/* ===========================================================
   x402pay.io — design system
   Palette: paper / ink / slate / amber / grey
   Type: serif display, grotesk body, mono for protocol artifacts
=========================================================== */

:root {
  --paper: #FAFAF7;
  --paper-dim: #F1EFE8;
  --ink: #1A2332;
  --ink-soft: #2E3B4E;
  --slate: #5B7C99;
  --slate-dim: #C9D6DF;
  --amber: #C8954B;
  --amber-soft: #E9D3AC;
  --grey: #8B92A0;
  --line: #DEDAD0;
  --code-bg: #1A2332;
  --code-text: #E8E6DE;
  --code-green: #8FBC8F;
  --code-amber: #D4A86A;

  --serif: "Source Serif 4", "Iowan Old Style", "Georgia", serif;
  --grotesk: "Inter", -apple-system, "Segoe UI", sans-serif;
  --mono: "IBM Plex Mono", "SF Mono", "Consolas", monospace;

  --max-w: 760px;
  --max-w-wide: 1040px;
}

* { box-sizing: border-box; }

html {
  scroll-behavior: smooth;
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  * { animation-duration: 0.01ms !important; transition-duration: 0.01ms !important; }
}

body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: var(--grotesk);
  font-size: 17px;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

a {
  color: var(--slate);
  text-decoration: none;
  border-bottom: 1px solid var(--slate-dim);
  transition: border-color 0.15s ease, color 0.15s ease;
}

a:hover { color: var(--ink); border-color: var(--ink); }

a:focus-visible,
button:focus-visible {
  outline: 2px solid var(--amber);
  outline-offset: 3px;
}

h1, h2, h3 {
  font-family: var(--serif);
  font-weight: 600;
  color: var(--ink);
  line-height: 1.2;
  letter-spacing: -0.01em;
}

p { margin: 0 0 1.1em 0; }

code, .mono { font-family: var(--mono); }

/* ---------- Header / nav ---------- */

.site-header {
  border-bottom: 1px solid var(--line);
  background: var(--paper);
  position: sticky;
  top: 0;
  z-index: 10;
}

.site-header__inner {
  max-width: var(--max-w-wide);
  margin: 0 auto;
  padding: 18px 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.brand {
  display: flex;
  align-items: baseline;
  gap: 8px;
  font-family: var(--serif);
  font-size: 1.15rem;
  font-weight: 600;
  color: var(--ink);
  border-bottom: none;
}

.brand .stamp {
  font-family: var(--mono);
  font-size: 0.62rem;
  background: var(--ink);
  color: var(--paper);
  padding: 2px 6px;
  border-radius: 3px;
  letter-spacing: 0.04em;
}

nav.site-nav {
  display: flex;
  gap: 28px;
}

nav.site-nav a {
  font-size: 0.92rem;
  color: var(--ink-soft);
  border-bottom: none;
}

nav.site-nav a:hover { color: var(--slate); }

/* ---------- Hero ---------- */

.hero {
  max-width: var(--max-w-wide);
  margin: 0 auto;
  padding: 64px 24px 48px;
  display: grid;
  grid-template-columns: 1.1fr 1fr;
  gap: 56px;
  align-items: center;
}

@media (max-width: 860px) {
  .hero { grid-template-columns: 1fr; padding: 40px 20px 32px; gap: 36px; }
}

.eyebrow {
  font-family: var(--mono);
  font-size: 0.78rem;
  color: var(--grey);
  letter-spacing: 0.06em;
  text-transform: uppercase;
  margin-bottom: 14px;
}

.hero h1 {
  font-size: 2.55rem;
  margin: 0 0 18px 0;
}

@media (max-width: 600px) {
  .hero h1 { font-size: 2rem; }
}

.hero p.lede {
  font-size: 1.12rem;
  color: var(--ink-soft);
  max-width: 480px;
}

.hero-ctas {
  margin-top: 26px;
  display: flex;
  gap: 14px;
  flex-wrap: wrap;
}

