First and Last item padding

main.dart

import 'package:flutter/material.dart';

void main() {
  runApp(const MyApp());
}

class MyApp extends StatelessWidget {
  const MyApp({super.key});

  static const items = ['First', "Second", "Thirds"];

  @override
  Widget build(BuildContext context) {
    final screenWidth = MediaQuery.of(context).size.width;
    const itemWidth = 305.0;
    const horizontalPadding = 24.0;

    final viewportFraction = itemWidth / (screenWidth - horizontalPadding);
    return MaterialApp(
      debugShowCheckedModeBanner: false,
      home: Scaffold(
        body: PageView.builder(
          padEnds: false,
          controller: PageController(viewportFraction: viewportFraction),
          itemCount: items.length,
          itemBuilder: (context, index) {
            return Padding(
              padding: EdgeInsets.only(
                left: index == 0 ? 24 : 0,
                right: index == items.length - 1 ? 24 : 0,
              ),
              child: SizedBox(
                width: 305,
                child: Card(child: Center(child: Text(items[index]))),
              ),
            );
          },
        ),
      ),
    );
  }
}