diff --git a/agaric/templates/block/block.html.twig b/agaric/templates/block/block.html.twig
index be78dc3..dca6f48 100644
--- a/agaric/templates/block/block.html.twig
+++ b/agaric/templates/block/block.html.twig
@@ -1,50 +1,37 @@
-{% extends "@stable/block/block.html.twig" %}
-{# Child templates can override the default classes. #}
-{%
- set classes = classes ?? [
- 'block',
- 'block-' ~ configuration.provider|clean_class,
- 'block-' ~ plugin_id|clean_class,
- 'clearfix',
- ]
-%}
-{# Footer blocks display in columns. #}
-{% if region == 'footer' %}
- {%
- set classes = classes|merge([
- 'column',
- 'is-narrow',
- ])
- %}
-{% endif %}
-{% if block_panel_style %}
- {% set classes = classes|merge(['panel']) %}
- {%
- set title_classes = title_classes ?? []
- %}
- {%
- set title_classes = title_classes|merge([
- 'panel-heading',
- ])
- %}
-{% elseif not title_classes %}
- {%
- set title_classes = [
- 'subtitle',
- 'is-4',
- 'is-uppercase'
- ]
- %}
-{% endif %}
-{% set attributes = attributes.addClass(classes) %}
-{% set title_attributes = title_attributes.addClass(title_classes) %}
-{# Override the content block to conditionally add a panel wrapper. #}
-{% block content %}
- {% if block_panel_style %}
-
+{#
+/**
+ * @file
+ * Theme override to display a block.
+ *
+ * Available variables:
+ * - plugin_id: The ID of the block implementation.
+ * - label: The configured label of the block if visible.
+ * - configuration: A list of the block's configuration values.
+ * - label: The configured label for the block.
+ * - label_display: The display settings for the label.
+ * - provider: The module or other provider that provided this block plugin.
+ * - Block plugin specific settings will also be stored here.
+ * - content: The content of this block.
+ * - attributes: array of HTML attributes populated by modules, intended to
+ * be added to the main container tag of this template.
+ * - id: A valid HTML ID and guaranteed unique.
+ * - title_attributes: Same as attributes, except applied to the main title
+ * tag that appears in the template.
+ * - title_prefix: Additional output populated by modules, intended to be
+ * displayed in front of the main title tag that appears in the template.
+ * - title_suffix: Additional output populated by modules, intended to be
+ * displayed after the main title tag that appears in the template.
+ *
+ * @see template_preprocess_block()
+ */
+#}
+
+ {{ title_prefix }}
+ {% if label %}
+
{{ label }}
{% endif %}
- {{ content }}
- {% if block_panel_style %}
-
- {% endif %}
-{% endblock %}
+ {{ title_suffix }}
+ {% block content %}
+ {{ content }}
+ {% endblock %}
+