/* Sprout reference surface — framework-free, responsive, and WCAG 2.2-minded.
   The visual language borrows from a field specimen label crossed with an eval trace:
   quiet paper, precise utility type, and one visible source-to-answer chain. */

:root {
  --ink: #14231a;
  --paper: #f3f7f4;
  --surface: #ffffff;
  --surface-soft: #e7f0e9;
  --leaf: #1f6842;
  --leaf-deep: #12442b;
  --blue: #234e70;
  --blue-soft: #e5eef5;
  --rule: #b8c8bc;
  --muted: #44564a;
  --warning-bg: #fff2cb;
  --warning-ink: #523900;
  --warning-border: #8b6100;
  --focus: #0c52a1;
  --shadow: 0 1.4rem 3.5rem rgb(20 35 26 / 0.1);
  --radius: 0.45rem;
  --display: "DIN Alternate", "Arial Narrow", "Avenir Next Condensed", sans-serif;
  --body: "Avenir Next", Avenir, "Segoe UI", sans-serif;
  --utility: ui-monospace, "SFMono-Regular", Consolas, monospace;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  color: var(--ink);
  background-color: var(--paper);
  background-image:
    linear-gradient(rgb(31 104 66 / 0.045) 1px, transparent 1px),
    linear-gradient(90deg, rgb(31 104 66 / 0.045) 1px, transparent 1px);
  background-size: 2.4rem 2.4rem;
  font: 1rem/1.65 var(--body);
}

a { color: var(--leaf-deep); }

a:hover { color: var(--blue); }

.skip-link {
  position: fixed;
  left: 1rem;
  top: -6rem;
  z-index: 100;
  padding: 0.65rem 1rem;
  color: #fff;
  background: var(--ink);
  border-radius: var(--radius);
}

.skip-link:focus { top: 1rem; }

.site-header {
  position: relative;
  z-index: 10;
  border-bottom: 1px solid var(--rule);
  background: var(--paper);
}

.header-inner,
main,
footer {
  width: min(100% - 2rem, 76rem);
  margin-inline: auto;
}

.header-inner {
  min-height: 4.75rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 2rem;
}

.wordmark {
  display: inline-flex;
  align-items: center;
  gap: 0.65rem;
  color: var(--ink);
  font-family: var(--display);
  font-size: 1.35rem;
  font-weight: 800;
  letter-spacing: 0.02em;
  text-decoration: none;
}

.wordmark-mark {
  width: 2rem;
  height: 2rem;
  display: grid;
  place-items: center;
  color: #fff;
  background: var(--leaf-deep);
  border-radius: 50% 50% 50% 0.25rem;
  transform: rotate(-10deg);
}

.wordmark-mark + span { transform: translateY(0.05rem); }

nav {
  display: flex;
  align-items: center;
  gap: clamp(0.8rem, 3vw, 2rem);
}

nav a {
  color: var(--muted);
  font-family: var(--utility);
  font-size: 0.78rem;
  font-weight: 700;
  letter-spacing: 0.07em;
  text-decoration: none;
  text-transform: uppercase;
}

nav a:hover { color: var(--leaf-deep); }

main { background: var(--paper); }

.hero {
  min-height: 37rem;
  display: grid;
  grid-template-columns: minmax(0, 1.35fr) minmax(18rem, 0.65fr);
  align-items: center;
  gap: clamp(3rem, 8vw, 7rem);
  padding: clamp(5rem, 10vw, 8.5rem) clamp(0rem, 2vw, 2rem);
}

.eyebrow,
.utility-label {
  margin: 0 0 0.85rem;
  color: var(--leaf-deep);
  font-family: var(--utility);
  font-size: 0.75rem;
  font-weight: 750;
  letter-spacing: 0.1em;
  text-transform: uppercase;
}

h1,
h2,
h3,
h4 {
  color: var(--ink);
  font-family: var(--display);
  line-height: 1.08;
}

h1 {
  max-width: 13ch;
  margin: 0;
  font-size: clamp(3.25rem, 7.2vw, 6.7rem);
  font-stretch: condensed;
  letter-spacing: -0.045em;
}

h2 {
  margin: 0;
  font-size: clamp(2.25rem, 4.7vw, 4.35rem);
  letter-spacing: -0.035em;
}

h3 { font-size: 1.35rem; }

.lede {
  max-width: 41rem;
  margin: 1.8rem 0 0;
  color: var(--muted);
  font-size: clamp(1.12rem, 2vw, 1.3rem);
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 1rem 1.4rem;
  margin-top: 2.3rem;
}

.button-link,
button {
  min-height: 2.75rem;
  min-width: 2.75rem;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.65rem 1.1rem;
  color: #fff;
  background: var(--leaf-deep);
  border: 2px solid var(--leaf-deep);
  border-radius: var(--radius);
  font: 700 0.95rem/1.2 var(--body);
  text-decoration: none;
  cursor: pointer;
}

.button-link:hover,
button:hover {
  color: #fff;
  background: var(--blue);
  border-color: var(--blue);
}

