.container {
    margin-top: 50px;
    width: 100%;
    height: auto;
    text-align: center;
    vertical-align: middle;
}
.container img {
    vertical-align: middle;
}

img {
  display: block;
  width: 100%;
  max-width: 600px;
  margin-left: auto;
  margin-right: auto;
  height: auto;
}

.footer {
    padding-top: 20px;
}