:root {
  --bg: #f7f8fa;
  --panel: #ffffff;
  --border: #e5e7eb;
  --text: #1f2937;
  --muted: #6b7280;
  --accent: #4f46e5;
  --accent-soft: #eef2ff;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
  line-height: 1.75;
  font-size: 16px;
}

a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }

.site-header {
  background: var(--panel);
  border-bottom: 1px solid var(--border);
}
.site-header .wrap {
  max-width: 860px;
  margin: 0 auto;
  padding: 14px 20px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}
.brand { font-size: 18px; font-weight: 700; color: var(--text); }
.brand small { font-weight: 400; color: var(--muted); margin-left: 6px; }
.site-header nav a { margin-left: 18px; color: var(--muted); font-size: 14px; }

.wrap { max-width: 860px; margin: 0 auto; padding: 24px 20px 64px; }

.hero { padding: 40px 0 16px; }
.hero h1 { font-size: 30px; margin: 0 0 8px; }
.hero p { color: var(--muted); margin: 0; font-size: 16px; }

.article {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 36px 40px;
}
.article h1 { font-size: 26px; line-height: 1.4; margin: 0 0 8px; }
.article .meta { color: var(--muted); font-size: 13px; margin: 0 0 24px; }
.article h2 {
  font-size: 20px;
  margin: 32px 0 12px;
  padding-left: 10px;
  border-left: 3px solid var(--accent);
}
.article h3 { font-size: 17px; margin: 24px 0 8px; }
.article p { margin: 12px 0; }
.article ul, .article ol { padding-left: 22px; margin: 12px 0; }
.article li { margin: 6px 0; }
.article img { max-width: 100%; border-radius: 8px; border: 1px solid var(--border); }

.table-wrap { overflow-x: auto; margin: 16px 0; }
table { border-collapse: collapse; width: 100%; font-size: 14px; }
th, td { border: 1px solid var(--border); padding: 10px 12px; text-align: left; vertical-align: top; }
th { background: var(--accent-soft); font-weight: 600; }

.faq { margin-top: 28px; border-top: 1px solid var(--border); padding-top: 20px; }
.faq h2 { border-left: none; padding-left: 0; }
.faq h3 { font-size: 15px; color: var(--accent); }

.cta {
  margin-top: 32px;
  background: var(--accent-soft);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 20px 24px;
}
.cta p { margin: 0 0 10px; }
.cta .btn {
  display: inline-block;
  background: var(--accent);
  color: #fff;
  padding: 10px 22px;
  border-radius: 8px;
  font-size: 15px;
  font-weight: 600;
}
.cta .btn:hover { text-decoration: none; opacity: .92; }

.card-list { display: grid; gap: 14px; margin-top: 20px; }
.card {
  display: block;
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 18px 22px;
  color: var(--text);
}
.card:hover { border-color: var(--accent); text-decoration: none; }
.card h2 { margin: 0 0 6px; font-size: 18px; }
.card p { margin: 0; color: var(--muted); font-size: 14px; }

.site-footer { border-top: 1px solid var(--border); color: var(--muted); font-size: 13px; }
.site-footer .wrap { padding-top: 20px; padding-bottom: 20px; }

.breadcrumb { font-size: 13px; color: var(--muted); margin-bottom: 12px; }
.breadcrumb a { color: var(--muted); }

@media (max-width: 640px) {
  .article { padding: 24px 20px; }
  .article h1 { font-size: 22px; }
}