/* Auto Decision Engine: static presentation page. No external resources. */

/*
  Visual system: the page speaks in a plain sans; only the illustrative brief
  uses a serif, so it reads as a document. Labels use the system monospace.
  The single accent marks the next step and the contact address, nothing else.
*/

:root {
  --paper: #f6f6f3;
  --paper-band: #ededea;
  --sheet: #fdfdfb;
  --ink: #151a26;
  --ink-soft: #4a5060;
  --rule: rgba(21, 26, 38, 0.13);
  --rule-strong: rgba(21, 26, 38, 0.38);
  --signal: #b3341c;

  --serif: "Iowan Old Style", Charter, "Bitstream Charter", "Palatino Linotype", Palatino, Georgia, ui-serif, serif;
  --sans: system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --mono: ui-monospace, "SF Mono", "Cascadia Mono", "Segoe UI Mono", Menlo, Consolas, monospace;

  --gutter: clamp(1.25rem, 5vw, 4rem);
  --measure: 36rem;
}

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

html {
  -webkit-text-size-adjust: 100%;
  text-size-adjust: 100%;
}

@media (prefers-reduced-motion: no-preference) {
  html {
    scroll-behavior: smooth;
  }
}

body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: var(--sans);
  font-size: 1.0625rem;
  line-height: 1.6;
  overflow-wrap: break-word;
  -webkit-font-smoothing: antialiased;
}

::selection {
  background: var(--ink);
  color: var(--paper);
}

h1,
h2,
h3 {
  font-family: var(--sans);
  font-weight: 600;
  line-height: 1.12;
  letter-spacing: -0.02em;
  margin: 0;
}

p,
ul,
ol,
dl,
dd,
figure {
  margin: 0;
}

a {
  color: inherit;
  text-decoration-thickness: 1px;
  text-underline-offset: 0.22em;
}

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

a:focus-visible {
  outline: 3px solid var(--signal);
  outline-offset: 3px;
  border-radius: 2px;
}

.wrap {
  max-width: 78rem;
  margin-inline: auto;
  padding-inline: var(--gutter);
}

.kicker {
  font-family: var(--mono);
  font-size: 0.75rem;
  font-weight: 500;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--ink-soft);
}

/* Skip link */

.skip-link {
  position: absolute;
  left: 0.75rem;
  top: -4rem;
  z-index: 10;
  padding: 0.6rem 1rem;
  background: var(--ink);
  color: var(--paper);
  text-decoration: none;
}

.skip-link:focus {
  top: 0.75rem;
  color: var(--paper);
}

/* Header */

.site-header .wrap {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 0.5rem 1.25rem;
  padding-block: 1.25rem;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 0.6rem;
  text-decoration: none;
  font-weight: 600;
  font-size: 0.95rem;
  letter-spacing: -0.005em;
}

.brand svg {
  flex: none;
}

.site-nav ul {
  display: flex;
  gap: 1.1rem;
  list-style: none;
  padding: 0;
  font-size: 0.9rem;
}

.site-nav a {
  text-decoration: none;
  color: var(--ink-soft);
}

.site-nav a:hover {
  color: var(--ink);
  text-decoration: underline;
}

@media (min-width: 40rem) {
  .site-nav ul {
    gap: 1.75rem;
  }
}

/* Hero */

.hero {
  display: grid;
  gap: clamp(2.5rem, 6vw, 4.5rem);
  padding-block: clamp(2rem, 7vw, 5.5rem) clamp(3.5rem, 8vw, 6.5rem);
}

.status {
  display: flex;
  align-items: center;
  gap: 0.65rem;
  font-family: var(--mono);
  font-size: 0.75rem;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--ink-soft);
}

.status::before {
  content: "";
  width: 1.5rem;
  border-top: 1px solid var(--rule-strong);
  flex: none;
}

.hero h1 {
  margin-top: clamp(1.1rem, 3vw, 1.75rem);
  font-size: clamp(2.05rem, 4.6vw, 3.55rem);
  line-height: 1.06;
  letter-spacing: -0.032em;
  max-width: 12em;
  text-wrap: balance;
}

