/* Open News Protocol — site styles.
   Palette sampled from the ONP mark: ink navy #092137, signal blue #165EB4. */

:root {
  --ink: #0a1a2e;
  --navy: #092137;
  --signal: #165eb4;
  --signal-lift: #4d93e8;
  --paper: #f6f7f9;
  --white: #ffffff;
  --rule: #dde3ea;
  --rule-soft: #e9edf2;
  --muted: #56687e;
  --verified: #0b7a55;
  --broken: #b23a32;
  --amber: #9a6b00;

  --display: "Newsreader", Georgia, serif;
  --sans: "IBM Plex Sans", system-ui, -apple-system, sans-serif;
  --mono: "IBM Plex Mono", ui-monospace, "SF Mono", Menlo, monospace;

  --wrap: 1120px;
  --gap: clamp(3rem, 7vw, 6rem);
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  * { animation-duration: 0.001ms !important; transition-duration: 0.001ms !important; }
}

body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: var(--sans);
  font-size: 17px;
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
}

a { color: var(--signal); text-decoration-thickness: 1px; text-underline-offset: 2px; }
a:hover { color: var(--navy); }

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

.wrap { width: min(100% - 2.5rem, var(--wrap)); margin-inline: auto; }

/* ---------- masthead ---------- */

.masthead {
  border-bottom: 1px solid var(--rule);
  background: var(--white);
  position: sticky;
  top: 0;
  z-index: 20;
}
.masthead .wrap {
  display: flex;
  align-items: center;
  gap: 1.5rem;
  min-height: 78px;
}
.brand { display: flex; align-items: center; gap: 0.7rem; text-decoration: none; color: inherit; }
.brand img { width: auto; display: block; }
/* Wide screens get the full horizontal lockup (mark + wordmark);
   narrow ones get the mark alone, because the wordmark alone is nine
   times wider than tall and would crowd out the navigation. */
.brand .lockup { height: 46px; }
.brand .mark { height: 40px; display: none; }
@media (max-width: 900px) {
  .brand .lockup { display: none; }
  .brand .mark { display: block; }
}
.brand b {
  font-family: var(--mono);
  font-weight: 600;
  font-size: 0.95rem;
  letter-spacing: 0.02em;
  color: var(--navy);
}
.masthead nav { margin-left: auto; display: flex; gap: 1.5rem; align-items: center; flex-wrap: wrap; }
.masthead nav a {
  font-size: 0.9rem;
  color: var(--muted);
  text-decoration: none;
  font-weight: 500;
}
.masthead nav a:hover { color: var(--navy); }

@media (max-width: 720px) {
  .masthead .wrap { min-height: 62px; gap: 1rem; }
  .brand .mark { height: 36px; }
  /* Nav becomes a single scrollable strip instead of wrapping into
     three rows and pushing the page down. */
  .masthead nav {
    gap: 1.1rem;
    flex-wrap: nowrap;
    overflow-x: auto;
    scrollbar-width: none;
    -webkit-overflow-scrolling: touch;
    margin-left: auto;
    padding-left: 0.5rem;
    mask-image: linear-gradient(to right, transparent 0, #000 12px);
  }
  .masthead nav::-webkit-scrollbar { display: none; }
  .masthead nav a { font-size: 0.82rem; white-space: nowrap; }
  .masthead nav a[href*="#how"] { display: none; }
}

/* ---------- type ---------- */

h1, h2, h3 { font-family: var(--display); font-weight: 500; letter-spacing: -0.015em; line-height: 1.12; margin: 0; }
h1 { font-size: clamp(2.4rem, 5.5vw, 4.1rem); }
h2 { font-size: clamp(1.8rem, 3.4vw, 2.6rem); }
h3 { font-size: 1.22rem; line-height: 1.3; }

.eyebrow {
  font-family: var(--mono);
  font-size: 0.735rem;
  letter-spacing: 0.13em;
  text-transform: uppercase;
  color: var(--signal);
  font-weight: 500;
  margin: 0 0 1rem;
}
.lede { font-size: 1.17rem; color: var(--muted); max-width: 62ch; }

/* ---------- hero ---------- */

.hero { padding: clamp(2.5rem, 8vw, 6rem) 0 2.5rem; }
.hero h1 { max-width: 17ch; }
.hero h1 em { font-style: italic; color: var(--signal); }
.hero .lede { margin: 1.6rem 0 2rem; font-size: 1.24rem; }

.actions { display: flex; gap: 0.85rem; flex-wrap: wrap; }
.btn {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.72rem 1.35rem;
  border-radius: 3px;
  font-size: 0.94rem;
  font-weight: 500;
  text-decoration: none;
  border: 1px solid transparent;
  transition: background 0.15s, border-color 0.15s, color 0.15s;
}
.btn-primary { background: var(--navy); color: var(--white); }
.btn-primary:hover { background: var(--signal); color: var(--white); }
.btn-ghost { border-color: var(--rule); color: var(--navy); background: var(--white); }
.btn-ghost:hover { border-color: var(--navy); color: var(--navy); }

