Fix blinking animation bug for Status Running component (#706)

* Refer to keyframe as a material-ul variable

https://material-ui.com/guides/migration-v3/\#styles

* Update background color of Status

The background color should match with the theme's background color.

packages/core/src/components/Status/Status.tsx

@@ -47,7 +47,7 @@ const useStyles = makeStyles<BackstageTheme>(theme => ({
     backgroundColor: 'rgba(245, 155, 35, 0.5)',
   },
   running: {
-    animation: 'blink 0.8s step-start 0s infinite',
+    animation: '$blink 0.8s step-start 0s infinite',
     backgroundColor: theme.palette.status.running,
   },
   '@keyframes blink': {

packages/theme/src/themes.ts

@@ -28,7 +28,7 @@ export const lightTheme = createTheme({
     error: '#CA001B',
     running: '#BEBEBE',
     pending: '#5BC0DE',
-    background: '#FEFEFE',
+    background: '#F8F8F8',
   },
   bursts: {
     fontColor: '#FEFEFE',
@@ -68,7 +68,7 @@ export const darkTheme = createTheme({
     error: '#CA001B',
     running: '#BEBEBE',
     pending: '#5BC0DE',
-    background: '#FEFEFE',
+    background: '#282828',
   },
   bursts: {
     fontColor: '#FEFEFE',