.btn {
  display: inline-block;
  font-family: var(--grotesk);
  font-size: 0.94rem;
  font-weight: 600;
  padding: 12px 22px;
  border-radius: 4px;
  border: 1px solid var(--ink);
  cursor: pointer;
}

.btn-primary {
  background: var(--ink);
  color: var(--paper);
  border-bottom: none;
}
.btn-primary:hover { background: var(--ink-soft); color: var(--paper); }

.btn-secondary {
  background: transparent;
  color: var(--ink);
  border-bottom: none;
}
.btn-secondary:hover { background: var(--paper-dim); }

/* ---------- Terminal artifact (signature element) ---------- */

.terminal {
  background: var(--code-bg);
  border-radius: 8px;
  overflow: hidden;
  box-shadow: 0 18px 40px -12px rgba(26, 35, 50, 0.35);
}

.terminal__bar {
  display: flex;
  gap: 6px;
  padding: 11px 14px;
  background: rgba(255,255,255,0.04);
}

.terminal__bar span {
  width: 9px; height: 9px;
  border-radius: 50%;
  background: rgba(255,255,255,0.18);
}

.terminal__body {
  padding: 20px 22px 24px;
  font-family: var(--mono);
  font-size: 0.84rem;
  color: var(--code-text);
}

.terminal__body .line { margin-bottom: 9px; white-space: pre-wrap; }
.terminal__body .muted { color: #6B7585; }
.terminal__body .status-402 { color: var(--code-amber); font-weight: 600; }
.terminal__body .status-200 { color: var(--code-green); font-weight: 600; }
.terminal__body .arrow { color: var(--grey); }

/* ---------- Sections ---------- */

.section {
  max-width: var(--max-w-wide);
  margin: 0 auto;
  padding: 56px 24px;
}

.section--narrow { max-width: var(--max-w); }

.section--divider {
  border-top: 1px solid var(--line);
}

.section-head {
  margin-bottom: 36px;
}

.section-head h2 {
  font-size: 1.7rem;
  margin: 0 0 10px 0;
}

.section-head .deck {
  color: var(--grey);
  font-size: 1rem;
  max-width: 540px;
}

/* ---------- Card grid ---------- */

.grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 22px;
}

@media (max-width: 860px) {
  .grid { grid-template-columns: 1fr; }
}

.card {
  border: 1px solid var(--line);
  background: var(--paper);
  border-radius: 6px;
  padding: 26px 24px;
  transition: border-color 0.15s ease, transform 0.15s ease;
}

.card:hover {
  border-color: var(--slate);
}

.card .ledger-mark {
  font-family: var(--mono);
  font-size: 0.72rem;
  color: var(--amber);
  letter-spacing: 0.04em;
  margin-bottom: 10px;
  display: block;
}

.card h3 {
  font-size: 1.1rem;
  margin: 0 0 8px 0;
}

.card p {
  color: var(--ink-soft);
  font-size: 0.95rem;
  margin-bottom: 0;
}

/* ---------- Article list ---------- */

.article-list {
  display: flex;
  flex-direction: column;
}

.article-row {
  display: grid;
  grid-template-columns: 110px 1fr auto;
  gap: 24px;
  align-items: baseline;
  padding: 20px 0;
  border-top: 1px solid var(--line);
}

.article-row:first-child { border-top: none; }

@media (max-width: 640px) {
  .article-row { grid-template-columns: 1fr; gap: 6px; }
}

.article-row .tag {
  font-family: var(--mono);
  font-size: 0.72rem;
  color: var(--grey);
  text-transform: uppercase;
  letter-spacing: 0.04em;
}

.article-row a.title {
  font-family: var(--serif);
  font-size: 1.12rem;
  color: var(--ink);
  border-bottom: none;
}

.article-row a.title:hover { color: var(--slate); }

.article-row .read {
  font-size: 0.85rem;
  color: var(--grey);
  white-space: nowrap;
}

