:root {
  --paper: #efe6d2;
  --ink: #1a1610;
  --muted: #6b5f4e;
  --copper: #b56a32;
  --oxide: #2f5d54;
  --gold: #c4a04a;
  --deep: #12100c;
  --line: #d3c4a6;
  --line-dark: #3a3428;
  --ease: cubic-bezier(0.22, 1, 0.36, 1);
  --serif: "Fraunces", "Iowan Old Style", "Palatino Linotype", serif;
  --mono: "IBM Plex Mono", ui-monospace, monospace;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
html, body { margin: 0; }
::selection { background: var(--copper); color: var(--paper); }
body {
  background: var(--paper);
  color: var(--ink);
  font-family: var(--mono);
  font-size: 15px;
  line-height: 1.55;
}

.skip {
  position: absolute;
  left: 1rem;
  top: -4rem;
  background: var(--gold);
  color: var(--deep);
  padding: 0.4rem 0.7rem;
  z-index: 90;
}
.skip:focus { top: 0.6rem; }

.progress {
  position: fixed;
  top: 0;
  left: 0;
  height: 3px;
  width: 0;
  background: linear-gradient(90deg, var(--copper), var(--gold));
  z-index: 60;
  transform-origin: left;
}
img { max-width: 100%; display: block; }
a { color: var(--copper); text-decoration-thickness: 1px; text-underline-offset: 3px; }
a:hover { color: var(--ink); }

.grain {
  pointer-events: none;
  position: fixed;
  inset: 0;
  z-index: 80;
  opacity: 0.07;
  mix-blend-mode: multiply;
  background-image: url("data:image/svg+xml;utf8,<svg xmlns='http://www.w3.org/2000/svg' width='160' height='160'><filter id='n'><feTurbulence type='fractalNoise' baseFrequency='0.85' numOctaves='2'/></filter><rect width='100%' height='100%' filter='url(%23n)'/></svg>");
}

nav {
  position: sticky;
  top: 0;
  z-index: 40;
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 1rem;
  padding: 0.7rem 6vw;
  background: color-mix(in srgb, var(--paper) 88%, transparent);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--line);
  font-size: 10px;
  letter-spacing: 0.12em;
  text-transform: uppercase;
}
nav .mark {
  font-family: var(--serif);
  font-weight: 700;
  letter-spacing: 0;
  text-transform: none;
  font-size: 1.15rem;
  white-space: nowrap;
  flex-shrink: 0;
}
nav .mark em { font-style: italic; color: var(--copper); font-weight: 400; }
nav ul { display: flex; gap: 1.2rem; list-style: none; margin: 0; padding: 0; flex-wrap: wrap; }
nav a { color: var(--muted); text-decoration: none; }
nav a:hover, nav a[aria-current="page"], nav a.is-here { color: var(--ink); }
nav a.is-here { box-shadow: inset 0 -2px 0 var(--copper); }

.banner {
  display: grid;
  grid-template-columns: 1fr 1fr 1fr;
  border-bottom: 1px solid var(--line);
  background: var(--paper);
  font-size: 0.72rem;
  letter-spacing: 0.04em;
}
.banner div {
  padding: 0.85rem 1.4rem;
  border-right: 1px solid var(--line);
}
.banner div:last-child { border-right: 0; }
.banner b { display: block; font-family: var(--serif); font-size: 0.95rem; color: var(--ink); letter-spacing: 0; font-weight: 600; }
.banner span { color: var(--muted); text-transform: uppercase; letter-spacing: 0.12em; font-size: 0.62rem; }

.pill .tag {
  display: inline-block;
  margin-top: 0.35rem;
  color: var(--copper);
  font-size: 0.58rem;
  letter-spacing: 0.14em;
}

