;
}

[data-theme="dark"] {
  --bg: #11110f;
  --surface: #171715;
  --text: #eeeae1;
  --muted: #aaa59a;
  --line: #34322d;
  --accent: #9db4ff;
  --accent-soft: #202b4a;
  --shadow: 0 20px 60px rgba(0, 0, 0, 0.26);
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: var(--sans);
  font-size: 16px;
  line-height: 1.65;
  text-rendering: optimizeLegibility;
  -webkit-font-smoothing: antialiased;
}

a { color: inherit; }
button { font: inherit; }

::selection { background: var(--accent-soft); }

.skip-link {
  position: fixed;
  top: 10px;
  left: 10px;
  z-index: 200;
  padding: 8px 12px;
  background: var(--text);
  color: var(--bg);
  transform: translateY(-160%);
}
.skip-link:focus { transform: translateY(0); }

.shell { width: min(1160px, calc(100% - 48px)); margin: 0 auto; }

.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  border-bottom: 1px solid color-mix(in srgb, var(--line) 82%, transparent);
  background: color-mix(in srgb, var(--bg) 88%, transparent);
  backdrop-filter: blur(15px);
}

.nav-wrap {
  min-height: 70px;
  display: grid;
  grid-template-columns: 1fr auto auto;
  align-items: center;
  gap: 28px;
}

.brand {
  width: max-content;
  display: inline-flex;
  align-items: center;
  gap: 11px;
  text-decoration: none;
  font-weight: 650;
  letter-spacing: -0.02em;
}

.brand-mark {
  display: grid;
  place-items: center;
  width: 31px;
  height: 31px;
  border: 1px solid var(--text);
  border-radius: 50%;
  font-family: var(--serif);
  font-size: 12px;
}

.nav { display: flex; align-items: center; gap: 24px; }
.nav a {
  color: var(--muted);
  text-decoration: none;
  font-size: 14px;
  transition: color 160ms ease;
}
.nav a:hover { color: var(--text); }

.theme-toggle {
  width: 34px;
  height: 34px;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: transparent;
  color: var(--text);
  cursor: pointer;
}
.theme-toggle:hover { border-color: var(--text); }

.hero {
  min-height: 650px;
  display: grid;
  grid-template-columns: minmax(0, 1.35fr) minmax(320px, 0.65fr);
  gap: 8vw;
  align-items: center;
  padding-top: 90px;
  padding-bottom: 92px;
}

.eyebrow {
  margin: 0 0 18px;
  color: var(--accent);
  font-size: 12px;
  font-weight: 750;
  letter-spacing: 0.14em;
  text-transform: uppercase;
}

.hero h1,
.section h2 {
  font-family: var(--serif);
  font-weight: 500;
  letter-spacing: -0.045em;
}

.hero h1 {
  max-width: 800px;
  margin: 0;
  font-size: clamp(56px, 7vw, 96px);
  line-height: 0.97;
}

.lede {
  max-width: 680px;
  margin: 32px 0 0;
  color: var(--muted);
  font-family: var(--serif);
  font-size: clamp(19px, 2vw, 24px);
  line-height: 1.5;
}

.hero-links { display: flex; flex-wrap: wrap; gap: 24px; margin-top: 32px; }
.text-link, .item-links a {
  text-decoration: none;
  border-bottom: 1px solid var(--text);
  padding-bottom: 2px;
  font-size: 14px;
  font-weight: 650;
}
.text-link:hover, .item-links a:hover { color: var(--accent); border-color: var(--accent); }

.equation-card {
  position: relative;
  min-height: 340px;
  display: flex;
  flex-direction: column;
  justify-content: center;
  padding: 40px;
  background:
    linear-gradient(var(--line) 1px, transparent 1px),
    linear-gradient(90deg, var(--line) 1px, transparent 1px),
    var(--surface);
  background-size: 34px 34px;
  border: 1px solid var(--line);
  box-shadow: var(--shadow);
  overflow: hidden;
}
.equation-card::before {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(135deg, color-mix(in srgb, var(--surface) 95%, transparent), transparent 70%);
  pointer-events: none;
}
.equation-card > * { position: relative; z-index: 1; }
.equation-kicker { color: var(--muted); font-size: 12px; text-transform: uppercase; letter-spacing: 0.12em; }
.equation {
  margin: 30px 0 24px;
  font-family: var(--serif);
  font-style: italic;
  font-size: clamp(31px, 3.1vw, 44px);
  letter-spacing: -0.025em;
  white-space: nowrap;
}
.equation sub { font-size: 0.52em; }
.equation-card p { margin: 0; max-width: 330px; color: var(--muted); font-size: 14px; }
.corner-note { position: absolute; right: 18px; bottom: 14px; color: var(--muted); font-family: var(--mono); font-size: 10px; }

.section { padding: 108px 0; border-top: 1px solid var(--line); }
.section-heading { margin-bottom: 48px; }
.section h2 { margin: 0; font-size: clamp(38px, 4.5vw, 61px); line-height: 1.05; }
.split-heading { display: grid; grid-template-columns: 1fr minmax(260px, 0.45fr); gap: 48px; align-items: end; }
.section-note { margin: 0 0 5px; color: var(--muted); max-width: 440px; }

