{% load brickwork_components %}
{% comment %}
Card (CMP-014 to CMP-017): the elevated composition surface. Structural, so it
is consumed via {% include %} (like _page_header.html and _data_table.html).
Its five named regions are blocks, all empty by default: an unfilled region
emits NO markup at all (matching _alert.html's {% block alert_body %}
convention), so a card with nothing filled renders a bare elevated surface
(resting --bw-elevation-1, radius-lg, density-aware padding; AC-BW-070).

Named blocks (semver-public, BR-BW-TPL-001), in document order:
  header, title, actions, body, footer: present SINCE 3.4.0, the concise
      names (ADR-077 SS4; the declaring template is the scope, so a
      component prefix carries no information). Each wraps the
      corresponding deprecated prefixed block below, so a call site
      filling only the concise name renders exactly the same output the
      prefixed block always produced.
  card_header, card_title, card_actions, card_body, card_footer: present
      since before 3.4.0 (unchanged back to at least 3.2.1). DEPRECATED,
      removed at 4.0 (ADR-077 SS4, BR-BW-TPL-001/BR-BW-VER-001). Kept as
      additional empty extension points for backwards compatibility: a
      shipped block name cannot be renamed silently. Both a concise block
      and its deprecated counterpart render when both are filled; a caller
      migrating to the concise name fills header/title/actions/body/footer
      only.

A block name this file does not define is SILENTLY DISCARDED by Django:
no error, no warning, DEBUG=True does not catch it. A consumer pinned
below 3.4.0 who reads header/title/actions/body/footer from a newer
checkout gets a structurally valid, entirely empty region that still
passes template loading; check this header against your pinned version
before relying on a name.

DUAL CONSUMPTION on `title` only (icvoss/django-brickwork#398): the
`title` block also renders a `title` context variable, wrapped in the
same <h2 class="bw-card__title"> a caller filling the block by hand
would write itself (matching the header/title block's own filler example
below), so `{% include %} with title="..."` (the shape a copy-paste band
example uses, since {% include %} cannot fill a block at all) now
renders a real heading instead of silently discarding the value. The
wrapper is conditional on `title` being truthy, so a bare card with no
title supplied still emits no empty region markup (matching the
unfilled-region convention every other block on this file follows).
`{% block title %}` still overrides the whole thing, exactly as block
override already does everywhere else, so a caller who supplies both
gets the block's content: no new precedence rule, just the block winning
by construction. The deprecated `card_title` block deliberately does NOT
get this treatment (BR-BW-TPL-001's retirement of the prefixed names
would otherwise be undone by giving a retiring name a new reason to be
used).

header, footer, body, actions, and every card_-prefixed block remain
markup-only extension points with no matching context variable: their
own docstring paragraph below documents why (the filler owns the whole
wrapper element for each, e.g. a header row pairing a heading with an
actions cluster, not a bare string), so passing a context variable under
these names is still silently discarded, correctly, because there is no
single string these regions could sensibly wrap.

Filling blocks from an include call site: {% include %} cannot fill a block,
so a caller that needs a region writes a small template that EXTENDS this one
and includes THAT (the mechanism patterns/_table_card.html uses):

    {% extends "brickwork/components/_card.html" %}
    {% block header %}
      <div class="bw-card__header">
        <h2 class="bw-card__title">{% translate "Members" %}</h2>
        <div class="bw-card__actions">{% bw_button label="Add" variant="secondary" size="sm" %}</div>
      </div>
    {% endblock %}
    {% block body %}...{% endblock %}
    {% block footer %}<div class="bw-card__footer">...</div>{% endblock %}

The region classes (bw-card__header/__title/__actions/__body/__footer) are the
styling hooks for that filler markup: the header row is a flex row with the
title (heading-md voice) at the inline start and the actions cluster at the
end; the footer is a quiet caption band under a hairline. The filler owns the
wrapper element, so an unfilled region never leaves empty chrome behind.

bw-card__body carries NO rule of its own (icvoss/django-brickwork#130): it is
a positioning-only hook. The card's own padding already sets the inset on all
four sides, and the header/footer margins already open the gap on their own
edge when present, so a bare bw-card__body wrapper needs nothing beyond
grouping the body markup under a name a consumer's own selectors can target.
If body content ever needs spacing of its own, style it on that content's
element, not by adding weight to this class.

Required context: none. Optional:
  title: rendered inside the title block when that block is not overridden
      (icvoss/django-brickwork#398). A caller that also fills
      {% block title %} gets the block's content; the context variable is
      the fallback for the common {% include %} case, since {% include %}
      has no other way to reach a block-shaped region. header, footer,
      body, actions and the card_-prefixed blocks have no equivalent
      context variable: see the docstring paragraph above for why.
  interactive (bool, default False): rests at --bw-elevation-1 and raises to
      --bw-elevation-2 on hover/focus-within, shadow only, never a transform
      (MOT-010, AC-BW-071).
  href: when set the WHOLE card is a clickable anchor (CMP-017) and the
      interactive treatment always applies (a clickable card is
      definitionally hoverable, so bw-card--interactive is emitted
      regardless of the interactive flag).
  bordered (bool, default False, CMP-015): the hairline alone carries the
      boundary (elevation-0), for a flat-design context.
  size ("sm"|"md"|"lg", default "md"): emitted as bw-card--size-<value> only
      when supplied, composing with (never overriding) the density axis's
      --bw-density-card-padding (AC-BW-072). Renamed from padding in 3.0.0
      (ADR-060 SS1b): scale is spelled size= everywhere.

The root element opens and closes in matching {% if href %} branches (an <a>
for a linked card, a <div> otherwise) because a named block may appear only
once per template, so the regions cannot be duplicated across two branches
the way _button.html duplicates its label.

States: resting (--bw-elevation-1) and, when interactive=True or href is
  set, a raised (--bw-elevation-2) hover/focus-within state, shadow only,
  never a transform (MOT-010). A linked card (href) is always interactive;
  the flag only matters for a non-linked card.
Accessibility: purely structural, no role or live behaviour of its own; a
  linked card renders as a real <a> so it is a native focusable, activatable
  target rather than a div with a click handler. Not covered by a dedicated
  card fixture in the a11y suite (usedByArchetypes/usedBySections are both
  empty in the catalogue manifest: no shipped example composes it directly
  today), so its accessibility floor rests on the WCAG 2.2 AA rules axe
  checks against whatever markup a consumer fills its blocks with, not a
  brickwork-authored render.
Responsive: no breakpoint switch; no width-dependent CSS on any .bw-card*
  selector. Sizing is the fixed size="sm"|"md"|"lg" token scale, composed
  with the density axis's own padding token, never a viewport-driven rule.
{% endcomment %}
{% if href %}<a class="bw-card bw-card--interactive{% if bordered %} bw-card--bordered{% endif %}{% if size %} bw-card--size-{{ size }}{% endif %}" {% bw_attr "href" href %}>{% else %}<div class="bw-card{% if interactive %} bw-card--interactive{% endif %}{% if bordered %} bw-card--bordered{% endif %}{% if size %} bw-card--size-{{ size }}{% endif %}">{% endif %}
{% block header %}{% endblock %}
{% block card_header %}{% endblock %}
{% block title %}{% if title %}<h2 class="bw-card__title">{{ title }}</h2>{% endif %}{% endblock %}
{% block card_title %}{% endblock %}
{% block actions %}{% endblock %}
{% block card_actions %}{% endblock %}
{% block body %}{% endblock %}
{% block card_body %}{% endblock %}
{% block footer %}{% endblock %}
{% block card_footer %}{% endblock %}
{% if href %}</a>{% else %}</div>{% endif %}