.main {
    width:90%;
    margin: auto;
}
img {
  box-shadow: 0 4px 8px 0 rgba(0, 0, 0, 0.2), 0 6px 20px 0 rgba(0, 0, 0, 0.19);
  width: 45%;
  height:auto;
  float: left;
  margin-left:10px;
}
body{
    background-color:#e7fce3;
}

@media screen and (max-width: 1200px) {
img {
  box-shadow: 0 4px 8px 0 rgba(0, 0, 0, 0.2), 0 6px 20px 0 rgba(0, 0, 0, 0.19);
  width: 100%;
  float: none;
  margin-left: 0;
}
}