body {
  font-family: sans-serif;
  text-align: center;
}

h1 {
  margin: 40px 0 20px;
}

input[type=radio] {
  display: none;
}

label {
  display: inline-block;
  padding: 10px 20px;
  background-color: lightgray;
  color: #333;
  cursor: pointer;
  border-radius: 4px;
  margin-right: 20px;
  transition: all 0.2s ease-in-out;
}

label:hover {
  background-color: blue;
  color: #fff;
}

input[type=radio]:checked + label {
  background-color: blue;
  color: #fff;
}

article {
  display: none;
  padding: 20px;
  background-color: lightgray;
  border-radius: 4px;
  margin: 20px 0;
}

article.on {
  display: block;
}

input[type=text],
input[type=tel],
textarea {
  width: 100%;
  padding: 10px;
  margin: 10px 0;
  border: 1px solid lightgray;
  border-radius: 4px;
  box-sizing: border-box;
  font-size: 16px;
}

#qrcode {
  margin: 40px 0;
}

#previewImg {
  margin: 40px 0;
}

.button {
  background-color: blue;
  color: #fff;
  padding: 10px 20px;
  border: 1px solid lightgray;
  border-radius: 4px;
  cursor: pointer;
  text-decoration: none;
  transition: all 0.2s ease-in-out;
}

.button:hover {
  background-color: #fff;
  color: blue;
}

@media (max-width: 767px) {
  label {
    display: block;
    margin: 20px 0;
  }

  article {
    margin: 20px 0 0;
  }
}