/* ---------- Comparison table ---------- */

table.compare {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.92rem;
}

table.compare th, table.compare td {
  text-align: left;
  padding: 12px 14px;
  border-bottom: 1px solid var(--line);
}

table.compare th {
  font-family: var(--mono);
  font-size: 0.72rem;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  color: var(--grey);
  font-weight: 500;
}

table.compare td.highlight {
  color: var(--ink);
  font-weight: 600;
}

/* ---------- Article page ---------- */

.article-header {
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 56px 24px 28px;
}

.article-header .eyebrow { margin-bottom: 16px; }

.article-header h1 {
  font-size: 2.1rem;
  margin-bottom: 14px;
}

.article-meta {
  font-family: var(--mono);
  font-size: 0.78rem;
  color: var(--grey);
}

.prose {
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 0 24px 64px;
}

.prose h2 {
  font-size: 1.4rem;
  margin: 2em 0 0.6em;
}

.prose h3 {
  font-size: 1.15rem;
  margin: 1.6em 0 0.5em;
}

.prose p { color: var(--ink-soft); }

.prose ul, .prose ol {
  color: var(--ink-soft);
  padding-left: 1.4em;
}
.prose li { margin-bottom: 0.5em; }

.prose .callout {
  background: var(--paper-dim);
  border-left: 3px solid var(--amber);
  padding: 16px 20px;
  border-radius: 0 4px 4px 0;
  margin: 1.6em 0;
  font-size: 0.95rem;
}

.prose code {
  background: var(--paper-dim);
  padding: 2px 6px;
  border-radius: 3px;
  font-size: 0.88em;
}

.prose hr {
  border: none;
  border-top: 1px solid var(--line);
  margin: 2.4em 0;
}

/* ---------- Footer ---------- */

.site-footer {
  border-top: 1px solid var(--line);
  background: var(--paper-dim);
}

.site-footer__inner {
  max-width: var(--max-w-wide);
  margin: 0 auto;
  padding: 40px 24px;
  display: flex;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 20px;
}

.site-footer p {
  font-size: 0.85rem;
  color: var(--grey);
  margin: 0;
  max-width: 520px;
}

.site-footer .disclosure {
  font-family: var(--mono);
  font-size: 0.74rem;
  color: var(--grey);
}

.back-link {
  display: inline-block;
  margin: 0 auto;
  max-width: var(--max-w);
  padding: 0 24px;
  font-family: var(--mono);
  font-size: 0.82rem;
}

/* ---------- Sub-nav (secondary pages) ---------- */

.subnav {
  max-width: var(--max-w-wide);
  margin: 0 auto;
  padding: 14px 24px 0;
  display: flex;
  gap: 22px;
  flex-wrap: wrap;
}

.subnav a {
  font-size: 0.85rem;
  border-bottom: none;
  color: var(--grey);
}

.subnav a.active { color: var(--ink); font-weight: 600; }
.subnav a:hover { color: var(--slate); }

/* ---------- Ecosystem list ---------- */

.eco-list {
  display: flex;
  flex-direction: column;
}

.eco-row {
  display: grid;
  grid-template-columns: 1fr 140px 120px 110px;
  gap: 18px;
  align-items: center;
  padding: 18px 0;
  border-top: 1px solid var(--line);
}

.eco-row:first-child { border-top: none; }

@media (max-width: 720px) {
  .eco-row { grid-template-columns: 1fr; gap: 6px; padding: 16px 0; }
}

.eco-row .name {
  font-family: var(--serif);
  font-size: 1.02rem;
  color: var(--ink);
}

.eco-row .desc {
  display: block;
  font-size: 0.86rem;
  color: var(--grey);
  font-family: var(--grotesk);
  margin-top: 2px;
}

.eco-row .category {
  font-family: var(--mono);
  font-size: 0.74rem;
  color: var(--slate);
  text-transform: uppercase;
  letter-spacing: 0.03em;
}

.eco-row .network {
  font-family: var(--mono);
  font-size: 0.78rem;
  color: var(--ink-soft);
}

.status-pill {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-family: var(--mono);
  font-size: 0.72rem;
  text-transform: uppercase;
  letter-spacing: 0.03em;
  padding: 4px 10px;
  border-radius: 100px;
  width: fit-content;
}