.hero {
  min-height: 100vh;
  display: grid;
  grid-template-columns: 1.05fr 0.95fr;
  background:
    radial-gradient(ellipse at 80% 20%, #2a2218 0%, transparent 50%),
    var(--deep);
  color: var(--paper);
  position: relative;
  overflow: hidden;
}
.hero::before {
  content: "";
  position: absolute;
  inset: 0;
  background:
    repeating-linear-gradient(90deg, transparent 0 47px, rgba(196,160,74,0.06) 48px),
    repeating-linear-gradient(0deg, transparent 0 47px, rgba(181,106,50,0.05) 48px);
  pointer-events: none;
}
.hero-copy, .hero-stage { position: relative; z-index: 1; }
.hero-copy {
  padding: 8vh 6vw 8vh 7vw;
  display: flex;
  flex-direction: column;
  justify-content: center;
}
.kicker {
  font-size: 11px;
  letter-spacing: 0.22em;
  text-transform: uppercase;
  color: var(--gold);
  margin: 0 0 1.2rem;
}
h1 {
  font-family: var(--serif);
  font-weight: 500;
  font-optical-sizing: auto;
  font-size: clamp(3.2rem, 7vw, 6.4rem);
  line-height: 0.92;
  letter-spacing: -0.035em;
  margin: 0 0 1.2rem;
}
h1 i { font-style: italic; color: var(--copper); font-weight: 400; }
.lede {
  max-width: 42ch;
  color: #cfc3ab;
  font-size: 0.92rem;
  margin: 0 0 2rem;
}
.pills {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0.7rem;
  max-width: 28rem;
}
.pill {
  border: 1px solid var(--line-dark);
  padding: 0.85rem 0.95rem;
  background: #18150f;
}
.pill b {
  display: block;
  font-family: var(--serif);
  font-size: 1.85rem;
  color: var(--gold);
  font-weight: 500;
}
.pill span {
  display: block;
  color: #9a8f78;
  font-size: 0.68rem;
  letter-spacing: 0.06em;
  text-transform: uppercase;
}

.hero-stage {
  min-height: 70vh;
  border-left: 1px solid var(--line-dark);
  background:
    url("../media/board_iso_navy.png") center 58% / 88% no-repeat,
    radial-gradient(ellipse at 50% 70%, #2c241b 0%, #12100c 70%);
}
model-viewer {
  width: 100%;
  height: 100%;
  min-height: 70vh;
  --poster-color: transparent;
  background: radial-gradient(ellipse at 50% 70%, #2c241b 0%, #12100c 70%);
}
.orbit-hint {
  position: absolute;
  bottom: 1.4rem;
  right: 1.6rem;
  font-size: 10px;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: #8a7f6c;
}

section { padding: 5.5rem 7vw; scroll-margin-top: 4.2rem; }
h2 {
  font-family: var(--serif);
  font-weight: 500;
  font-size: clamp(2rem, 4vw, 3.1rem);
  letter-spacing: -0.03em;
  margin: 0 0 0.4rem;
}
.sec-kicker {
  font-size: 11px;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--copper);
  margin: 0 0 0.6rem;
}
.prose { max-width: 68ch; color: var(--muted); }
.prose strong { color: var(--ink); font-weight: 600; }
.rule { height: 1px; background: var(--line); border: 0; margin: 1.4rem 0 2rem; }

.triptych {
  display: grid;
  grid-template-columns: 1fr 1fr 1fr;
  gap: 1rem;
  margin-top: 2rem;
}
.card {
  background: #f7f0de;
  border: 1px solid var(--line);
  padding: 1.1rem 1.15rem 1.2rem;
}
.card h3 {
  font-family: var(--serif);
  font-size: 1.35rem;
  margin: 0 0 0.35rem;
  font-weight: 500;
}
.card p { margin: 0; color: var(--muted); font-size: 0.82rem; }
.card.goldfish h3 { color: var(--copper); }
.card.stubborn h3 { color: var(--oxide); }
.card.guard h3 { color: #8a7028; }

.figure { margin: 2rem 0 0; }
.figure img {
  width: 100%;
  border: 1px solid var(--line);
  background: #fbf6e8;
}
.figure figcaption {
  margin-top: 0.55rem;
  font-size: 0.72rem;
  color: var(--muted);
}

.deep { background: var(--deep); color: var(--paper); }
.deep a { color: var(--gold); }
.deep a:hover { color: var(--paper); }
.deep .prose, .deep .sec-kicker { color: #c4b69a; }
.deep h2 { color: var(--paper); }
.deep .figure img { border-color: var(--line-dark); }
.deep .rule { background: var(--line-dark); }

.arch-layout {
  display: grid;
  grid-template-columns: 0.88fr 1.12fr;
  gap: 2.4rem;
  align-items: start;
}
.arch-sticky { position: sticky; top: 4.4rem; }
.stack { display: grid; gap: 1.35rem; }
.block {
  display: grid;
  grid-template-columns: 5.4rem 1fr;
  gap: 1.2rem;
  border-top: 1px solid var(--line-dark);
  padding-top: 1.1rem;
}
.block .n {
  font-family: var(--serif);
  font-size: 2.4rem;
  color: var(--gold);
  line-height: 1;
}
.block h3 { font-family: var(--serif); margin: 0 0 0.3rem; font-weight: 500; font-size: 1.35rem; }
.block p { margin: 0; color: #c4b69a; font-size: 0.88rem; }
.eq { font-size: 0.78rem; color: var(--gold); margin-top: 0.45rem; }

table.data {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.82rem;
  margin: 1.4rem 0;
}
.table-wrap { overflow-x: auto; }
table.data th, table.data td {
  text-align: left;
  padding: 0.7rem 0.75rem;
  border-bottom: 1px solid var(--line);
}
table.data th {
  color: var(--muted);
  font-weight: 500;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  font-size: 0.68rem;
}
table.data tr.win td {
  background: color-mix(in srgb, var(--oxide) 14%, var(--paper));
  font-weight: 600;
}
.bad { color: var(--copper); }
.ok { color: var(--oxide); }

