/* ─────────────────────────────────────────────────────────
   Structure-Centric ML — Editorial Design System
   ───────────────────────────────────────────────────────── */

:root {
  --paper:        #F4EDE0;
  --paper-deep:   #E8DFCC;
  --paper-soft:   #FAF5EA;
  --ink:          #1A1814;
  --ink-soft:     #3A342C;
  --ink-mute:     #6A6258;
  --rule:         #2C2820;
  --rule-soft:    #C8C0AE;
  --accent:       #B8412C;     /* warm red */
  --accent-soft:  #C9485B;
  --navy:         #2A4A6A;
  --navy-soft:    #3D6385;
  --good:         #4A6B47;
  --gold:         #B89530;
  --shadow:       rgba(40, 30, 20, 0.08);
}

* { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  background: var(--paper);
  color: var(--ink);
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
  font-size: 17px;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}
img { max-width: 100%; height: auto; display: block; }

/* ─── Typography ─── */
.serif       { font-family: 'Fraunces', 'Iowan Old Style', Georgia, serif; }
.mono        { font-family: 'JetBrains Mono', 'Menlo', monospace; }
h1, h2, h3, h4 { font-family: 'Fraunces', 'Iowan Old Style', Georgia, serif; }
h1 { font-weight: 700; letter-spacing: -0.04em; line-height: 0.96; }
h2 { font-weight: 600; letter-spacing: -0.025em; line-height: 1.06; }
h3 { font-weight: 600; letter-spacing: -0.015em; line-height: 1.18; }
em, .it { font-style: italic; }

a {
  color: var(--accent);
  text-decoration: none;
  border-bottom: 1px solid currentColor;
  transition: color 120ms ease, border-color 120ms ease;
}
a:hover { color: var(--ink); }

/* ─── Layout primitives ─── */
.container { max-width: 1240px; margin: 0 auto; padding: 0 48px; }
.narrow    { max-width: 820px;  margin: 0 auto; padding: 0 32px; }
.medium    { max-width: 1080px; margin: 0 auto; padding: 0 40px; }

@media (max-width: 720px) {
  .container, .medium, .narrow { padding-left: 24px; padding-right: 24px; }
  body { font-size: 16px; }
}

/* ─── Top navigation ─── */
.topnav {
  position: sticky; top: 0; z-index: 50;
  background: rgba(244, 237, 224, 0.92);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--rule-soft);
}
.topnav-inner {
  display: flex; align-items: center; justify-content: space-between;
  padding: 18px 48px; max-width: 1400px; margin: 0 auto;
}
.topnav .brand {
  font-family: 'Fraunces', serif;
  font-weight: 600; font-size: 17px;
  letter-spacing: -0.01em;
  color: var(--ink); border: none;
}
.topnav .brand .accent { color: var(--accent); font-style: italic; font-weight: 500; }
.topnav nav { display: flex; gap: 28px; align-items: center; }
.topnav nav a {
  color: var(--ink-soft); border: none;
  font-size: 14px; font-weight: 500;
  letter-spacing: 0.01em;
}
.topnav nav a:hover { color: var(--accent); }
.topnav nav a.current { color: var(--ink); }

@media (max-width: 720px) {
  .topnav-inner { padding: 14px 24px; flex-wrap: wrap; gap: 12px; }
  .topnav nav { gap: 18px; flex-wrap: wrap; }
  .topnav nav a { font-size: 13px; }
}

/* ─── Issue plate (top of every page) ─── */
.issue-plate {
  display: flex; justify-content: space-between; align-items: flex-start;
  border-top: 2px solid var(--rule);
  padding-top: 12px;
  font-family: 'JetBrains Mono', monospace;
  font-size: 11px;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--ink-soft);
  margin-bottom: 36px;
}
.issue-plate .right { text-align: right; }

/* ─── Hero / page header ─── */
.page-hero { padding: 60px 0 30px; }
.kicker {
  font-family: 'Fraunces', serif;
  font-style: italic; font-weight: 400;
  font-size: 22px; color: var(--ink-soft);
  margin-bottom: 16px; letter-spacing: -0.01em;
}
.page-hero h1 {
  font-size: clamp(48px, 7vw, 92px);
  margin-bottom: 24px;
}
.page-hero h1 .em { font-style: italic; font-weight: 400; color: var(--accent); }
.page-hero .lede {
  font-family: 'Fraunces', serif;
  font-size: clamp(20px, 2.2vw, 26px);
  line-height: 1.45;
  color: var(--ink-soft);
  max-width: 780px;
  margin-top: 24px;
}