.featured-item {
  display: grid;
  grid-template-columns: 150px 1fr;
  gap: 40px;
  padding: 38px 0 48px;
  border-top: 1px solid var(--text);
  border-bottom: 1px solid var(--line);
}
.item-year { font-family: var(--serif); font-size: 26px; }
.item-meta { margin-bottom: 7px; color: var(--accent); font-size: 12px; font-weight: 750; letter-spacing: 0.1em; text-transform: uppercase; }
.item-main h3 { margin: 0; max-width: 850px; font-family: var(--serif); font-size: clamp(29px, 3.4vw, 47px); font-weight: 500; line-height: 1.14; letter-spacing: -0.035em; }
.authors { margin: 16px 0 0; color: var(--muted); }
.item-description { max-width: 780px; margin: 22px 0 0; color: var(--muted); }
.item-links { display: flex; gap: 20px; margin-top: 25px; }

.interest-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 1px; margin-top: 70px; background: var(--line); border: 1px solid var(--line); }
.interest-card { min-height: 240px; padding: 30px; background: var(--bg); }
.interest-card span { color: var(--accent); font-family: var(--mono); font-size: 11px; }
.interest-card h3 { margin: 30px 0 10px; font-family: var(--serif); font-size: 25px; font-weight: 500; letter-spacing: -0.025em; }
.interest-card p { margin: 0; color: var(--muted); font-size: 14px; }

.archive-list { border-top: 1px solid var(--text); }
.archive-row {
  display: grid;
  grid-template-columns: 130px 1fr 100px;
  gap: 28px;
  align-items: center;
  padding: 28px 0;
  border-bottom: 1px solid var(--line);
}
.archive-date { font-family: var(--serif); font-size: 24px; }
.archive-main h3 { margin: 0; font-family: var(--serif); font-size: 24px; font-weight: 500; letter-spacing: -0.025em; }
.archive-main p { margin: 5px 0 0; color: var(--muted); font-size: 14px; }
.archive-actions { text-align: right; }
.muted-action { color: var(--muted); font-family: var(--mono); font-size: 12px; text-transform: uppercase; }
.template-row { opacity: 0.56; }
code { font-family: var(--mono); font-size: 0.9em; }

.resource-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 18px; }
.resource-card {
  min-height: 320px;
  display: flex;
  flex-direction: column;
  padding: 28px;
  border: 1px solid var(--line);
  background: var(--surface);
  text-decoration: none;
  transition: transform 180ms ease, border-color 180ms ease, box-shadow 180ms ease;
}
a.resource-card:hover { transform: translateY(-4px); border-color: var(--text); box-shadow: var(--shadow); }
.resource-type { color: var(--accent); font-family: var(--mono); font-size: 11px; letter-spacing: 0.08em; text-transform: uppercase; }
.resource-card h3 { margin: 40px 0 14px; font-family: var(--serif); font-size: 30px; font-weight: 500; line-height: 1.15; letter-spacing: -0.03em; }
.resource-card p { margin: 0; color: var(--muted); font-size: 14px; }
.resource-arrow { margin-top: auto; padding-top: 26px; font-size: 13px; font-weight: 650; }
.ghost-card { background: transparent; }

.compact-section { padding-bottom: 84px; }
.about-line { display: grid; grid-template-columns: 1fr 1fr; gap: 80px; align-items: end; }
.about-line h2 { max-width: 620px; }
.about-line > p { margin: 0 0 8px; color: var(--muted); font-family: var(--serif); font-size: 20px; }

.site-footer { border-top: 1px solid var(--line); padding: 30px 0 44px; }
.footer-wrap { display: flex; justify-content: space-between; gap: 20px; color: var(--muted); font-size: 12px; }
.footer-wrap p { margin: 0; }
.footer-wrap a { text-decoration: none; border-bottom: 1px solid var(--line); }

@media (max-width: 900px) {
  .hero { grid-template-columns: 1fr; min-height: auto; gap: 58px; padding-top: 76px; }
  .equation-card { min-height: 280px; }
  .interest-grid, .resource-grid { grid-template-columns: 1fr; }
  .interest-card { min-height: 190px; }
  .split-heading, .about-line { grid-template-columns: 1fr; gap: 22px; }
  .featured-item { grid-template-columns: 90px 1fr; }
}

@media (max-width: 680px) {
  .shell { width: min(100% - 30px, 1160px); }
  .site-header { position: static; }
  .nav-wrap { min-height: 64px; grid-template-columns: 1fr auto; }
  .nav { display: none; }
  .brand-text { display: none; }
  .hero { padding-top: 58px; padding-bottom: 72px; }
  .hero h1 { font-size: clamp(49px, 16vw, 70px); }
  .lede { font-size: 19px; }
  .equation-card { padding: 28px; min-height: 250px; }
  .equation { white-space: normal; }
  .section { padding: 76px 0; }
  .featured-item { grid-template-columns: 1fr; gap: 15px; }
  .archive-row { grid-template-columns: 56px 1fr; gap: 16px; }
  .archive-actions { display: none; }
  .resource-card { min-height: 270px; }
  .footer-wrap { flex-direction: column; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { transition: none !important; }
}