.đầu {
  background-image: url(https://upload.wikimedia.org/wikipedia/commons/thumb/5/57/NASA-Apollo8-Dec24-Earthrise-b.jpg/1024px-NASA-Apollo8-Dec24-Earthrise-b.jpg);
  background-size: cover;
  width: 100%;

  position: relative; 
}
a.new:link {
  color: #cda7fa;
}
a.new:visited {
  color: #cda7fa;
}
a.new:hover {
  color: #deb8fb;
}
a.new:active {
  color: #cda7fa;
}