From 10c2f304eebb98478511a3b8e369d605ce4f9170 Mon Sep 17 00:00:00 2001
From: Lea Verou <lea@verou.me>
Date: Tue, 25 Mar 2025 13:35:23 -0400
Subject: [PATCH] [Card] Support `appearance`, rel #609

---
 docs/docs/components/card.md | 26 +++++++++++++++++++++++---
 src/components/card/card.css | 31 +++++++++++++++++++++++++------
 src/components/card/card.ts  | 10 ++++++++--
 3 files changed, 56 insertions(+), 11 deletions(-)

diff --git a/docs/docs/components/card.md b/docs/docs/components/card.md
index d1cd32a64..c6b3d9d4c 100644
--- a/docs/docs/components/card.md
+++ b/docs/docs/components/card.md
@@ -177,8 +177,28 @@ Use the `size` attribute to change a card's size.
   </footer>
 </wa-card>
 </div>
-
 ```
 
-<style>
-</style>
+### Appearance
+
+Use the `appearance` attribute to change the card's visual appearance.
+
+```html {.example}
+<div class="wa-grid">
+<wa-card>
+  <div slot="header">Outlined (default)</div>
+  Card content.
+</wa-card>
+{% for appearance in ['outlined filled', 'outlined accent', 'plain', 'filled', 'accent'] -%}
+<wa-card appearance="{{ appearance }}">
+  <div slot="header">{{ appearance | capitalize }}</div>
+  Card content.
+</wa-card>
+{%- endfor %}
+</div>
+```
+
+
+</div>
+```
+
diff --git a/src/components/card/card.css b/src/components/card/card.css
index 8be8a0d9a..f121ff65a 100644
--- a/src/components/card/card.css
+++ b/src/components/card/card.css
@@ -5,15 +5,15 @@
 
   --spacing: var(--wa-space);
   --border-width: var(--wa-panel-border-width);
-  --border-color: var(--wa-color-surface-border);
+  --outlined-border-color: var(--wa-color-surface-border);
   --border-radius: var(--wa-panel-border-radius);
-
   --inner-border-radius: calc(var(--border-radius) - var(--border-width));
+  --inner-border-color: var(--outlined-border-color);
 
   display: flex;
   flex-direction: column;
-  background-color: var(--wa-color-surface-default);
-  border-color: var(--border-color);
+  background-color: var(--background-color, var(--wa-color-surface-default));
+  border-color: var(--border-color, var(--wa-color-surface-border));
   border-radius: var(--border-radius);
   border-style: var(--wa-panel-border-style);
   box-shadow: var(--wa-shadow-s);
@@ -21,6 +21,25 @@
   color: var(--wa-color-text-normal);
 }
 
+:host(:is([appearance~='filled'], [appearance~='accent'], .wa-filled, .wa-accent)) {
+  color: var(--text-color, var(--wa-color-text-normal));
+}
+
+:host([appearance~='filled']),
+:host(.wa-filled) {
+  --inner-border-color: oklab(from var(--outlined-border-color) l a b / 65%);
+}
+
+:host([appearance='plain']) {
+  --inner-border-color: transparent;
+}
+
+:host([appearance='plain']),
+:host([appearance='accent']),
+:host([appearance='filled']) {
+  box-shadow: none;
+}
+
 /* Take care of top and bottom radii */
 .image,
 :host(:not([with-image])) .header,
@@ -49,7 +68,7 @@
 .header {
   display: block;
   border-block-end-style: inherit;
-  border-block-end-color: var(--border-color);
+  border-block-end-color: var(--inner-border-color);
   border-block-end-width: var(--border-width);
   padding: calc(var(--spacing) / 2) var(--spacing);
 }
@@ -62,7 +81,7 @@
 .footer {
   display: block;
   border-block-start-style: inherit;
-  border-block-start-color: var(--border-color);
+  border-block-start-color: var(--inner-border-color);
   border-block-start-width: var(--border-width);
   padding: var(--spacing);
 }
diff --git a/src/components/card/card.ts b/src/components/card/card.ts
index 2c9317d9a..6bf2693ce 100644
--- a/src/components/card/card.ts
+++ b/src/components/card/card.ts
@@ -2,6 +2,7 @@ import { html } from 'lit';
 import { customElement, property } from 'lit/decorators.js';
 import { HasSlotController } from '../../internal/slot.js';
 import WebAwesomeElement from '../../internal/webawesome-element.js';
+import appearanceStyles from '../../styles/utilities/appearance.css';
 import sizeStyles from '../../styles/utilities/size.css';
 import styles from './card.css';
 
@@ -22,19 +23,24 @@ import styles from './card.css';
  * @csspart footer - The container that wraps the card's footer.
  *
  * @cssproperty [--border-radius=var(--wa-panel-border-radius)] - The radius for the card's corners. Expects a single value.
- * @cssproperty [--border-color=var(--wa-color-surface-border)] - The color of the card's borders, including inner borders. Expects a single value.
+ * @cssproperty [--border-color=var(--wa-color-surface-border)] - The color of the card's borders. Expects a single value.
+ * @cssproperty [--inner-border-color=var(--wa-color-surface-border)] - The color of the card's inner borders, e.g. those separating headers and footers from the main content. Expects a single value.
  * @cssproperty [--border-width=var(--wa-panel-border-width)] - The width of the card's borders. Expects a single value.
  * @cssproperty [--spacing=var(--wa-space)] - The amount of space around and between sections of the card. Expects a single value.
  */
 @customElement('wa-card')
 export default class WaCard extends WebAwesomeElement {
-  static shadowStyle = [sizeStyles, styles];
+  static shadowStyle = [sizeStyles, appearanceStyles, styles];
 
   private readonly hasSlotController = new HasSlotController(this, 'footer', 'header', 'image');
 
   /** The component's size. Will be inherited by any descendants with a `size` attribute. */
   @property({ reflect: true, initial: 'medium' }) size: 'small' | 'medium' | 'large' | 'inherit' = 'inherit';
 
+  /** The card's visual appearance. */
+  @property({ reflect: true })
+  appearance: 'accent' | 'filled' | 'outlined' | 'plain' = 'outlined';
+
   /** Renders the card with a header. Only needed for SSR, otherwise is automatically added. */
   @property({ attribute: 'with-header', type: Boolean, reflect: true }) withHeader = false;