:root {
  color-scheme: dark;
  --ink: #07111f;
  --navy: #0c1c32;
  --navy-raised: #112640;
  --paper: #f6f8fb;
  --white: #ffffff;
  --text: #eaf2fa;
  --muted: #a9bbcd;
  --line: #2a4058;
  --sky: #5fc3ff;
  --sky-soft: #bce7ff;
  --teal: #4ed6c0;
  --coral: #ff806f;
  --yellow: #f5cf70;
  --max-width: 75rem;
  --radius-sm: .5rem;
  --radius: .85rem;
  --radius-lg: 1.25rem;
  --shadow: 0 1.5rem 4rem rgb(0 0 0 / 24%);
  --step--1: clamp(.82rem, .79rem + .15vw, .9rem);
  --step-0: clamp(1rem, .96rem + .2vw, 1.1rem);
  --step-1: clamp(1.2rem, 1.12rem + .4vw, 1.45rem);
  --step-2: clamp(1.5rem, 1.34rem + .8vw, 2rem);
  --step-3: clamp(1.9rem, 1.55rem + 1.75vw, 3rem);
  --step-4: clamp(2.35rem, 1.65rem + 3.5vw, 4.6rem);
}

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

html {
  background: var(--ink);
  scroll-behavior: smooth;
  scroll-padding-top: 5rem;
}

body {
  min-width: 20rem;
  margin: 0;
  background:
    radial-gradient(circle at 10% 0%, rgb(95 195 255 / 10%), transparent 32rem),
    var(--ink);
  color: var(--text);
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  font-size: var(--step-0);
  line-height: 1.65;
  text-rendering: optimizeLegibility;
}

img, svg { display: block; max-width: 100%; height: auto; }
button, input, select, textarea { font: inherit; }
a { color: var(--sky-soft); text-underline-offset: .2em; text-decoration-thickness: .08em; }
a:hover { color: var(--white); }
:focus-visible { outline: .2rem solid var(--yellow); outline-offset: .2rem; }
::selection { color: var(--ink); background: var(--teal); }

.skip-link {
  position: fixed;
  z-index: 100;
  top: .5rem;
  left: .5rem;
  padding: .65rem 1rem;
  border-radius: var(--radius-sm);
  background: var(--white);
  color: var(--ink);
  transform: translateY(-150%);
}
.skip-link:focus { transform: translateY(0); }

.container,
.site-header__inner,
.site-footer__inner {
  width: min(100% - 2rem, var(--max-width));
  margin-inline: auto;
}

.site-header {
  position: sticky;
  z-index: 20;
  top: 0;
  border-bottom: 1px solid rgb(95 195 255 / 18%);
  background: rgb(7 17 31 / 88%);
  backdrop-filter: blur(1rem);
}
.site-header__inner { display: flex; align-items: center; justify-content: space-between; min-height: 4rem; gap: 1rem; }
.site-title, .brand { color: var(--white); font-weight: 800; letter-spacing: -.02em; text-decoration: none; }
.site-nav ul { display: flex; flex-wrap: wrap; gap: .35rem 1rem; margin: 0; padding: 0; list-style: none; }
.site-nav a { color: var(--muted); font-size: var(--step--1); text-decoration: none; }
.site-nav a:hover, .site-nav a[aria-current="page"] { color: var(--white); }

main > section,
.section { padding-block: clamp(3.25rem, 8vw, 7rem); }
main > section + section { border-top: 1px solid rgb(169 187 205 / 15%); }
.section--light { background: var(--paper); color: #142337; }
.section--raised { background: var(--navy); }
.section-heading { max-width: 48rem; margin-bottom: 2rem; }
.eyebrow {
  margin: 0 0 .8rem;
  color: var(--teal);
  font-size: .78rem;
  font-weight: 800;
  letter-spacing: .13em;
  text-transform: uppercase;
}
h1, h2, h3 { margin: 0 0 .75em; color: var(--white); font-weight: 800; line-height: 1.08; letter-spacing: -.035em; text-wrap: balance; }
h1 { max-width: 15ch; font-size: var(--step-4); }
h2 { max-width: 24ch; font-size: var(--step-3); }
h3 { font-size: var(--step-1); line-height: 1.25; }
.section--light h2, .section--light h3 { color: #0b1b30; }
p { max-width: 72ch; margin-block: 0 1.1rem; }
.lede { max-width: 62ch; color: #c9d8e7; font-size: var(--step-1); line-height: 1.5; }
.section--light .lede, .section--light .muted { color: #496078; }
.muted, small { color: var(--muted); }