/* ---------- verifier (signature element) ---------- */

.verifier {
  background: var(--navy);
  color: #e8eef6;
  padding: clamp(2rem, 5vw, 3.2rem) 0 clamp(2.5rem, 5vw, 3.5rem);
}
.verifier-head { display: flex; align-items: flex-end; justify-content: space-between; gap: 2rem; flex-wrap: wrap; margin-bottom: 1.6rem; }
.verifier-head h2 { color: var(--white); font-size: clamp(1.5rem, 3vw, 2.1rem); }
.verifier-head p { margin: 0.6rem 0 0; color: #9db2ca; max-width: 54ch; font-size: 0.98rem; }
.verifier .eyebrow { color: var(--signal-lift); }

.verifier-grid { display: grid; grid-template-columns: minmax(0, 1.25fr) minmax(0, 1fr); gap: 1.5rem; align-items: start; }
@media (max-width: 860px) { .verifier-grid { grid-template-columns: 1fr; } }
@media (max-width: 560px) {
  #doc { min-height: 260px; font-size: 0.735rem; }
  .verifier-head { align-items: flex-start; }
}

.panel {
  background: #061524;
  border: 1px solid #1c3550;
  border-radius: 4px;
  overflow: hidden;
}
.panel-bar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  padding: 0.6rem 0.9rem;
  border-bottom: 1px solid #1c3550;
  font-family: var(--mono);
  font-size: 0.72rem;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: #7f9ab6;
}
.panel-bar .hint { text-transform: none; letter-spacing: 0; color: var(--signal-lift); font-size: 0.75rem; }

#doc {
  width: 100%;
  min-height: 340px;
  field-sizing: content;
  border: 0;
  resize: vertical;
  background: transparent;
  color: #cfe0f2;
  font-family: var(--mono);
  font-size: 0.795rem;
  line-height: 1.72;
  padding: 1rem;
  tab-size: 2;
  display: block;
}
#doc:focus { outline: none; box-shadow: inset 0 0 0 1px var(--signal); }

.verdict {
  padding: 1.1rem 1.1rem 1.15rem;
  border-bottom: 1px solid #1c3550;
  display: flex;
  gap: 0.85rem;
  align-items: flex-start;
}
.verdict .dot {
  width: 11px; height: 11px; border-radius: 50%;
  margin-top: 0.42rem; flex: none;
  background: #4a627d;
  transition: background 0.25s;
}
.verdict-text strong {
  display: block;
  font-family: var(--mono);
  font-size: 0.94rem;
  letter-spacing: 0.04em;
  color: var(--white);
}
.verdict-text span { font-size: 0.86rem; color: #9db2ca; }
.verdict.is-valid .dot { background: #16c48a; box-shadow: 0 0 0 4px rgba(22, 196, 138, 0.16); }
.verdict.is-valid strong { color: #16c48a; }
.verdict.is-broken .dot { background: #ff6b5e; box-shadow: 0 0 0 4px rgba(255, 107, 94, 0.16); }
.verdict.is-broken strong { color: #ff6b5e; }

.steps { list-style: none; margin: 0; padding: 0.5rem 0; }
.steps li {
  display: grid;
  grid-template-columns: 1.5rem 1fr auto;
  gap: 0.7rem;
  align-items: baseline;
  padding: 0.5rem 1.1rem;
  font-size: 0.85rem;
  color: #9db2ca;
}
.steps .mark { font-family: var(--mono); font-size: 0.8rem; color: #4a627d; }
.steps .who { font-family: var(--mono); font-size: 0.7rem; color: #4a627d; letter-spacing: 0.04em; }
.steps li.pass .mark { color: #16c48a; }
.steps li.pass { color: #dbe7f4; }
.steps li.fail .mark { color: #ff6b5e; }
.steps li.fail { color: #ffb3ac; }
.steps li.skip { opacity: 0.45; }

.verifier-foot {
  margin-top: 1.1rem;
  font-size: 0.83rem;
  color: #7f9ab6;
  display: flex;
  gap: 1.2rem;
  flex-wrap: wrap;
  align-items: center;
}
.verifier-foot code { font-family: var(--mono); color: #b9cde3; font-size: 0.8rem; }
.reset {
  background: none;
  border: 1px solid #2b4a6d;
  color: #b9cde3;
  font: inherit;
  font-size: 0.8rem;
  padding: 0.3rem 0.8rem;
  border-radius: 3px;
  cursor: pointer;
}
.reset:hover { border-color: var(--signal-lift); color: var(--white); }

