:root {
  --prussian: #061428;
  --plate: #0a1f3d;
  --cyanotype: #1e5aa8;
  --cyan-mid: #2f7fd4;
  --bleach: #e8f0f7;
  --sun: #f5f8fc;
  --ink: #061018;
  --muted: #4a6078;
  --rust: #c45c26;
  --line: rgba(30, 90, 168, 0.28);
  --font-display: "Literata", "Iowan Old Style", Georgia, serif;
  --font-body: "Source Sans 3", "Source Sans Pro", system-ui, sans-serif;
  --font-mono: "IBM Plex Mono", ui-monospace, monospace;
  --max: 68rem;
  --pad: clamp(1.25rem, 4vw, 2.5rem);
}

*, *::before, *::after { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  color: var(--ink);
  background: var(--sun);
  font-family: var(--font-body);
  font-size: 1.0625rem;
  line-height: 1.65;
  background-image:
    radial-gradient(ellipse 120% 80% at 10% -10%, rgba(30, 90, 168, 0.12), transparent 55%),
    linear-gradient(180deg, var(--bleach) 0%, var(--sun) 28%, var(--sun) 100%);
  min-height: 100vh;
}
img { max-width: 100%; height: auto; }
a { color: var(--cyanotype); text-underline-offset: 0.18em; }
a:hover { color: var(--rust); }
a:focus-visible, button:focus-visible {
  outline: 2px solid var(--rust);
  outline-offset: 3px;
}

.skip {
  position: absolute;
  left: -999px;
  top: 0;
  background: var(--prussian);
  color: var(--sun);
  padding: 0.5rem 1rem;
  z-index: 100;
}
.skip:focus { left: var(--pad); top: 0.5rem; }

.wrap { width: min(100% - 2 * var(--pad), var(--max)); margin-inline: auto; }

.site-header {
  position: sticky;
  top: 0;
  z-index: 40;
  backdrop-filter: blur(10px);
  background: color-mix(in srgb, var(--sun) 86%, transparent);
  border-bottom: 1px solid var(--line);
}
.site-header .bar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  padding: 0.9rem 0;
}
.brand {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 1.2rem;
  letter-spacing: -0.02em;
  color: var(--prussian);
  text-decoration: none;
}
.brand span { color: var(--cyanotype); }
.nav {
  display: flex;
  flex-wrap: wrap;
  gap: 0.85rem 1.15rem;
  font-size: 0.95rem;
}
.nav a { color: var(--plate); text-decoration: none; }
.nav a:hover { color: var(--cyanotype); text-decoration: underline; }

.hero {
  position: relative;
  isolation: isolate;
  overflow: hidden;
  min-height: min(88vh, 42rem);
  display: grid;
  align-items: end;
  padding: clamp(3rem, 10vh, 6rem) 0 clamp(2.5rem, 6vh, 4rem);
  color: var(--sun);
  background:
    linear-gradient(165deg, rgba(6, 20, 40, 0.35) 0%, rgba(6, 20, 40, 0.72) 48%, rgba(6, 20, 40, 0.92) 100%),
    radial-gradient(circle at 78% 22%, rgba(47, 127, 212, 0.45), transparent 42%),
    linear-gradient(120deg, var(--prussian), var(--plate) 55%, #123a6a);
}
.hero::before {
  content: "";
  position: absolute;
  inset: -10% -5%;
  z-index: -1;
  background:
    repeating-linear-gradient(
      12deg,
      transparent 0 18px,
      rgba(245, 248, 252, 0.07) 18px 19px
    ),
    repeating-linear-gradient(
      -8deg,
      transparent 0 34px,
      rgba(245, 248, 252, 0.05) 34px 35px
    );
  animation: isoline-drift 28s linear infinite;
  opacity: 0.9;
}
.hero::after {
  content: "";
  position: absolute;
  inset: 0;
  z-index: -1;
  background:
    radial-gradient(ellipse 50% 40% at 20% 80%, rgba(196, 92, 38, 0.18), transparent 60%),
    radial-gradient(ellipse 40% 50% at 90% 10%, rgba(232, 240, 247, 0.12), transparent 50%);
  pointer-events: none;
}
@keyframes isoline-drift {
  from { transform: translate3d(0, 0, 0); }
  to { transform: translate3d(-2.5%, 1.5%, 0); }
}
@media (prefers-reduced-motion: reduce) {
  .hero::before { animation: none; }
  html { scroll-behavior: auto; }
}

.hero-kicker {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: color-mix(in srgb, var(--bleach) 80%, white);
  margin: 0 0 1rem;
}
.hero h1 {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(2.35rem, 6.5vw, 4.1rem);
  line-height: 1.08;
  letter-spacing: -0.03em;
  max-width: 14ch;
  margin: 0 0 1rem;
}
.hero-lead {
  max-width: 38rem;
  font-size: 1.125rem;
  color: color-mix(in srgb, var(--bleach) 92%, white);
  margin: 0 0 1.75rem;
}
.hero-cta {
  display: inline-flex;
  gap: 0.75rem;
  flex-wrap: wrap;
}
.btn {
  display: inline-block;
  padding: 0.7rem 1.15rem;
  border: 1px solid color-mix(in srgb, var(--sun) 55%, transparent);
  color: var(--sun);
  text-decoration: none;
  font-weight: 600;
  background: transparent;
}
.btn-solid {
  background: var(--sun);
  color: var(--prussian);
  border-color: var(--sun);
}
.btn:hover { border-color: var(--rust); color: var(--rust); }
.btn-solid:hover { background: var(--bleach); color: var(--prussian); border-color: var(--bleach); }

