:root {
  --ink: #172033;
  --muted: #5d6878;
  --line: #d9e1ec;
  --paper: #ffffff;
  --wash: #f4f7fb;
  --navy: #163b64;
  --green: #1c7a5b;
  --gold: #8d6115;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: "Noto Sans SC", "Microsoft YaHei", Arial, sans-serif;
  color: var(--ink);
  background: var(--wash);
  line-height: 1.75;
}

a {
  color: inherit;
}

.topic-header,
.topic-footer {
  background: var(--paper);
  border-bottom: 1px solid var(--line);
}

.topic-header-inner,
.topic-footer-inner,
.topic-main {
  width: min(1120px, calc(100% - 32px));
  margin: 0 auto;
}

.topic-header-inner {
  min-height: 72px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
}

.brand {
  display: flex;
  align-items: center;
  gap: 12px;
  text-decoration: none;
  font-weight: 800;
}

.brand img {
  width: 44px;
  height: 44px;
}

.topic-nav {
  display: flex;
  align-items: center;
  gap: 16px;
  flex-wrap: wrap;
  font-size: 14px;
}

.topic-nav a {
  text-decoration: none;
  color: var(--muted);
}

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

.topic-main {
  padding: 56px 0 64px;
}

.topic-hero {
  display: grid;
  gap: 18px;
  padding-bottom: 36px;
}

.eyebrow {
  margin: 0;
  color: var(--gold);
  font-weight: 800;
  letter-spacing: 0;
}

h1 {
  margin: 0;
  max-width: 900px;
  font-size: clamp(34px, 5vw, 58px);
  line-height: 1.12;
  letter-spacing: 0;
}

.lead {
  max-width: 820px;
  margin: 0;
  color: var(--muted);
  font-size: 18px;
}

.topic-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 8px;
}

.button {
  display: inline-flex;
  min-height: 44px;
  align-items: center;
  justify-content: center;
  padding: 10px 18px;
  border: 1px solid var(--navy);
  text-decoration: none;
  font-weight: 800;
  border-radius: 8px;
}

.button.primary {
  color: #fff;
  background: var(--navy);
}

.button.secondary {
  color: var(--navy);
  background: transparent;
}

.topic-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 320px;
  gap: 28px;
  align-items: start;
}

.topic-content,
.topic-aside {
  background: var(--paper);
  border: 1px solid var(--line);
  border-radius: 8px;
}

.topic-content {
  padding: clamp(22px, 4vw, 40px);
}

.topic-content section + section {
  margin-top: 34px;
  padding-top: 30px;
  border-top: 1px solid var(--line);
}

h2 {
  margin: 0 0 14px;
  font-size: clamp(24px, 3vw, 34px);
  line-height: 1.25;
  letter-spacing: 0;
}

h3 {
  margin: 22px 0 8px;
  font-size: 20px;
  line-height: 1.3;
}

p,
li {
  color: var(--muted);
}

.topic-content p {
  margin: 0 0 12px;
}

.topic-content ul,
.topic-content ol {
  margin: 10px 0 0;
  padding-left: 22px;
}

.fact-list {
  display: grid;
  gap: 10px;
  padding: 0;
  margin: 16px 0 0;
  list-style: none;
}

.fact-list li {
  padding: 12px 14px;
  background: var(--wash);
  border-radius: 8px;
}

.compare {
  width: 100%;
  border-collapse: collapse;
  margin-top: 14px;
  overflow: hidden;
  border: 1px solid var(--line);
}

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

.compare th {
  background: #edf3f8;
  color: var(--ink);
}

.faq details {
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 14px 16px;
  background: #fbfcfe;
}

.faq details + details {
  margin-top: 10px;
}

.faq summary {
  cursor: pointer;
  font-weight: 800;
}

.topic-aside {
  position: sticky;
  top: 18px;
  padding: 22px;
}

.topic-aside h2 {
  font-size: 22px;
}

.topic-aside a {
  color: var(--navy);
  font-weight: 800;
}

.topic-links {
  display: grid;
  gap: 10px;
  margin-top: 18px;
}

.topic-links a {
  display: block;
  padding: 10px 12px;
  border: 1px solid var(--line);
  border-radius: 8px;
  text-decoration: none;
  background: var(--wash);
}

.topic-footer {
  border-top: 1px solid var(--line);
  border-bottom: 0;
}

.topic-footer-inner {
  display: flex;
  justify-content: space-between;
  gap: 20px;
  padding: 28px 0;
  color: var(--muted);
  font-size: 14px;
}

@media (max-width: 860px) {
  .topic-header-inner,
  .topic-footer-inner {
    align-items: flex-start;
    flex-direction: column;
  }

  .topic-grid {
    grid-template-columns: 1fr;
  }

  .topic-aside {
    position: static;
  }
}