Code created by Claude Sonnet 3.5:<!DOCTYPE html><html lang="en"><head>

Code created by Claude Sonnet 3.5:

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Two-Player Line Game</title>
    <style>
        body {
            display: flex;
            justify-content: center;
            align-items: center;
            height: 100vh;
            margin: 0;
            font-family: Arial, sans-serif;
        }
        #gameContainer {
            width: 600px;
            height: 300px;
            position: relative;
            overflow: hidden;
        }
        #player1, #player2 {
            position: absolute;
            top: 0;
            height: 100%;
            display: flex;
            align-items: center;
            justify-content: center;
            font-size: 48px;
            color: white;
        }
        #player1 {
            left: 0;
            background-color: red;
        }
        #player2 {
            right: 0;
            background-color: blue;
        }
        #divider {
            position: absolute;
            top: 0;
            width: 4px;
            height: 100%;
            background-color: black;
        }
        #instructions {
            position: absolute;
            bottom: 10px;
            text-align: center;
            width: 100%;
        }
    </style>
</head>
<body>
    <div id="gameContainer">
        <div id="player1"></div>
        <div id="player2"></div>
        <div id="divider"></div>
        <div id="instructions">Player 1: Press 'A' | Player 2: Press 'L'</div>
    </div>

    <script>
        const gameContainer = document.getElementById('gameContainer');
        const player1 = document.getElementById('player1');
        const player2 = document.getElementById('player2');
        const divider = document.getElementById('divider');

        let gameWidth = gameContainer.offsetWidth;
        let dividerPosition = gameWidth / 2;
        let isMoving = false;
        let moveDirection = 0;
        let moveSpeed = 1;

        function updateGame() {
            player1.style.width = `${dividerPosition}px`;
            player2.style.width = `${gameWidth - dividerPosition}px`;
            divider.style.left = `${dividerPosition}px`;

            player1.textContent = dividerPosition > 0 ? 'A' : '';
            player2.textContent = dividerPosition < gameWidth ? 'L' : '';

            if (dividerPosition <= 0 || dividerPosition >= gameWidth) {
                endGame();
            }
        }

        function startMoving() {
            if (!isMoving) {
                isMoving = true;
                moveDirection = Math.random() > 0.5 ? 1 : -1;
                moveDivider();
            }
        }

        function moveDivider() {
            if (isMoving) {
                dividerPosition += moveDirection * moveSpeed;
                updateGame();
                requestAnimationFrame(moveDivider);
            }
        }

        function stopMoving() {
            if (isMoving) {
                isMoving = false;
                setTimeout(startMoving, 1000);
            }
        }

        function endGame() {
            isMoving = false;
            alert(dividerPosition <= 0 ? "Player 2 (L) wins!" : "Player 1 (A) wins!");
        }

        document.addEventListener('keydown', (event) => {
            if (event.key.toLowerCase() === 'a' && moveDirection > 0) {
                stopMoving();
            } else if (event.key.toLowerCase() === 'l' && moveDirection < 0) {
                stopMoving();
            }
        });

        updateGame();
        setTimeout(startMoving, 1000);
    </script>
</body>
</html>