/* ─── Section heading ─── */
.section { padding: 80px 0; }
.section-tag {
  font-family: 'JetBrains Mono', monospace;
  font-size: 12px; letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 14px;
  display: flex; align-items: center; gap: 12px;
}
.section-tag::before {
  content: ''; width: 36px; height: 1.5px;
  background: var(--accent); display: inline-block;
}
.section h2 {
  font-size: clamp(36px, 5vw, 60px);
  margin-bottom: 24px;
  letter-spacing: -0.03em;
}
.section h2 .em { font-style: italic; font-weight: 400; color: var(--accent); }
.section p {
  font-size: 18px;
  line-height: 1.7;
  color: var(--ink-soft);
  margin-bottom: 18px;
  max-width: 760px;
}
.section p strong { color: var(--ink); font-weight: 600; }

/* ─── Stat tiles ─── */
.stat-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 32px;
  margin: 48px 0;
}
.stat {
  border-top: 2px solid var(--rule);
  padding-top: 18px;
}
.stat .num {
  font-family: 'Fraunces', serif;
  font-weight: 700;
  font-size: clamp(44px, 5vw, 64px);
  line-height: 1;
  color: var(--ink);
  letter-spacing: -0.03em;
}
.stat .num .unit { font-weight: 400; font-size: 0.5em; color: var(--ink-mute); margin-left: 6px; }
.stat .label {
  font-family: 'JetBrains Mono', monospace;
  font-size: 11px;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--ink-soft);
  margin-top: 12px;
}
.stat .desc {
  font-size: 14px;
  color: var(--ink-soft);
  margin-top: 8px;
  line-height: 1.5;
}

/* ─── Cards ─── */
.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 24px;
  margin: 40px 0;
}
.card {
  background: var(--paper-soft);
  border: 1px solid var(--rule-soft);
  padding: 32px 28px;
  transition: transform 200ms ease, border-color 200ms ease;
}
.card:hover { transform: translateY(-2px); border-color: var(--ink-soft); }
.card .num {
  font-family: 'JetBrains Mono', monospace;
  font-size: 13px; color: var(--accent);
  letter-spacing: 0.12em;
  margin-bottom: 10px;
}
.card h3 {
  font-size: 24px;
  margin-bottom: 14px;
  color: var(--ink);
}
.card p {
  font-size: 15px;
  line-height: 1.6;
  color: var(--ink-soft);
  margin-bottom: 16px;
}
.card .arrow {
  font-family: 'JetBrains Mono', monospace;
  font-size: 12px; letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--accent);
  border: none;
}

/* ─── Figure (image + caption) ─── */
figure {
  margin: 40px 0;
  background: var(--paper-soft);
  border: 1px solid var(--rule-soft);
  padding: 16px;
}
figure img { width: 100%; }
figure figcaption {
  font-family: 'Fraunces', serif;
  font-size: 14px; font-style: italic;
  color: var(--ink-soft);
  margin-top: 14px;
  padding: 0 8px 4px;
  line-height: 1.5;
}
figure figcaption .src {
  font-family: 'JetBrains Mono', monospace;
  font-style: normal;
  font-size: 11px;
  color: var(--ink-mute);
  letter-spacing: 0.08em;
  text-transform: uppercase;
  margin-top: 6px;
  display: block;
}

/* ─── Big quote / callout ─── */
.callout {
  border-left: 3px solid var(--accent);
  padding: 24px 32px;
  margin: 48px 0;
  background: var(--paper-soft);
}
.callout .pull {
  font-family: 'Fraunces', serif;
  font-size: clamp(22px, 2.6vw, 30px);
  font-style: italic;
  line-height: 1.35;
  color: var(--ink);
  margin-bottom: 16px;
}
.callout .pull::before { content: '"'; }
.callout .pull::after  { content: '"'; }
.callout .attribution {
  font-family: 'JetBrains Mono', monospace;
  font-size: 11px;
  text-transform: uppercase;
  letter-spacing: 0.18em;
  color: var(--ink-soft);
}