.status-pill.live { background: #E5EFE5; color: #3E6B3E; }
.status-pill.beta { background: var(--amber-soft); color: #7A5826; }
.status-pill.watch { background: var(--paper-dim); color: var(--grey); }

.eco-filter-note {
  font-size: 0.88rem;
  color: var(--grey);
  margin-bottom: 28px;
}

/* ---------- FAQ accordion ---------- */

.faq-item {
  border-top: 1px solid var(--line);
}
.faq-item:last-child { border-bottom: 1px solid var(--line); }

.faq-item summary {
  font-family: var(--serif);
  font-size: 1.05rem;
  color: var(--ink);
  padding: 20px 4px;
  cursor: pointer;
  list-style: none;
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 16px;
}

.faq-item summary::-webkit-details-marker { display: none; }

.faq-item summary .icon {
  font-family: var(--mono);
  color: var(--amber);
  font-size: 1.1rem;
  flex-shrink: 0;
  transition: transform 0.15s ease;
}

.faq-item[open] summary .icon { transform: rotate(45deg); }

.faq-item .faq-answer {
  padding: 0 4px 22px;
  color: var(--ink-soft);
  font-size: 0.96rem;
  max-width: 640px;
}

.faq-item .faq-answer p:last-child { margin-bottom: 0; }

/* ---------- Email capture ---------- */

.email-capture {
  background: var(--ink);
  border-radius: 8px;
  padding: 40px 36px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 32px;
  flex-wrap: wrap;
}

.email-capture h3 {
  color: var(--paper);
  font-size: 1.25rem;
  margin: 0 0 6px 0;
}

.email-capture p {
  color: var(--slate-dim);
  margin: 0;
  font-size: 0.92rem;
  max-width: 360px;
}

.email-capture form {
  display: flex;
  gap: 10px;
  flex-wrap: wrap;
}

.email-capture input[type="email"] {
  font-family: var(--grotesk);
  font-size: 0.92rem;
  padding: 11px 14px;
  border-radius: 4px;
  border: 1px solid rgba(255,255,255,0.2);
  background: rgba(255,255,255,0.06);
  color: var(--paper);
  min-width: 220px;
}

.email-capture input[type="email"]::placeholder { color: var(--grey); }

.email-capture .btn-primary {
  background: var(--amber);
  border-color: var(--amber);
  color: var(--ink);
}
.email-capture .btn-primary:hover { background: var(--amber-soft); color: var(--ink); }

.email-capture .form-note {
  width: 100%;
  font-size: 0.76rem;
  color: var(--grey);
  margin-top: 4px;
}

/* ---------- Changelog ---------- */

.changelog-entry {
  display: grid;
  grid-template-columns: 110px 1fr;
  gap: 24px;
  padding: 24px 0;
  border-top: 1px solid var(--line);
}

.changelog-entry:first-child { border-top: none; }

@media (max-width: 640px) {
  .changelog-entry { grid-template-columns: 1fr; gap: 6px; }
}

.changelog-entry .date {
  font-family: var(--mono);
  font-size: 0.78rem;
  color: var(--grey);
  white-space: nowrap;
}

.changelog-entry h3 {
  font-size: 1.02rem;
  margin: 0 0 6px 0;
}

.changelog-entry p {
  font-size: 0.92rem;
  color: var(--ink-soft);
  margin: 0;
}

/* ---------- Simple contact form ---------- */

.contact-form {
  display: flex;
  flex-direction: column;
  gap: 16px;
  max-width: 480px;
}

.contact-form label {
  font-family: var(--mono);
  font-size: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.03em;
  color: var(--grey);
  display: block;
  margin-bottom: 6px;
}

.contact-form input,
.contact-form textarea {
  width: 100%;
  font-family: var(--grotesk);
  font-size: 0.94rem;
  padding: 11px 14px;
  border-radius: 4px;
  border: 1px solid var(--line);
  background: var(--paper);
  color: var(--ink);
}

.contact-form textarea { min-height: 120px; resize: vertical; }