/* ── Design Tokens ── */
.tree {
  --tree-indent: 24px;
  --tree-line-color: rgba(0, 0, 0, 0.14);
  --tree-line-width: 1px;
  --tree-radius: 6px;
  --tree-node-height: 28px;
  --tree-hover: rgba(0, 0, 0, 0.04);
  --tree-selected: #e8f0fe;
  --tree-selected-text: #1a1a1a;
  --tree-selected-icon: #2563eb;
  --tree-transition: 180ms ease-out;
  --tree-icon-size: 15px;
  --tree-font-size: 13px;
  --tree-gap: 4px;
  --tree-padding: 3px 8px;

  list-style: none;
  padding: 0;
  margin: 0;
  font-size: var(--tree-font-size);
  line-height: 1.4;
  color: #374151;
  font-family: inherit;
}

/* ── Nested Children ── */
.tree ul {
  list-style: none;
  padding: 0;
  margin: 0;
  padding-left: var(--tree-indent);
  position: relative;
}

/* Vertical connector */
.tree ul::before {
  content: '';
  position: absolute;
  left: calc(var(--tree-indent) / 2);
  top: 0;
  bottom: 0;
  width: var(--tree-line-width);
  background: var(--tree-line-color);
  border-radius: var(--tree-line-width);
}

/* ── Tree Item ── */
.tree li {
  position: relative;
}

/* Horizontal connector from vertical line to node */
.tree li::before {
  content: '';
  position: absolute;
  left: calc(-1 * var(--tree-indent) / 2);
  top: calc(var(--tree-node-height) / 2 - var(--tree-line-width) / 2);
  width: calc(var(--tree-indent) / 2);
  height: var(--tree-line-width);
  background: var(--tree-line-color);
  border-radius: var(--tree-line-width);
}

/* Rounded join at intersection */
.tree li::after {
  content: '';
  position: absolute;
  left: calc(-1 * var(--tree-indent) / 2);
  top: calc(var(--tree-node-height) / 2 - 3px);
  width: 6px;
  height: 6px;
  border-left: var(--tree-line-width) solid var(--tree-line-color);
  border-bottom: var(--tree-line-width) solid var(--tree-line-color);
  border-radius: 0 0 0 3px;
  opacity: 0.5;
}

/* ── Node Wrapper (injected by JS) ── */
.tree-node {
  display: flex;
  align-items: center;
  gap: 6px;
  height: var(--tree-node-height);
  padding: var(--tree-padding);
  margin: calc(var(--tree-gap) / 2) calc(-1 * var(--tree-padding));
  border-radius: var(--tree-radius);
  cursor: pointer;
  user-select: none;
  transition: background var(--tree-transition), color var(--tree-transition);
  position: relative;
  z-index: 1;
  width: 100%;
  box-sizing: border-box;
}

.tree-node:hover {
  background: var(--tree-hover);
}

/* Selected state */
.tree > li > .tree-node[aria-selected="true"],
.tree li .tree-node[aria-selected="true"] {
  background: var(--tree-selected);
  color: var(--tree-selected-text);
  font-weight: 600;
}

.tree-node[aria-selected="true"] .tree-icon {
  color: var(--tree-selected-icon);
}

/* ── Icon ── */
.tree-icon {
  width: var(--tree-icon-size);
  height: var(--tree-icon-size);
  flex-shrink: 0;
  color: #6b7280;
  transition: color var(--tree-transition), transform var(--tree-transition);
}

.tree-node:hover .tree-icon {
  color: #374151;
}

/* ── Label ── */
.tree-label {
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

/* ── Children Animation ── */
.tree ul {
  overflow: hidden;
  transition:
    opacity var(--tree-transition),
    transform var(--tree-transition),
    max-height var(--tree-transition);
  transform-origin: top;
}

.tree ul.collapsed {
  opacity: 0;
  transform: translateY(-4px) scaleY(0.96);
  max-height: 0 !important;
  pointer-events: none;
}

/* ── Disabled State ── */
.tree-node[aria-disabled="true"] {
  opacity: 0.5;
  cursor: not-allowed;
  pointer-events: none;
}

/* ── Focus Ring ── */
.tree-node:focus-visible {
  outline: 2px solid #2563eb;
  outline-offset: -2px;
  border-radius: var(--tree-radius);
}

/* ── Root Adjustments ── */
.tree > li {
  padding-left: 0;
}

.tree > li::before {
  display: none;
}

.tree > li::after {
  display: none;
}

.tree > ul {
  padding-left: 0;
}

.tree > ul::before {
  display: none;
}