.prog-hdr {
  background-color: #3bcee3;
  
  background-image: none; 
  background-repeat: no-repeat;
    background-position: bottom;
}

@media (min-width: 640px) {
  .prog-hdr {
    background-image: url(https://d293qfd0kygxt9.cloudfront.net/058a0000-0aff-0242-e253-08dae1ffe364_w1800.jpg);
  background-size: cover; 
    }