fix(input): fixing Firefox placeholder color

CHANGELOG.md

@@ -24,6 +24,7 @@ This project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.htm
 ### Fixes
 - ESC key pressed on a trigger element should propagate event if `Popup` is closed @sophieH29 ([#1373](https://github.com/stardust-ui/react/pull/1373))
 - Changing icon behavior as for some cases icon could be visible @kolaps33 ([#1327](https://github.com/stardust-ui/react/pull/1327))
+- Firefox: placeholder color should match redlines @notandrew ([#1406](https://github.com/stardust-ui/react/pull/1406))
 - `Popup` - fix proptypes for `content` and `trigger` props @miroslavstastny ([#1420](https://github.com/stardust-ui/react/pull/1420))
 - Make `contentRef` prop optional for `Accordion.Title` @Bugaa92 ([#1418](https://github.com/stardust-ui/react/pull/1418))
 - Call `getDerivedStateFromProps()` from `AutoControlledComponent` in `Dropdown` ([#1416](https://github.com/stardust-ui/react/pull/1416))
@@ -34,7 +35,7 @@ This project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.htm
 - Replace `react-popper` package with custom `Popper` component and exposed as `UNSTABLE_Popper` positioning helper @Bugaa92 ([#1358](https://github.com/stardust-ui/react/pull/1358))
 - Add strict types for the `colorScheme` props used in the components' `variables` @mnajdova ([#1340](https://github.com/stardust-ui/react/pull/1340))
 - Export `message-seen`, `presence-available`, `presence-stroke`, `open-outside` and `eye-friendlier`  icons to Teams theme @joheredi ([#1390](https://github.com/stardust-ui/react/pull/1390))
-- Add 'lightning' icon @notandrew ([#1385](https://github.com/stardust-ui/react/pull/1385))
+- Add 'lightning' icon to Teams theme @notandrew ([#1385](https://github.com/stardust-ui/react/pull/1385))
 - Add automatic positioning inside viewport for `Menu` with submenus @Bugaa92 ([#1384](https://github.com/stardust-ui/react/pull/1384))
 - Add `align`, `position`, `offset` props for `Dropdown` component @Bugaa92 ([#1312](https://github.com/stardust-ui/react/pull/1312))
 

packages/react/src/themes/base/components/Input/inputStyles.ts

@@ -31,6 +31,7 @@ const inputStyles: ComponentSlotStylesInput<InputProps, InputVariables> = {
 
     '::placeholder': {
       color: v.placeholderColor,
+      opacity: 1, // undo Firefox default opacity
     },
 
     ':focus': {