.lead {
  margin-top: clamp(1.1rem, 3vw, 1.6rem);
  max-width: 34rem;
  font-size: clamp(1.03rem, 1.5vw, 1.15rem);
  line-height: 1.6;
  color: var(--ink-soft);
}

.hero-links {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 1rem 1.75rem;
  margin-top: clamp(1.6rem, 4vw, 2.25rem);
  font-size: 0.97rem;
  font-weight: 600;
}

.hero-links a {
  text-decoration-color: var(--rule-strong);
}

.hero-links .link-primary {
  padding: 0.7rem 1.2rem;
  background: var(--ink);
  color: var(--paper);
  border-radius: 2px;
  text-decoration: none;
}

.hero-links .link-primary:hover {
  background: #262d3d;
  color: var(--paper);
}

@media (min-width: 66rem) {
  .hero {
    grid-template-columns: minmax(0, 1fr) minmax(0, 29rem);
    align-items: start;
    gap: 5rem;
  }

  /* Keep the heading near the top of the brief, not centred against it */
  .hero-text {
    padding-top: 2rem;
  }
}

/* Illustrative decision brief: a static, fictional example */

.brief {
  background: var(--sheet);
  border: 1px solid var(--rule-strong);
  border-top: 2px solid var(--ink);
  font-size: 0.95rem;
  line-height: 1.5;
}

.brief > * {
  padding-inline: clamp(1.15rem, 4vw, 1.75rem);
}

.brief-head {
  padding-block: 1.2rem 1.1rem;
  border-bottom: 1px solid var(--rule);
}

.brief-flag,
.brief-items dt,
.brief-next-label {
  font-family: var(--mono);
  font-size: 0.72rem;
  font-weight: 500;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.brief-flag {
  color: var(--ink);
}

.brief-car {
  margin-top: 0.45rem;
  font-family: var(--serif);
  font-size: 1.2rem;
  line-height: 1.3;
}

.brief-context {
  margin-top: 0.5rem;
  color: var(--ink-soft);
}

.brief-context span,
.brief-next-why span {
  font-weight: 600;
  color: var(--ink);
  margin-right: 0.4em;
}

.brief-context span::after,
.brief-next-why span::after {
  content: ":";
}

.brief-items div {
  position: relative;
  padding: 0.95rem 0 0.95rem 1.4rem;
  border-bottom: 1px solid var(--rule);
}

.brief-items dt {
  color: var(--ink-soft);
}

.brief-items dd {
  margin-top: 0.2rem;
}

.brief-items .tag {
  display: inline-block;
  margin-left: 0.4em;
  padding: 0 0.4em;
  border: 1px solid var(--rule-strong);
  border-radius: 2px;
  color: var(--ink);
  letter-spacing: 0.06em;
}

/* Markers differ by shape as well as label, never by colour alone:
   open square = claimed, short bar = missing */
.brief-items div::before {
  content: "";
  position: absolute;
  left: 0;
  top: 1.2rem;
  width: 0.6rem;
  height: 0.6rem;
}

.is-claimed::before {
  border: 1.5px solid var(--ink);
}

.brief-items .is-missing::before {
  top: 1.45rem;
  height: 0;
  border-top: 1.5px solid var(--ink-soft);
}

/* One-line limitation under the evidence rows */
.brief-limit {
  padding-block: 0.7rem;
  border-bottom: 1px solid var(--rule);
  font-size: 0.88rem;
  color: var(--ink-soft);
}

.brief-next {
  padding-block: 1.1rem 1.25rem;
  border-left: 3px solid var(--signal);
  margin-top: -1px;
}

.brief-next-label {
  color: var(--signal);
}

.brief-next-action {
  margin-top: 0.3rem;
  font-family: var(--serif);
  font-size: 1.15rem;
  line-height: 1.35;
}