.grid2 { display: grid; grid-template-columns: 1fr 1fr; gap: 1.1rem; }
.grid3 { display: grid; grid-template-columns: 1fr 1fr 1fr; gap: 1rem; }
.cad-grid { display: grid; grid-template-columns: 1.15fr 0.85fr; gap: 1rem; align-items: start; }

.warn {
  border-left: 3px solid var(--copper);
  padding: 0.2rem 0 0.2rem 1rem;
  color: var(--muted);
}

pre {
  background: var(--deep);
  color: #efe6d2;
  padding: 1.1rem 1.2rem;
  overflow: auto;
  font-size: 0.78rem;
  border: 1px solid var(--line-dark);
}
code { font-family: var(--mono); }

footer {
  padding: 2.5rem 7vw 3.5rem;
  border-top: 1px solid var(--line);
  color: var(--muted);
  font-size: 0.78rem;
  display: grid;
  gap: 0.6rem;
}

.reveal {
  animation: rise 0.9s var(--ease) forwards;
  animation-timeline: view();
  animation-range: entry 0% cover 28%;
}
.reveal.is-in { animation: rise 0.8s var(--ease) both; }
@keyframes rise {
  from { opacity: 0; transform: translateY(28px); }
  to { opacity: 1; transform: none; }
}

.hw-viewer {
  position: relative;
  border: 1px solid var(--line-dark);
  min-height: 52vh;
  margin: 1.6rem 0 0;
}
.hw-viewer model-viewer { min-height: 52vh; }

.deep table.data th, .deep table.data td { border-bottom-color: var(--line-dark); color: #efe6d2; }
.deep table.data th { color: #9a8f78; }
.deep table.data tr.win td { background: color-mix(in srgb, var(--oxide) 22%, var(--deep)); }

.article {
  max-width: 46rem;
  margin: 0 auto;
  padding: 4.5rem 6vw 5rem;
}
.article h1 {
  font-size: clamp(2.4rem, 5vw, 3.8rem);
  margin-bottom: 0.5rem;
}
.article .meta {
  color: var(--muted);
  font-size: 0.78rem;
  margin: 0 0 2rem;
}
.article p, .article li { color: var(--ink); font-size: 0.95rem; line-height: 1.65; }
.article p { margin: 0 0 1.05rem; }
.article h2 {
  font-size: 1.55rem;
  margin: 2.1rem 0 0.7rem;
}
.article h3 {
  font-family: var(--serif);
  font-size: 1.2rem;
  font-weight: 500;
  margin: 1.6rem 0 0.55rem;
}
.article ul { padding-left: 1.15rem; margin: 0 0 1.2rem; }
.article .takes {
  list-style: none;
  padding: 0;
  margin: 0 0 1.4rem;
  counter-reset: take;
}
.article .takes li {
  position: relative;
  padding: 0.85rem 0 0.85rem 3.1rem;
  border-top: 1px solid var(--line);
  color: var(--ink);
}
.article .takes li:last-child { border-bottom: 1px solid var(--line); }
.article .takes li::before {
  counter-increment: take;
  content: counter(take, decimal-leading-zero);
  position: absolute;
  left: 0;
  top: 0.85rem;
  font-family: var(--serif);
  font-size: 1.15rem;
  color: var(--copper);
}
.article h2, .article h3 { scroll-margin-top: 5.6rem; }
.article .pull {
  font-family: var(--serif);
  font-size: 1.45rem;
  font-style: italic;
  font-weight: 400;
  line-height: 1.35;
  color: var(--copper);
  border-left: 2px solid var(--gold);
  padding-left: 1rem;
  margin: 1.6rem 0 1.8rem;
  max-width: 38ch;
}

.path-grid {
  display: grid;
  grid-template-columns: 1fr 1fr 1fr;
  gap: 1rem;
  margin: 2rem 0 1.6rem;
}
.path-card {
  border: 1px solid var(--line);
  background: #f7f0de;
  padding: 1.15rem 1.2rem 1.25rem;
}
.path-card span {
  display: block;
  font-size: 0.62rem;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--copper);
  margin-bottom: 0.45rem;
}
.path-card h3 {
  font-family: var(--serif);
  font-size: 1.35rem;
  font-weight: 500;
  margin: 0 0 0.4rem;
}
.path-card p { margin: 0; color: var(--muted); font-size: 0.82rem; }

