Refactor color variables and styles across components for a cohesive design update

- Updated active state colors in ToastSelect component for better visibility.
- Adjusted box-shadow and border colors in ModelMappingDiagram styles.
- Changed provider colors in ModelMappingDiagram for improved aesthetics.
- Modified background and border styles in ProviderNav for a more modern look.
- Updated accent colors in StatCards to align with new color scheme.
- Refined token colors in TokenBreakdownChart for consistency.
- Adjusted sparkline colors in useSparklines hook to match new design.
- Changed error icon color in AiProvidersOpenAIEditPage for better contrast.
- Updated failure badge styles in AiProvidersPage for a cleaner appearance.
- Refined various status styles in AuthFilesPage for improved clarity.
- Updated colors in ConfigPage to use new variable definitions.
- Refined error and warning styles in LoginPage for better user feedback.
- Adjusted log status colors in LogsPage for consistency with new theme.
- Updated OAuthPage styles to reflect new color variables.
- Refined quota styles in QuotaPage for better visual hierarchy.
- Updated system page styles for improved user experience.
- Adjusted usage page styles to align with new design language.
- Refactored component styles to use new color variables in components.scss.
- Updated layout styles to reflect new primary color definitions.
- Refined theme colors in themes.scss for a more cohesive look.
- Updated color variables in variables.scss to reflect new design choices.
- Adjusted chart colors in usage.ts for consistency with new color scheme.

src/pages/OAuthPage.module.scss

@@ -61,13 +61,13 @@
   }
 
   &.error {
-    background-color: rgba(239, 68, 68, 0.1);
-    color: #dc2626;
+    background-color: rgba($error-color, 0.12);
+    color: $error-color;
   }
 
   &.waiting {
-    background-color: rgba(59, 130, 246, 0.1);
-    color: #3b82f6;
+    background-color: rgba($primary-color, 0.12);
+    color: var(--primary-color);
   }
 }