body {
  margin: 0;
  height: 100%;
  background-image: linear-gradient(to bottom right, #212529, #6c757d);
  background-repeat: no-repeat;
  background-attachment: fixed;
  color: rgba(255,255,255,.75);
  font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
}

#hello {
  padding: 5rem 1.5rem;
  width: 50%;
  margin: auto;
}

.hide {
  display: none;
}

.form {
  padding: 1.5rem;
  width: 50%;
  margin: auto;
}

.form-label {
  margin-bottom: 1rem;
  margin-top: 0;
}

.form-control {
  display: block;
  margin-top: 0.5rem;
  margin-bottom: 1rem;
  width: 50%;
  padding: 0.375rem 0.75rem;
  font-size: 1rem;
  font-weight: 400;
  line-height: 1.5;
  color: #212529;
  background-color: rgb(240, 240, 240);
  background-clip: padding-box;
  border: 1px solid #ced4da;
  -webkit-appearance: none;
  -moz-appearance: none;
  appearance: none;
  border-radius: 0.25rem;
  transition: border-color .15s ease-in-out,box-shadow .15s ease-in-out;
}

button.primary {
  border-radius: .25rem;
  padding: 0.3rem;
  cursor: pointer;
  background-color: rgb(0, 255, 0);
  border-color: rgb(0, 92, 0);
  color: #212529;
}
button.primary:hover {
  background-color: rgb(70, 255, 70);
  border-color: rgb(0, 255, 0);
}

#added-content {
  color: red;
  margin-top: 2rem;
}

#added-content b {
  color: green;
  margin-top: 2rem;
}

#added-content i {
  color: yellow;
  margin-top: 2rem;
}