fix(item): ios active state has correct contrast (#27134)

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## What is the current behavior?
<!-- Please describe the current behavior that you are modifying. -->


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Issue URL: resolves
https://github.com/ionic-team/ionic-framework/issues/27130

The active/focus background colors on ion-item for iOS are always #000.
This allows for the correct contrast on light mode. This is a problem on
dark mode because the item background color defaults to #000 as well.

## What is the new behavior?
<!-- Please describe the behavior or changes that are being added by
this PR. -->

- Updates the default active/focus colors to be the text color. This
ensures that the active/focus colors are always the opposite of what the
default item background color is.

## Does this introduce a breaking change?

- [ ] Yes
- [x] No

Note: We are updating the default values of CSS Variables, but our
implementation of the spec is wrong and creates color contrast issues.

<!-- If this introduces a breaking change, please describe the impact
and migration path for existing applications below. -->


## Other information

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screenshots of how the component looks before and after the change. -->

---------

Co-authored-by: ionitron <hi@ionicframework.com>

core/src/components/item/item.ios.scss

@@ -11,8 +11,18 @@
   --inner-padding-end: #{$item-ios-padding-end};
   --inner-border-width: #{0px 0px $item-ios-border-bottom-width 0px};
   --background: #{$item-ios-background};
-  --background-activated: #000;
-  --background-focused: #000;
+  /**
+   * The active/focus states need
+   * to be the opposite of the background color
+   * so there is enough contrast. The background
+   * defaults to var(--ion-background-color), so we
+   * default to var(--ion-text-color) which will give us
+   * the opposite color.
+   * i.e. if var(--ion-background-color) is #000
+   * then var(--ion-text-color) will be #fff.
+   */
+  --background-activated: #{$text-color};
+  --background-focused: #{$text-color};
   --background-hover: currentColor;
   --background-activated-opacity: .12;
   --background-focused-opacity: .15;

