/* Settle — settleverify.com
   Text-first. No external assets. System font stacks only.
   Light warm paper, deep-navy ink accent, single vertical hairline guide.
   One progressive-enhancement script on the home page (canvas hero);
   the page is complete and readable with JavaScript disabled. */

:root {
  --c-bg: hsl(40, 9%, 96%);
  --c-bg-alt: hsl(40, 6%, 91%);
  --c-text: hsl(0, 0%, 7%);
  --c-text-alt: hsl(0, 0%, 42%);
  --c-accent: #082D4F;
  --c-line: hsl(40, 6%, 85%);
  --mono: ui-monospace, "SF Mono", "Cascadia Mono", Menlo, Consolas, monospace;
  --sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
}

@media (prefers-color-scheme: dark) {
  :root {
    --c-bg: hsl(0, 0%, 6%);
    --c-bg-alt: hsl(0, 0%, 14%);
    --c-text: hsl(0, 0%, 96%);
    --c-text-alt: hsl(0, 0%, 62%);
    --c-accent: #9fc2e8;
    --c-line: hsl(0, 0%, 20%);
  }
}

* { margin: 0; padding: 0; box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  background: var(--c-bg);
  color: var(--c-text);
  font-family: var(--sans);
  font-size: 15px;
  line-height: 1.65;
  font-feature-settings: "onum", "kern", "liga";
  -webkit-font-smoothing: antialiased;
}

/* The vertical hairline — structural guide down the left edge */
body::after {
  content: "";
  position: fixed;
  top: 0; bottom: 0;
  left: 2ch;
  width: 1px;
  background: var(--c-line);
  pointer-events: none;
}
@media (min-width: 1150px) {
  body::after { left: calc(50% - 34ch); }
}

.wrap {
  max-width: 72ch;
  margin: 0 auto;
  padding: 0 4ch 0 6ch;
}

/* ---------- header ---------- */
header.site {
  padding: 3.2rem 0 2.4rem;
  border-bottom: 1px solid var(--c-line);
}
header.site .wrap {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  flex-wrap: wrap;
  gap: 1rem;
}
.wordmark {
  font-family: var(--mono);
  font-weight: 700;
  font-size: 1.25rem;
  letter-spacing: 0.02em;
  color: var(--c-text);
  text-decoration: none;
}
.wordmark span { color: var(--c-accent); }
nav.site {
  font-family: var(--mono);
  font-size: 0.78rem;
  display: flex;
  gap: 1.6ch;
  flex-wrap: wrap;
}
nav.site a {
  color: var(--c-text-alt);
  text-decoration: none;
  padding-bottom: 2px;
  border-bottom: 1px solid transparent;
}
nav.site a:hover { color: var(--c-accent); border-bottom-color: var(--c-accent); }
nav.site a[aria-current="page"] { color: var(--c-accent); border-bottom-color: var(--c-accent); }

/* ---------- main ---------- */
main { padding: 3.4rem 0 4rem; }

h1 {
  font-size: 1.9rem;
  line-height: 1.2;
  letter-spacing: -0.015em;
  font-weight: 650;
  max-width: 26ch;
}
h1 + .lede { margin-top: 1.1rem; }
.lede {
  font-size: 1.06rem;
  color: var(--c-text-alt);
  max-width: 56ch;
}

section { margin-top: 3.6rem; }
h2 {
  font-family: var(--mono);
  font-size: 0.8rem;
  font-weight: 600;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--c-accent);
  margin-bottom: 1.2rem;
}
h2::before { content: "§ "; color: var(--c-text-alt); }

p { max-width: 62ch; }
p + p { margin-top: 0.9rem; }

a { color: var(--c-accent); }

/* ---------- records / lists ---------- */
.record {
  border-top: 1px solid var(--c-line);
  padding: 1.3rem 0;
}
.record:last-of-type { border-bottom: 1px solid var(--c-line); }
.record .meta {
  font-family: var(--mono);
  font-size: 0.75rem;
  color: var(--c-text-alt);
  letter-spacing: 0.04em;
  margin-bottom: 0.35rem;
}
.record h3 {
  font-size: 1.05rem;
  font-weight: 600;
  margin-bottom: 0.4rem;
}
.record p { color: var(--c-text); font-size: 0.95rem; }

ul.plain { list-style: none; }
ul.plain li {
  padding-left: 2.2ch;
  position: relative;
  margin-top: 0.55rem;
  max-width: 62ch;
}
ul.plain li::before {
  content: "+";
  position: absolute;
  left: 0;
  color: var(--c-accent);
  font-family: var(--mono);
}

