clang-tools-extra/pseudo/tool/HTMLForest.css

body {
  position: absolute;
  top: 0;
  bottom: 0;
  right: 0;
  left: 0;

  display: flex;
  align-items: stretch;
  margin: 0;
  font-family: sans-serif;
  white-space: nowrap;
  height: 100%;
}
body > * {
  overflow-y: auto; /* Scroll sections independently*/
  margin: 0;
}

#code {
  font-size: 18px;
  line-height: 36px;
  flex-grow: 1;
  padding-right: 10em; /* Leave space for #info */
}
#code span {
  padding: 9px 0; /* No "gaps" between lines due to line-height */
}
.node.ambiguous::before, .ancestors.ambiguous::after, .tree-node.ambiguous > header::after {
  content: /*the thinking man's emoji*/'\01F914';
}

#info {
  position: fixed;
  right: 2em;
  top: 1em;
  width: 25em;
  border: 1px solid black;
  min-height: 20em;
  background-color: whiteSmoke;
  overflow-x: clip;
  box-shadow: 3px 3px 5px rgba(0,0,0,0.2);
}
#info header {
  background-color: black;
  color: white;
  font-size: larger;
  padding: 0.5em;
}
#info.ambiguous header { background-color: #803; }
#info.sequence header { background-color: darkBlue; }
#info.terminal header { background-color: darkGreen; }
#info.opaque header { background-color: orangeRed; }
#i_kind {
  float: right;
  font-size: small;
}
#info section {
  padding: 0.5em;
  border-top: 1px solid lightGray;
  overflow-x: auto;
}
#i_ancestors { font-size: small; }

#tree {
  flex-grow: 0;
  min-width: 20em;
  margin-right: 1em;
  border-right: 1px solid darkGray;
  background-color: azure;
  font-size: small;
  overflow-x: auto;
  resize: horizontal;
}
#tree ul {
  margin: 0;
  display: inline-block;
  padding-left: 6px;
  border-left: 1px solid rgba(0,0,0,0.2);
  list-style: none;
}
#tree > ul { border-left: none; }
.tree-node.selected > header .name { font-weight: bold; }
.tree-node.terminal .name { font-family: monospace; }
.tree-node.ambiguous > header .name { color: #803; font-weight: bold; }
.tree-node.sequence > header .name { color: darkBlue; }
.tree-node.terminal > header .name { color: darkGreen; }
.tree-node.opaque > header .name { color: orangeRed; }

.selected { outline: 1px dashed black; }
.abbrev { opacity: 50%; }
.abbrev::after { content: '~'; }
.opaque { background-color: bisque; }