body { 
  background: #0f1320;
  margin: 0;
}
  
main {
  width: 800px;
  margin 40px auto;
  background: #cfcfcf;
}

header {
  background: linear-gradient(#2c4b91, #1b2e5f);
  color: white;
}

section {
  padding: 16px;
}