The Ball is not jumping

So i am making an HTML file but… the ball isn’t jumping at all! here is the code if someone can help:

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Idle Game!</title>
    <style>
        body {
            background-color: royalblue;
            font-family: system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, 'Open Sans';
            margin: 0; /* Remove default margin */
            padding: 0; /* Remove default padding */
            cursor: default;
            position: relative; /* Add position relative to the body */
            height: 100vh; /* Ensure body takes full viewport height */
        }

        .button {
            background-color: rgb(0, 153, 255);
            border-radius: 10px; /* Adjust the radius as needed */
            font-family: 'Ubuntu', sans-serif;
            position: absolute;
            height: 100px;
            width: 100px;
            text-decoration: solid;
            top: 20px; /* Adjust as needed */
            right: 20px; /* Adjust as needed */
            cursor: pointer; /* Change cursor on hover */
            display: flex;
            justify-content: center;
            align-items: center;
            color: white; /* Optional: to make the text visible on the button */
            text-align: center; /* Optional: to center the text */
        }

        .circle {
            background-color: dodgerblue;
            border-radius: 100%;
            height: 100px;
            width: 100px;
            position: absolute;
            top: 10px; /* Initial top position */
            left: 10px; /* Initial left position */
        }

        .pad {
            background-color: rgb(0, 25, 105); /* Changed color for better visibility */
            border-radius: 40px;
            width: 100%;
            height: 50px; /* Increased height for better visibility */
            position: absolute;
            bottom: 0; /* Position it at the bottom */
            border: 2px solid black; /* Add a border to make it stand out */
            z-index: 10; /* Ensure it's on top of other elements */
            text-align: center; /* Center text inside pad */
            line-height: 50px; /* Center text vertically */
        }
    </style>
</head>
<body>
    <div class="pad">Pad</div>
    <div class="circle"></div>
    <div class="button" onclick="startGame()">Start the game!</div>

    <script>
        let dy = 2; // vertical speed
        let interval;
        let y; // Declare y outside the event listener function
        let collision = false;
        
        function startGame() {
            let circle = document.querySelector('.circle');
            y = parseInt(circle.style.top) || 10; // Initial top position
            let pad = document.querySelector('.pad');
            let padTop = window.innerHeight - pad.offsetHeight; // Get the top position of the pad
            
            console.log("Pad height:", pad.offsetHeight);
            console.log("Pad top position:", padTop);

            interval = setInterval(function () {
                // Check if the circle reaches the top of the pad
                if (y + circle.offsetHeight >= padTop) {
                    clearInterval(interval); // Stop the circle
                    dy = 0; // Reset vertical speed
                    collision = true;
                    circle.style.top = (padTop - circle.offsetHeight) + 'px'; // Correct position
                    console.log("touchè")
                } else {
                    collision = false; // Circle is not colliding with the pad
                    // Move the circle downwards
                    y += dy;
                }

                // Update circle position
                circle.style.top = y + 'px';
            }, 10); // Move every 10 milliseconds
        }

        // Add event listener for space bar key press
        document.addEventListener('keydown', function(event) {
            if (event.code === 'Space') {
                console.log(y);
                let circle = document.querySelector('.circle');
                if (collision) { // Only allow jumping when the circle is on the pad
                    dy = -10; // Set the vertical speed to -10 to make the circle jump upwards
                } else {
                    console.log("Nuh uh, jump when on pod. this ain't your double jump type shi..."); // Inform the user that jumping is only allowed when on the pad
                }
            }
        });
    </script>
</body>
</html>

i tried to add the Y in the event.key for the space BUT THEN IT ISN’t FALLING!
i also tried to make the collision check (which worked) but it isn;t working still! WHy is the Y changing but the circle is at same place? Please someone help me!