:root {
  --steel: #3d4f5c;
  --steel-deep: #1b252c;
  --mist: #d5dee5;
  --shop: #e9eff2;
  --chip: #f4f7f9;
  --oil: #6a7a32;
  --oil-deep: #3e4a1c;
  --oil-sheen: rgba(106, 122, 50, 0.18);
  --brass: #c4a035;
  --brass-dark: #8a7020;
  --ink: #1b252c;
  --muted: #5a6b76;
  --line: rgba(61, 79, 92, 0.22);
  --font-display: "Big Shoulders Text", sans-serif;
  --font-body: "Source Serif 4", Georgia, serif;
  --font-mono: "IBM Plex Mono", ui-monospace, monospace;
  --wrap: min(1120px, calc(100% - 2.5rem));
  --narrow: min(680px, calc(100% - 2.5rem));
}

*, *::before, *::after { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  color: var(--ink);
  background:
    radial-gradient(ellipse 80% 50% at 10% -10%, var(--oil-sheen), transparent 55%),
    linear-gradient(165deg, var(--shop) 0%, var(--chip) 45%, #dfe8ee 100%);
  font-family: var(--font-body);
  font-size: 1.0625rem;
  line-height: 1.65;
  min-height: 100vh;
}
img, svg { max-width: 100%; height: auto; display: block; }
a { color: var(--oil-deep); text-underline-offset: 0.18em; }
a:hover { color: var(--brass-dark); }
:focus-visible { outline: 2px solid var(--brass); outline-offset: 3px; }

.skip { position: absolute; left: -9999px; top: 0; background: var(--steel-deep); color: var(--chip); padding: 0.6rem 1rem; z-index: 100; }
.skip:focus { left: 0.75rem; top: 0.75rem; }

.wrap { width: var(--wrap); margin-inline: auto; }
.narrow { width: var(--narrow); margin-inline: auto; }

.top {
  position: sticky; top: 0; z-index: 20;
  backdrop-filter: blur(10px);
  background: color-mix(in srgb, var(--chip) 82%, transparent);
  border-bottom: 1px solid var(--line);
}
.top__row { display: flex; align-items: center; justify-content: space-between; gap: 1rem; padding: 0.85rem 0; }
.brand {
  display: inline-flex; align-items: center; gap: 0.65rem; text-decoration: none; color: var(--steel-deep);
  font-family: var(--font-display); font-weight: 700; font-size: 1.45rem; letter-spacing: 0.02em; text-transform: uppercase;
}
.brand__mark { width: 1.7rem; height: 1.7rem; flex-shrink: 0; }
.nav { display: flex; gap: 1.25rem; flex-wrap: wrap; }
.nav a { font-family: var(--font-mono); font-size: 0.78rem; letter-spacing: 0.04em; text-transform: uppercase; text-decoration: none; color: var(--steel); }
.nav a:hover { color: var(--brass-dark); }

