:root {
  --bg: #f5f7fb;
  --surface: #ffffff;
  --text: #172033;
  --muted: #5d6679;
  --primary: #1f6fe0;
  --primary-dark: #1553ad;
  --border: #e3e7ef;
}

* { box-sizing: border-box; margin: 0; padding: 0; }

body {
  font-family: "Segoe UI", Arial, sans-serif;
  color: var(--text);
  background: var(--bg);
  line-height: 1.65;
}

a { color: var(--primary); }

header.top {
  background: var(--surface);
  border-bottom: 1px solid var(--border);
}

.wrap { width: min(960px, 100%); margin: 0 auto; padding: 0 20px; }

.nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding: 14px 0;
  flex-wrap: wrap;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-weight: 800;
  font-size: 20px;
  color: var(--text);
  text-decoration: none;
}

.brand img { width: 40px; height: 40px; }

.nav nav { display: flex; gap: 18px; flex-wrap: wrap; font-size: 15px; }
.nav nav a { text-decoration: none; color: var(--muted); }
.nav nav a:hover { color: var(--primary); }

.hero { padding: 64px 0 40px; text-align: center; }
.hero img { width: 120px; height: 120px; margin-bottom: 18px; }
.hero h1 { font-size: clamp(32px, 6vw, 52px); line-height: 1.1; margin-bottom: 16px; }
.hero p { max-width: 640px; margin: 0 auto; color: var(--muted); font-size: 18px; }

.grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 16px;
  padding: 24px 0 48px;
}

.card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 14px;
  padding: 22px;
}

.card h2 { font-size: 18px; margin-bottom: 8px; }
.card p { color: var(--muted); font-size: 15px; }

.note {
  background: var(--surface);
  border: 1px solid var(--border);
  border-left: 4px solid var(--primary);
  border-radius: 10px;
  padding: 18px 20px;
  margin-bottom: 48px;
}

.note h2 { font-size: 18px; margin-bottom: 6px; }

.doc { padding: 40px 0 56px; }
.doc h1 { font-size: clamp(28px, 5vw, 40px); line-height: 1.15; margin-bottom: 6px; }
.doc .updated { color: var(--muted); font-size: 14px; margin-bottom: 28px; }
.doc h2 { font-size: 21px; margin: 30px 0 10px; }
.doc p, .doc li { margin-bottom: 10px; }
.doc ul { padding-left: 22px; }

footer.bottom {
  border-top: 1px solid var(--border);
  background: var(--surface);
  color: var(--muted);
  font-size: 14px;
  padding: 20px 0;
}

footer.bottom .wrap { display: flex; justify-content: space-between; gap: 12px; flex-wrap: wrap; }
footer.bottom a { color: var(--muted); margin-left: 14px; }
footer.bottom a:first-child { margin-left: 0; }