._xxxxxxxxx_collapse_button
{
  background-color: #eee;
  display:inline;
  cursor: pointer;
  padding: 0.6em;
  border: none;
  outline: none;
  font-size: inherit;
  color: inherit;
  padding-left:0.5em;
}



.collapsing_h2
{
  font-size: 1.5em;
  font-weight: bold;
}

.collapse_button
{
  background-color: #eee;
  display: inline-flex;
  cursor: pointer;
  padding: 0.2em;
  margin: 0;
  border: 0.1ch;
  border-color: gray;
  border-style: solid;
  outline: none;
  color: inherit;
  border-radius: 0.3em;
  /*place-content: center;*/
  box-shadow: 0.1em 0.1em 0.5em 0 #ccc;
  margin-right: 1ch;
  padding: 0.4em;
}

.collapse_button .arrow
{
  width: 0;
  height: 0;
  border-left: 0.3em solid transparent;
  border-right: 0.3em solid transparent;
  border-top: 0.6em solid gray;
  transition: transform 0.3s ease-out;
}

  .collapse_button.expanded .arrow
  {
    transform: rotate(-180deg);
  }


h2 .collapse_button
{
  display:inline;
}

div.collapsible_content
{
  max-height: 0em;
  display: block;
  overflow: hidden;
  padding: 0 18px;
  transition: max-height 0.3s ease-out;
}


div.collapsible_content.expanded
{
  max-height:50em;
}

li.collapsible_content:not(.expanded)
{
  max-height: 0em;
  background-color: #ccc;
  transition: background-color 0.3s, max-height 0.3s ease-out;
  overflow: hidden;
  padding-bottom: 0.1em;
}

li.collapsible_content.expanded
{
  max-height: 30em;
  transition: background-color 0.3s, max-height 0.3s;
}


._xxxxxxxx_collapse_button:after
{
  content: '\002B';
  font-weight: bold;
  float: left;
}

._xxxxxxxx_collapse_button.expanded:after
{
  content: "\2212";
}