.collapsible {
  background-color:white;
  color: black;
  cursor: pointer;
  padding: 2px;
  width: 100%;
  border: none;
  text-align: left;
  outline: none;
  font-size: 14px;
}

  .active, .collapsible:hover {
    background-color: #555;
  }

  .collapsible:after {
    content: '\002B';
    color: white;
    font-weight: bold;
    float: right;
    margin-left: 5px;
  }

.active:after {
  content: "\2212";
}

.content {
  padding: 0 10px;
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.2s ease-out;
  background-color: #f1f1f1;
}