我有一个画布，显示矩阵二进制代码雨下来。我想添加一个图像在画布上的问题
这是我的

<div class="rain">
            <canvas id="Matrix"></canvas>
             <div class ="imgclass">
                <img class="imgclass" src="assets/image.jpg"/>
            </div>
        </div>

用于画布的JavaScript

const canvas = document.getElementById('Matrix');
const context = canvas.getContext('2d');

canvas.width = window.innerWidth;
canvas.height = window.innerHeight;
const latin = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ';
const nums = '0123456789';

const alphabet = latin + nums;

const fontSize = 16;
const columns = canvas.width/fontSize;

const rainDrops = [];

for( let x = 0; x < columns; x++ ) {
    rainDrops[x] = 1;
}

const draw = () => {
    context.fillStyle = 'rgba(0, 0, 0, 0.05)';
    context.fillRect(0, 0, canvas.width, canvas.height);
    
    context.fillStyle = '#0F0';
    context.font = fontSize + 'px monospace';

    for(let i = 0; i < rainDrops.length; i++)
    {
        const text = alphabet.charAt(Math.floor(Math.random() * alphabet.length));
        context.fillText(text, i*fontSize, rainDrops[i]*fontSize);
        
        if(rainDrops[i]*fontSize > canvas.height && Math.random() > 0.975){
            rainDrops[i] = 0;
        }
        rainDrops[i]++;
    }
};

setInterval(draw, 30);

和CSS：

.rain {
    background: black;
    height: 40%;
    overflow: hidden;
}

canvas {
    background-image: url("assets/img.jpg");
}

现在，有问题的图像出现在画布下方，而不是画布上（即中间）。