style.css

@import url(https://fonts.googleapis.com/css?family=Quicksand:300,regular,500,600,700);
* {
  padding: 0;
  margin: 0;
  box-sizing: border-box;
}

.main {
  width: 100%;
  min-height: 100vh;
  display: flex;
  justify-content: center;
  align-items: center;
  background: #ff5f6d; /* fallback for old browsers */
  background: -webkit-linear-gradient(
    to right,
    #ffc371,
    #ff5f6d
  ); /* Chrome 10-25, Safari 5.1-6 */
  background: linear-gradient(
    to right,
    #ffc371,
    #ff5f6d
  ); /* W3C, IE 10+/ Edge, Firefox 16+, Chrome 26+, Opera 12+, Safari 7+ */
}

.qrbox {
  max-width: 40rem;
  width: 20rem;
  padding: 1rem 1rem;
  background-color: #fff;
  border-radius: 1rem;
  font-family: 'Quicksand', sans-serif;
  
}
h2{
  text-align: center;
  font-weight: bold;
}

.active{
  height: 20rem;
}

input {
  width: 100%;
  margin-top: 1.2rem;
  padding: 10px 5px;
  border: 1px solid #a2a2a28d;
  border-radius: 5px;
}

input:focus {
  outline: 0;
}

button {
  display: block;
  margin-top: 1rem;
  width: 100%;
  padding: 0.5rem 0;
  background-color: #ff5f6d;
  color: #fff;
  border: 0;
  border-radius: 0.3125rem;
}

button:hover {
  background-color: #bb2632;
  cursor: pointer;
}

.qr-img{
  width: 100%;
  height: 100%;
  object-fit: cover;
  margin-top: 2rem;
  text-align: center;
}

.qr-img img{
  max-width: 100%;
  max-height: 100%;

}