:root {
  --bg: #f7f8fb;
  --panel: #ffffff;
  --ink: #1c2434;
  --muted: #5c6575;
  --line: #e4e8f0;
  --accent: #3455db;
  --accent-soft: #e8ecff;
  font-family: "PingFang SC", "Noto Sans SC", "Microsoft YaHei", system-ui, -apple-system, sans-serif;
}

* { box-sizing: border-box; }
body {
  margin: 0;
  color: var(--ink);
  background: var(--bg);
  line-height: 1.7;
}
a { color: var(--accent); }
.wrap { max-width: 720px; margin: 0 auto; padding: 28px 20px 72px; }
.top {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 16px;
  margin-bottom: 28px;
}
.brand { display: flex; gap: 12px; align-items: center; text-decoration: none; color: inherit; }
.mark {
  width: 42px; height: 42px; border-radius: 12px; flex: none;
  display: grid; place-items: center; color: #fff; font-weight: 700; font-size: 14px;
  background: linear-gradient(135deg, #3455db, #6a8bff);
}
.brand strong { display: block; font-size: 16px; }
.brand span { display: block; color: var(--muted); font-size: 12px; }
nav { display: flex; gap: 14px; font-size: 14px; }
.card {
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 16px;
  padding: 22px 22px 8px;
  box-shadow: 0 8px 30px rgba(28, 36, 52, 0.05);
}
h1 { font-size: 28px; line-height: 1.35; margin: 0 0 12px; }
h2 { font-size: 18px; margin: 28px 0 8px; }
p, li { font-size: 15px; }
.muted { color: var(--muted); }
.actions { display: flex; flex-wrap: wrap; gap: 10px; margin: 18px 0 8px; }
.button {
  display: inline-block;
  text-decoration: none;
  background: var(--accent);
  color: #fff;
  border-radius: 10px;
  padding: 10px 14px;
  font-size: 14px;
}
.button.secondary { background: var(--accent-soft); color: var(--accent); }
footer { margin-top: 28px; color: var(--muted); font-size: 13px; }
code { font-size: 0.92em; }