:root {
  --bg: #f6f7f9;
  --surface: #ffffff;
  --ink: #16191d;
  --muted: #6b7280;
  --line: #e5e7eb;
  --accent: #2f6feb;
  --radius: 14px;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
    "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  line-height: 1.75;
  -webkit-font-smoothing: antialiased;
}

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

.wrap { max-width: 780px; margin: 0 auto; padding: 0 24px; }

.site-header { background: var(--surface); border-bottom: 1px solid var(--line); }
.site-header .wrap {
  display: flex; align-items: center; justify-content: space-between;
  padding-top: 14px; padding-bottom: 14px; gap: 16px; flex-wrap: wrap;
}
.brand { font-size: 17px; font-weight: 650; color: var(--ink); }
.brand small { font-weight: 400; color: var(--muted); margin-left: 8px; font-size: 14px; }
.nav a { margin-left: 20px; font-size: 14px; color: var(--muted); }
.nav a.active { color: var(--accent); font-weight: 600; }

main.wrap { padding-top: 44px; padding-bottom: 60px; }

.eyebrow {
  color: var(--accent); font-size: 13px; font-weight: 650;
  letter-spacing: .08em; text-transform: uppercase; margin: 0;
}
h1 { font-size: 34px; line-height: 1.3; margin: 10px 0 4px; letter-spacing: -.02em; }
h2 { font-size: 21px; margin: 34px 0 8px; line-height: 1.4; }
h3 { font-size: 16px; margin: 24px 0 2px; line-height: 1.5; }
p { margin: 8px 0; }
.lede { font-size: 17px; }
.en { color: var(--muted); font-size: .9em; line-height: 1.65; margin-top: 2px; }
.meta { color: var(--muted); font-size: 14px; }

.cards {
  display: grid; grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 14px; margin: 28px 0 8px;
}
.card {
  display: block; background: var(--surface); border: 1px solid var(--line);
  border-radius: var(--radius); padding: 18px 20px; color: var(--ink);
  transition: border-color .15s ease, transform .15s ease;
}
.card:hover { border-color: var(--accent); text-decoration: none; transform: translateY(-2px); }
.card h2 { font-size: 17px; margin: 0 0 4px; }
.card .en { font-size: 13px; margin: 0 0 8px; }
.card p { margin: 0; color: var(--muted); font-size: 14px; }

.box {
  background: var(--surface); border: 1px solid var(--line);
  border-radius: var(--radius); padding: 18px 22px; margin: 16px 0;
}
.box p:last-child, .box ul:last-child { margin-bottom: 0; }

code {
  background: #f0f2f5; padding: 2px 6px; border-radius: 5px;
  font-size: .88em; word-break: break-all;
}
ul { padding-left: 20px; margin: 8px 0; }
li { margin: 4px 0; }
hr { border: 0; border-top: 1px solid var(--line); margin: 34px 0; }

.site-footer { border-top: 1px solid var(--line); background: var(--surface); }
.site-footer .wrap { padding-top: 18px; padding-bottom: 18px; color: var(--muted); font-size: 13px; }

@media (max-width: 600px) {
  h1 { font-size: 28px; }
  main.wrap { padding-top: 30px; }
  .nav a { margin-left: 12px; }
}