如何在iframe中放大文本？

<style>
    .iframe-container {
        position: relative;
        width: 500px;
        height: 300px;
    }
    .iframe-container iframe {
        position: absolute;
        top: 0;
        left: 0;
        width: 100%;
        height: 100%;
    }
</style>

<div class="iframe-container">
    <iframe src="your-iframe-url"></iframe>
    <button onclick="zoomIn()">放大</button>
</div>

<script>
    function zoomIn() {
        var iframe = document.querySelector('.iframe-container iframe');
        var iframeDocument = iframe.contentDocument || iframe.contentWindow.document;
        var iframeBody = iframeDocument.body;
        
        // 修改文本样式
        iframeBody.style.fontSize = '20px';
    }
</script>