/* Theory of the Intersection of Fields — intersection-fields.org
   Sober academic landing site. One accent, one geometric motif (the interface Σ). */

:root {
  --paper:      #FBFBF8;
  --ink:        #17181A;
  --muted:      #63656B;
  --rule:       #E4E4DF;
  --accent:     #2B4A6F;   /* deep, quiet ink-blue */
  --accent-ink: #21395A;
  --tint:       #F1F4F8;   /* very light accent surface, used once */
  --measure:    68ch;
}

*{ box-sizing: border-box; }

html { -webkit-text-size-adjust: 100%; }

body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: "Source Serif 4", Charter, Georgia, "Times New Roman", serif;
  font-size: 19px;
  line-height: 1.62;
  font-weight: 380;
  text-rendering: optimizeLegibility;
  -webkit-font-smoothing: antialiased;
}

.wrap {
  max-width: 46rem;
  margin: 0 auto;
  padding: 0 1.5rem;
}

/* ---- header ---- */
.site-head {
  border-bottom: 1px solid var(--rule);
}
.site-head .wrap {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 1rem;
  padding-top: 1.4rem;
  padding-bottom: 1.4rem;
}
.brand {
  font-size: 1.02rem;
  font-weight: 600;
  letter-spacing: 0.01em;
  color: var(--ink);
  text-decoration: none;
}
.brand:hover { color: var(--accent); }
.nav a {
  color: var(--muted);
  text-decoration: none;
  font-size: 0.95rem;
  margin-left: 1.3rem;
}
.nav a:hover { color: var(--accent); text-decoration: underline; text-underline-offset: 3px; }

/* ---- hero ---- */
.hero { padding: 4.2rem 0 2.6rem; }
.hero h1 {
  font-size: clamp(2.1rem, 5.4vw, 3.15rem);
  line-height: 1.08;
  font-weight: 560;
  letter-spacing: -0.012em;
  margin: 0 0 0.9rem;
}
.hero .lede {
  font-size: 1.24rem;
  color: var(--muted);
  max-width: 40rem;
  margin: 0 0 2rem;
  line-height: 1.5;
}

/* the interface Σ motif — the three-field junction */
.sigma-fig {
  margin: 2rem auto 0.5rem;
  max-width: 26rem;
  text-align: center;
}
.sigma {
  display: block;
  width: 100%;
  max-width: 16rem;
  height: auto;
  margin: 0 auto;
}
.sigma-fig figcaption {
  font-size: 1.14rem;
  color: var(--muted);
  margin: 0.9rem auto 0;
  max-width: 26rem;
  line-height: 1.45;
  text-align: center;
}

/* ---- generic prose ---- */
p { max-width: var(--measure); }
a { color: var(--accent); text-decoration-thickness: 1px; text-underline-offset: 2px; }
a:hover { color: var(--accent-ink); }

h2 {
  font-size: 1.42rem;
  font-weight: 560;
  letter-spacing: -0.005em;
  margin: 3rem 0 1rem;
  padding-top: 1.4rem;
  border-top: 1px solid var(--rule);
}
h2.no-rule { border-top: none; padding-top: 0; margin-top: 2.2rem; }

.eq {
  font-variant-numeric: tabular-nums;
  white-space: nowrap;
}

/* ---- works list (home) ---- */
.work {
  padding: 1.8rem 0;
  border-top: 1px solid var(--rule);
}
.work:last-of-type { border-bottom: 1px solid var(--rule); }
.work h3 {
  font-size: 1.28rem;
  font-weight: 560;
  line-height: 1.25;
  margin: 0 0 0.5rem;
}
.work h3 a { color: var(--ink); text-decoration: none; }
.work h3 a:hover { color: var(--accent); }
.work .meta {
  font-size: 0.92rem;
  color: var(--muted);
  margin: 0 0 0.7rem;
}
.work p { margin: 0.4rem 0 0.9rem; font-size: 1.02rem; color: #2C2E33; }
.work .links a {
  font-size: 0.95rem;
  margin-right: 1.4rem;
  white-space: nowrap;
}

/* ---- predictions strip ---- */
.preds {
  background: var(--tint);
  border: 1px solid #E3E9F1;
  border-radius: 3px;
  padding: 1.3rem 1.5rem;
  margin: 1.6rem 0;
}
.preds ul { margin: 0.4rem 0 0; padding-left: 1.1rem; }
.preds li { margin: 0.3rem 0; font-size: 1.0rem; }
.preds .cap { font-size: 0.9rem; color: var(--muted); margin: 0; }

/* ---- landing page article ---- */
.article-meta {
  color: var(--muted);
  font-size: 0.98rem;
  margin: 0.4rem 0 1.8rem;
  line-height: 1.5;
}
.abstract { font-size: 1.06rem; }
.actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.7rem;
  margin: 1.8rem 0 0.6rem;
}
.btn {
  display: inline-block;
  padding: 0.55rem 1.1rem;
  border-radius: 3px;
  font-size: 0.98rem;
  text-decoration: none;
  border: 1px solid var(--accent);
}
.btn-primary { background: var(--accent); color: #fff; }
.btn-primary:hover { background: var(--accent-ink); color: #fff; }
.btn-ghost { color: var(--accent); background: transparent; }
.btn-ghost:hover { background: var(--tint); }

.doi {
  font-family: ui-monospace, "SFMono-Regular", Menlo, Consolas, monospace;
  font-size: 0.9rem;
  color: var(--muted);
  word-break: break-all;
}
.cite {
  font-size: 0.95rem;
  color: #2C2E33;
  background: #F6F6F3;
  border-left: 2px solid var(--rule);
  padding: 0.9rem 1.1rem;
  margin: 1.2rem 0;
  line-height: 1.5;
}

/* ---- footer ---- */
.site-foot {
  border-top: 1px solid var(--rule);
  margin-top: 4rem;
  padding: 2rem 0 3rem;
  color: var(--muted);
  font-size: 0.9rem;
}
.site-foot a { color: var(--muted); }
.site-foot p { margin: 0.3rem 0; }

/* ---- small screens ---- */
@media (max-width: 560px) {
  body { font-size: 18px; }
  .site-head .wrap { flex-direction: column; gap: 0.5rem; }
  .nav a { margin-left: 0; margin-right: 1.2rem; }
  .hero { padding-top: 3rem; }
}

@media (prefers-reduced-motion: no-preference) {
  a, .btn { transition: color .15s ease, background-color .15s ease; }
}

:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; }