:root {
  --bg: #f7f7fb;
  --card: #ffffff;
  --ink: #16181d;
  --muted: #5b6270;
  --accent: #1a237e;
  --line: #e4e6ee;
}
* { box-sizing: border-box; }
body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  background: var(--bg);
  color: var(--ink);
  line-height: 1.6;
  -webkit-text-size-adjust: 100%;
}
.wrap { max-width: 760px; margin: 0 auto; padding: 24px 20px 80px; }
header.site {
  display: flex; align-items: center; justify-content: space-between;
  gap: 12px; flex-wrap: wrap; margin-bottom: 8px;
}
.brand { font-weight: 800; font-size: 18px; color: var(--accent); text-decoration: none; }
.toggle { display: inline-flex; border: 1px solid var(--line); border-radius: 999px; overflow: hidden; background: var(--card); }
.toggle button {
  border: 0; background: transparent; padding: 7px 14px; font-size: 14px; font-weight: 600;
  color: var(--muted); cursor: pointer;
}
.toggle button.active { background: var(--accent); color: #fff; }
.card {
  background: var(--card); border: 1px solid var(--line); border-radius: 16px;
  padding: 28px 26px; margin-top: 16px;
}
h1 { font-size: 26px; margin: 0 0 4px; }
h2 { font-size: 18px; margin: 28px 0 8px; }
.eff { color: var(--muted); font-size: 14px; margin: 0 0 8px; }
p, li { color: var(--ink); font-size: 15.5px; }
.muted { color: var(--muted); }
a { color: var(--accent); }
ul { padding-left: 20px; }
.lead { background: #eef1ff; border: 1px solid #d9e0ff; border-radius: 12px; padding: 14px 16px; font-size: 14.5px; }
.foot { margin-top: 26px; font-size: 13px; color: var(--muted); }
nav.pages { margin-top: 10px; font-size: 14px; }
nav.pages a { margin-right: 14px; }
[data-lang] { display: none; }
[data-lang].show { display: block; }