Just Replace Full template node_list_category with :
PHP:
<xf:macro name="depth1" arg-node="!" arg-extras="!" arg-children="!" arg-childExtras="!" arg-depth="1">
<div class="block block--category block--category{$node.node_id} collapsible-nodes">
<span class="u-anchorTarget" id="{$node.Data.getCategoryAnchor()}"></span>
<div class="block-container">
<h2 class="block-header">
<div class="block-header--left">
<a href="{{ link('categories', $node) }}">{$node.title}</a>
<xf:if is="{$node.description}"><div class="block-desc">{$node.description|raw}</div></xf:if></div>
<span id="collapse-{$node.node_id}" class="collapseTrigger collapseTrigger--block is-active" data-xf-click="toggle" data-xf-init="toggle-storage" data-target=".block--category{$node.node_id} .block-body" data-storage-key="_node-{$node.node_id}"></span>
</h2>
<div class="block-body block-body--collapsible is-active">
<xf:macro template="forum_list" name="node_list"
arg-children="{$children}"
arg-extras="{$childExtras}"
arg-depth="{{ $depth + 1 }}" />
</div>
</div>
</div>
</xf:macro>
<xf:macro name="depth2" arg-node="!" arg-extras="!" arg-children="!" arg-childExtras="!" arg-depth="1">
<div class="node node--id{$node.node_id} node--depth{$depth} node--category {{ $extras.hasNew ? 'node--unread' : 'node--read' }}">
<div class="node-body">
<span class="node-icon" aria-hidden="true"><i></i></span>
<div class="node-main js-nodeMain">
<xf:set var="$descriptionDisplay" value="{{ property('nodeListDescriptionDisplay') }}" />
<h3 class="node-title">
<a href="{{ link('categories', $node) }}" data-xf-init="{{ $descriptionDisplay == 'tooltip' ? 'element-tooltip' : '' }}" data-shortcut="node-description">{$node.title}</a>
</h3>
<xf:if is="$descriptionDisplay != 'none' && $node.description">
<div class="node-description {{ $descriptionDisplay == 'tooltip' ? 'node-description--tooltip js-nodeDescTooltip' : '' }}">{$node.description|raw}</div>
</xf:if>
<div class="node-meta">
<xf:if is="!{$extras.privateInfo}">
<div class="node-statsMeta">
<dl class="pairs pairs--inline">
<dt>{{ phrase('threads') }}</dt>
<dd>{$extras.discussion_count|number}</dd>
</dl>
<dl class="pairs pairs--inline">
<dt>{{ phrase('messages') }}</dt>
<dd>{$extras.message_count|number}</dd>
</dl>
</div>
</xf:if>
<xf:if is="$depth == 2 AND property('nodeListSubDisplay') == 'menu'">
<xf:macro template="forum_list" name="sub_nodes_menu"
arg-children="{$children}"
arg-childExtras="{$childExtras}"
arg-depth="{{ $depth + 1 }}" />
</xf:if>
</div>
<xf:if is="$depth == 2 AND property('nodeListSubDisplay') == 'flat'">
<xf:macro template="forum_list" name="sub_nodes_flat"
arg-children="{$children}"
arg-childExtras="{$childExtras}"
arg-depth="{{ $depth + 1 }}" />
</xf:if>
</div>
<xf:if is="!{$extras.privateInfo}">
<div class="node-stats">
<dl class="pairs pairs--rows">
<dt>{{ phrase('threads') }}</dt>
<dd>{$extras.discussion_count|number}</dd>
</dl>
<dl class="pairs pairs--rows">
<dt>{{ phrase('messages') }}</dt>
<dd>{$extras.message_count|number}</dd>
</dl>
</div>
</xf:if>
<div class="node-extra">
<xf:if is="{$extras.privateInfo}">
<span class="node-extra-placeholder">{{ phrase('private') }}</span>
<xf:elseif is="{$extras.last_post_date}" />
<div class="node-extra-row"><a href="{{ link('posts', {'post_id': $extras.last_post_id}) }}" class="node-extra-title" title="{$extras.last_thread_title}">{$extras.last_thread_title}</a></div>
<div class="node-extra-row">
<ul class="listInline listInline--bullet">
<li class="node-extra-date"><xf:date time="{$extras.last_post_date}" /></li>
<xf:if is="$xf.visitor.isIgnoring($extras.last_post_user_id)">
<li class="node-extra-user">{{ phrase('ignored_member') }}</li>
<xf:else />
<li class="node-extra-user"><xf:username user="{{ {'user_id': $extras.last_post_user_id, 'username': $extras.last_post_username} }}" /></li>
</xf:if>
</ul>
</div>
<xf:else />
<span class="node-extra-placeholder">{{ phrase('none') }}</span>
</xf:if>
</div>
</div>
</div>
</xf:macro>
<xf:macro name="depthN" arg-node="!" arg-extras="!" arg-children="!" arg-childExtras="!" arg-depth="1">
<li>
<a href="{{ link('categories', $node) }}" class="subNodeLink subNodeLink--category {{ $extras.hasNew ? 'subNodeLink--unread' : '' }}">{$node.title}</a>
<xf:macro template="forum_list" name="sub_node_list"
arg-children="{$children}"
arg-childExtras="{$childExtras}"
arg-depth="{{ $depth + 1 }}" />
</li>
</xf:macro>
CSS:
/* Node Collapse */
.block--category
{
.collapseTrigger
{
opacity: 0.5;
transition: opacity 0.3s;
margin-right: 10px;
&.is-active:before
{
content: "\f205";
transform: scale(-1, 1);
margin-right: -8px;
}
&:before
{
content: "\f205";
font-size: 80%;
}
}
.block-container:hover .collapseTrigger
{
opacity: 1;
}
}
.collapsible-nodes
{
.block-header
{
display: flex;
}
.block-header--left
{
margin-right: auto;
max-width: 100%;
}
.block-body
{
transition: all 0.75s cubic-bezier(0.68, -0.55, 0.27, 1.55);
-webkit-transition-property: all, -xf-opacity;
transition-property: all, -xf-opacity;
overflow-y: hidden;
height: 0;
-webkit-transition-property: all, -xf-height;
transition-property: all, -xf-height;
&.is-active
{
height: auto;
}
}
}
/* Node Collapse */