Error previewing in browser

[ZhhHugoChang]

<style>
    p:first-child {
        color: aqua;
    }
</style>

<p>text01</p>
<p>This is a passage of text</p>
<p>This is a passage of text</p>
<div>
    <p>text02</p>
    <marquee>
        <p>text03</p>
        <p>This is a passage of text</p>
    </marquee>
    <p>This is a passage of text</p>
    <p>This is a passage of text</p>
    <p>This is a passage of text</p>
</div>
<p>dasd</p>

Run the above code “text01” style is not displayed

[ZhhHugoChang]