:root {
  --bg: #071018;
  --bg-2: #0e1c2b;
  --panel: #122433;
  --line: #234056;
  --ink: #e7f2f4;
  --muted: #93aeb8;
  --ice: #5eebc8;
  --ice-ink: #04241c;
  --amber: #f0b429;
  --focus: #f6e3a4;
  --display: Candara, "Segoe UI", sans-serif;
  --sans: "Segoe UI", sans-serif;
  --mono: Consolas, "Courier New", monospace;
  --max: 74rem;
  --mast: 4.5rem;
}

*,
*::before,
*::after {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }
}

body {
  margin: 0;
  color: var(--ink);
  background-color: var(--bg);
  background-image:
    linear-gradient(rgba(94, 235, 200, 0.045) 1px, transparent 1px),
    linear-gradient(90deg, rgba(94, 235, 200, 0.045) 1px, transparent 1px);
  background-size: 52px 52px;
  font-family: var(--sans);
  font-size: 1.05rem;
  line-height: 1.65;
}

body::before {
  content: "";
  position: fixed;
  inset: 0 auto 0 0;
  width: 6px;
  background: var(--ice);
  z-index: 40;
}

img {
  max-width: 100%;
  height: auto;
  display: block;
}

a {
  color: var(--ice);
}

a:focus-visible,
button:focus-visible {
  outline: 3px solid var(--focus);
  outline-offset: 3px;
}

.skip {
  position: absolute;
  left: 1rem;
  top: -4rem;
  background: var(--ice);
  color: var(--ice-ink);
  padding: 0.55rem 0.85rem;
  z-index: 50;
}

.skip:focus {
  top: 0.6rem;
}

.ticker {
  margin: 0;
  padding: 0.45rem 1.25rem 0.45rem 1.5rem;
  color: var(--muted);
  background: #050c12;
  border-bottom: 1px solid var(--line);
  font-family: var(--mono);
  font-size: 0.78rem;
  letter-spacing: 0.04em;
}

.mast {
  position: sticky;
  top: 0;
  z-index: 20;
  display: flex;
  align-items: center;
  gap: 1rem;
  min-height: var(--mast);
  padding: 0.7rem 1.25rem 0.7rem 1.5rem;
  background: #071018;
  border-bottom: 1px solid var(--line);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 0.7rem;
  color: var(--ink);
  text-decoration: none;
  font-family: var(--display);
  font-size: 1.25rem;
  letter-spacing: 0.02em;
}

.brand img {
  width: 32px;
  height: 32px;
}

.navbtn {
  display: none;
  margin-left: auto;
  min-height: 44px;
  min-width: 88px;
  border: 1px solid var(--line);
  background: var(--panel);
  color: var(--ink);
  font: inherit;
}

.railnav {
  display: flex;
  align-items: center;
  gap: 1.1rem;
  margin-left: auto;
}

.railnav a {
  color: var(--muted);
  text-decoration: none;
}

.railnav a[aria-current="true"] {
  color: var(--ink);
  box-shadow: inset 0 -2px 0 var(--ice);
}

.goto {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 48px;
  min-width: 15.5rem;
  padding: 0.65rem 1.2rem;
  border-radius: 999px;
  background: var(--ice);
  color: var(--ice-ink);
  text-decoration: none;
  font-weight: 700;
}

.railnav .goto {
  min-width: 14.5rem;
  color: var(--ice-ink);
  box-shadow: none;
}

.quiet {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 48px;
  min-width: 11rem;
  padding: 0.65rem 1rem;
  border-radius: 999px;
  border: 1px solid var(--line);
  color: var(--ink);
  text-decoration: none;
}

main {
  width: min(var(--max), calc(100% - 2.4rem));
  margin: 0 auto;
  padding-bottom: 3rem;
}

.hero {
  display: grid;
  grid-template-columns: 1.35fr 0.75fr;
  gap: 1.5rem;
  align-items: end;
  padding: 2.4rem 0 1.2rem;
}