.hero { overflow: hidden; padding-block: clamp(4.5rem, 11vw, 9rem); }
.hero__grid { display: grid; grid-template-columns: minmax(0, 1.35fr) minmax(17rem, .65fr); align-items: end; gap: clamp(2rem, 7vw, 6rem); }
.hero__meta { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: .75rem; }
.stat, .fact {
  padding: 1rem;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: rgb(17 38 64 / 64%);
}
.stat strong, .fact strong { display: block; margin-bottom: .15rem; color: var(--white); font-size: var(--step-1); }

.grid { display: grid; gap: 1rem; }
.grid--2 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
.grid--3 { grid-template-columns: repeat(3, minmax(0, 1fr)); }
.grid--4 { grid-template-columns: repeat(4, minmax(0, 1fr)); }
.card {
  min-width: 0;
  padding: clamp(1.15rem, 3vw, 1.75rem);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--navy-raised);
}
.section--light .card { border-color: #cbd8e5; background: var(--white); box-shadow: 0 .8rem 2rem rgb(21 45 70 / 7%); }
.card--rag { border-top: .3rem solid var(--sky); }
.card--fine-tuning { border-top: .3rem solid var(--coral); }
.card--hybrid { border-top: .3rem solid var(--teal); }
.card--warning { border-left: .3rem solid var(--yellow); }
.card > :last-child { margin-bottom: 0; }
.card dl { margin-block: 0; }
.card dt { margin-top: 1rem; color: var(--white); font-weight: 800; }
.card dt:first-child { margin-top: 0; }
.card dd { margin: .2rem 0 0; color: var(--muted); }
.section--light .card dt { color: #0b1b30; }
.section--light .card dd { color: #496078; }

.button-row { display: flex; flex-wrap: wrap; gap: .75rem; margin-top: 1.5rem; }
.button, button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 2.8rem;
  padding: .7rem 1rem;
  border: 1px solid var(--sky);
  border-radius: var(--radius-sm);
  background: var(--sky);
  color: #061523;
  font-weight: 800;
  line-height: 1.2;
  text-decoration: none;
  cursor: pointer;
}
.button:hover, button:hover { background: var(--sky-soft); color: var(--ink); }
.button--secondary, button.secondary { border-color: var(--line); background: transparent; color: var(--text); }
.button--secondary:hover, button.secondary:hover { border-color: var(--sky); background: rgb(95 195 255 / 8%); color: var(--white); }
button:disabled { opacity: .55; cursor: not-allowed; }

.decision-tool { display: grid; grid-template-columns: minmax(0, 1.25fr) minmax(18rem, .75fr); align-items: start; gap: 1.25rem; }
.decision-form, .result-panel { border: 1px solid var(--line); border-radius: var(--radius-lg); background: var(--navy); }
.decision-form { padding: clamp(1rem, 3vw, 2rem); }
.result-panel { position: sticky; top: 5.25rem; padding: clamp(1.2rem, 3vw, 2rem); }
.result-panel[aria-live] { min-height: 16rem; }
fieldset { margin: 0; padding: 1.25rem 0; border: 0; border-top: 1px solid var(--line); }
fieldset:first-of-type { border-top: 0; }
legend { width: 100%; padding: 0; color: var(--white); font-weight: 750; line-height: 1.35; }
.hint { display: block; margin-block: .35rem .75rem; color: var(--muted); font-size: var(--step--1); }
.choice-group { display: flex; flex-wrap: wrap; gap: .5rem; }
.choice-group label { position: relative; }
.choice-group input { position: absolute; width: 1px; height: 1px; opacity: 0; }
.choice-group span {
  display: block;
  padding: .5rem .8rem;
  border: 1px solid var(--line);
  border-radius: 999px;
  color: var(--muted);
  cursor: pointer;
}
.choice-group input:checked + span { border-color: var(--teal); background: rgb(78 214 192 / 12%); color: var(--white); }
.choice-group input:focus-visible + span { outline: .2rem solid var(--yellow); outline-offset: .15rem; }
input[type="text"], input[type="number"], select, textarea {
  width: 100%; min-height: 2.8rem; padding: .65rem .75rem; border: 1px solid var(--line); border-radius: var(--radius-sm); background: var(--ink); color: var(--text);
}
.result-badge, .tag {
  display: inline-flex;
  padding: .28rem .6rem;
  border: 1px solid currentColor;
  border-radius: 999px;
  color: var(--teal);
  font-size: .78rem;
  font-weight: 800;
  letter-spacing: .04em;
  text-transform: uppercase;
}
.result-badge--rag { color: var(--sky); }
.result-badge--fine-tuning { color: var(--coral); }
.result-badge--blocked { color: var(--yellow); }

