body {
  margin: 0;
  padding: 0;
  font-family: Arial, sans-serif;
}
main {
  max-width: 900px;
  margin: 0 auto;
  padding: 20px;
}
article {
  margin-bottom: 40px;
  text-align: center;
}
img {
  display: block;         
  max-width: 100%;        
  height: auto;
  margin: 20px auto;       
}
h1, h2 {
  text-align: center;
}
a {
  display: inline-block;
  margin-top: 10px;
  color: #0066cc;
  text-decoration: none;
}

a:hover {
  text-decoration: underline;
}