:root {
  --bg: #eef1f7;
  --ink: #1e1b4b;
  --muted: #475569;
  --card: #ffffff;
  --line: #d4d8e8;
  --nav: #111827;
  --accent: #4f46e5;
  --l1: #4f46e5;
  --l2: #0ea5e9;
  --l3: #64748b;
}

* { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: auto; }
body {
  font-family: "Helvetica Neue", "PingFang SC", "Microsoft YaHei", sans-serif;
  background: var(--bg);
  color: var(--ink);
  line-height: 1.75;
}

.mast {
  background: var(--nav);
  color: #e5e7eb;
  padding: 12px 28px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 20px;
}
.mast .name {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 700;
}
.mast nav { display: flex; gap: 16px; flex-wrap: wrap; }
.mast a { color: #c7d2fe; text-decoration: none; font-size: 14px; }
.mast a:hover { color: #fff; }

.intro {
  padding: 32px 28px 18px;
  background: linear-gradient(180deg, #e0e7ff 0%, var(--bg) 100%);
}
.intro .tag {
  display: inline-block;
  background: #c7d2fe;
  color: #312e81;
  font-size: 12px;
  font-weight: 700;
  padding: 3px 8px;
  margin-bottom: 10px;
}
.intro h1 { font-size: 30px; line-height: 1.35; max-width: 18em; margin-bottom: 12px; }
.intro p { max-width: 46em; color: var(--muted); }

.depth-row {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 12px;
  padding: 0 28px 8px;
}
.depth {
  background: var(--card);
  border-top: 4px solid var(--accent);
  padding: 14px 14px 12px;
  border-right: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
  border-left: 1px solid var(--line);
}
.depth:nth-child(2) { border-top-color: var(--l2); }
.depth:nth-child(3) { border-top-color: var(--l3); }
.depth b { display: block; font-size: 12px; letter-spacing: 0.08em; margin-bottom: 6px; }
.depth h3 { font-size: 16px; margin-bottom: 6px; }
.depth p { font-size: 14px; color: var(--muted); }

.feed-wrap { padding: 20px 28px 48px; }
.feed-wrap > h2,
.layer > h2,
.bound > h2,
.pace > h2,
.faq-block h2 {
  font-size: 22px;
  margin: 22px 0 12px;
}
.feed-wrap > p,
.layer p,
.bound p,
.pace p { margin-bottom: 12px; }

.feed {
  display: grid;
  gap: 12px;
  max-width: 760px;
}
.card {
  background: var(--card);
  border: 1px solid var(--line);
  padding: 14px 16px 12px;
  box-shadow: 0 8px 20px rgba(30, 27, 75, 0.04);
}
.card-hd {
  display: flex;
  gap: 10px;
  align-items: center;
  margin-bottom: 8px;
}
.ava {
  width: 36px;
  height: 36px;
  border-radius: 10px;
  background: #c7d2fe;
  display: grid;
  place-items: center;
}
.card-hd strong { display: block; font-size: 14px; }
.card-hd span { font-size: 12px; color: #64748b; }
.card p { font-size: 14px; color: #334155; margin-bottom: 8px; }
.react {
  display: flex;
  gap: 14px;
  font-size: 12px;
  color: #64748b;
}
.react em { font-style: normal; color: var(--accent); font-weight: 700; }
.lvl {
  float: right;
  font-size: 11px;
  background: #eef2ff;
  color: #3730a3;
  padding: 2px 6px;
}

.layer, .bound, .pace {
  background: var(--card);
  border: 1px solid var(--line);
  padding: 18px 20px;
  margin-top: 18px;
  max-width: 760px;
}
.dots { display: flex; gap: 8px; margin: 10px 0 4px; flex-wrap: wrap; }
.dots span {
  border: 1px solid var(--line);
  padding: 4px 8px;
  font-size: 12px;
  background: #f8fafc;
}

.faq-block {
  background: #e0e7ff;
  padding: 28px;
  border-top: 1px solid #c7d2fe;
}
.faq-block article {
  background: #fff;
  border: 1px solid var(--line);
  padding: 14px 16px;
  margin-bottom: 10px;
  max-width: 760px;
}
.faq-block h3 { font-size: 16px; margin-bottom: 6px; }

footer {
  background: var(--nav);
  color: #cbd5e1;
  padding: 20px 28px 26px;
  font-size: 13px;
  display: grid;
  gap: 6px;
}

@media (max-width: 800px) {
  .depth-row { grid-template-columns: 1fr; }
  .intro h1 { font-size: 24px; }
}