core/src/components/item/test/buttons/index.html

@@ -12,6 +12,165 @@
     <script src="../../../../../scripts/testing/scripts.js"></script>
     <script nomodule src="../../../../../dist/ionic/ionic.js"></script>
     <script type="module" src="../../../../../dist/ionic/ionic.esm.js"></script>
+
+    <style>
+      /*
+       * Dark Colors
+       * -------------------------------------------
+       */
+
+      body.dark {
+        --ion-color-primary: #428cff;
+        --ion-color-primary-rgb: 66, 140, 255;
+        --ion-color-primary-contrast: #ffffff;
+        --ion-color-primary-contrast-rgb: 255, 255, 255;
+        --ion-color-primary-shade: #3a7be0;
+        --ion-color-primary-tint: #5598ff;
+
+        --ion-color-secondary: #50c8ff;
+        --ion-color-secondary-rgb: 80, 200, 255;
+        --ion-color-secondary-contrast: #ffffff;
+        --ion-color-secondary-contrast-rgb: 255, 255, 255;
+        --ion-color-secondary-shade: #46b0e0;
+        --ion-color-secondary-tint: #62ceff;
+
+        --ion-color-tertiary: #6a64ff;
+        --ion-color-tertiary-rgb: 106, 100, 255;
+        --ion-color-tertiary-contrast: #ffffff;
+        --ion-color-tertiary-contrast-rgb: 255, 255, 255;
+        --ion-color-tertiary-shade: #5d58e0;
+        --ion-color-tertiary-tint: #7974ff;
+
+        --ion-color-success: #2fdf75;
+        --ion-color-success-rgb: 47, 223, 117;
+        --ion-color-success-contrast: #000000;
+        --ion-color-success-contrast-rgb: 0, 0, 0;
+        --ion-color-success-shade: #29c467;
+        --ion-color-success-tint: #44e283;
+
+        --ion-color-warning: #ffd534;
+        --ion-color-warning-rgb: 255, 213, 52;
+        --ion-color-warning-contrast: #000000;
+        --ion-color-warning-contrast-rgb: 0, 0, 0;
+        --ion-color-warning-shade: #e0bb2e;
+        --ion-color-warning-tint: #ffd948;
+
+        --ion-color-danger: #ff4961;
+        --ion-color-danger-rgb: 255, 73, 97;
+        --ion-color-danger-contrast: #ffffff;
+        --ion-color-danger-contrast-rgb: 255, 255, 255;
+        --ion-color-danger-shade: #e04055;
+        --ion-color-danger-tint: #ff5b71;
+
+        --ion-color-dark: #f4f5f8;
+        --ion-color-dark-rgb: 244, 245, 248;
+        --ion-color-dark-contrast: #000000;
+        --ion-color-dark-contrast-rgb: 0, 0, 0;
+        --ion-color-dark-shade: #d7d8da;
+        --ion-color-dark-tint: #f5f6f9;
+
+        --ion-color-medium: #989aa2;
+        --ion-color-medium-rgb: 152, 154, 162;
+        --ion-color-medium-contrast: #000000;
+        --ion-color-medium-contrast-rgb: 0, 0, 0;
+        --ion-color-medium-shade: #86888f;
+        --ion-color-medium-tint: #a2a4ab;
+
+        --ion-color-light: #222428;
+        --ion-color-light-rgb: 34, 36, 40;
+        --ion-color-light-contrast: #ffffff;
+        --ion-color-light-contrast-rgb: 255, 255, 255;
+        --ion-color-light-shade: #1e2023;
+        --ion-color-light-tint: #383a3e;
+      }
+
+      /*
+       * iOS Dark Theme
+       * -------------------------------------------
+       */
+
+      .ios body.dark {
+        --ion-background-color: #000000;
+        --ion-background-color-rgb: 0, 0, 0;
+
+        --ion-text-color: #ffffff;
+        --ion-text-color-rgb: 255, 255, 255;
+
+        --ion-color-step-50: #0d0d0d;
+        --ion-color-step-100: #1a1a1a;
+        --ion-color-step-150: #262626;
+        --ion-color-step-200: #333333;
+        --ion-color-step-250: #404040;
+        --ion-color-step-300: #4d4d4d;
+        --ion-color-step-350: #595959;
+        --ion-color-step-400: #666666;
+        --ion-color-step-450: #737373;
+        --ion-color-step-500: #808080;
+        --ion-color-step-550: #8c8c8c;
+        --ion-color-step-600: #999999;
+        --ion-color-step-650: #a6a6a6;
+        --ion-color-step-700: #b3b3b3;
+        --ion-color-step-750: #bfbfbf;
+        --ion-color-step-800: #cccccc;
+        --ion-color-step-850: #d9d9d9;
+        --ion-color-step-900: #e6e6e6;
+        --ion-color-step-950: #f2f2f2;
+
+        --ion-item-background: #000000;
+
+        --ion-card-background: #1c1c1d;
+      }
+
+      .ios body.dark ion-modal {
+        --ion-background-color: var(--ion-color-step-100);
+        --ion-toolbar-background: var(--ion-color-step-150);
+        --ion-toolbar-border-color: var(--ion-color-step-250);
+        --ion-item-background: var(--ion-color-step-150);
+      }
+
+      /*
+       * Material Design Dark Theme
+       * -------------------------------------------
+       */
+
+      .md body.dark {
+        --ion-background-color: #121212;
+        --ion-background-color-rgb: 18, 18, 18;
+
+        --ion-text-color: #ffffff;
+        --ion-text-color-rgb: 255, 255, 255;
+
+        --ion-border-color: #222222;
+
+        --ion-color-step-50: #1e1e1e;
+        --ion-color-step-100: #2a2a2a;
+        --ion-color-step-150: #363636;
+        --ion-color-step-200: #414141;
+        --ion-color-step-250: #4d4d4d;
+        --ion-color-step-300: #595959;
+        --ion-color-step-350: #656565;
+        --ion-color-step-400: #717171;
+        --ion-color-step-450: #7d7d7d;
+        --ion-color-step-500: #898989;
+        --ion-color-step-550: #949494;
+        --ion-color-step-600: #a0a0a0;
+        --ion-color-step-650: #acacac;
+        --ion-color-step-700: #b8b8b8;
+        --ion-color-step-750: #c4c4c4;
+        --ion-color-step-800: #d0d0d0;
+        --ion-color-step-850: #dbdbdb;
+        --ion-color-step-900: #e7e7e7;
+        --ion-color-step-950: #f3f3f3;
+
+        --ion-item-background: #1e1e1e;
+
+        --ion-toolbar-background: #1f1f1f;
+
+        --ion-tab-bar-background: #1f1f1f;
+
+        --ion-card-background: #1e1e1e;
+      }
+    </style>
   </head>
 
   <body>
@@ -188,6 +347,12 @@
     </style>
 
     <script>
+      // TODO FW-4005
+      const params = new URL(window.location).searchParams;
+      const dark = params.get('dark');
+      if (dark !== null) {
+        document.body.classList.add('dark');
+      }
       const attach = document.getElementById('attachClick');
 
       attach.addEventListener('click', (ev) => {

core/src/components/item/test/buttons/item.e2e.ts

@@ -15,4 +15,14 @@ test.describe('item: buttons', () => {
 
     await expect(page).toHaveScreenshot(`item-buttons-diff-${page.getSnapshotSettings()}.png`);
   });
+
+  test('should not have visual regressions in dark', async ({ page, skip }) => {
+    skip.rtl();
+
+    await page.goto(`/src/components/item/test/buttons?dark=true`);
+
+    await page.setIonViewport();
+
+    await expect(page).toHaveScreenshot(`item-buttons-dark-diff-${page.getSnapshotSettings()}.png`);
+  });
 });