:root {
  --bg: #f7f7f5;
  --card: #ffffff;
  --text: #1c1c1e;
  --muted: #4a4a50;
  --border: #e2e2de;
  --accent: #1f5fbf;
  --accent-bg: #eef3fb;
}
* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  font-size: 17px;
  line-height: 1.6;
}
a { color: var(--accent); }
a:hover { text-decoration-thickness: 2px; }
.wrap { max-width: 760px; margin: 0 auto; padding: 0 20px; }
header { padding: 48px 0 24px; }
header h1 { font-size: 2rem; line-height: 1.2; margin: 0 0 6px; }
header .meta { color: var(--muted); margin: 0 0 16px; }
.contact-box {
  background: var(--accent-bg);
  border: 1px solid #cddcf3;
  border-radius: 12px;
  padding: 14px 18px;
  margin: 0;
}
nav { margin: 20px 0 0; display: flex; flex-wrap: wrap; gap: 8px 16px; font-size: 0.95rem; }
section {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 14px;
  padding: 22px 24px;
  margin: 0 0 20px;
}
section h2 { font-size: 1.3rem; margin: 0 0 10px; }
section h3 { font-size: 1.05rem; margin: 18px 0 4px; }
section p { margin: 0 0 12px; }
section p:last-child, section ul:last-child, section ol:last-child { margin-bottom: 0; }
ul, ol { padding-left: 1.3em; margin: 0 0 12px; }
li { margin: 4px 0; }
code, kbd {
  font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  font-size: 0.92em;
  background: #f0f0ec;
  border: 1px solid var(--border);
  border-radius: 5px;
  padding: 1px 6px;
}
.tip {
  border-left: 4px solid #c98a00;
  background: #fff8e6;
  padding: 10px 14px;
  border-radius: 6px;
}
dl { margin: 0; }
dt { font-weight: 600; margin: 16px 0 2px; }
dt:first-child { margin-top: 0; }
dd { margin: 0; color: var(--muted); }
footer { color: var(--muted); font-size: 0.9rem; padding: 12px 0 40px; text-align: center; }
@media (max-width: 520px) {
  body { font-size: 16px; }
  header { padding: 32px 0 18px; }
  header h1 { font-size: 1.65rem; }
  section { padding: 18px 16px; }
}