/* ---------- generic sections ---------- */

section.band { padding: var(--gap) 0; }
section.band + section.band { border-top: 1px solid var(--rule); }
.band.on-white { background: var(--white); }

.section-head { max-width: 60ch; margin-bottom: 2.6rem; }
.section-head p { margin: 1rem 0 0; color: var(--muted); }

.cards { display: grid; grid-template-columns: repeat(auto-fit, minmax(240px, 1fr)); gap: 1.6rem 2rem; }
.card h3 { margin-bottom: 0.5rem; }
.card p { margin: 0; color: var(--muted); font-size: 0.96rem; }
.card .tag {
  font-family: var(--mono);
  font-size: 0.7rem;
  letter-spacing: 0.08em;
  color: var(--signal);
  display: block;
  margin-bottom: 0.7rem;
}

/* chain: the retrieval walkthrough */
.chain { display: grid; gap: 0; }
.chain-step {
  display: grid;
  grid-template-columns: 8.5rem 1fr;
  gap: 2rem;
  padding: 1.5rem 0;
  border-top: 1px solid var(--rule);
  align-items: start;
}
.chain-step:last-child { border-bottom: 1px solid var(--rule); }
.chain-step .stage {
  font-family: var(--mono);
  font-size: 0.72rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--muted);
  padding-top: 0.28rem;
}
.chain-step h3 { font-family: var(--sans); font-size: 1rem; font-weight: 600; letter-spacing: 0; }
.chain-step p { margin: 0.4rem 0 0; color: var(--muted); font-size: 0.95rem; }
.chain-step code {
  font-family: var(--mono);
  font-size: 0.82rem;
  background: var(--white);
  border: 1px solid var(--rule);
  border-radius: 3px;
  padding: 0.1rem 0.4rem;
  color: var(--navy);
  word-break: break-all;
}
.band.on-white .chain-step code { background: var(--paper); }

/* spec layer table */
.layers { width: 100%; border-collapse: collapse; font-size: 0.94rem; }
.layers th, .layers td { text-align: left; padding: 0.85rem 1rem 0.85rem 0; border-bottom: 1px solid var(--rule); vertical-align: top; }
.layers th { font-family: var(--mono); font-size: 0.72rem; letter-spacing: 0.09em; text-transform: uppercase; color: var(--muted); font-weight: 500; }
.layers td.range { font-family: var(--mono); font-size: 0.85rem; color: var(--signal); white-space: nowrap; padding-right: 1.5rem; }
.layers td.what { color: var(--muted); }

/* status strip */
.facts { display: grid; grid-template-columns: repeat(auto-fit, minmax(170px, 1fr)); gap: 1.5rem; margin-top: 2.4rem; }
.fact { border-top: 2px solid var(--navy); padding-top: 0.8rem; }
.fact b { display: block; font-family: var(--display); font-size: 2.1rem; font-weight: 500; line-height: 1; }
.fact span { font-size: 0.87rem; color: var(--muted); }

.note {
  border-left: 2px solid var(--amber);
  padding: 0.1rem 0 0.1rem 1.1rem;
  color: var(--muted);
  font-size: 0.95rem;
  max-width: 66ch;
}

/* ---------- footer ---------- */

footer.site {
  background: var(--navy);
  color: #9db2ca;
  padding: 3.2rem 0 2.4rem;
  font-size: 0.9rem;
}
footer.site .cols { display: grid; grid-template-columns: 1.4fr repeat(3, minmax(0, 1fr)); gap: 2rem; }
@media (max-width: 760px) { footer.site .cols { grid-template-columns: 1fr 1fr; } }
footer.site h4 { font-family: var(--mono); font-size: 0.72rem; letter-spacing: 0.1em; text-transform: uppercase; color: #7f9ab6; margin: 0 0 0.9rem; font-weight: 500; }
footer.site ul { list-style: none; margin: 0; padding: 0; display: grid; gap: 0.5rem; }
footer.site a { color: #cfe0f2; text-decoration: none; }
footer.site a:hover { color: var(--white); text-decoration: underline; }
footer.site .colophon { margin-top: 2.6rem; padding-top: 1.4rem; border-top: 1px solid #1c3550; font-size: 0.84rem; color: #7f9ab6; }

/* ---------- spec pages ---------- */

.doc-layout { display: grid; grid-template-columns: minmax(0, 1fr) 15rem; gap: 3.5rem; padding: 3rem 0 5rem; align-items: start; }
@media (max-width: 900px) { .doc-layout { grid-template-columns: 1fr; gap: 2rem; } }