.hero { position: relative; overflow: hidden; padding: 3.5rem 0 3rem; border-bottom: 1px solid var(--line); }
.hero::before {
  content: ""; position: absolute; inset: 0; pointer-events: none;
  background:
    repeating-linear-gradient(90deg, transparent, transparent 47px, rgba(61, 79, 92, 0.05) 47px, rgba(61, 79, 92, 0.05) 48px),
    radial-gradient(circle at 78% 42%, rgba(196, 160, 53, 0.16), transparent 42%),
    radial-gradient(circle at 18% 70%, var(--oil-sheen), transparent 38%);
  animation: oilDrift 18s ease-in-out infinite alternate;
}
@keyframes oilDrift {
  from { transform: translate3d(0, 0, 0) scale(1); opacity: 0.85; }
  to { transform: translate3d(-1.5%, 1%, 0) scale(1.03); opacity: 1; }
}
.hero__grid { position: relative; display: grid; grid-template-columns: 1.05fr 0.95fr; gap: 2.5rem; align-items: center; }
.pilot-label { margin: 0 0 0.75rem; font-family: var(--font-mono); font-size: 0.75rem; letter-spacing: 0.12em; text-transform: uppercase; color: var(--oil); }
.hero h1 {
  margin: 0 0 1rem; font-family: var(--font-display); font-weight: 700;
  font-size: clamp(2.4rem, 5.2vw, 3.75rem); line-height: 1.05; letter-spacing: 0.01em;
  text-transform: uppercase; color: var(--steel-deep); max-width: 14ch;
}
.hero__lead { margin: 0 0 1.5rem; color: var(--muted); max-width: 38ch; font-size: 1.08rem; }
.hero__art { margin: 0; position: relative; }
.hero__art svg {
  width: 100%; border: 1px solid var(--line);
  background: linear-gradient(145deg, #cfd9e1 0%, #eef3f6 55%, #c7d3dc 100%);
  box-shadow: inset 0 0 0 1px rgba(255, 255, 255, 0.35);
}
.bit-spin { transform-origin: 200px 160px; animation: bitSpin 14s linear infinite; }
@keyframes bitSpin { from { transform: rotate(0deg); } to { transform: rotate(360deg); } }

.btn {
  display: inline-block; padding: 0.7rem 1.15rem; background: var(--steel-deep); color: var(--chip);
  text-decoration: none; font-family: var(--font-mono); font-size: 0.78rem; letter-spacing: 0.06em;
  text-transform: uppercase; border: 1px solid var(--steel-deep); transition: background 0.2s, color 0.2s, border-color 0.2s;
}
.btn:hover { background: var(--brass); border-color: var(--brass); color: var(--steel-deep); }
.btn--ghost { background: transparent; color: var(--steel-deep); border-color: var(--steel); margin-left: 0.5rem; }
.btn--ghost:hover { background: var(--mist); border-color: var(--brass-dark); color: var(--steel-deep); }

.band { padding: 2.75rem 0; background: linear-gradient(90deg, rgba(62, 74, 28, 0.06), transparent 40%), var(--mist); border-bottom: 1px solid var(--line); }
.path { display: grid; grid-template-columns: repeat(3, 1fr); gap: 1.5rem; }
.path__step { position: relative; padding: 0.25rem 0 0.25rem 1rem; border-left: 3px solid var(--brass); }
.path__step h3 { margin: 0 0 0.4rem; font-family: var(--font-display); font-size: 1.35rem; text-transform: uppercase; letter-spacing: 0.03em; color: var(--steel-deep); }
.path__step p { margin: 0; color: var(--muted); font-size: 0.98rem; }
.path__n { font-family: var(--font-mono); font-size: 0.72rem; color: var(--oil); letter-spacing: 0.08em; margin-bottom: 0.35rem; }

.section { padding: 3rem 0; }
.section h2 { margin: 0 0 1.25rem; font-family: var(--font-display); font-size: clamp(1.8rem, 3vw, 2.35rem); text-transform: uppercase; letter-spacing: 0.03em; color: var(--steel-deep); }

.library { display: grid; gap: 0; }
.hole { display: grid; grid-template-columns: 4.5rem 1fr; gap: 1.25rem; padding: 1.35rem 0; border-top: 1px solid var(--line); }
.hole:last-child { border-bottom: 1px solid var(--line); }
.hole__n { font-family: var(--font-mono); font-size: 0.85rem; color: var(--brass-dark); padding-top: 0.35rem; }
.hole h3 { margin: 0 0 0.4rem; font-family: var(--font-display); font-size: 1.4rem; text-transform: uppercase; letter-spacing: 0.02em; }
.hole h3 a { text-decoration: none; color: var(--steel-deep); }
.hole h3 a:hover { color: var(--brass-dark); }
.hole p { margin: 0 0 0.55rem; color: var(--muted); }
.hole__more { font-family: var(--font-mono); font-size: 0.75rem; letter-spacing: 0.06em; text-transform: uppercase; text-decoration: none; color: var(--oil-deep); }

