diff --git a/core/modules/system/templates/field-multiple-value-form.html.twig b/core/modules/system/templates/field-multiple-value-form.html.twig
index f18a853..e9370e9 100644
--- a/core/modules/system/templates/field-multiple-value-form.html.twig
+++ b/core/modules/system/templates/field-multiple-value-form.html.twig
@@ -20,13 +20,13 @@
  */
 #}
 {% if multiple %}
-  <div class="form-item">
+  <div>
     {{ table }}
     {% if description %}
-      <div class="description">{{ description }}</div>
+      <div>{{ description }}</div>
     {% endif %}
     {% if button %}
-      <div class="clearfix">{{ button }}</div>
+      <div>{{ button }}</div>
     {% endif %}
   </div>
 {% else %}
diff --git a/core/modules/system/templates/fieldset.html.twig b/core/modules/system/templates/fieldset.html.twig
index ab6796c..1b40395 100644
--- a/core/modules/system/templates/fieldset.html.twig
+++ b/core/modules/system/templates/fieldset.html.twig
@@ -32,16 +32,16 @@
   <legend{{ legend.attributes }}>
     <span{{ legend_span.attributes.addClass(legend_span_classes) }}>{{ legend.title }}</span>
   </legend>
-  <div class="fieldset-wrapper">
+  <div>
     {% if prefix %}
-      <span class="field-prefix">{{ prefix }}</span>
+      <span>{{ prefix }}</span>
     {% endif %}
     {{ children }}
     {% if suffix %}
-      <span class="field-suffix">{{ suffix }}</span>
+      <span>{{ suffix }}</span>
     {% endif %}
     {% if description.content %}
-      <div{{ description.attributes.addClass('description') }}>{{ description.content }}</div>
+      <div>{{ description.content }}</div>
     {% endif %}
   </div>
 </fieldset>
diff --git a/core/modules/system/templates/form-element.html.twig b/core/modules/system/templates/form-element.html.twig
index a961801..52bb77e 100644
--- a/core/modules/system/templates/form-element.html.twig
+++ b/core/modules/system/templates/form-element.html.twig
@@ -65,7 +65,7 @@
     {{ label }}
   {% endif %}
   {% if prefix is not empty %}
-    <span class="field-prefix">{{ prefix }}</span>
+    <span>{{ prefix }}</span>
   {% endif %}
   {% if description_display == 'before' and description.content %}
     <div{{ description.attributes }}>
@@ -74,7 +74,7 @@
   {% endif %}
   {{ children }}
   {% if suffix is not empty %}
-    <span class="field-suffix">{{ suffix }}</span>
+    <span>{{ suffix }}</span>
   {% endif %}
   {% if label_display == 'after' %}
     {{ label }}
diff --git a/core/themes/classy/templates/feed-icon.html.twig b/core/themes/classy/templates/feed-icon.html.twig
new file mode 100644
index 0000000..b3c10d1
--- /dev/null
+++ b/core/themes/classy/templates/feed-icon.html.twig
@@ -0,0 +1,18 @@
+{#
+/**
+ * @file
+ * Default theme implementation for a feed icon.
+ *
+ * Available variables:
+ * - url: An internal system path or a fully qualified external URL of the feed.
+ * - icon: The rendered HTML (<img> tag) for the feed icon image.
+ * - attributes: Remaining HTML attributes for the feed link.
+ *   - title: A descriptive title of the feed link.
+ *   - class: HTML classes to be applied to the feed link.
+ *
+ * @see template_preprocess_feed_icon()
+ *
+ * @ingroup themeable
+ */
+#}
+<a href="{{ url }}"{{ attributes.addClass('feed-icon') }}>{{ icon }}</a>
diff --git a/core/themes/classy/templates/field-multiple-value-form.html.twig b/core/themes/classy/templates/field-multiple-value-form.html.twig
new file mode 100644
index 0000000..f18a853
--- /dev/null
+++ b/core/themes/classy/templates/field-multiple-value-form.html.twig
@@ -0,0 +1,36 @@
+{#
+/**
+ * @file
+ * Default theme implementation for an individual form element.
+ *
+ * Available variables for all fields:
+ * - multiple: Whether there are multiple instances of the field.
+ *
+ * Available variables for single cardinality fields:
+ * - elements: Form elements to be rendered.
+ *
+ * Available variables when there are multiple fields.
+ * - table: Table of field items.
+ * - description: Description text for the form element.
+ * - button: "Add another item" button.
+ *
+ * @see template_preprocess_field_multiple_value_form()
+ *
+ * @ingroup themeable
+ */
+#}
+{% if multiple %}
+  <div class="form-item">
+    {{ table }}
+    {% if description %}
+      <div class="description">{{ description }}</div>
+    {% endif %}
+    {% if button %}
+      <div class="clearfix">{{ button }}</div>
+    {% endif %}
+  </div>
+{% else %}
+  {% for element in elements %}
+    {{ element }}
+  {% endfor %}
+{% endif %}
diff --git a/core/themes/classy/templates/field.html.twig b/core/themes/classy/templates/field.html.twig
new file mode 100644
index 0000000..5fcfd4f
--- /dev/null
+++ b/core/themes/classy/templates/field.html.twig
@@ -0,0 +1,63 @@
+{#
+/**
+ * @file
+ * Default theme implementation for a field.
