:root {
  --ink: #1c1916;
  --muted: #5c564e;
  --paper: #f7f3ee;
  --card: #fffdf9;
  --line: #e6dfd4;
  --orange: #e86a12;
  --orange-dark: #c4530a;
  --orange-soft: #fff1e4;
  --max: 72rem;
  --read: 42rem;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  font-family: "Iowan Old Style", "Palatino Linotype", Palatino, Georgia, serif;
  color: var(--ink);
  background: var(--paper);
  line-height: 1.65;
  font-size: 1.125rem;
}

a { color: var(--orange-dark); }
a:hover { color: var(--ink); }

.skip {
  position: absolute;
  left: -999px;
  top: 0;
  background: var(--ink);
  color: #fff;
  padding: 0.5rem 1rem;
}
.skip:focus { left: 0; z-index: 10; }

.topbar {
  background: var(--ink);
  color: #fff;
  font-family: ui-sans-serif, system-ui, sans-serif;
  font-size: 0.8rem;
  letter-spacing: 0.04em;
  padding: 0.45rem 1.25rem;
  display: flex;
  justify-content: space-between;
  gap: 1rem;
  flex-wrap: wrap;
}
.topbar a { color: #fff; text-decoration: none; }
.topbar a:hover { color: #ffd0a8; }

.site-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1.5rem;
  padding: 1rem 1.5rem;
  border-bottom: 1px solid var(--line);
  background: var(--card);
  position: sticky;
  top: 0;
  z-index: 5;
}
.logo {
  font-family: ui-sans-serif, system-ui, sans-serif;
  font-weight: 700;
  letter-spacing: -0.03em;
  text-decoration: none;
  color: var(--ink);
  font-size: 1.05rem;
}
.logo span { color: var(--orange); }
.nav {
  display: flex;
  gap: 1.1rem;
  flex-wrap: wrap;
  font-family: ui-sans-serif, system-ui, sans-serif;
  font-size: 0.88rem;
}
.nav a { text-decoration: none; color: var(--muted); }
.nav a:hover, .nav a[aria-current="page"] { color: var(--ink); }

.hero-index {
  padding: 3.5rem 1.5rem 2rem;
  max-width: var(--max);
  margin: 0 auto;
}
.kicker {
  font-family: ui-sans-serif, system-ui, sans-serif;
  font-size: 0.75rem;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--orange);
  font-weight: 700;
  margin: 0 0 0.6rem;
}
.hero-index h1 {
  font-size: clamp(2rem, 4vw, 3.4rem);
  line-height: 1.1;
  letter-spacing: -0.03em;
  margin: 0 0 0.8rem;
  max-width: 18ch;
}
.lede {
  max-width: 40rem;
  color: var(--muted);
  font-size: 1.2rem;
}

.grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(16.5rem, 1fr));
  gap: 1.25rem;
  max-width: var(--max);
  margin: 0 auto 4rem;
  padding: 0 1.5rem;
}
.card {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 1rem;
  overflow: hidden;
  text-decoration: none;
  color: inherit;
  display: flex;
  flex-direction: column;
  transition: transform 0.15s ease, box-shadow 0.15s ease;
}
.card:hover {
  transform: translateY(-3px);
  box-shadow: 0 12px 30px rgba(28, 25, 22, 0.08);
}
.card img { width: 100%; height: 14rem; object-fit: cover; }
.card-body { padding: 1.1rem 1.15rem 1.3rem; }
.card time, .meta {
  font-family: ui-sans-serif, system-ui, sans-serif;
  font-size: 0.75rem;
  color: var(--muted);
  letter-spacing: 0.04em;
}
.card h2, .card h3 {
  font-size: 1.25rem;
  line-height: 1.25;
  margin: 0.35rem 0 0.45rem;
  letter-spacing: -0.02em;
}
.card p { margin: 0; color: var(--muted); font-size: 0.98rem; }

.wrap {
  display: grid;
  grid-template-columns: 16rem minmax(0, var(--read));
  gap: 2.5rem;
  max-width: var(--max);
  margin: 0 auto;
  padding: 2rem 1.5rem 4rem;
}
@media (max-width: 900px) {
  .wrap { grid-template-columns: 1fr; }
  .toc { position: static !important; }
}

.toc {
  position: sticky;
  top: 5rem;
  align-self: start;
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 0.9rem;
  padding: 1rem 1rem 1.1rem;
  font-family: ui-sans-serif, system-ui, sans-serif;
  font-size: 0.82rem;
}
.toc h2 {
  font-size: 0.72rem;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  margin: 0 0 0.7rem;
  color: var(--muted);
}
.toc ol { margin: 0; padding-left: 1.1rem; color: var(--muted); }
.toc a { text-decoration: none; color: var(--ink); }
.toc a:hover { color: var(--orange-dark); }

article h1 {
  font-size: clamp(1.8rem, 3.4vw, 2.7rem);
  line-height: 1.15;
  letter-spacing: -0.03em;
  margin: 0.2rem 0 0.7rem;
}
article h2 {
  font-size: 1.55rem;
  letter-spacing: -0.02em;
  margin: 2.2rem 0 0.7rem;
}
article h3 { font-size: 1.28rem; margin: 1.6rem 0 0.5rem; }
article h4 { font-size: 1.12rem; margin: 1.3rem 0 0.4rem; }
article h5 { font-size: 1.02rem; margin: 1.1rem 0 0.35rem; }
article h6 {
  font-size: 0.95rem;
  margin: 1rem 0 0.3rem;
  font-family: ui-sans-serif, system-ui, sans-serif;
}
.h7 {
  font-family: ui-sans-serif, system-ui, sans-serif;
  font-size: 0.78rem;
  font-weight: 700;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--orange-dark);
  margin: 1.1rem 0 0.35rem;
}