.callout {
  border-left: 3px solid var(--gold);
  background: color-mix(in srgb, var(--gold) 10%, var(--paper));
  padding: 1rem 1.2rem;
  margin: 0.4rem 0 0;
  max-width: 78ch;
}
.callout p { margin: 0; color: var(--ink); font-size: 0.88rem; }

.glossary {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1.1rem 1.4rem;
  margin-top: 2rem;
}
.glossary article {
  border-top: 1px solid var(--line-dark);
  padding-top: 1rem;
}
.glossary h3 {
  font-family: var(--serif);
  font-size: 1.4rem;
  font-weight: 500;
  margin: 0 0 0.4rem;
  color: var(--gold);
}
.glossary p { margin: 0; color: #c4b69a; font-size: 0.86rem; }
.glossary strong { color: var(--paper); font-weight: 600; }

.pull-dark {
  font-family: var(--serif);
  font-size: clamp(1.35rem, 2.4vw, 1.85rem);
  font-style: italic;
  font-weight: 400;
  line-height: 1.35;
  color: var(--gold);
  border-left: 2px solid var(--copper);
  padding: 0.2rem 0 0.2rem 1.15rem;
  margin: 1.8rem 0;
  max-width: 42ch;
}

.method-stack { margin-top: 2rem; max-width: 58rem; }
.block.light {
  border-top-color: var(--line);
  grid-template-columns: 5.4rem 1fr;
}
.block.light .n { color: var(--copper); }
.block.light h3 { color: var(--ink); }
.block.light p { color: var(--muted); }
.block.light .eq { color: var(--oxide); }
.plain-label {
  font-size: 0.58rem;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--copper);
  margin: 0 0 0.35rem;
}

.layers {
  list-style: none;
  margin: 2rem 0 0;
  padding: 0;
  display: grid;
  gap: 0;
  border: 1px solid var(--line-dark);
}
.layers li {
  padding: 1.15rem 1.3rem 1.25rem;
  border-bottom: 1px solid var(--line-dark);
  background: linear-gradient(90deg, rgba(196,160,74,0.08), transparent 42%);
}
.layers li:nth-child(2) {
  background: linear-gradient(90deg, rgba(47,93,84,0.16), transparent 42%);
}
.layers li:nth-child(3) {
  background: linear-gradient(90deg, rgba(181,106,50,0.14), transparent 42%);
}
.layers li:last-child { border-bottom: 0; }
.layers span {
  display: block;
  font-size: 0.62rem;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--gold);
  margin-bottom: 0.25rem;
}
.layers b {
  display: block;
  font-family: var(--serif);
  font-size: 1.35rem;
  font-weight: 500;
  margin-bottom: 0.35rem;
}
.layers p { margin: 0; color: #c4b69a; font-size: 0.86rem; }

.fpga-plain {
  margin-top: 2.2rem;
  max-width: 68ch;
}
.fpga-plain h3,
.subhead {
  font-family: var(--serif);
  font-size: 1.45rem;
  font-weight: 500;
  margin: 2rem 0 0.6rem;
  color: var(--paper);
}
#limits .subhead { color: var(--paper); }
.fpga-plain p { margin: 0; color: #c4b69a; font-size: 0.9rem; }

.parts {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1rem;
  margin: 0 0 1.8rem;
}
.parts article {
  border: 1px solid var(--line);
  background: #f7f0de;
  padding: 1.05rem 1.15rem 1.15rem;
}
.parts h3 {
  font-family: var(--serif);
  font-size: 1.2rem;
  font-weight: 500;
  margin: 0 0 0.35rem;
}
.parts p { margin: 0; color: var(--muted); font-size: 0.82rem; }

.limits {
  max-width: 72ch;
  margin: 1.4rem 0 0;
  padding-left: 1.15rem;
  color: #c4b69a;
}
.limits li { margin: 0 0 0.85rem; }
.limits strong { color: var(--paper); }

@media (max-width: 900px) {
  .hero, .triptych, .grid2, .grid3, .cad-grid, .block, .arch-layout, .banner,
  .path-grid, .glossary, .parts { grid-template-columns: 1fr; }
  .arch-sticky { position: static; }
  nav ul { gap: 0.55rem 0.9rem; font-size: 10px; }
  .banner div { border-right: 0; border-bottom: 1px solid var(--line); }
  section { padding: 3.4rem 6vw; }
  .hero-copy { padding: 5rem 6vw 2rem; }
  .hero-stage { border-left: 0; border-top: 1px solid var(--line-dark); }
}

@media (max-width: 560px) {
  nav {
    flex-wrap: wrap;
    align-items: flex-start;
  }
  nav ul {
    flex: 1 1 100%;
    width: 100%;
  }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .reveal { animation: none; }
}