body {
  background-color: #333;
  color: #fff;
  font-family: Arial, sans-serif;
  display: flex;
  flex-direction: column;
  align-items: center;
  padding: 20px;
}

h1 {
  margin-bottom: 20px;
}

form {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
}

input[type="checkbox"] {
  margin: 10px;
  width: 20px;
  height: 20px;
}

label {
  margin: 10px;
}

button {
  background-color: #444;
  color: #fff;
  border: none;
  border-radius: 5px;
  padding: 0.5em 1em;
  margin-top: 2em;
}

textarea {
  width: 80%;
  height: 5em;
  background-color: #444;
  color: #fff;
  border: none;
  border-radius: 5px;
  padding: 1em;
  margin-top: 2em;
}

#copyBtn {
  background-color: #fff;
  color: #333;
  border: none;
  padding: 10px 20px;
  border-radius: 5px;
  margin-top: 20px;
  cursor: pointer;
}

#output {
  margin-top: 20px;
  width: 50%;
  height: 50px;
  background-color: #333;
  color: #fff;
  border: none;
  padding: 10px;
}

@media only screen and (max-width: 767px) {
  form {
    flex-direction: column;
  }

  input[type="checkbox"] {
    margin: 10px 0;
  }
}