.tree {
  --spacing: 1.5rem;
  --radius: 6px;
}


.tree li {
  display: block;
  position: relative;
  padding-left: calc(2 * var(--spacing) - var(--radius) - 2px);  
  nowrap;
  font-size: 10pt;
  font-family: "Arial Narrow";
}

.tree ul {
  margin-left: calc(var(--radius) - var(--spacing));
  padding-left: 0;
}

.tree ul li {
  border-left: 2px solid #ddd;
}

.tree ul li div{
  background-color: transparent;
  padding-left:4px;
}
.tree ul li a{
  background-color: transparent;
  padding-left:4px;
  color: lightgray;
}
.tree ul li a:hover{
  color: white;
  cursor: pointer;
}

.tree ul li:last-child {
  border-color: transparent;
}
.tree ul li img: {
  display:inline;
  width:20px;
  height:20px;
}
.tree ul li a: {
  display:inline;
  height:20px;
  background-color: transparent;
  color:white;
  font-size: 8px;
}

.tree ul li::before {
  content: '';
  display: block;
  position: absolute;
  top: calc(var(--spacing) / -2);
  left: -2px;
  width: calc(var(--spacing) + 2px);
  height: calc(var(--spacing) + 1px);
  border: solid #ddd;
  border-width: 0 0 2px 2px;
}

.tree summary {
  display: block;
  cursor: default;
}
.tree summary a{
  cursor: pointer;
  text-decoration-line: none;
}

.tree summary::marker,
.tree summary::-webkit-details-marker {
  display: none;
}

.tree summary:focus {
  outline: none;
}

.tree summary:focus-visible {
  outline: 1px dotted #000;
}

.tree li::after,
.tree summary::before {
  content: '';
  display: block;
  position: absolute;
  top: calc(var(--spacing) / 2 - var(--radius));
  left: calc(var(--spacing) - var(--radius) - 1px);
  width: calc(2 * var(--radius));
  height: calc(2 * var(--radius));
  border-radius: 50%;
  background: #ddd;
  border:1px solid green;
}

.tree summary::before {
  z-index: 1;
  background: #696 ;/*url('../images/tree/expand-collapse.svg') 0 0;*/
  
}

.tree details[open] > summary::before {
  background-position: calc(-2 * var(--radius)) 0;
}
* {
  box-sizing: border-box;
}