:root {
  --bg: #4a90d9;
  --card: #ffffff;
  --text: #1a2950;
  --subtle: #5a6b8a;
  --accent: #ff8a3d;
}
* { box-sizing: border-box; }
body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "Hiragino Sans",
    "Yu Gothic", sans-serif;
  background: linear-gradient(180deg, #9fd5f5 0%, #4a90d9 100%);
  color: var(--text);
  min-height: 100vh;
  -webkit-font-smoothing: antialiased;
}
.wrap {
  max-width: 720px;
  margin: 0 auto;
  padding: 32px 20px 80px;
}
.card {
  background: var(--card);
  border-radius: 18px;
  padding: 28px 24px;
  box-shadow: 0 12px 32px rgba(0, 0, 0, 0.18);
}
header h1 {
  color: #fff;
  font-size: 32px;
  margin: 0 0 4px;
  text-shadow: 0 2px 6px rgba(0,0,0,0.20);
}
header .sub { color: rgba(255,255,255,.85); font-size: 14px; margin-bottom: 20px; }
header .sub .lang { margin-left: 8px; }
header .sub .lang a { color: #fff; }
nav a {
  color: #fff;
  text-decoration: none;
  margin-right: 14px;
  font-size: 14px;
  border-bottom: 1px solid rgba(255,255,255,.4);
  padding-bottom: 1px;
}
nav { margin-bottom: 18px; }
h2 {
  color: var(--text);
  font-size: 20px;
  margin: 24px 0 8px;
  padding-bottom: 6px;
  border-bottom: 2px solid var(--accent);
  display: inline-block;
}
h3 { color: var(--text); font-size: 16px; margin: 16px 0 6px; }
p { line-height: 1.7; margin: 8px 0; }
ul { line-height: 1.7; padding-left: 22px; }
a { color: var(--accent); }
.muted { color: var(--subtle); font-size: 13px; margin-top: 24px; }
footer {
  text-align: center;
  margin-top: 32px;
  color: rgba(255,255,255,.7);
  font-size: 13px;
}