.brief-next-why {
  margin-top: 0.5rem;
  color: var(--ink-soft);
}

/* Conditional branches after the first step */
.brief-branches {
  padding-block: 0.35rem 0.5rem;
  border-top: 1px solid var(--rule);
}

.brief-branches div {
  padding: 0.6rem 0 0.6rem 1.4rem;
  position: relative;
}

.brief-branches div + div {
  border-top: 1px dashed var(--rule);
}

.brief-branches div::before {
  content: "→";
  content: "→" / "";
  position: absolute;
  left: 0;
  top: 0.6rem;
  color: var(--ink-soft);
}

.brief-branches dt {
  font-weight: 600;
}

.brief-branches dd {
  color: var(--ink-soft);
}

.brief figcaption {
  padding-block: 0.8rem 0.9rem;
  border-top: 1px solid var(--rule);
  background: var(--paper);
  font-size: 0.82rem;
  color: var(--ink-soft);
}

/* Approach */

.approach {
  background: var(--paper-band);
  border-block: 1px solid var(--rule);
  padding-block: clamp(3rem, 8vw, 5.5rem);
}

.approach h2 {
  margin-top: 0.75rem;
  font-size: clamp(1.6rem, 3.2vw, 2.3rem);
  max-width: 22ch;
  text-wrap: balance;
}

.approach-lead {
  margin-top: 1rem;
  max-width: var(--measure);
  color: var(--ink-soft);
}

.steps {
  list-style: none;
  padding: 0;
  margin-top: clamp(2rem, 5vw, 3.25rem);
  display: grid;
  gap: 1.75rem;
  counter-reset: step;
}

.steps li {
  counter-increment: step;
  padding-top: 1.1rem;
  border-top: 1px solid var(--rule-strong);
}

.steps h3 {
  font-size: 1.12rem;
  line-height: 1.3;
  letter-spacing: -0.01em;
}

.steps h3::before {
  content: counter(step, decimal-leading-zero);
  display: block;
  margin-bottom: 0.55rem;
  font-family: var(--mono);
  font-size: 0.75rem;
  font-weight: 500;
  letter-spacing: 0.06em;
  color: var(--ink-soft);
}

.steps p {
  margin-top: 0.45rem;
  max-width: 52ch;
  color: var(--ink-soft);
}

.note {
  margin-top: clamp(2rem, 5vw, 3rem);
  max-width: var(--measure);
  padding-left: 1rem;
  border-left: 2px solid var(--rule-strong);
  color: var(--ink-soft);
}

@media (min-width: 50rem) {
  .steps {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 2.25rem 3.5rem;
  }
}

/* Stage and contact */

.closing {
  display: grid;
  gap: 3rem;
  padding-block: clamp(3rem, 8vw, 5.5rem);
}

.closing h2 {
  margin-top: 0.75rem;
  font-size: clamp(1.45rem, 2.6vw, 1.9rem);
}

.closing h2 + p {
  margin-top: 1rem;
}

.closing p:not(.kicker) {
  max-width: var(--measure);
}

.stage p:not(.kicker) {
  color: var(--ink-soft);
}

.contact-name {
  margin-top: 1.5rem;
  font-weight: 600;
}

.email {
  display: inline-block;
  margin-top: 0.2rem;
  font-size: clamp(1.25rem, 5vw, 1.75rem);
  font-weight: 500;
  letter-spacing: -0.015em;
  line-height: 1.3;
  text-decoration-color: var(--signal);
  text-decoration-thickness: 2px;
  overflow-wrap: anywhere;
}

@media (min-width: 56rem) {
  .closing {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 0;
  }

  .stage {
    padding-right: clamp(2.5rem, 5vw, 4.5rem);
  }

  .contact {
    padding-left: clamp(2.5rem, 5vw, 4.5rem);
    border-left: 1px solid var(--rule);
  }
}

/* Footer */

.site-footer .wrap {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: 0.5rem 2rem;
  padding-block: 1.5rem 2rem;
  border-top: 1px solid var(--rule);
  font-size: 0.88rem;
  color: var(--ink-soft);
}