Styling

The tree comes with very basic style.
The following classes are available for customization:

.angular-tree-component
.angular-tree-component-rtl
.tree-node
.tree-node-wrapper
.tree-node-expanded
.tree-node-collapsed
.tree-node-focused
.tree-node-active
.tree-node-level-X
.tree-node-leaf
.node-wrapper
.toggle-children-wrapper
.toggle-children
.toggle-children-placeholder
.node-content-wrapper
.tree-children
.tree-node-loading
.node-drop-slot
.is-dragging-over
.is-dragging-over-disabled

Overriding style

Surround your tree with a class, and add your custom style to your style.scss file.
Scope all the custom rules under your custom class - and that's it!

Example styles

These styles were provided by the community. They might be outdated.
If you find an error in these styles please suggest an edit - don't open a github issue.

Thanks

Branch lines

This theme puts explorer like branch lines that connect the parents with their children

.node-content-wrapper, .tree-children {
  position: relative;
}

.node-content-wrapper::before, .tree-children::after {
  content: "";
  position: absolute;
}

.node-content-wrapper::before {
  border-bottom: 1px solid lightgrey;
  border-left: 1px solid lightgrey;
  height: 28px;
  top: -17px;
  width: 20px;
  left: -28px;
}

.tree-node-level-1 > tree-node-wrapper > .node-wrapper > .node-content-wrapper::before {
  display: none;
}

.tree-node-leaf > .node-wrapper > .node-content-wrapper::before {
  width: 25px;
}

.tree-children::after {
  border-left: 1px solid lightgrey;
  height: 100%;
  top: -15px;
  left: -15px;
}

tree-node:last-child > .tree-node > .tree-children::after {
  border-left: none;
}

.toggle-children {
  z-index: 1;
}

Pull right

This theme allows placing items in the right side of the tree nodes using pull-right class.
It is based on flexbox, so relevant only to browsers who support it

.tree {
  width: 300px;
}

.node-content-wrapper {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
}

.node-content-wrapper {
  flex-grow: 1;
  position: relative;
}

.pull-right {
  position: absolute;
  right: 10px;
}

ACE Admin theme

ACE Admin theme style.
Credit to Viet Anh Do for sending this theme!

div.tree div.tree-children::before,
div.tree::before {
    content: "";
    position: absolute;
    border-left: 1px dotted #23527c;
    height: 100%;
    top: -14px;
    left: 12px
}

div.tree {
    padding-left: 0;
    margin-left: -5px
}

div.tree div.tree-children {
    position: relative;
    padding-left: 0;
    margin-left: 16px
}

div.tree div.tree-children::before {
    left: 5px
}

div.tree tree-node>div>.node-wrapper {
    margin-left: 24px
}

div.tree tree-node>div>.node-wrapper>.node-content-wrapper {
    margin-left: 4px
}

div.tree tree-node>div.tree-node-leaf>.node-wrapper {
    margin-left: 0
}

div.tree tree-node>div::before {
    content: "";
    position: absolute;
    border-bottom: 1px dotted #23527c;
    width: 7px;
    margin-top: 12px;
    left: 7px
}

div.tree tree-node>div .toggle-children-wrapper {
    width: 13px;
    height: 13px;
    border: 1px solid #23527c;
    position: absolute;
    left: 15px;
    margin-top: 5px;
    margin-left: 0;
    display: inline-block;
    background-color: #fff;
    z-index: 1
}

div.tree tree-node>div .toggle-children-wrapper::before {
    content: "";
    display: inline-block;
    width: 7px;
    border-top: 1px solid #23527c;
    position: absolute;
    top: 5px;
    left: 2px
}

div.tree tree-node>div .toggle-children-wrapper.toggle-children-wrapper-collapsed::after {
    content: "";
    display: inline-block;
    height: 7px;
    border-left: 1px solid #23527c;
    position: absolute;
    top: 2px;
    left: 5px
}

div.tree tree-node>div .toggle-children-wrapper .toggle-children {
    display: none
}

div.tree tree-node>div .node-content-wrapper {
    margin-left: 4px
}

div.tree>tree-node>div::before {
    left: 14px
}

div.tree>tree-node>div>.node-wrapper>tree-node-expander>.toggle-children-wrapper {
    left: 22px
}

Send me your theme

If you've created a nice style for the tree, I will appreciate if you send me and I will showcase it here and give you credit.
You can suggest an edit using the top right link.