+ *
+ * To override output, copy the "field.html.twig" from the templates directory
+ * to your theme's directory and customize it, just like customizing other
+ * Drupal templates such as page.html.twig or node.html.twig.
+ *
+ * For example, for a field named 'body' displayed on the 'article' content
+ * type, any of the following templates will override this default
+ * implementation. The first of these templates that exists is used:
+ * - field--body--article.html.twig
+ * - field--article.html.twig
+ * - field--body.html.twig
+ * - field.html.twig
+ *
+ * Available variables:
+ * - attributes: HTML attributes for the containing element.
+ * - label_hidden: Whether to show the field label or not.
+ * - title_attributes: HTML attributes for the title.
+ * - label: The label for the field.
+ * - content_attributes: HTML attributes for the content.
+ * - items: List of all the field items. Each item contains:
+ *   - attributes: List of HTML attributes for each item.
+ *   - content: The field item's content.
+ * - entity_type: The entity type to which the field belongs.
+ * - field_name: The name of the field.
+ * - field_type: The type of the field.
+ * - label_display: The display settings for the label.
+ *
+ * @see template_preprocess_field()
+ *
+ * @ingroup themeable
+ */
+#}
+{% set field_name_class = field_name|clean_class %}
+{%
+  set classes = [
+    'field',
+    'field-' ~ entity_type|clean_class ~ '--' ~ field_name_class,
+    'field-name-' ~ field_name_class,
+    'field-type-' ~ field_type|clean_class,
+    'field-label-' ~ label_display,
+    label_display == 'inline' ? 'clearfix',
+  ]
+%}
+{%
+  set title_classes = [
+    'field-label',
+    label_display == 'visually_hidden' ? 'visually-hidden',
+  ]
+%}
+<div{{ attributes.addClass(classes) }}>
+  {% if not label_hidden %}
+    <div{{ title_attributes.addClass(title_classes) }}>{{ label }}</div>
+  {% endif %}
+  <div{{ content_attributes.addClass('field-items') }}>
+    {% for item in items %}
+      <div{{ item.attributes.addClass('field-item') }}>{{ item.content }}</div>
+    {% endfor %}
+  </div>
+</div>
diff --git a/core/themes/classy/templates/fieldset.html.twig b/core/themes/classy/templates/fieldset.html.twig
new file mode 100644
index 0000000..ab6796c
--- /dev/null
+++ b/core/themes/classy/templates/fieldset.html.twig
@@ -0,0 +1,47 @@
+{#
+/**
+ * @file
+ * Default theme implementation for a fieldset element and its children.
+ *
+ * Available variables:
+ * - attributes: HTML attributes for the fieldset element.
+ * - required: Boolean indicating whether the fieldeset element is required.
+ * - legend: The legend element containing the following properties:
+ *   - title: Title of the fieldset, intended for use as the text of the legend.
+ *   - attributes: HTML attributes to apply to the legend.
+ * - description: The description element containing the following properties:
+ *   - content: The description content of the fieldset.
+ *   - attributes: HTML attributes to apply to the description container.
+ * - children: The rendered child elements of the fieldset.
+ * - prefix: The content to add before the fieldset children.
+ * - suffix: The content to add after the fieldset children.
+ *
+ * @see template_preprocess_fieldset()
+ *
+ * @ingroup themeable
+ */
+#}
+<fieldset{{ attributes.addClass('form-item', 'form-wrapper') }}>
+  {%
+    set legend_span_classes = [
+      'fieldset-legend',
+      required ? 'form-required',
+    ]
+  %}
+  {#  Always wrap fieldset legends in a SPAN for CSS positioning. #}
+  <legend{{ legend.attributes }}>
+    <span{{ legend_span.attributes.addClass(legend_span_classes) }}>{{ legend.title }}</span>
+  </legend>
+  <div class="fieldset-wrapper">
+    {% if prefix %}
+      <span class="field-prefix">{{ prefix }}</span>
+    {% endif %}
+    {{ children }}
+    {% if suffix %}
+      <span class="field-suffix">{{ suffix }}</span>
+    {% endif %}
+    {% if description.content %}
+      <div{{ description.attributes.addClass('description') }}>{{ description.content }}</div>
+    {% endif %}
+  </div>
+</fieldset>
diff --git a/core/themes/classy/templates/form-element-label.html.twig b/core/themes/classy/templates/form-element-label.html.twig
new file mode 100644
index 0000000..6ececd9
--- /dev/null
+++ b/core/themes/classy/templates/form-element-label.html.twig
@@ -0,0 +1,26 @@
+{#
+/**
+ * @file
+ * Default theme implementation for a form element label.
