伪选择n-子问题

Question

我只想选择第一个图像来向上移动：

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#rockfon_mono:nth-child(1) img {
	margin-top:-40px;
  border: solid green;
	
}

<div id="rockfon_mono">
<img src="images/products/rockfon-mono/rockfon-header.png" alt="" />
 <h2>Mono® Acoustic TE</h2>

<p>Seamless acoustic ceiling and wall lining |  Acoustic and aesthetic comfort | No more compromises</p>
<p>The current trend in architectural design favours the use of highly reflective, sturdy materials such</p>
<div id="rockfonImageOne"> 
    <img src="images/products/rockfon-mono/Mono.png" alt="" />
</div>
 <h2>Acoustics</h2>

<p>Full acoustic control for any space | Acoustic enhancement for new and refurbished spaces | High sound absorption | Improved speech intelligibility</p>
<p>Acoustic and aesthetic comfort Mono Acoustic TE’s aesthetic quality matches its acoustic quality. Mono Acoustic TE provides high sound absorption, echo reduction, a significant decrease in reverberation</p>
<div id="rockfonImageOne"> 
    <img src="images/products/rockfon-mono/Acoustics.png" alt="" />
</div>
 <h2>Characteristics</h2>

<p>System description and performance the unique Mono Acoustic TE system is a highly acoustic monolithic ceiling and wall lining. This patented innovation is made of high quality stone wool for optimum</p>

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然而，它正在选择整个页面中的每一幅图像。

Answer 1

在特定的HTML中，您可以使用直接子标记，因为其他imgs不是直接子程序。

#rockfon_mono > img {
    margin-top:-40px;
    border: solid green;
}

演示