/* ---------- code / hashes ---------- */
code, .hash {
  font-family: var(--mono);
  font-size: 0.82em;
  background: var(--c-bg-alt);
  padding: 0.1em 0.45em;
  border-radius: 2px;
  word-break: break-all;
}
pre {
  font-family: var(--mono);
  font-size: 0.8rem;
  line-height: 1.55;
  background: var(--c-bg-alt);
  border: 1px solid var(--c-line);
  border-radius: 3px;
  padding: 1.1rem 1.3rem;
  overflow-x: auto;
  margin-top: 1rem;
  max-width: 68ch;
}
pre code { background: none; padding: 0; }

/* ---------- verify steps ---------- */
ol.steps {
  list-style: none;
  counter-reset: step;
}
ol.steps li {
  counter-increment: step;
  border-top: 1px solid var(--c-line);
  padding: 1.4rem 0 1.4rem 7ch;
  position: relative;
  max-width: 66ch;
}
ol.steps li::before {
  content: counter(step, decimal-leading-zero);
  position: absolute;
  left: 0; top: 1.45rem;
  font-family: var(--mono);
  font-size: 0.85rem;
  color: var(--c-accent);
}
ol.steps li:last-child { border-bottom: 1px solid var(--c-line); }
ol.steps h3 { font-size: 1rem; margin-bottom: 0.4rem; }
ol.steps p { font-size: 0.95rem; color: var(--c-text); }

/* ---------- hash-chain diagram (pure CSS draw) ---------- */
.chain { margin: 2.6rem 0 0.6rem; max-width: 640px; }
.chain svg { display: block; width: 100%; height: auto; }
.chain .link-line {
  stroke-dasharray: 60;
  stroke-dashoffset: 60;
  animation: draw 0.7s ease-out forwards;
}
.chain .blk {
  opacity: 0;
  animation: appear 0.4s ease-out forwards;
}
.chain .lbl {
  opacity: 0;
  animation: appear 0.4s ease-out forwards;
}
.chain .d0 { animation-delay: 0.1s; }
.chain .d1 { animation-delay: 0.7s; }
.chain .d2 { animation-delay: 1.1s; }
.chain .d3 { animation-delay: 1.7s; }
.chain .d4 { animation-delay: 2.1s; }
.chain .d5 { animation-delay: 2.7s; }
.chain .d6 { animation-delay: 3.1s; }
@keyframes draw { to { stroke-dashoffset: 0; } }
@keyframes appear { to { opacity: 1; } }
.chain-caption {
  font-family: var(--mono);
  font-size: 0.72rem;
  color: var(--c-text-alt);
  margin-top: 0.8rem;
}
@media (prefers-reduced-motion: reduce) {
  .chain .link-line, .chain .blk, .chain .lbl { animation: none; opacity: 1; stroke-dashoffset: 0; }
  html { scroll-behavior: auto; }
}

/* ---------- footer ---------- */
footer.site {
  border-top: 1px solid var(--c-line);
  padding: 2.2rem 0 3rem;
  font-size: 0.85rem;
  color: var(--c-text-alt);
}
footer.site p { max-width: 62ch; }
footer.site .mono { font-family: var(--mono); font-size: 0.75rem; margin-top: 1rem; }

@media (max-width: 640px) {
  .wrap { padding: 0 3ch 0 4ch; }
  h1 { font-size: 1.5rem; }
  ol.steps li { padding-left: 5.5ch; }
}

/* ---------- home hero canvas (progressive enhancement) ---------- */
#heroCanvas { display: none; width: 100%; margin: 2.2rem 0 0; color: var(--c-accent); }
#chainHero svg { display: block; width: 100%; }