styles: add mixin for regenerate button

Author: Alyar

packages/devextreme-scss/scss/widgets/base/gridBase/layout/aiChat/_index.scss

@@ -44,14 +44,6 @@
   gap: $ai-chat-message-gap;
 }
 
-.dx-ai-chat__message-regenerate-button {
-  cursor: pointer;
-
-  &:hover {
-    border-radius: 4px;
-  }
-}
-
 .dx-ai-chat__action-list {
   display: flex;
   flex-flow: column;

packages/devextreme-scss/scss/widgets/base/gridBase/layout/aiChat/_mixins.scss

@@ -1,3 +1,5 @@
+@use './variables' as *;
+
 @mixin ai-chat-messagelist-empty(
   $messagelist-empty-icon-color,
   $messagelist-empty-icon-background-color,
@@ -46,3 +48,16 @@
     border-color: $border-color;
   }
 }
+
+@mixin ai-chat-message-regenerate-button(
+  $hover-background-color,
+) {
+  .dx-ai-chat__message-regenerate-button {
+    cursor: pointer;
+
+    &:hover::before {
+      border-radius: $ai-chat-message-regenerate-button-border-radius;
+      background-color: $hover-background-color;
+    }
+  }
+}

packages/devextreme-scss/scss/widgets/base/gridBase/layout/aiChat/_variables.scss

@@ -1,3 +1,4 @@
 $ai-chat-message-gap: 8px;
 $ai-chat-message-content-gap: 4px;
 $ai-chat-message-width: 280px;
+$ai-chat-message-regenerate-button-border-radius: 4px;

packages/devextreme-scss/scss/widgets/fluent/gridBase/layout/aiChat/_index.scss

@@ -9,3 +9,4 @@
 @include ai-chat-message-success($base-success);
 @include ai-chat-message-error($base-danger);
 @include ai-chat-messagebubble-border($base-border-color);
+@include ai-chat-message-regenerate-button($button-normal-active-bg);

packages/devextreme-scss/scss/widgets/generic/gridBase/layout/aiChat/_index.scss

@@ -9,3 +9,4 @@
 @include ai-chat-message-success($base-success);
 @include ai-chat-message-error($base-danger);
 @include ai-chat-messagebubble-border($base-border-color);
+@include ai-chat-message-regenerate-button($button-normal-outlined-bg-active);

packages/devextreme-scss/scss/widgets/material/gridBase/layout/aiChat/_index.scss

@@ -9,3 +9,4 @@
 @include ai-chat-message-success($base-success);
 @include ai-chat-message-error($base-danger);
 @include ai-chat-messagebubble-border($base-border-color);
+@include ai-chat-message-regenerate-button($button-normal-active-bg);