Web darkmode fixes (#474)

* Change dark mode borders to be slightly lighter than the bg rather than slightly darker

* Add dark mode styling to web composer

* Fix editprofile darkmode

src/lib/themes.ts

@@ -297,7 +297,7 @@ export const darkTheme: Theme = {
       textLight: colors.gray3,
       textInverted: colors.black,
       link: colors.blue3,
-      border: colors.black,
+      border: colors.gray7,
       borderDark: colors.gray6,
       icon: colors.gray4,