main section {
  width: 90%;
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  padding: 20px;
}

section h3 {
  font-size: 28px;
  margin: 10px 0;
}

section div {
  padding: 30px 0;
}

section div a {
  color: black;
  font-size: 20px;
  text-decoration: none;
  padding: 10px 5px;
  box-shadow: 0 2px 5px 0 #c3cc46;
}

.btn {
  border: none;
  padding: 10px 40px;
  background-color: #c3cc46;
  cursor: pointer;
  font-size: 20px;
  font-weight: normal;
  font-family: inherit;
}

div.unauthorized-author {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  font-size: 20px;
}

div.unauthorized-author h3 {
  font-size: 28px;
  margin: 30px;
}

div.unauthorized-author .btn {
  color: black;
  text-decoration: none;
}

@media screen and (max-width: 640px) {
  main section {
    width: 100%;
  }
}