.table-wrap { overflow-x: auto; border: 1px solid var(--line); border-radius: var(--radius); }
table { width: 100%; min-width: 44rem; border-collapse: collapse; background: var(--navy); font-size: var(--step--1); }
caption { padding: 1rem; color: var(--muted); text-align: left; }
th, td { padding: .85rem 1rem; border-bottom: 1px solid var(--line); text-align: left; vertical-align: top; }
th { color: var(--white); background: #10243d; font-weight: 800; }
tbody tr:last-child td { border-bottom: 0; }
tbody tr:hover { background: rgb(95 195 255 / 5%); }

details { border-top: 1px solid var(--line); }
details:last-child { border-bottom: 1px solid var(--line); }
summary { padding: 1rem 2rem 1rem 0; color: var(--white); font-weight: 750; cursor: pointer; }
details > :not(summary) { margin-right: 2rem; }
.diagram { margin-block: 1.5rem; padding: clamp(.5rem, 2vw, 1rem); border: 1px solid var(--line); border-radius: var(--radius); background: #09172a; }
.diagram figcaption { max-width: 75ch; margin: .75rem auto .25rem; color: var(--muted); font-size: var(--step--1); }
.source-list { padding-left: 1.25rem; }
.source-list li + li { margin-top: .7rem; }
.callout { padding: 1.2rem 1.3rem; border-left: .3rem solid var(--teal); background: rgb(78 214 192 / 8%); }
.warning { border-left-color: var(--yellow); background: rgb(245 207 112 / 8%); }

.site-footer { padding-block: 2.5rem; border-top: 1px solid var(--line); background: #050d18; color: var(--muted); font-size: var(--step--1); }
.site-footer__inner { display: flex; flex-wrap: wrap; justify-content: space-between; gap: 1rem; }
.site-footer p { margin: 0; }

@media (max-width: 62rem) {
  .hero__grid, .decision-tool { grid-template-columns: 1fr; }
  .result-panel { position: static; }
  .grid--4 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}

@media (max-width: 44rem) {
  .site-header { position: static; }
  .site-header__inner { align-items: flex-start; flex-direction: column; padding-block: .8rem; }
  .site-nav ul { gap: .3rem .75rem; }
  .hero__grid, .grid--2, .grid--3, .grid--4 { grid-template-columns: 1fr; }
  .hero__meta { grid-template-columns: 1fr; }
  main > section, .section { padding-block: 3.25rem; }
  .choice-group { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); }
  .choice-group span { text-align: center; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { scroll-behavior: auto !important; animation-duration: .01ms !important; animation-iteration-count: 1 !important; transition-duration: .01ms !important; }
}

@media print {
  :root { color-scheme: light; }
  body { background: #fff; color: #111; font-size: 10.5pt; }
  .site-header, .button-row, button, .skip-link { display: none !important; }
  .container { width: 100%; }
  main > section, .section { padding-block: 1.2rem; break-inside: avoid; }
  h1, h2, h3, legend, summary, .stat strong, .fact strong { color: #111; }
  a { color: #111; text-decoration: underline; }
  a[href]::after { content: " (" attr(href) ")"; font-size: 8pt; overflow-wrap: anywhere; }
  .card, .decision-form, .result-panel, .table-wrap, table, th, .diagram { border-color: #bbb; background: #fff; color: #111; box-shadow: none; }
  .result-panel { position: static; }
  .muted, .hint, small, .diagram figcaption { color: #444; }
  details { display: block; }
  details > * { display: block; }
  .site-footer { background: #fff; color: #333; }
}