/* ─── Tables ─── */
table {
  width: 100%; border-collapse: collapse;
  margin: 28px 0;
  font-size: 15px;
}
th, td {
  padding: 12px 14px; text-align: left;
  border-bottom: 1px solid var(--rule-soft);
}
th {
  font-family: 'JetBrains Mono', monospace;
  font-size: 11px; letter-spacing: 0.12em;
  text-transform: uppercase; color: var(--ink-soft);
  font-weight: 500;
  border-bottom: 2px solid var(--rule);
}
td.num, th.num { text-align: right; font-variant-numeric: tabular-nums; }
td.win { color: var(--good); font-weight: 600; }
td.loss { color: var(--accent); font-weight: 600; }
.bg-row { background: var(--paper-soft); }

/* ─── Stack diagram (used on Low-D / High-D pages) ─── */
.stack {
  display: grid; gap: 16px;
  margin: 40px 0;
}
.stack .layer {
  display: grid;
  grid-template-columns: 60px 1fr;
  gap: 24px; align-items: start;
  padding: 24px; background: var(--paper-soft);
  border: 1px solid var(--rule-soft);
}
.stack .layer .num {
  font-family: 'Fraunces', serif;
  font-weight: 800; font-size: 36px;
  line-height: 1; color: var(--accent);
  font-feature-settings: "lnum";
}
.stack .layer h3 { font-size: 22px; margin-bottom: 6px; }
.stack .layer .role {
  font-family: 'JetBrains Mono', monospace;
  font-size: 11px; letter-spacing: 0.12em;
  text-transform: uppercase; color: var(--ink-soft);
  margin-bottom: 10px;
}
.stack .layer p { font-size: 15px; margin-bottom: 0; }

/* ─── Footer ─── */
.site-footer {
  border-top: 2px solid var(--rule);
  margin-top: 100px;
  padding: 60px 0 50px;
  background: var(--paper-deep);
}
.site-footer .footer-inner {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr;
  gap: 48px;
  max-width: 1240px; margin: 0 auto;
  padding: 0 48px;
}
.site-footer h4 {
  font-family: 'JetBrains Mono', monospace;
  font-size: 11px; font-weight: 500;
  letter-spacing: 0.18em;
  text-transform: uppercase; color: var(--ink-soft);
  margin-bottom: 14px;
}
.site-footer .credit {
  font-family: 'Fraunces', serif; font-size: 14px;
  font-style: italic; color: var(--ink-soft);
  line-height: 1.5;
}
.site-footer ul { list-style: none; }
.site-footer ul li { margin-bottom: 8px; font-size: 14px; }
.site-footer a { color: var(--ink-soft); border: none; }
.site-footer a:hover { color: var(--accent); }
.site-footer .colophon {
  text-align: center; margin-top: 40px;
  font-family: 'JetBrains Mono', monospace;
  font-size: 11px; color: var(--ink-mute);
  letter-spacing: 0.1em;
}

@media (max-width: 720px) {
  .site-footer .footer-inner { grid-template-columns: 1fr; gap: 32px; padding: 0 24px; }
}

/* ─── Hero takeaway full-bleed ─── */
.full-bleed {
  width: 100%;
  margin: 60px 0;
  border: 1px solid var(--rule-soft);
}
.full-bleed img { width: 100%; display: block; }

/* ─── Misc helpers ─── */
.mt-0  { margin-top: 0 !important; }
.mt-2  { margin-top: 16px; }
.mt-4  { margin-top: 32px; }
.mt-6  { margin-top: 48px; }
.muted { color: var(--ink-mute); }
.divider { height: 1px; background: var(--rule-soft); margin: 60px 0; }
.heavy-divider { height: 2px; background: var(--rule); margin: 60px 0; }

.pillrow { display: flex; flex-wrap: wrap; gap: 8px; margin: 16px 0; }
.pill {
  font-family: 'JetBrains Mono', monospace;
  font-size: 11px; letter-spacing: 0.1em;
  text-transform: uppercase;
  padding: 4px 10px;
  border: 1px solid var(--rule-soft);
  color: var(--ink-soft);
  background: var(--paper-soft);
}
.pill.accent { color: var(--accent); border-color: var(--accent); }
.pill.good   { color: var(--good); border-color: var(--good); }