style.css

* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

body {
  background: #0f0c29; /* fallback for old browsers */
  background: -webkit-linear-gradient(to right, #24243e, #302b63, #0f0c29); /* Chrome 10-25, Safari 5.1-6 */
  background: linear-gradient(to right, #24243e, #302b63, #0f0c29); /* W3C, IE 10+/ Edge, Firefox 16+, Chrome 26+, Opera 12+, Safari 7+ */
  font-family: 'Roboto', sans-serif;
  font-size: 16px;
  color: #fff;
}

.container {
  width: 80%;
  margin: 0 auto;
  text-align: center;
}

h1 {
  font-size: 3rem;
  margin-top: 2rem;
}

p {
  font-size: 1.2rem;
  margin-top: 2rem;
}

input[type=text] {
  width: 100%;
  padding: 1rem;
  border-radius: 10px;
  border: none;
  margin-top: 1rem;
}

#imgBox {
  margin-top: 2rem;
}

#qrImage {
  max-width: 100%;
}

button {
  margin-top: 2rem;
  padding: 1rem 2rem;
  background-color: #d43f8d;
  color: #fff;
  border: none;
  border-radius: 10px;
  cursor: pointer;
  transition: all 0.3s ease-in-out;
}

button:hover {
  background-color: #c4337e;
}

@media (max-width: 768px) {
  h1 {
      font-size: 2rem;
  }
  
  p {
      font-size: 1rem;
  }
  
  input[type=text] {
      font-size: 1rem;
  }
  
  button {
      font-size: 1rem;
      padding: 0.8rem 1.5rem;
  }
}