Add themes and drawing field for kanji

lib/components/flashcard.dart

@@ -104,7 +104,10 @@ class _FlashCardPaper extends StatelessWidget {
             child: Row(
               crossAxisAlignment: CrossAxisAlignment.end,
               children: [
-                Text((cardIndex != null) ? (cardIndex! + 1).toString() : "?")
+                Text(
+                  (cardIndex != null) ? (cardIndex! + 1).toString() : "?",
+                  style: const TextStyle(color: Colors.black),
+                )
               ],
             ),
           ),
@@ -140,13 +143,19 @@ class _NorwegianContent extends StatelessWidget {
       child: FittedBox(
         fit: BoxFit.fitHeight,
         child: DefaultTextStyle.merge(
-          style: const TextStyle(fontFamily: 'Heart Warming'),
+          style: const TextStyle(
+            fontFamily: 'Heart Warming',
+            color: Colors.black,
+          ),
           child: Column(
             children: card.norwegian.map((n) {
               final text = (n.hints == null)
                   ? n.word
                   : "${n.word} (${n.hints?.join(', ')})";
-              return Text(text);
+              return Text(
+                text,
+                style: const TextStyle(color: Colors.black),
+              );
             }).toList(),
           ),
         ),
@@ -170,7 +179,10 @@ class _JapaneseContent extends StatelessWidget {
       child: FittedBox(
         fit: BoxFit.fitHeight,
         child: DefaultTextStyle.merge(
-          style: const TextStyle(fontFamily: 'K Gothic'),
+          style: const TextStyle(
+            fontFamily: 'K Gothic',
+            color: Colors.black,
+          ),
           child: Row(
             mainAxisAlignment: MainAxisAlignment.center,
             children: card.japanese

lib/components/navigation_buttons.dart

@@ -0,0 +1,57 @@
+import 'package:flutter/material.dart';
+
+class NavigationButtons extends StatelessWidget {
+  final String middleText;
+  final void Function() onNextCard;
+  final void Function() onPreviousCard;
+  final void Function()? onMiddlePressed;
+
+  const NavigationButtons({
+    Key? key,
+    required this.middleText,
+    required this.onNextCard,
+    required this.onPreviousCard,
+    this.onMiddlePressed,
+  }) : super(key: key);
+
+  @override
+  Widget build(BuildContext context) =>
+          Container(
+            decoration: BoxDecoration(
+              color: Colors.blue,
+              borderRadius: BorderRadius.circular(10),
+            ),
+            child: ButtonBar(
+              alignment: MainAxisAlignment.center,
+              children: [
+                IconButton(
+                  padding: const EdgeInsets.all(20),
+                  color: Colors.white,
+                  onPressed: onPreviousCard,
+                  icon: const Icon(Icons.arrow_back),
+                ),
+                const SizedBox(width: 10),
+                InkWell(
+                  onTap: onMiddlePressed,
+                  child: Padding(
+                    padding: const EdgeInsets.all(10),
+                    child: Text(
+                      middleText,
+                      style: Theme.of(context)
+                          .textTheme
+                          .headline6!
+                          .merge(const TextStyle(color: Colors.white)),
+                    ),
+                  ),
+                ),
+                const SizedBox(width: 10),
+                IconButton(
+                  padding: const EdgeInsets.all(20),
+                  color: Colors.white,
+                  onPressed: onNextCard,
+                  icon: const Icon(Icons.arrow_forward),
+                ),
+              ],
+            ),
+          );
+}