+ *
+ * Available variables:
+ * - title: The label's text.
+ * - title_display: Elements title_display setting.
+ * - required: An indicator for whether the associated form element is required.
+ * - attributes: A list of HTML attributes for the label.
+ *
+ * @see template_preprocess_form_element_label()
+ *
+ * @ingroup themeable
+ */
+#}
+{%
+  set classes = [
+    title_display == 'after' ? 'option',
+    title_display == 'invisible' ? 'visually-hidden',
+    required ? 'form-required',
+  ]
+%}
+{% if title is not empty or required -%}
+  <label{{ attributes.addClass(classes) }}>{{ title }}</label>
+{%- endif %}
diff --git a/core/themes/classy/templates/form-element.html.twig b/core/themes/classy/templates/form-element.html.twig
new file mode 100644
index 0000000..a961801
--- /dev/null
+++ b/core/themes/classy/templates/form-element.html.twig
@@ -0,0 +1,87 @@
+{#
+/**
+ * @file
+ * Default theme implementation for a form element.
+ *
+ * Available variables:
+ * - attributes: HTML attributes for the containing element.
+ * - prefix: (optional) The form element prefix, may not be set.
+ * - suffix: (optional) The form element suffix, may not be set.
+ * - required: The required marker, or empty if the associated form element is
+ *   not required.
+ * - type: The type of the element.
+ * - name: The name of the element.
+ * - label: A rendered label element.
+ * - label_display: Label display setting. It can have these values:
+ *   - before: The label is output before the element. This is the default.
+ *     The label includes the #title and the required marker, if #required.
+ *   - after: The label is output after the element. For example, this is used
+ *     for radio and checkbox #type elements. If the #title is empty but the
+ *     field is #required, the label will contain only the required marker.
+ *   - invisible: Labels are critical for screen readers to enable them to
+ *     properly navigate through forms but can be visually distracting. This
+ *     property hides the label for everyone except screen readers.
+ *   - attribute: Set the title attribute on the element to create a tooltip but
+ *     output no label element. This is supported only for checkboxes and radios
+ *     in \Drupal\Core\Render\Element\CompositeFormElementTrait::preRenderCompositeFormElement().
+ *     It is used where a visual label is not needed, such as a table of
+ *     checkboxes where the row and column provide the context. The tooltip will
+ *     include the title and required marker.
+ * - description: (optional) A list of description properties containing:
+ *    - content: A description of the form element, may not be set.
+ *    - attributes: (optional) A list of HTML attributes to apply to the
+ *      description content wrapper. Will only be set when description is set.
+ * - description_display: Description display setting. It can have these values:
+ *   - before: The description is output before the element.
+ *   - after: The description is output after the element. This is the default
+ *     value.
+ *   - invisible: The description is output after the element, hidden visually
+ *     but available to screen readers.
+ * - disabled: True if the element is disabled.
+ * - title_display: Title display setting.
+ *
+ * @see template_preprocess_form_element()
+ *
+ * @ingroup themeable
+ */
+#}
+{%
+  set classes = [
+    'form-item',
+    'form-type-' ~ type|clean_class,
+    'form-item-' ~ name|clean_class,
+    title_display not in ['after', 'before'] ? 'form-no-label',
+    disabled == 'disabled' ? 'form-disabled',
+  ]
+%}
+{%
+  set description_classes = [
+    'description',
+    description_display == 'invisible' ? 'visually-hidden',
+  ]
+%}
+<div{{ attributes.addClass(classes) }}>
+  {% if label_display in ['before', 'invisible'] %}
+    {{ label }}
+  {% endif %}
+  {% if prefix is not empty %}
+    <span class="field-prefix">{{ prefix }}</span>
+  {% endif %}
+  {% if description_display == 'before' and description.content %}
+    <div{{ description.attributes }}>
+      {{ description.content }}
+    </div>
+  {% endif %}
+  {{ children }}
+  {% if suffix is not empty %}
+    <span class="field-suffix">{{ suffix }}</span>
+  {% endif %}
+  {% if label_display == 'after' %}
+    {{ label }}
+  {% endif %}
+  {% if description_display in ['after', 'invisible'] and description.content %}
+    <div{{ description.attributes.addClass(description_classes) }}>
+      {{ description.content }}
+    </div>
+  {% endif %}
+</div>
diff --git a/core/themes/classy/templates/form.html.twig b/core/themes/classy/templates/form.html.twig
new file mode 100644
index 0000000..2cd1e95
--- /dev/null
+++ b/core/themes/classy/templates/form.html.twig
@@ -0,0 +1,17 @@
+{#
+/**
+ * @file
+ * Default theme implementation for a 'form' element.
+ *
+ * Available variables
+ * - attributes: A list of HTML attributes for the wrapper element.
+ * - children: The child elements of the form.
+ *
+ * @see template_preprocess_form()
+ *
+ * @ingroup themeable
+ */
+#}
+<form{{ attributes }}>
+  {{ children }}
+</form>