/* hood402 docs — dark-first, one accent gradient, system type stack */
:root {
  --bg: #0a0a0c;
  --bg-raised: #121216;
  --bg-inset: #0e0e11;
  --border: #232329;
  --border-strong: #34343c;
  --text: #ededf0;
  --text-dim: #9c9ca6;
  --text-faint: #62626c;
  --accent-a: #7ef29a;
  --accent-b: #4cc9f0;
  --accent-grad: linear-gradient(96deg, var(--accent-a), var(--accent-b));
  --mono: ui-monospace, 'SF Mono', SFMono-Regular, Menlo, Consolas, monospace;
  --sans: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
  --up: #6fe08a;
  --down: #f26d7e;
  --paid: #7ef29a;
}
* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font: 15px/1.6 var(--sans);
  -webkit-font-smoothing: antialiased;
}
a { color: inherit; text-decoration: none; }
a:hover { color: var(--accent-a); }
a:focus-visible, button:focus-visible {
  outline: 2px solid var(--accent-b);
  outline-offset: 2px;
  border-radius: 4px;
}
code, pre { font-family: var(--mono); font-size: 0.86em; }
pre {
  background: var(--bg-inset);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 16px 18px;
  overflow-x: auto;
  line-height: 1.55;
}
code:not(pre code) {
  background: var(--bg-raised);
  border: 1px solid var(--border);
  border-radius: 5px;
  padding: 1px 6px;
}

.wrap { max-width: 1060px; margin: 0 auto; padding: 0 22px; }

/* nav */
nav.top {
  position: sticky; top: 0; z-index: 10;
  background: color-mix(in srgb, var(--bg) 82%, transparent);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
}
nav.top .wrap { display: flex; align-items: center; gap: 22px; height: 56px; }
.brand { font-weight: 700; letter-spacing: -0.02em; font-size: 16px; }
.brand .tick { background: var(--accent-grad); -webkit-background-clip: text; background-clip: text; color: transparent; }
nav.top .links { display: flex; gap: 18px; margin-left: auto; font-size: 14px; color: var(--text-dim); }
nav.top .links a { padding: 4px 2px; transition: color 0.15s ease; }

/* hero */
.hero { padding: 84px 0 40px; }
.hero h1 {
  font-size: clamp(30px, 5.4vw, 52px);
  line-height: 1.08;
  letter-spacing: -0.035em;
  margin: 0 0 14px;
  font-weight: 750;
}
.hero h1 .grad { background: var(--accent-grad); -webkit-background-clip: text; background-clip: text; color: transparent; }
.hero p.lede { color: var(--text-dim); font-size: 17px; max-width: 640px; margin: 0 0 26px; }
.cta { display: flex; gap: 12px; flex-wrap: wrap; }
.btn {
  display: inline-flex; align-items: center; gap: 8px;
  border-radius: 8px; padding: 9px 18px; font-size: 14px; font-weight: 600;
  border: 1px solid var(--border-strong);
  background: var(--bg-raised);
  color: var(--text);
  cursor: pointer;
  transition: transform 0.12s ease, border-color 0.15s ease, background 0.15s ease;
}
.btn:hover { border-color: var(--accent-a); color: var(--text); transform: translateY(-1px); }
.btn.primary { background: var(--accent-grad); color: #0a0f0b; border: none; }
.btn.primary:hover { filter: brightness(1.06); color: #0a0f0b; }
.install {
  font-family: var(--mono); font-size: 13.5px;
  color: var(--text-dim);
  background: var(--bg-inset);
  border: 1px solid var(--border);
  border-radius: 8px; padding: 10px 16px;
  display: inline-flex; gap: 10px; align-items: center;
}
.install .dollar { color: var(--accent-a); user-select: none; }

