:root {
  color-scheme: light;
  --bg: #0b1220;
  --surface: #121a2b;
  --text: #e8edf8;
  --muted: #a6b0c7;
  --accent: #7cc4ff;
  --line: #253250;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  background: linear-gradient(180deg, var(--bg), #0e172a);
  color: var(--text);
  line-height: 1.6;
}

.container {
  max-width: 860px;
  margin: 0 auto;
  padding: 28px 20px 40px;
}

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

h1, h2, h3 {
  margin: 0 0 12px;
  line-height: 1.25;
}

h1 {
  font-size: 30px;
}

h2 {
  font-size: 22px;
  margin-top: 24px;
}

p, li {
  color: var(--text);
}

small, .muted {
  color: var(--muted);
}

nav {
  display: flex;
  gap: 10px;
  flex-wrap: wrap;
  margin-bottom: 18px;
}

.btn {
  display: inline-block;
  border: 1px solid var(--line);
  color: var(--text);
  text-decoration: none;
  padding: 10px 14px;
  border-radius: 10px;
  background: #16203a;
}

.btn:hover {
  border-color: var(--accent);
}

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