.a1{
  text-align: center;
  color: white;
  
}

#b1{
  background-color: yellow;
  color: red;
}
#a1{
  background-color: red;
  text-align: center;
}
footer{
  color: red;
}
.i1{
  height: 500px;
  width: 400px;
}