:root{
  --primary:#0a1cff;
  --dark:#0a0a0a;
  --light:#ffffff;
}

body{
  margin:0;
  font-family:Inter,system-ui;
  background:#f4f6fb;
}

header{
  background:var(--dark);
  color:#fff;
  padding:15px;
}

.card{
  background:#fff;
  border-radius:12px;
  box-shadow:0 10px 30px rgba(0,0,0,.08);
  padding:20px;
}

.button{
  background:var(--primary);
  color:#fff;
  padding:12px 18px;
  border-radius:8px;
  text-decoration:none;
  display:inline-block;
}