.standards { margin: 0; padding: 0; list-style: none; display: grid; gap: 0.85rem; }
.standards li { padding: 0.9rem 1rem; border-left: 3px solid var(--oil); background: color-mix(in srgb, var(--chip) 70%, white); }

.not-list { margin: 0; padding-left: 1.15rem; color: var(--muted); }
.not-list li { margin-bottom: 0.45rem; }

.faq { display: grid; gap: 0.85rem; }
.faq details { border: 1px solid var(--line); background: var(--chip); padding: 0.85rem 1rem; }
.faq summary { cursor: pointer; font-family: var(--font-display); font-size: 1.15rem; text-transform: uppercase; letter-spacing: 0.02em; color: var(--steel-deep); }
.faq p { margin: 0.65rem 0 0; color: var(--muted); }

.support-block {
  margin-top: 2rem; padding: 1.25rem 1.35rem; border: 1px solid var(--brass);
  background: linear-gradient(135deg, rgba(196, 160, 53, 0.12), transparent 55%), var(--chip);
}
.support-block h2 { margin-bottom: 0.5rem; }
.support-block p { margin: 0; color: var(--muted); }

.pagehead {
  padding: 2.75rem 0 1.5rem; border-bottom: 1px solid var(--line);
  background: radial-gradient(circle at 90% 20%, rgba(196, 160, 53, 0.12), transparent 40%), transparent;
}
.pagehead h1 { margin: 0 0 0.5rem; font-family: var(--font-display); font-size: clamp(2rem, 4vw, 2.8rem); text-transform: uppercase; letter-spacing: 0.02em; }
.pagehead__intro { margin: 0; color: var(--muted); max-width: 42ch; }

.paper { padding: 2.25rem 0 3rem; }
.prose h2 { margin: 1.75rem 0 0.6rem; font-family: var(--font-display); font-size: 1.45rem; text-transform: uppercase; letter-spacing: 0.02em; color: var(--steel-deep); }
.prose p { margin: 0 0 1rem; }
.prose ul { margin: 0 0 1rem; padding-left: 1.2rem; color: var(--muted); }
.prose .note { margin-top: 1.5rem; padding: 0.85rem 1rem; border-left: 3px solid var(--brass); background: var(--mist); color: var(--muted); font-size: 0.95rem; }

.foot { margin-top: 2rem; padding: 2.5rem 0 1.5rem; background: var(--steel-deep); color: var(--mist); }
.foot a { color: var(--brass); }
.foot a:hover { color: #e6c96a; }
.foot__grid { display: grid; grid-template-columns: 1.4fr 1fr; gap: 2rem; padding-bottom: 1.5rem; border-bottom: 1px solid rgba(213, 222, 229, 0.18); }
.foot__brand { display: inline-flex; align-items: center; gap: 0.55rem; margin: 0 0 0.65rem; font-family: var(--font-display); font-size: 1.25rem; text-transform: uppercase; letter-spacing: 0.03em; color: var(--chip); }
.foot__lead { margin: 0; color: rgba(213, 222, 229, 0.78); max-width: 38ch; }
.foot__nav { display: grid; grid-template-columns: 1fr 1fr; gap: 0.45rem 1rem; align-content: start; }
.foot__nav a { font-family: var(--font-mono); font-size: 0.75rem; letter-spacing: 0.05em; text-transform: uppercase; text-decoration: none; }
.foot__base { display: flex; justify-content: space-between; gap: 1rem; flex-wrap: wrap; padding-top: 1rem; font-size: 0.9rem; color: rgba(213, 222, 229, 0.65); }
.foot__base p { margin: 0; }

@media (max-width: 840px) {
  .hero__grid, .path, .foot__grid { grid-template-columns: 1fr; }
  .hero { padding-top: 2.5rem; }
  .hole { grid-template-columns: 3rem 1fr; }
}
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .hero::before, .bit-spin { animation: none; }
}