:root {
  --ink: #111111;
  --paper: #FFFFFF;
  --wa: #25D366;
  --mute: #6B7280;
  --wash: #F3F4F6;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: Georgia, "Songti SC", "SimSun", serif;
  line-height: 1.75;
}

.shell {
  width: min(860px, calc(100% - 48px));
  margin: 0 auto;
}

.linebar {
  border-top: 3px solid var(--ink);
  border-bottom: 1px solid #e5e7eb;
  background: var(--paper);
}
.linebar .shell {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  padding: 18px 0;
}
.brand {
  margin: 0;
  font-weight: 700;
  letter-spacing: 0.04em;
}
nav { display: flex; gap: 28px; }
nav a {
  color: var(--ink);
  text-decoration: none;
  font-size: 14px;
  letter-spacing: 0.08em;
  text-transform: none;
}
nav a:hover { text-decoration: underline; }

.hero { padding: 96px 0 72px; }
.brand-line {
  margin: 0 0 24px;
  font-size: 13px;
  letter-spacing: 0.18em;
  color: var(--mute);
}
h1 {
  margin: 0 0 32px;
  font-size: clamp(2.6rem, 7vw, 4.6rem);
  line-height: 1.08;
  font-weight: 700;
  letter-spacing: -0.03em;
}
.hero-p {
  margin: 0 0 16px;
  font-size: 1.15rem;
  color: var(--mute);
  max-width: 36em;
}
.cta {
  display: inline-block;
  margin: 28px 0 56px;
  color: var(--ink);
  border-bottom: 2px solid var(--wa);
  text-decoration: none;
  font-weight: 700;
  font-size: 1.05rem;
  padding-bottom: 4px;
}
.cta:hover { color: #059669; }

.metrics {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 0;
  border-top: 1px solid var(--ink);
  border-bottom: 1px solid var(--ink);
}
.metrics div { padding: 28px 20px 28px 0; }
.metrics div + div { border-left: 1px solid #e5e7eb; padding-left: 20px; }
.m-num {
  margin: 0 0 8px;
  font-size: 1.4rem;
  font-weight: 700;
}
.metrics p:last-child { margin: 0; color: var(--mute); font-size: 0.95rem; }

.sec { padding: 88px 0; }
.sec.pale { background: var(--wash); }
h2 {
  margin: 0 0 40px;
  font-size: clamp(1.6rem, 3vw, 2.2rem);
  letter-spacing: -0.02em;
}

.type-list { display: grid; grid-template-columns: 1fr 1fr; gap: 48px 40px; }
.type-list article { display: flex; gap: 14px; align-items: flex-start; }
.type-list svg { flex: 0 0 auto; margin-top: 6px; }
.t { margin: 0 0 8px; font-weight: 700; font-size: 1.05rem; }
.type-list p:last-child, .clean-ol p:last-child, .sparse p:last-child, .line-steps p:last-child, .faq-ol p:last-child {
  margin: 0;
  color: var(--mute);
}

.clean-ol {
  margin: 0;
  padding-left: 1.2em;
}
.clean-ol li { margin-bottom: 28px; padding-left: 8px; }
.clean-ol li:last-child { margin-bottom: 0; }

.sparse {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 40px;
}
.sparse article { padding-top: 16px; border-top: 1px solid var(--ink); }

.line-steps {
  list-style: none;
  margin: 0;
  padding: 0;
  border-left: 1px solid var(--ink);
}
.line-steps li {
  display: flex;
  gap: 24px;
  padding: 0 0 36px 28px;
  position: relative;
}
.line-steps li:last-child { padding-bottom: 0; }
.line-steps span {
  font-variant-numeric: tabular-nums;
  font-weight: 700;
  min-width: 2em;
}

.rule-sec hr {
  border: 0;
  border-top: 1px solid var(--ink);
  margin: 0 0 28px;
}
.rule-sec hr:last-of-type { margin: 28px 0 0; }
.rule-sec p { color: var(--mute); margin: 0 0 16px; }

.plain-ul {
  margin: 0;
  padding-left: 1.1em;
  color: var(--mute);
}
.plain-ul li { margin-bottom: 14px; }

.thin {
  width: 100%;
  border-collapse: collapse;
  margin-top: 28px;
}
.thin th, .thin td {
  text-align: left;
  padding: 12px 10px;
  border-bottom: 1px solid #d1d5db;
  vertical-align: top;
  font-size: 0.95rem;
}
.thin th { border-bottom: 1px solid var(--ink); font-family: Georgia, serif; }

.faq-ol {
  list-style: none;
  margin: 0;
  padding: 0;
  counter-reset: q;
}
.faq-ol li {
  counter-increment: q;
  padding: 32px 0 32px 0;
  border-top: 1px solid #e5e7eb;
}
.faq-ol li:last-child { border-bottom: 1px solid #e5e7eb; }
.faq-ol .t {
  font-size: 1.35rem;
  line-height: 1.3;
}
.faq-ol .t::before {
  content: counter(q, decimal-leading-zero) "  ";
  color: var(--mute);
  font-size: 0.85em;
}

footer {
  border-top: 3px solid var(--ink);
  padding: 36px 0 48px;
  font-size: 14px;
  color: var(--mute);
  font-family: "Segoe UI", "PingFang SC", sans-serif;
}
footer p { margin: 0 0 8px; }

@media (max-width: 760px) {
  .linebar .shell { flex-direction: column; gap: 12px; }
  .metrics, .type-list, .sparse { grid-template-columns: 1fr; }
  .metrics div + div { border-left: 0; border-top: 1px solid #e5e7eb; padding-left: 0; }
  .hero { padding: 56px 0 48px; }
  .sec { padding: 56px 0; }
}

#news .news-list { list-style: none; border-top: 1px solid #111; }
#news .news-list li { padding: 22px 0; border-bottom: 1px solid #e5e7eb; }
#news time { font-size: 0.75rem; letter-spacing: 0.08em; color: #6b7280; }
#news .news-list h3 { font-size: 1.35rem; font-weight: 650; margin: 8px 0; }