:root {
  --bg: #0b1220;
  --fg: #e8eef7;
  --muted: #9aacbf;
  --accent: #2dd4bf;
  --btn: #1e3a5f;
}
* { box-sizing: border-box; }
body {
  margin: 0;
  min-height: 100vh;
  font-family: "Segoe UI", system-ui, sans-serif;
  color: var(--fg);
  background: var(--bg);
}
.shell {
  max-width: 36rem;
  margin: 0 auto;
  padding: 18vh 1.5rem 3rem;
}
.brand {
  font-size: 1.5rem;
  font-weight: 700;
  margin: 0 0 1rem;
  color: var(--accent);
}
h1 { font-size: 1.75rem; margin: 0 0 0.75rem; }
.lead { color: var(--muted); margin: 0 0 1.5rem; line-height: 1.5; }
.btn {
  display: inline-block;
  padding: 0.65rem 1.1rem;
  border-radius: 0.4rem;
  text-decoration: none;
  color: var(--fg);
  background: var(--btn);
  border: 1px solid #334155;
}