.doc-meta {
  font-family: var(--mono);
  font-size: 0.76rem;
  letter-spacing: 0.05em;
  color: var(--muted);
  display: flex;
  gap: 1rem;
  flex-wrap: wrap;
  padding-bottom: 1.2rem;
  margin-bottom: 2rem;
  border-bottom: 1px solid var(--rule);
}
.doc-meta .status { color: var(--signal); }

.prose { max-width: 74ch; }
.prose h1 { font-size: clamp(2rem, 4vw, 2.9rem); margin-bottom: 0.8rem; }
.prose h2 { font-size: 1.55rem; margin: 2.8rem 0 0.9rem; padding-top: 0.4rem; }
.prose h3 { font-family: var(--sans); font-weight: 600; font-size: 1.06rem; letter-spacing: 0; margin: 2rem 0 0.6rem; }
.prose p { margin: 0 0 1.1rem; }
.prose ul, .prose ol { margin: 0 0 1.2rem; padding-left: 1.3rem; }
.prose li { margin-bottom: 0.45rem; }
.prose code { font-family: var(--mono); font-size: 0.86em; background: var(--white); border: 1px solid var(--rule); border-radius: 3px; padding: 0.08em 0.34em; }
.prose pre {
  background: var(--navy);
  color: #cfe0f2;
  padding: 1.1rem 1.2rem;
  border-radius: 4px;
  overflow-x: auto;
  font-size: 0.82rem;
  line-height: 1.65;
  margin: 0 0 1.4rem;
}
.prose pre code { background: none; border: 0; padding: 0; color: inherit; font-size: inherit; }
.prose table { width: 100%; border-collapse: collapse; font-size: 0.92rem; margin: 0 0 1.6rem; }
.prose th, .prose td { text-align: left; padding: 0.6rem 0.8rem 0.6rem 0; border-bottom: 1px solid var(--rule); vertical-align: top; }
.prose th { font-family: var(--mono); font-size: 0.72rem; letter-spacing: 0.07em; text-transform: uppercase; color: var(--muted); font-weight: 500; }
.prose blockquote { margin: 0 0 1.2rem; padding-left: 1.1rem; border-left: 2px solid var(--rule); color: var(--muted); }
.prose hr { border: 0; border-top: 1px solid var(--rule); margin: 2.4rem 0; }

.toc { position: sticky; top: 102px; font-size: 0.87rem; }
.toc h4 { font-family: var(--mono); font-size: 0.7rem; letter-spacing: 0.1em; text-transform: uppercase; color: var(--muted); margin: 0 0 0.8rem; font-weight: 500; }
.toc ul { list-style: none; margin: 0; padding: 0; display: grid; gap: 0.45rem; border-left: 1px solid var(--rule); }
.toc a { color: var(--muted); text-decoration: none; display: block; padding-left: 0.9rem; margin-left: -1px; border-left: 1px solid transparent; line-height: 1.35; }
.toc a:hover { color: var(--navy); border-left-color: var(--signal); }
@media (max-width: 900px) { .toc { position: static; } }

/* spec index */
.spec-series { margin-bottom: 3rem; }
.spec-series h2 { font-size: 1.35rem; font-family: var(--sans); font-weight: 600; letter-spacing: 0; margin-bottom: 0.3rem; }
.spec-series > p { color: var(--muted); font-size: 0.95rem; margin: 0 0 1.2rem; max-width: 62ch; }
.spec-list { display: grid; gap: 0; }
.spec-list a {
  display: grid;
  grid-template-columns: 6rem minmax(0, 1fr) auto;
  gap: 1.2rem;
  align-items: baseline;
  padding: 0.8rem 0.6rem 0.8rem 0;
  border-top: 1px solid var(--rule-soft);
  text-decoration: none;
  color: var(--ink);
}
.spec-list a:last-child { border-bottom: 1px solid var(--rule-soft); }
.spec-list a:hover { background: var(--white); }
.spec-list .num { font-family: var(--mono); font-size: 0.85rem; color: var(--signal); }
.spec-list .ver { font-family: var(--mono); font-size: 0.74rem; color: var(--muted); }
@media (max-width: 560px) {
  .spec-list a { grid-template-columns: 5rem 1fr; }
  .spec-list .ver { grid-column: 2; }
}


/* ---------- diagrams ---------- */

/* Below roughly 700px a full-width diagram scales its labels down to
   about five pixels, so the figure scrolls instead of shrinking. */
figure.diagram { margin: 2.6rem 0 0; }
figure.diagram .frame {
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
  border: 1px solid var(--rule);
  background: var(--white);
}
figure.diagram img { display: block; width: 100%; min-width: 660px; height: auto; }
figure.diagram figcaption {
  margin-top: .7rem;
  font-size: .85rem;
  color: var(--muted);
}
@media (max-width: 700px) {
  figure.diagram figcaption::after {
    content: " — scroll the diagram sideways to read it.";
    color: var(--signal);
  }
}