/* ── request/402/pay/200 flow diagram ─────────────────────────────── */
.flow-head { display: flex; align-items: baseline; gap: 12px; margin: 46px 0 18px; }
.flow-head h2 { margin: 0; font-size: 20px; letter-spacing: -0.02em; }
.flow {
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  align-items: center;
  gap: 18px;
  background: var(--bg-raised);
  border: 1px solid var(--border);
  border-radius: 16px;
  padding: 32px 28px;
}
.flow .actor { display: flex; flex-direction: column; align-items: center; gap: 10px; }
.flow .actor .avatar {
  width: 52px; height: 52px; border-radius: 14px;
  background: var(--bg-inset); border: 1px solid var(--border-strong);
  display: flex; align-items: center; justify-content: center;
  font-size: 22px;
}
.flow .actor .label { font-size: 12.5px; color: var(--text-dim); font-weight: 600; }
.flow .wire { position: relative; height: 90px; }
.flow .wire .track {
  position: absolute; top: 50%; left: 0; right: 0; height: 2px;
  background: var(--border-strong);
  transform: translateY(-50%);
}
.flow .wire .packet {
  position: absolute; top: 50%; width: 10px; height: 10px; border-radius: 50%;
  background: var(--accent-a);
  transform: translate(-50%, -50%);
  box-shadow: 0 0 10px color-mix(in srgb, var(--accent-a) 70%, transparent);
  animation: hood-packet 4.5s cubic-bezier(0.4, 0, 0.2, 1) infinite;
}
.flow .wire .packet.pay { background: var(--accent-b); animation-delay: -1.1s; box-shadow: 0 0 10px color-mix(in srgb, var(--accent-b) 70%, transparent); }
.flow .wire .caption {
  position: absolute; top: calc(50% - 26px); left: 50%; transform: translateX(-50%);
  font-family: var(--mono); font-size: 11px; color: var(--text-faint);
  white-space: nowrap;
  opacity: 0; animation: hood-caption 4.5s ease-in-out infinite;
}
.flow .wire .caption.c1 { animation-delay: 0s; }
.flow .wire .caption.c2 { animation-delay: -1.1s; color: var(--down); }
.flow .wire .caption.c3 { animation-delay: -2.25s; color: var(--accent-b); }
.flow .wire .caption.c4 { animation-delay: -3.4s; color: var(--paid); }
@keyframes hood-packet {
  0%   { left: 0%;   opacity: 0; }
  4%   { opacity: 1; }
  46%  { left: 100%; opacity: 1; }
  50%  { opacity: 0; left: 100%; }
  100% { opacity: 0; left: 100%; }
}
@keyframes hood-caption {
  0%   { opacity: 0; }
  4%   { opacity: 1; }
  22%  { opacity: 1; }
  28%  { opacity: 0; }
  100% { opacity: 0; }
}
.flow-legend {
  display: flex; gap: 18px; flex-wrap: wrap;
  margin-top: 14px; font-size: 12.5px; color: var(--text-faint);
}
.flow-legend span { display: inline-flex; align-items: center; gap: 6px; }
.flow-legend .dot { width: 8px; height: 8px; border-radius: 50%; display: inline-block; }
.flow-legend .dot.req { background: var(--accent-a); }
.flow-legend .dot.pay { background: var(--accent-b); }
@media (prefers-reduced-motion: reduce) {
  .flow .wire .packet, .flow .wire .caption { animation: none; opacity: 0; }
}

/* sections */
section.block { margin: 64px 0; }
section.block h2 { font-size: 22px; letter-spacing: -0.02em; margin: 0 0 6px; }
section.block p.sub { color: var(--text-dim); margin: 0 0 20px; max-width: 640px; }
.grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(300px, 1fr)); gap: 12px; }
.card {
  background: var(--bg-raised);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 18px 20px;
  transition: border-color 0.15s ease, transform 0.12s ease;
}
.card:hover { border-color: var(--border-strong); transform: translateY(-1px); }
.card h3 { margin: 0 0 6px; font-size: 15px; }
.card h3 code { font-size: 13px; }
.card p { margin: 0; color: var(--text-dim); font-size: 13.5px; }

.disclosure {
  border: 1px solid var(--border);
  border-left: 3px solid var(--accent-b);
  background: var(--bg-inset);
  border-radius: 10px;
  padding: 14px 18px;
  color: var(--text-dim);
  font-size: 13.5px;
  margin: 26px 0;
}

table { border-collapse: collapse; width: 100%; font-size: 13.5px; }
.table-scroll { overflow-x: auto; border: 1px solid var(--border); border-radius: 12px; }
th, td { text-align: left; padding: 9px 14px; border-bottom: 1px solid var(--border); }
th { color: var(--text-faint); font-weight: 600; font-size: 12px; text-transform: uppercase; letter-spacing: 0.06em; }
tr:last-child td { border-bottom: none; }
td code { white-space: nowrap; }
td.yes { color: var(--up); }
td.no { color: var(--text-faint); }

.tabs { display: flex; gap: 8px; margin-bottom: 14px; flex-wrap: wrap; }
.tab-btn {
  background: var(--bg-inset); border: 1px solid var(--border); color: var(--text-dim);
  border-radius: 8px; padding: 7px 14px; font-size: 13px; font-weight: 600; cursor: pointer;
  transition: all 0.15s ease;
}
.tab-btn[aria-selected="true"] { background: var(--accent-grad); color: #0a0f0b; border-color: transparent; }
.tab-panel { display: none; }
.tab-panel.active { display: block; }

footer {
  border-top: 1px solid var(--border);
  margin-top: 80px; padding: 28px 0 44px;
  color: var(--text-faint); font-size: 13.5px;
}
footer .wrap { display: flex; gap: 16px; flex-wrap: wrap; justify-content: space-between; }

@media (max-width: 720px) {
  .hero { padding: 56px 0 28px; }
  nav.top .links { gap: 12px; }
  nav.top .links a.hide-sm { display: none; }
  .flow { grid-template-columns: 1fr; }
  .flow .wire { height: 60px; transform: rotate(90deg); width: 60px; margin: 0 auto; }
}