Added theme, reworked UI

lib/theme.dart

@@ -0,0 +1,69 @@
+import 'package:flutter/material.dart';
+
+const lightColorScheme = ColorScheme(
+  brightness: Brightness.light,
+  primary: Color(0xFF006C45),
+  onPrimary: Color(0xFFFFFFFF),
+  primaryContainer: Color(0xFF51FFB1),
+  onPrimaryContainer: Color(0xFF002112),
+  secondary: Color(0xFF4E6355),
+  onSecondary: Color(0xFFFFFFFF),
+  secondaryContainer: Color(0xFFD0E8D7),
+  onSecondaryContainer: Color(0xFF0B1F15),
+  tertiary: Color(0xFF3C6472),
+  onTertiary: Color(0xFFFFFFFF),
+  tertiaryContainer: Color(0xFFBFE9F9),
+  onTertiaryContainer: Color(0xFF001F28),
+  error: Color(0xFFBA1A1A),
+  errorContainer: Color(0xFFFFDAD6),
+  onError: Color(0xFFFFFFFF),
+  onErrorContainer: Color(0xFF410002),
+  background: Color(0xFFFBFDF8),
+  onBackground: Color(0xFF191C1A),
+  surface: Color(0xFFFBFDF8),
+  onSurface: Color(0xFF191C1A),
+  surfaceVariant: Color(0xFFDCE5DC),
+  onSurfaceVariant: Color(0xFF404943),
+  outline: Color(0xFF707972),
+  onInverseSurface: Color(0xFFEFF1ED),
+  inverseSurface: Color(0xFF2E312E),
+  inversePrimary: Color(0xFF21E297),
+  shadow: Color(0xFF000000),
+  surfaceTint: Color(0xFF006C45),
+  outlineVariant: Color(0xFFC0C9C1),
+  scrim: Color(0xFF000000),
+);
+
+const darkColorScheme = ColorScheme(
+  brightness: Brightness.dark,
+  primary: Color(0xFF21E297),
+  onPrimary: Color(0xFF003822),
+  primaryContainer: Color(0xFF005233),
+  onPrimaryContainer: Color(0xFF51FFB1),
+  secondary: Color(0xFFB4CCBB),
+  onSecondary: Color(0xFF203529),
+  secondaryContainer: Color(0xFF364B3E),
+  onSecondaryContainer: Color(0xFFD0E8D7),
+  tertiary: Color(0xFFA4CDDD),
+  onTertiary: Color(0xFF043542),
+  tertiaryContainer: Color(0xFF234C59),
+  onTertiaryContainer: Color(0xFFBFE9F9),
+  error: Color(0xFFFFB4AB),
+  errorContainer: Color(0xFF93000A),
+  onError: Color(0xFF690005),
+  onErrorContainer: Color(0xFFFFDAD6),
+  background: Color(0xFF191C1A),
+  onBackground: Color(0xFFE1E3DF),
+  surface: Color(0xFF191C1A),
+  onSurface: Color(0xFFE1E3DF),
+  surfaceVariant: Color(0xFF404943),
+  onSurfaceVariant: Color(0xFFC0C9C1),
+  outline: Color(0xFF8A938B),
+  onInverseSurface: Color(0xFF191C1A),
+  inverseSurface: Color(0xFFE1E3DF),
+  inversePrimary: Color(0xFF006C45),
+  shadow: Color(0xFF000000),
+  surfaceTint: Color(0xFF21E297),
+  outlineVariant: Color(0xFF404943),
+  scrim: Color(0xFF000000),
+);