:root {
  --ink: #111111;
  --muted: #5a5a5a;
  --line: #d8d8d8;
  --paper: #ffffff;
  --green: #25d366;
  --green-soft: #e9f9ef;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  color: var(--ink);
  background: var(--paper);
  font-family: "Helvetica Neue", Helvetica, Arial, "PingFang SC", "Microsoft YaHei", sans-serif;
  font-size: 17px;
  line-height: 1.75;
}

img,
svg {
  display: block;
}

a {
  color: inherit;
}

.skip {
  position: absolute;
  left: -999px;
}

.wrap {
  width: min(1120px, calc(100% - 64px));
  margin: 0 auto;
}

.topbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 28px 0 8px;
}

.brand {
  display: flex;
  align-items: center;
  gap: 12px;
  text-decoration: none;
  font-weight: 700;
  letter-spacing: 0.02em;
}

.brand svg {
  width: 32px;
  height: 32px;
}

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

.nav a {
  text-decoration: none;
  color: var(--muted);
  font-size: 14px;
  letter-spacing: 0.08em;
}

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

.hero {
  padding: 72px 0 28px;
}

.hero h1 {
  margin: 0 0 28px;
  max-width: 16ch;
  font-size: clamp(2.6rem, 7vw, 4.6rem);
  line-height: 1.12;
  font-weight: 700;
  letter-spacing: -0.04em;
}

.hero-copy {
  max-width: 46rem;
  color: var(--muted);
}

.hero-copy p {
  margin: 0 0 16px;
}

.btn {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  margin-top: 12px;
  padding: 14px 28px;
  background: var(--ink);
  color: #fff;
  text-decoration: none;
  font-size: 15px;
  letter-spacing: 0.04em;
}

.btn i {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--green);
}

.hero-visual {
  margin-top: 56px;
  padding: 28px 0 8px;
}

.nodes {
  display: grid;
  grid-template-columns: 1fr auto 1fr auto 1fr;
  align-items: center;
  gap: 12px;
}

.node {
  text-align: center;
}

.node b {
  display: block;
  margin-bottom: 6px;
  font-size: 14px;
}

.node span {
  color: var(--muted);
  font-size: 13px;
}

.node-line {
  height: 1px;
  background: var(--ink);
  position: relative;
}

.node-line::after {
  content: "";
  position: absolute;
  right: -4px;
  top: -3px;
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--green);
}

.section {
  padding: 72px 0;
}

.section h2 {
  margin: 0 0 20px;
  max-width: 18ch;
  font-size: clamp(1.6rem, 3vw, 2.1rem);
  line-height: 1.25;
  letter-spacing: -0.03em;
}

.lead,
.section p {
  max-width: 46rem;
}

.section p {
  margin: 0 0 16px;
  color: var(--muted);
}

.tile-track {
  margin-top: 36px;
  overflow-x: auto;
  padding-bottom: 8px;
}

.tiles {
  display: grid;
  grid-template-columns: repeat(6, minmax(160px, 1fr));
  gap: 16px;
  min-width: 980px;
}

.tile {
  min-height: 168px;
  padding: 20px 18px;
  border: 1px solid var(--line);
  background: var(--paper);
}

.tile svg {
  width: 22px;
  height: 22px;
  margin-bottom: 18px;
}

.tile strong {
  display: block;
  margin-bottom: 8px;
  font-size: 15px;
}

.tile p {
  margin: 0;
  font-size: 13px;
  line-height: 1.6;
}

.steps {
  padding: 24px 0 8px;
}

.kicker {
  margin: 0 0 28px;
  font-size: 12px;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--muted);
}

.progress {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  position: relative;
  gap: 20px;
}

.progress::before {
  content: "";
  position: absolute;
  left: 8%;
  right: 8%;
  top: 7px;
  height: 1px;
  background: var(--line);
}

.step {
  position: relative;
}

.step i {
  display: block;
  width: 15px;
  height: 15px;
  border-radius: 50%;
  border: 1px solid var(--ink);
  background: var(--paper);
  margin-bottom: 16px;
}

.step:first-child i {
  background: var(--green);
  border-color: var(--green);
}

.step b {
  display: block;
  margin-bottom: 6px;
  font-size: 14px;
}

.step p {
  margin: 0;
  color: var(--muted);
  font-size: 13px;
}

.list {
  margin: 20px 0 0;
  padding: 0;
  list-style: none;
}

.list li {
  padding: 10px 0;
  border-bottom: 1px solid var(--line);
  color: var(--muted);
}

.table-wrap {
  margin-top: 28px;
  overflow-x: auto;
}

table {
  width: 100%;
  border-collapse: collapse;
}

th,
td {
  padding: 14px 12px;
  text-align: left;
  border-bottom: 1px solid var(--line);
  font-size: 14px;
  vertical-align: top;
}

th {
  font-weight: 600;
  color: var(--ink);
}

td {
  color: var(--muted);
}

.faq {
  padding-top: 24px;
}

details {
  border: 0;
  border-bottom: 1px solid var(--line);
  padding: 18px 0;
}

summary {
  cursor: pointer;
  font-weight: 600;
  list-style: none;
}

summary::-webkit-details-marker {
  display: none;
}

details p {
  margin: 12px 0 0;
}

.foot {
  padding: 48px 0 64px;
}

.foot hr {
  border: 0;
  border-top: 1px solid var(--line);
  margin: 0 0 20px;
}

.foot p {
  margin: 0 0 10px;
  color: var(--muted);
  font-size: 13px;
  max-width: none;
}

@media (max-width: 860px) {
  .wrap {
    width: min(1120px, calc(100% - 32px));
  }

  .topbar {
    flex-direction: column;
    align-items: flex-start;
    gap: 16px;
  }

  .nodes,
  .progress {
    grid-template-columns: 1fr;
  }

  .node-line,
  .progress::before {
    display: none;
  }

  .tiles {
    min-width: 0;
    grid-template-columns: repeat(2, 1fr);
  }
}

#news .news-list { border-top: 1px solid var(--line); }
#news article { display: grid; grid-template-columns: 1fr auto; gap: 6px 24px; padding: 22px 0; border-bottom: 1px solid var(--line); }
#news h3 { margin: 0; font-weight: 600; font-size: 18px; grid-column: 1; }
#news time { grid-column: 2; grid-row: 1; color: var(--green); font-size: 12px; letter-spacing: .08em; text-transform: uppercase; }
#news p { grid-column: 1 / -1; margin: 0; color: var(--muted); font-size: 14px; }
@media (max-width: 640px) { #news article { grid-template-columns: 1fr; } #news time { grid-column: 1; } }