refactor: adjust primer colors used for background (#2254)

Signed-off-by: Adam Setch <adam.setch@outlook.com>

Author: setchy

tailwind.config.ts

@@ -20,7 +20,6 @@ const config: Config = {
       colors: {
         gitify: {
           font: 'var(--fgColor-default)',
-          background: 'var(--bgColor-muted)',
           sidebar: '#24292e',
           footer: 'var(--bgColor-neutral-muted)',
 
@@ -76,6 +75,8 @@ const config: Config = {
       // TODO - ideally we would use GitHub Primer Design Tokens instead of TailwindCSS
       addBase({
         '[data-color-mode="light"]': {
+          '--gitify-background': 'var(--bgColor-default)',
+
           '--gitify-scrollbar-track': colors.gray[100],
           '--gitify-scrollbar-thumb': colors.gray[300],
           '--gitify-scrollbar-thumb-hover': colors.gray[400],
@@ -85,6 +86,8 @@ const config: Config = {
           '--gitify-counter-text': colors.gray[800],
         },
         '[data-color-mode="dark"]': {
+          '--gitify-background': 'var(--bgColor-muted)',
+
           '--gitify-scrollbar-track': colors.gray[900],
           '--gitify-scrollbar-thumb': colors.gray[700],
           '--gitify-scrollbar-thumb-hover': colors.gray[600],