section { padding: clamp(2.5rem, 6vw, 4.5rem) 0; }
section + section { border-top: 1px solid var(--line); }
.section-label {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--cyanotype);
  margin: 0 0 0.6rem;
}
h2 {
  font-family: var(--font-display);
  font-size: clamp(1.7rem, 3.5vw, 2.35rem);
  line-height: 1.15;
  letter-spacing: -0.02em;
  color: var(--prussian);
  margin: 0 0 0.75rem;
}
h3 {
  font-family: var(--font-display);
  font-size: 1.25rem;
  color: var(--plate);
  margin: 1.5rem 0 0.5rem;
}
.lede { max-width: 40rem; color: var(--muted); margin: 0 0 1.5rem; }

.library { display: grid; gap: 1.25rem; }
@media (min-width: 720px) {
  .library { grid-template-columns: repeat(3, 1fr); gap: 1.5rem; }
}
.library article {
  padding: 1.25rem 0 0;
  border-top: 2px solid var(--cyanotype);
}
.library .meta {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  color: var(--muted);
  letter-spacing: 0.04em;
  margin: 0 0 0.5rem;
}
.library h3 { margin-top: 0; font-size: 1.15rem; }
.library h3 a { color: var(--prussian); text-decoration: none; }
.library h3 a:hover { color: var(--cyanotype); text-decoration: underline; }
.library p { margin: 0.5rem 0 0; color: var(--muted); font-size: 0.98rem; }

.standards ul { margin: 0; padding: 0; display: grid; gap: 0.85rem; }
@media (min-width: 800px) {
  .standards ul { grid-template-columns: 1fr 1fr; }
}
.standards li {
  list-style: none;
  margin: 0;
  padding: 1rem 0 1rem 1rem;
  border-left: 3px solid var(--cyan-mid);
  background: color-mix(in srgb, var(--bleach) 70%, white);
}
.standards strong {
  display: block;
  color: var(--prussian);
  font-family: var(--font-display);
  margin-bottom: 0.25rem;
}

.not-list {
  display: grid;
  gap: 0.65rem;
  margin: 0;
  padding: 0;
}
.not-list li {
  list-style: none;
  padding: 0.85rem 1rem;
  border: 1px solid var(--line);
  background: white;
}
.not-list li::before {
  content: "— ";
  color: var(--rust);
  font-family: var(--font-mono);
}

.faq details {
  border-bottom: 1px solid var(--line);
  padding: 0.85rem 0;
}
.faq summary {
  cursor: pointer;
  font-weight: 600;
  color: var(--prussian);
}
.faq p { margin: 0.6rem 0 0.2rem; color: var(--muted); }

.support-box {
  padding: 1.5rem;
  background: var(--plate);
  color: var(--bleach);
}
.support-box a { color: var(--sun); }
.support-box h2 { color: var(--sun); }

.site-footer {
  margin-top: 2rem;
  padding: 2rem 0 2.5rem;
  background: var(--prussian);
  color: color-mix(in srgb, var(--bleach) 85%, white);
  font-size: 0.95rem;
}
.site-footer a { color: var(--sun); }
.site-footer .grid { display: grid; gap: 1.25rem; }
@media (min-width: 700px) {
  .site-footer .grid { grid-template-columns: 2fr 1fr 1fr; }
}
.site-footer nav { display: grid; gap: 0.35rem; }
.fine { opacity: 0.75; font-size: 0.85rem; margin-top: 1.5rem; }

.page-hero {
  padding: 2.5rem 0 1.5rem;
  border-bottom: 1px solid var(--line);
}
.page-hero h1 {
  font-family: var(--font-display);
  font-size: clamp(1.9rem, 4vw, 2.8rem);
  color: var(--prussian);
  margin: 0 0 0.5rem;
  letter-spacing: -0.02em;
}
.prose { max-width: 42rem; padding: 2rem 0 3rem; }
.prose p { margin: 0 0 1rem; }
.prose ul, .prose ol { margin: 0 0 1rem; padding-left: 1.25rem; color: var(--muted); }
.prose li { margin: 0.35rem 0; }
.article-meta {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  color: var(--muted);
  margin-bottom: 1.25rem;
}
.sources {
  margin-top: 2rem;
  padding-top: 1rem;
  border-top: 1px solid var(--line);
  font-size: 0.92rem;
  color: var(--muted);
}

.contact-card {
  max-width: 36rem;
  padding: 1.25rem 1.4rem;
  background: white;
  border: 1px solid var(--line);
  border-left: 4px solid var(--cyanotype);
}

.error-page {
  min-height: 60vh;
  display: grid;
  place-content: center;
  text-align: center;
  padding: 3rem var(--pad);
}
.error-page h1 {
  font-family: var(--font-display);
  font-size: clamp(2rem, 5vw, 3rem);
  color: var(--prussian);
}