Improve light theme further and make System default

- Primary color is the same on all themes which means app bar matches status bar again
- All text in the title and header is now white for contrast
- Background is off-white to make it less blinding

JournalApp/Components/Pages/MainLayout.razor

@@ -27,12 +27,14 @@
 		{
 			Palette = new PaletteLight()
 			{
-				Primary = "#978dec",
-				PrimaryLighten = "#b6aff2",
+				Primary = "#776be7",
+				PrimaryLighten = "#978dec",
+				Background = "#f7f6fb",
 				TextDisabled = "#424242",
 			},
 			PaletteDark = new PaletteDark()
 			{
+				Primary = "#776be7",
 				TextDisabled = "#ffffffb2",
 			},
 			LayoutProperties = new() { AppbarHeight = "4em" },
@@ -43,7 +45,7 @@
 		base.OnInitialized();
 
 		AppThemeService.ThemeChanged += OnThemeChanged;
-		if (Enum.TryParse<AppTheme>(Preferences.Get("theme", "Dark"), out var parsed))
+		if (Enum.TryParse<AppTheme>(Preferences.Get("theme", "Unspecified"), out var parsed))
 			AppThemeService.SelectedAppTheme = parsed;
 
 		App.NewIntent += OnNewIntent;

JournalApp/wwwroot/app.css

@@ -48,12 +48,16 @@ button {
 	flex-direction: row;
 	align-items: center;
 	gap: 0.5em;
+	padding: 0;
 	box-shadow: none;
 	min-height: calc(var(--mud-appbar-height) - var(--mud-appbar-height) / 4);
 	background-color: var(--mud-palette-primary);
-	padding: 0;
 }
 
+	.page-header * {
+		color: var(--mud-palette-appbar-text);
+	}
+
 .mud-dialog-title, .page-title {
 	z-index: 999;
 	display: flex;
@@ -65,6 +69,10 @@ button {
 	background-color: var(--mud-palette-primary-lighten);
 }
 
+	.mud-dialog-title, .page-title * {
+		color: var(--mud-palette-appbar-text);
+	}
+
 .mud-dialog-content, .page-body {
 	max-width: 960px;
 	margin: 0 auto !important;