.hero-img {
  width: 100%;
  border-radius: 1rem;
  display: block;
  margin: 1rem 0 1.4rem;
  border: 1px solid var(--line);
}

table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.95rem;
  background: var(--card);
  margin: 1rem 0 1.4rem;
  font-family: ui-sans-serif, system-ui, sans-serif;
}
th, td {
  border: 1px solid var(--line);
  padding: 0.7rem 0.8rem;
  text-align: left;
  vertical-align: top;
}
th { background: var(--orange-soft); font-size: 0.78rem; letter-spacing: 0.04em; text-transform: uppercase; }

.cta {
  border-radius: 0.9rem;
  padding: 1.1rem 1.2rem;
  margin: 1.4rem 0;
  font-family: ui-sans-serif, system-ui, sans-serif;
}
.cta h2, .cta h3 { margin-top: 0; }
.cta p { margin: 0.35rem 0 0.9rem; }
.cta-row { display: flex; flex-wrap: wrap; gap: 0.55rem; }
.btn {
  display: inline-block;
  text-decoration: none;
  border-radius: 999px;
  padding: 0.55rem 1rem;
  font-size: 0.88rem;
  font-weight: 700;
}
.btn-buy { background: var(--orange); color: #fff; }
.btn-buy:hover { background: var(--orange-dark); color: #fff; }
.btn-do { background: var(--ink); color: #fff; }
.btn-do:hover { color: #ffd0a8; }
.btn-info {
  background: transparent;
  color: var(--ink);
  border: 1px solid var(--ink);
}
.cta-commercial { background: var(--orange-soft); border: 1px solid #f3d2b3; }
.cta-transactional { background: var(--ink); color: #fff; }
.cta-transactional h2, .cta-transactional h3 { color: #fff; }
.cta-transactional a { color: #ffd0a8; }
.cta-transactional p { color: #e8e2da; }
.cta-transactional .btn-info {
  color: #fff;
  border-color: #fff;
}
.cta-transactional .btn-buy { color: #fff; }
.cta-info { background: var(--card); border: 1px solid var(--line); }

.crumbs {
  font-family: ui-sans-serif, system-ui, sans-serif;
  font-size: 0.8rem;
  color: var(--muted);
  margin: 0 0 1rem;
}
.crumbs a { color: var(--muted); text-decoration: none; }
.crumbs a:hover { color: var(--ink); }
.crumbs ol { list-style: none; padding: 0; margin: 0; display: flex; flex-wrap: wrap; gap: 0.35rem; }
.crumbs li:not(:last-child)::after { content: "/"; margin-left: 0.35rem; color: var(--line); }

.index-table {
  max-width: var(--max);
  margin: 0 auto 2rem;
  padding: 0 1.5rem;
}
.index-table h2 {
  font-size: 1.1rem;
  margin: 0 0 0.6rem;
}

.blog-band {
  padding: 2.5rem 0 1rem;
  border-top: 1px solid var(--line);
}

.related {
  display: grid;
  gap: 0.6rem;
  margin: 1rem 0 0;
}
.related a {
  font-family: ui-sans-serif, system-ui, sans-serif;
  text-decoration: none;
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 0.7rem;
  padding: 0.75rem 0.9rem;
  color: var(--ink);
}
.related a:hover { border-color: var(--orange); }

details {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 0.7rem;
  padding: 0.75rem 0.95rem;
  margin: 0.5rem 0;
}
summary {
  cursor: pointer;
  font-family: ui-sans-serif, system-ui, sans-serif;
  font-weight: 700;
}
details p { margin: 0.55rem 0 0.15rem; color: var(--muted); }

.site-footer {
  border-top: 1px solid var(--line);
  padding: 2rem 1.5rem 2.5rem;
  font-family: ui-sans-serif, system-ui, sans-serif;
  font-size: 0.88rem;
  color: var(--muted);
  text-align: center;
}
.site-footer a { color: var(--ink); }

ul.plain { padding-left: 1.2rem; }
.figure-note {
  font-family: ui-sans-serif, system-ui, sans-serif;
  font-size: 0.8rem;
  color: var(--muted);
  margin: -0.9rem 0 1.4rem;
}

@media (max-width: 800px) {
  .site-header { flex-wrap: wrap; align-items: flex-start; }
  .nav { width: 100%; gap: 0.65rem 0.9rem; }
  article h1 { overflow-wrap: anywhere; }
}
.nav a[href="/engines/"] { font-weight: 700; color: var(--ink); }