.text-link { font-weight: 700; text-underline-offset: 0.25rem; }

/* EXP-02: two sources give a different numeric cadence — show both, resolve neither. */
.disagreement {
  margin: 1rem 0;
  padding: 0.8rem 1rem;
  background: var(--blue-soft);
  border: 2px solid var(--blue);
  border-radius: var(--radius);
  color: var(--blue);
}
.disagreement p { margin: 0.3rem 0; }
.disagreement p::before { content: "⚖ Sources differ: "; font-weight: 700; }

.claim-chain {
  padding: 1.25rem 1.25rem 1rem;
  background: var(--surface);
  border: 1px solid var(--rule);
  box-shadow: var(--shadow);
}

.claim-chain ol {
  position: relative;
  margin: 0;
  padding: 0;
  list-style: none;
}

.claim-chain ol::before {
  content: "";
  position: absolute;
  left: 1rem;
  top: 1.7rem;
  bottom: 1.7rem;
  width: 2px;
  background: var(--rule);
}

.claim-chain li {
  position: relative;
  display: grid;
  grid-template-columns: 2rem 1fr;
  gap: 0 0.9rem;
  padding: 0.8rem 0;
}

.claim-chain li > span {
  z-index: 1;
  width: 2rem;
  height: 2rem;
  display: grid;
  place-items: center;
  grid-row: 1 / 3;
  color: #fff;
  background: var(--leaf-deep);
  border: 1px solid var(--leaf);
  border-radius: 50%;
  font: 700 0.68rem/1 var(--utility);
}

.claim-chain strong { align-self: end; }

.claim-chain small { color: var(--muted); }

.reference-lab,
.evaluation,
.boundary,
.docs {
  padding: clamp(4.5rem, 8vw, 7rem) clamp(0rem, 2vw, 2rem);
  border-top: 1px solid var(--rule);
}

.section-intro {
  display: grid;
  grid-template-columns: minmax(13rem, 0.75fr) minmax(18rem, 1.25fr);
  gap: 0.5rem clamp(2rem, 7vw, 7rem);
  align-items: end;
  margin-bottom: 2.5rem;
}

.section-intro .eyebrow { grid-column: 1 / -1; }

.section-intro > p:last-child {
  max-width: 40rem;
  margin: 0;
  color: var(--muted);
  font-size: 1.08rem;
}

.section-intro.compact { align-items: start; }

.lab-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(20rem, 0.86fr);
  background: var(--surface);
  border: 1px solid var(--rule);
  box-shadow: var(--shadow);
}

.question-panel,
.evidence-panel { padding: clamp(1.35rem, 4vw, 2.5rem); }

.question-panel { border-right: 1px solid var(--rule); }

.help {
  margin-top: 0;
  color: var(--muted);
  font-size: 0.92rem;
}

label {
  display: block;
  margin-bottom: 0.4rem;
  font-weight: 700;
}

textarea {
  width: 100%;
  min-height: 8.5rem;
  resize: vertical;
  padding: 0.85rem 1rem;
  color: var(--ink);
  background: #fbfdfb;
  border: 2px solid var(--muted);
  border-radius: var(--radius);
  font: 1.05rem/1.5 var(--body);
}

.form-footer {
  display: flex;
  align-items: end;
  justify-content: space-between;
  gap: 1rem;
  margin-top: 1rem;
}

.lang {
  margin: 0;
  padding: 0;
  border: 0;
}

.lang legend {
  margin-bottom: 0.35rem;
  font-weight: 700;
}

.lang label {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  margin: 0 0.9rem 0 0;
  font-weight: 400;
}

.lang input {
  width: 1.05rem;
  height: 1.05rem;
}

.examples {
  margin-top: 2.25rem;
  padding-top: 1.4rem;
  border-top: 1px solid var(--rule);
}

.examples > div {
  display: flex;
  flex-wrap: wrap;
  gap: 0.55rem;
}

.examples button {
  min-height: 2.4rem;
  padding: 0.4rem 0.7rem;
  color: var(--leaf-deep);
  background: var(--surface-soft);
  border-color: var(--rule);
  font-size: 0.82rem;
}

.examples button:hover {
  color: #fff;
  background: var(--leaf-deep);
  border-color: var(--leaf-deep);
}

.evidence-panel {
  position: relative;
  min-height: 30rem;
  background: var(--blue-soft);
}

.panel-heading {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
}

.panel-heading .utility-label { margin: 0; color: var(--blue); }

.status-dot {
  width: 0.7rem;
  height: 0.7rem;
  background: var(--rule);
  border-radius: 50%;
}

.evidence-panel[aria-busy="true"] .status-dot { background: var(--blue); }

.evidence-panel h3 {
  margin: 1.3rem 0 0.75rem;
  font-size: clamp(1.75rem, 3vw, 2.45rem);
}

.status {
  min-height: 1.6rem;
  margin: 0;
  color: var(--muted);
}

.answer { margin-top: 1.4rem; }

.answer p {
  margin: 0 0 1rem;
  padding-left: 1rem;
  border-left: 3px solid var(--blue);
  font-size: 1.04rem;
}

