:root {
  color-scheme: light dark;
  --bg: #f6f7f9;
  --surface: #ffffff;
  --text: #18202a;
  --muted: #667085;
  --border: #e4e7ec;
  --accent: #3157d5;
  --accent-hover: #2647b5;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #111318;
    --surface: #1a1d24;
    --text: #f2f4f7;
    --muted: #a5adba;
    --border: #2d323c;
    --accent: #7d9bff;
    --accent-hover: #9bb0ff;
  }
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  min-height: 100vh;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Arial, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
}

main {
  width: min(820px, calc(100% - 40px));
  margin: 0 auto;
  padding: 80px 0;
}

.card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 18px;
  padding: 42px;
  box-shadow: 0 12px 32px rgba(0,0,0,.05);
}

h1 {
  margin: 0 0 12px;
  font-size: clamp(2rem, 6vw, 3.2rem);
  line-height: 1.1;
}

h2 {
  margin-top: 34px;
}

p {
  margin: 12px 0;
}

.lead {
  font-size: 1.15rem;
  color: var(--muted);
}

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

.button {
  display: inline-block;
  margin-top: 24px;
  padding: 11px 18px;
  border-radius: 10px;
  background: var(--accent);
  color: white;
  text-decoration: none;
  font-weight: 600;
}

.button:hover {
  background: var(--accent-hover);
}

footer {
  margin-top: 28px;
  color: var(--muted);
  font-size: .9rem;
}

nav {
  margin-top: 30px;
  display: flex;
  gap: 18px;
  flex-wrap: wrap;
}

nav a {
  text-decoration: none;
}