chore: Minor design adjustments

lib/config/themes.dart

@@ -58,7 +58,7 @@ abstract class FluffyThemes {
         inputDecorationTheme: InputDecorationTheme(
           border: UnderlineInputBorder(
             borderSide: BorderSide.none,
-            borderRadius: BorderRadius.circular(AppConfig.borderRadius),
+            borderRadius: BorderRadius.circular(AppConfig.borderRadius / 2),
           ),
           filled: true,
         ),
@@ -72,6 +72,20 @@ abstract class FluffyThemes {
             statusBarBrightness: brightness,
           ),
         ),
+        textButtonTheme: TextButtonThemeData(
+          style: TextButton.styleFrom(
+            shape: RoundedRectangleBorder(
+              borderRadius: BorderRadius.circular(AppConfig.borderRadius / 2),
+            ),
+          ),
+        ),
+        outlinedButtonTheme: OutlinedButtonThemeData(
+          style: OutlinedButton.styleFrom(
+            shape: RoundedRectangleBorder(
+              borderRadius: BorderRadius.circular(AppConfig.borderRadius / 2),
+            ),
+          ),
+        ),
         elevatedButtonTheme: ElevatedButtonThemeData(
           style: ElevatedButton.styleFrom(
             padding: const EdgeInsets.all(16),