.cite-marker {
  margin-left: 0.25rem;
  color: var(--blue);
  font: 700 0.75rem/1 var(--utility);
}

.safety {
  margin: 1.2rem 0;
  padding: 0.85rem 1rem;
  color: var(--warning-ink);
  background: var(--warning-bg);
  border: 2px solid var(--warning-border);
  border-radius: var(--radius);
}

.safety::before { content: "Safety — "; font-weight: 800; }

.sources {
  margin-top: 1.6rem;
  padding-top: 1rem;
  border-top: 1px solid var(--rule);
}

.sources h4 { margin: 0 0 0.5rem; }

.citations { margin: 0; padding-left: 1.2rem; }

.citations a { color: var(--blue); }

.meta {
  color: var(--muted);
  font-family: var(--utility);
  font-size: 0.75rem;
  line-height: 1.55;
}

.evaluation { background: var(--leaf-deep); }

.evaluation .eyebrow,
.evaluation h2,
.evaluation .section-intro > p:last-child { color: #fff; }

.evaluation .eyebrow { opacity: 0.74; }

.evaluation .section-intro > p:last-child { opacity: 0.82; }

.evidence-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  border: 1px solid rgb(255 255 255 / 0.35);
}

.evidence-grid article { padding: clamp(1.4rem, 3vw, 2.2rem); }

.evidence-grid article + article { border-left: 1px solid rgb(255 255 255 / 0.35); }

.evidence-grid .metric {
  margin: 0;
  color: #c9e6d1;
  font: 800 clamp(2.8rem, 5vw, 4.6rem)/1 var(--display);
  letter-spacing: -0.04em;
}

.evidence-grid h3 { margin: 0.9rem 0 0.6rem; color: #fff; }

.evidence-grid article > p:last-child { margin: 0; color: #d9e5dc; }

.report-link {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: 0.5rem 2rem;
  margin: 1.5rem 0 0;
  color: #d9e5dc;
}

.report-link a { color: #fff; font-weight: 800; text-underline-offset: 0.25rem; }

.boundary {
  display: grid;
  grid-template-columns: minmax(0, 0.9fr) minmax(30rem, 1.1fr);
  gap: clamp(2.5rem, 7vw, 6rem);
  background: var(--surface-soft);
}

.boundary-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  border-top: 3px solid var(--leaf-deep);
}

.boundary-grid article { padding: 1rem 1rem 0; }

.boundary-grid article + article { border-left: 1px solid var(--rule); }

.boundary-grid h3 { margin: 0 0 0.8rem; }

.boundary-grid ul { margin: 0; padding-left: 1.2rem; }

.boundary-grid li + li { margin-top: 0.4rem; }

.docs { background: var(--surface); }

.doc-links {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  border-top: 1px solid var(--rule);
}

.doc-links a {
  display: flex;
  flex-direction: column;
  gap: 0.25rem;
  padding: 1.4rem 1rem;
  color: var(--ink);
  border-bottom: 1px solid var(--rule);
  text-decoration: none;
}

.doc-links a:nth-child(odd) { border-right: 1px solid var(--rule); }

.doc-links a::after {
  content: "↗";
  align-self: end;
  margin-top: -2.2rem;
  color: var(--leaf);
  font-size: 1.2rem;
}

.doc-links a:hover { background: var(--surface-soft); }

.doc-links strong { font-size: 1.05rem; }

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

footer {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: 0.5rem 2rem;
  padding-block: 2rem;
  color: var(--muted);
  background: var(--paper);
  font-size: 0.82rem;
}

footer p { margin: 0; }

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

button:disabled { cursor: wait; opacity: 0.68; }

@media (max-width: 58rem) {
  .hero,
  .section-intro,
  .boundary { grid-template-columns: 1fr; }

  .hero { gap: 3rem; }

  .hero h1 { max-width: 11ch; }

  .section-intro { align-items: start; }

  .lab-grid { grid-template-columns: 1fr; }

  .question-panel {
    border-right: 0;
    border-bottom: 1px solid var(--rule);
  }

  .evidence-panel { min-height: 22rem; }

  .boundary { gap: 2.5rem; }
}

@media (max-width: 42rem) {
  .header-inner { align-items: flex-start; flex-direction: column; gap: 0.65rem; padding-block: 0.8rem; }

  nav { width: 100%; justify-content: space-between; }

  h1 { font-size: clamp(3.2rem, 17vw, 4.7rem); }

  .form-footer { align-items: stretch; flex-direction: column; }

  .form-footer button { width: 100%; }

  .evidence-grid,
  .boundary-grid,
  .doc-links { grid-template-columns: 1fr; }

  .evidence-grid article + article {
    border-left: 0;
    border-top: 1px solid rgb(255 255 255 / 0.35);
  }

  .boundary-grid article + article {
    border-left: 0;
    border-top: 1px solid var(--rule);
  }

  .doc-links a:nth-child(odd) { border-right: 0; }

  footer { flex-direction: column; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  * { animation: none !important; transition: none !important; }
}