body {
   margin: 0 auto;
   max-width: 800px;
   background-color: black;
}
header {
   text-align: center;
   background-color: white;
}
header h1 {
   padding: 0.5rem 0;
}
main {
   padding: 1rem 0.5rem;
   line-height: 1.4;
}
p {
   color: white;
}
footer { 
   position: absolute;
   bottom: 0.5rem;
   left: 50%;
   transform: translateX(-50%);
}