.markdown {
  width: 70%;
  margin: 1em auto;
}

.nousjoindre{
    max-height: 400px;
    Width: 300px;
    padding: 10px;
    margin: auto;
    margin-top: 10px;
    border: 1px solid #800;
    border-radius: 5px 5px 5px 5px;
}