.exercise {
  position: relative;
  border: 1px solid #ccc;
}

.exercise code {
  font-family: "Source Code Pro", monospace;
}

.exercise .btn {
  position: absolute;
  bottom: 0;
  right: 0;
}

.exercise {
  position: relative;
  border: 1px solid #ccc;

  & code {
    font-family: "Source Code Pro", monospace;
  }

  .btn {
    position: absolute;
    bottom: 0;
    right: 0;
  }
}