.kicker {
  margin: 0 0 0.6rem;
  color: var(--amber);
  font-family: var(--mono);
  font-size: 0.82rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

h1,
h2,
h3 {
  font-family: var(--display);
  line-height: 1.12;
}

h1 {
  margin: 0 0 1rem;
  font-size: clamp(2.1rem, 4.6vw, 3.6rem);
  letter-spacing: -0.03em;
}

h2 {
  margin: 0;
  font-size: clamp(1.6rem, 3vw, 2.15rem);
}

h3 {
  margin: 0 0 0.45rem;
  font-size: 1.2rem;
}

.actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  margin-top: 1.3rem;
}

.ledger {
  margin: 0;
  padding: 0.4rem 1rem;
  background: var(--bg-2);
  border: 1px solid var(--line);
  border-left: 4px solid var(--amber);
}

.ledger p {
  display: grid;
  grid-template-columns: 6.2rem 1fr;
  gap: 0.5rem;
  margin: 0;
  padding: 0.75rem 0;
  border-bottom: 1px solid var(--line);
  font-family: var(--mono);
  font-size: 0.92rem;
}

.ledger p:last-child {
  border-bottom: 0;
}

.ledger span {
  color: var(--muted);
}

.block,
.caution {
  scroll-margin-top: calc(var(--mast) + 0.6rem);
  padding-top: 2.2rem;
}

.block-head {
  display: flex;
  align-items: baseline;
  gap: 0.8rem;
  margin-bottom: 0.8rem;
}

.num {
  color: var(--ice);
  font-family: var(--mono);
  font-size: 0.95rem;
}

.schema {
  margin: 1.2rem 0 1.4rem;
}

.schema img {
  width: min(100%, 560px);
  height: auto;
  aspect-ratio: 560 / 360;
  background: var(--bg-2);
  border: 1px solid var(--line);
  border-radius: 18px;
}

figcaption {
  margin-top: 0.45rem;
  color: var(--muted);
  font-size: 0.92rem;
}

.steps {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 0.9rem;
  margin: 1.2rem 0;
  padding: 0;
  list-style: none;
  counter-reset: step;
}

.steps li {
  margin: 0;
  padding: 1rem 1rem 1.1rem;
  background: var(--panel);
  border: 1px solid var(--line);
  border-top: 3px solid var(--ice);
  counter-increment: step;
}

.steps li::before {
  content: counter(step, decimal-leading-zero);
  display: block;
  margin-bottom: 0.45rem;
  color: var(--amber);
  font-family: var(--mono);
  font-size: 0.82rem;
}

.steps p,
.block > p,
.caution p,
article p,
.colophon p {
  margin: 0 0 1rem;
}

#mobile-login article {
  padding: 0.2rem 0 0.4rem;
  border-bottom: 1px solid var(--line);
}

#mobile-login article:last-child {
  border-bottom: 0;
}

.sheet {
  margin: 0 0 1.2rem;
}

.sheet div {
  display: grid;
  grid-template-columns: 11rem 1fr;
  gap: 1rem;
  padding: 0.85rem 0;
  border-top: 1px solid var(--line);
}

.sheet dt {
  color: var(--amber);
  font-family: var(--mono);
  font-size: 0.92rem;
}

.sheet dd {
  margin: 0;
}

.caution {
  margin-top: 1.5rem;
  padding: 1.3rem 1.2rem 0.4rem;
  background: #102033;
  border-left: 4px solid var(--amber);
}

.colophon {
  padding: 2rem 1.25rem 2.4rem 1.5rem;
  background: #050c12;
  border-top: 1px solid var(--line);
}

.colophon section {
  width: min(var(--max), 100%);
  margin: 0 auto 1.2rem;
  scroll-margin-top: calc(var(--mast) + 0.6rem);
}

.fine {
  width: min(var(--max), 100%);
  margin: 0 auto;
  color: var(--muted);
}

.fine ul {
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem 1.2rem;
  margin: 0 0 0.8rem;
  padding: 0;
  list-style: none;
}

.fine a {
  color: var(--ink);
}

@media (max-width: 860px) {
  .navbtn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
  }

  .railnav {
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    flex-direction: column;
    align-items: stretch;
    gap: 0.2rem;
    margin: 0;
    padding: 0.6rem 1rem 1rem;
    background: #071018;
    border-bottom: 1px solid var(--line);
  }

  .railnav.is-open {
    display: flex;
  }

  .railnav a {
    min-height: 44px;
    display: flex;
    align-items: center;
  }

  .railnav .goto {
    min-width: 0;
  }

  .hero,
  .steps,
  .sheet div {
    grid-template-columns: 1fr;
  }

  .goto,
  .quiet {
    width: 100%;
    min-width: 0;
  }
}