:root {
  --ink: #1c1917;
  --ink-2: #292524;
  --paper: #fafaf9;
  --card: #ffffff;
  --rose: #be123c;
  --rose-soft: #ffe4e6;
  --line: #e7e5e4;
  --mute: #57534e;
  --max: 1100px;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  font-family: "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
  background: var(--paper);
  color: var(--ink);
  line-height: 1.65;
}

.masthead {
  position: sticky;
  top: 0;
  z-index: 20;
  background: var(--ink);
  color: #f5f5f4;
}
.mast-inner {
  max-width: var(--max);
  margin: 0 auto;
  padding: 0.85rem 1.2rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
}
.brand {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  color: #f5f5f4;
  text-decoration: none;
  font-weight: 700;
  letter-spacing: 0.02em;
  white-space: nowrap;
}
.brand svg { flex-shrink: 0; }
.mast-nav {
  display: flex;
  flex-wrap: wrap;
  justify-content: flex-end;
  gap: 0.45rem 0.9rem;
}
.mast-nav a {
  color: #d6d3d1;
  text-decoration: none;
  font-size: 0.86rem;
  border-bottom: 2px solid transparent;
  padding-bottom: 0.1rem;
}
.mast-nav a:hover {
  color: #fff;
  border-bottom-color: var(--rose);
}

.hero-split {
  max-width: var(--max);
  margin: 0 auto;
  padding: 2.4rem 1.2rem 1.6rem;
  display: grid;
  grid-template-columns: 1.15fr 0.85fr;
  gap: 1.6rem;
  align-items: start;
}
.hero-split h1 {
  margin: 0 0 0.9rem;
  font-size: clamp(1.55rem, 3vw, 2.15rem);
  line-height: 1.28;
}
.hero-copy p {
  margin: 0 0 0.7rem;
  color: var(--mute);
  max-width: 38rem;
}
.risk-board {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0.7rem;
}
.risk-tile {
  background: var(--card);
  border: 1px solid var(--line);
  padding: 0.85rem 0.9rem;
  min-height: 7.2rem;
}
.risk-tile svg { color: var(--rose); display: block; margin-bottom: 0.45rem; }
.risk-tile strong { display: block; font-size: 0.95rem; margin-bottom: 0.25rem; }
.risk-tile span { display: block; font-size: 0.82rem; color: var(--mute); }

.block {
  max-width: var(--max);
  margin: 0 auto;
  padding: 2rem 1.2rem;
}
.block h2 {
  margin: 0 0 0.75rem;
  font-size: 1.35rem;
  line-height: 1.35;
}
.lead {
  margin: 0 0 1.15rem;
  color: var(--mute);
  max-width: 46rem;
}

.layer-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0.9rem;
}
.layer-card {
  display: grid;
  grid-template-columns: 52px 1fr;
  gap: 0.85rem;
  background: var(--card);
  border: 1px solid var(--line);
  padding: 1rem 1.05rem;
}
.layer-card .ico {
  width: 52px;
  height: 52px;
  background: var(--rose-soft);
  color: var(--rose);
  display: flex;
  align-items: center;
  justify-content: center;
}
.layer-card h3 { margin: 0 0 0.35rem; font-size: 1.02rem; }
.layer-card p { margin: 0 0 0.45rem; color: var(--mute); font-size: 0.92rem; }
.layer-card p:last-child { margin-bottom: 0; }

.lock-table {
  width: 100%;
  border-collapse: collapse;
  background: var(--card);
  font-size: 0.92rem;
}
.lock-table th,
.lock-table td {
  border: 1px solid var(--line);
  padding: 0.7rem 0.75rem;
  text-align: left;
  vertical-align: top;
}
.lock-table th {
  background: var(--ink-2);
  color: #fafaf9;
  font-weight: 600;
}
.lock-table tr:nth-child(even) td { background: #f5f5f4; }

.close-track {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 0.7rem;
  position: relative;
}
.close-step {
  background: var(--card);
  border: 1px solid var(--line);
  padding: 1rem 0.85rem 1.05rem;
  position: relative;
}
.close-num {
  width: 2rem;
  height: 2rem;
  border-radius: 50%;
  background: var(--rose);
  color: #fff;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  margin-bottom: 0.55rem;
}
.close-step h3 { margin: 0 0 0.4rem; font-size: 0.98rem; }
.close-step p { margin: 0; color: var(--mute); font-size: 0.88rem; }

.layer-trio {
  display: grid;
  grid-template-columns: 1fr 1fr 1fr;
  gap: 0.85rem;
}
.trio-card {
  background: var(--card);
  border-top: 4px solid var(--rose);
  border-right: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
  border-left: 1px solid var(--line);
  padding: 1rem;
}
.trio-card h3 { margin: 0 0 0.45rem; font-size: 1rem; }
.trio-card p { margin: 0 0 0.5rem; color: var(--mute); font-size: 0.9rem; }
.trio-card p:last-child { margin-bottom: 0; }

.pair {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0.9rem;
}
.pair article {
  background: var(--card);
  border: 1px solid var(--line);
  padding: 1.1rem 1.15rem;
}
.pair h3 { margin: 0 0 0.5rem; font-size: 1.02rem; }
.pair p { margin: 0 0 0.5rem; color: var(--mute); }
.pair ul { margin: 0; padding-left: 1.1rem; color: var(--mute); }
.pair li { margin-bottom: 0.35rem; }

.remain-band {
  background: var(--ink);
  color: #e7e5e4;
}
.remain-band .block { padding-top: 2.2rem; padding-bottom: 2.2rem; }
.remain-band h2 { color: #fff; }
.remain-band .lead { color: #a8a29e; }
.remain-mini {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 0.7rem;
}
.remain-mini article {
  background: #292524;
  padding: 0.9rem;
}
.remain-mini h3 { margin: 0 0 0.4rem; color: #fda4af; font-size: 0.95rem; }
.remain-mini p { margin: 0; color: #d6d3d1; font-size: 0.86rem; }

.ask-list { display: grid; gap: 0.55rem; }
.ask-list details {
  background: var(--card);
  border: 1px solid var(--line);
  border-left: 4px solid var(--rose);
}
.ask-list summary {
  cursor: pointer;
  padding: 0.85rem 1rem;
  font-weight: 650;
}
.ask-list details p {
  margin: 0;
  padding: 0 1rem 0.95rem;
  color: var(--mute);
}

.colophon {
  background: #0c0a09;
  color: #a8a29e;
  padding: 1.6rem 1.2rem 2rem;
  font-size: 0.86rem;
}
.colophon-inner { max-width: var(--max); margin: 0 auto; }
.colophon p { margin: 0 0 0.45rem; }
.colophon .legal { color: #78716c; margin-top: 0.7rem; }

@media (max-width: 900px) {
  .hero-split,
  .layer-grid,
  .close-track,
  .layer-trio,
  .pair,
  .remain-mini { grid-template-columns: 1fr; }
  .mast-inner { flex-direction: column; align-items: flex-start; }
  .mast-nav { justify-content: flex-start; }
}