Visual changes

src/main.rs

@@ -1,4 +1,4 @@
-// #![windows_subsystem = "windows"]
+#![windows_subsystem = "windows"]
 mod data_provider;
 mod dictionary;
 mod dictionary_test;
@@ -25,7 +25,7 @@ use crate::quiz::*;
 use crate::repetitions::CardSetSettings;
 use crate::RootMessage::Keyboard;
 use iced::Font;
-use iced::{keyboard, Program, Subscription, Theme};
+use iced::{keyboard, Subscription, Theme};
 use rusqlite::Connection;
 
 const USER_FONT: Font = Font::with_name("Noto Sans JP");