arcTree.css

:root {
  --arctree-curves: #777;
  --arctree-ball-collapsed-color: rgb(1, 108, 90);
  --arctree-ball-expanded-color: rgb(106, 53, 171);
  --arctree-object-color: #3625b9;
  --arctree-dummy-color: rgb(129, 129, 129);
}

#arctree-container {
  padding: 10px;
  border: 1px solid #7c7c7c;
  border-radius: 0.3em;
  margin: 20px;
  font-family: sans-serif;
}

/* ================================= */
/* Tree Options */
#arctree-options {
  padding: 15px;
  max-width: 600px;
  min-width: 180px;
  background-color: #f3f2f2;
  border-radius: 0.3em;
  border: #505050 1px solid;
}

#arctree-options div {
  font-size: large;
  font-weight: bold;
}

#arctree-options input {
  margin: 5px;
  background-color: rgb(168, 168, 168);
  border: 1px solid transparent;
  border-radius: 0.5rem;
  box-sizing: border-box;
  cursor: pointer;
  flex: 0 0 auto;
  font-weight: 600;
  line-height: 1.3rem;
  padding: 0.25rem 1.2rem;
  text-align: center;
  text-decoration: none #6b7280 solid;
  text-decoration-thickness: auto;

  transition-property: background-color, border-color, color, fill, stroke;
  transition-timing-function: cubic-bezier(0.4, 0, 0.2, 1);
  user-select: none;
  -webkit-user-select: none;
  touch-action: manipulation;

  width: auto;
  /*
    transition-duration: 2.5s;
    box-shadow:
      rgba(44, 187, 99, 0.2) 0 -25px 18px -14px inset,
      rgba(44, 187, 99, 0.15) 0 1px 2px,
      rgba(44, 187, 99, 0.15) 0 2px 4px,
      rgba(44, 187, 99, 0.15) 0 4px 8px,
      rgba(44, 187, 99, 0.15) 0 8px 16px,
      rgba(44, 187, 99, 0.15) 0 16px 32px;
    */
  display: inline-block;
  transition: all 400ms;
}

#arctree-options [type="button"] {
  color: rgb(255, 255, 255);
}

#arctree-options input:hover {
  box-shadow: rgba(69, 103, 187, 0.35) 0 -25px 18px -14px inset,
    rgba(69, 103, 187, 0.35) 0 1px 2px, rgba(69, 103, 187, 0.35) 0 2px 4px,
    rgba(69, 103, 187, 0.35) 0 4px 8px, rgba(69, 103, 187, 0.35) 0 8px 16px,
    rgba(69, 103, 187, 0.35) 0 16px 32px;
  transform: scale(1.05) rotate(-1deg);
  background-color: #374151;
}

#arctree-options input:focus {
  box-shadow: none;
  outline: 2px solid transparent;
  outline-offset: 2px;
}

#arctree-font-size-label {
  font-size: medium;
  margin-top: 20px;
}

#arctree-font-size {
  width: 220px;
  margin-top: 50px;
}

#arctree-font-size-value {
  width: 2em;
  display: inline-block;
  /*background-color: #e5e5e5;
  border: #aaa 1px solid;*/
  padding: 2px;
}

#arctree-file {
  margin: 10px 5px;
}

#arctree-file-label {
  font-weight: 700;
}

/* ================================= */
/* Thx to https://codepen.io/bisserof/pen/nrMveb */
/* Core Tree Styles */
.arctree {
  margin: 0px;
  padding: 20px;
  border: 1px solid #a6a6a6;
  border-radius: 0.3em;
}

.arctree ul {
  /*list-style-type: none;*/
  padding: 0;
  margin: 0;
  /*background-color: #f3dd37;*/
}

/* for long 1st node that goes several lines long */
.arctree li {
  list-style-type: none;
}

.arctree input {
  position: absolute;
  clip-path: inset(0 0 0 0);
}

.arctree input ~ ul {
  display: none;
}

.arctree input:checked ~ ul {
  display: block;
}

/* Tree rows */
.arctree li {
  line-height: 1.2;
  position: relative;
  padding: 0 0 1em 1em;
}

.arctree ul li {
  padding: 1em 0 0 1em;
}

.arctree > li:last-child {
  padding-bottom: 0;
}

/* Tree labels */
.arctree-label {
  position: relative;
  display: inline-block;
  /* HACK: white background just hides the checkmark boxes; still seen if font size < 1 */
  background: #fff;
  color: #000;
}

label.arctree-label {
  cursor: pointer;
}

label.arctree-label:hover {
  color: #666;
}

/* Tree expanded icon */
label.arctree-label:before {
  background: var(--arctree-ball-expanded-color);
  color: #fff;
  position: relative;
  z-index: 1;
  float: left;
  margin: 0 1em 0 -2em;
  width: 1em;
  height: 1em;
  border-radius: 1em;
  content: "+";
  text-align: center;
  line-height: 0.9em;
}

/* Tree collapsed icon */
:checked ~ label.arctree-label:before {
  content: "–";
  background: var(--arctree-ball-collapsed-color);
}

/* Tree branches */
.arctree li:before {
  position: absolute;
  top: 0;
  bottom: 0;
  left: -0.5em;
  display: block;
  width: 0;
  border-left: 1px solid var(--arctree-curves);
  content: "";
  /* background-color: #f3dd37; */
}

.arctree-label:after {
  position: absolute;
  top: 0;
  left: -1.5em;
  display: block;
  height: 0.5em;
  width: 1em;
  border-bottom: 1px solid var(--arctree-curves); /* line extending right to the child, at child level */
  border-left: 1px solid var(--arctree-curves); /* vertical segment at bottom of the drop & curving into above lines */
  border-radius: 0 0 0 0.3em;
  content: "";
  /* background-color: #48c1fe; */
}

label.arctree-label:after {
  border-bottom: 0;
}

:checked ~ label.arctree-label:after {
  border-radius: 0 0.3em 0 0;
  border-top: 1px solid var(--arctree-curves); /* line extending right from + - marker */
  border-right: 1px solid var(--arctree-curves); /* initial drop, from above line */
  border-bottom: 0;
  border-left: 0;
  bottom: 0;
  top: 0.5em;
  height: auto;
}

/* Tree leaves - needed??? */
.arctree li:last-child:before {
  height: 1em;
  bottom: auto;
  /*background-color: #48c1fe;*/
}

.arctree > li:last-child:before {
  display: none;
  /* background-color: #48c1fe;*/
}

.arctree-dummy-node {
  color: var(--arctree-dummy-color);
  border-radius: 0.5rem;
  padding: 0.5rem;
  background-color: #ebebeb;
  opacity: 0.8;
}

.arctree-dummy-node a:link {
  color: #844163;
  text-decoration: none;
}

.arctree-dummy-node a:visited {
  color: #5c203e;
  text-decoration: none;
}
.arctree-dummy-node a:hover {
  color: #844163;
  font-weight: bold;
  /*text-decoration: none;*/
}
.arctree-dummy-node a:active {
  color: #c43a7f;
  font-weight: bold;
  /*text-decoration: none;*/
}

.arctree-dummy-ul {
  list-style-type: none;
  color: var(--arctree-dummy-color);
  border-radius: 0.5rem;
  padding: 0.5rem;
  /*background-color: #b6d671;*/
}

.arctree-object {
  color: var(--arctree-object-color);
}