HTML:

 <div class="top-container">
    <div class="primary-text">lorem</div>
    <div class="secondary-text">lorem</div>
</div>
<div class="secondary-container">
        <h2>Lorem ipsum dolor sit amet.</h2>
</div>
<div class="info-container">
   <div class="container-one">
       <div class="box1">1</div>
       <h3>lorem</h3>
       <p>Lorem ipsum, dolor sit amet consectetur adipisicing.</p>
    </div>
   <div class="container-two">
    <div class="box2">2</div>
    <h3>lorem</h3>
    <p>Lorem ipsum dolor sit amet, consectetur adipisicing.</p>
   </div>
   <div class="container-three">
    <div class="box">3</div>
    <h3>lorem</h3>
    <p>Lorem ipsum dolor sit amet consectetur adipisicing.</p>
</div>
</div>
<div class="info-sec">
    <img src="test.png" alt="blah">
    <p>Lorem ipsum dolor sit amet.</p>
</div>   

关联CSS:

 <div class="top-container">
    <div class="primary-text">lorem</div>
    <div class="secondary-text">lorem</div>
</div>
<div class="secondary-container">
        <h2>Lorem ipsum dolor sit amet.</h2>
</div>
<div class="info-container">
   <div class="container-one">
       <div class="box1">1</div>
       <h3>lorem</h3>
       <p>Lorem ipsum, dolor sit amet consectetur adipisicing.</p>
    </div>
   <div class="container-two">
    <div class="box2">2</div>
    <h3>lorem</h3>
    <p>Lorem ipsum dolor sit amet, consectetur adipisicing.</p>
   </div>
   <div class="container-three">
    <div class="box">3</div>
    <h3>lorem</h3>
    <p>Lorem ipsum dolor sit amet consectetur adipisicing.</p>
</div>
</div>
<div class="info-sec">
    <img src="test.png" alt="blah">
    <p>Lorem ipsum dolor sit amet.</p>
</div>   

如果我将悬停从框更改为信息容器，它可以正常工作:

 <div class="top-container">
    <div class="primary-text">lorem</div>
    <div class="secondary-text">lorem</div>
</div>
<div class="secondary-container">
        <h2>Lorem ipsum dolor sit amet.</h2>
</div>
<div class="info-container">
   <div class="container-one">
       <div class="box1">1</div>
       <h3>lorem</h3>
       <p>Lorem ipsum, dolor sit amet consectetur adipisicing.</p>
    </div>
   <div class="container-two">
    <div class="box2">2</div>
    <h3>lorem</h3>
    <p>Lorem ipsum dolor sit amet, consectetur adipisicing.</p>
   </div>
   <div class="container-three">
    <div class="box">3</div>
    <h3>lorem</h3>
    <p>Lorem ipsum dolor sit amet consectetur adipisicing.</p>
</div>
</div>
<div class="info-sec">
    <img src="test.png" alt="blah">
    <p>Lorem ipsum dolor sit amet.</p>
</div>   

但是使用框悬停不起作用。我也尝试过使用显示：没有；和显示：块；

codepen:https://codepen.io/colton-22/pen/jowomxl

顺晟科技：

+是相邻的同级选择器。因此，当您使用:

 <div class="top-container">
    <div class="primary-text">lorem</div>
    <div class="secondary-text">lorem</div>
</div>
<div class="secondary-container">
        <h2>Lorem ipsum dolor sit amet.</h2>
</div>
<div class="info-container">
   <div class="container-one">
       <div class="box1">1</div>
       <h3>lorem</h3>
       <p>Lorem ipsum, dolor sit amet consectetur adipisicing.</p>
    </div>
   <div class="container-two">
    <div class="box2">2</div>
    <h3>lorem</h3>
    <p>Lorem ipsum dolor sit amet, consectetur adipisicing.</p>
   </div>
   <div class="container-three">
    <div class="box">3</div>
    <h3>lorem</h3>
    <p>Lorem ipsum dolor sit amet consectetur adipisicing.</p>
</div>
</div>
<div class="info-sec">
    <img src="test.png" alt="blah">
    <p>Lorem ipsum dolor sit amet.</p>
</div>   

它之所以有效，是因为info-sec是info-container的第一个下一个同级。但是当您使用:

 <div class="top-container">
    <div class="primary-text">lorem</div>
    <div class="secondary-text">lorem</div>
</div>
<div class="secondary-container">
        <h2>Lorem ipsum dolor sit amet.</h2>
</div>
<div class="info-container">
   <div class="container-one">
       <div class="box1">1</div>
       <h3>lorem</h3>
       <p>Lorem ipsum, dolor sit amet consectetur adipisicing.</p>
    </div>
   <div class="container-two">
    <div class="box2">2</div>
    <h3>lorem</h3>
    <p>Lorem ipsum dolor sit amet, consectetur adipisicing.</p>
   </div>
   <div class="container-three">
    <div class="box">3</div>
    <h3>lorem</h3>
    <p>Lorem ipsum dolor sit amet consectetur adipisicing.</p>
</div>
</div>
<div class="info-sec">
    <img src="test.png" alt="blah">
    <p>Lorem ipsum dolor sit amet.</p>
</div>   

它不起作用，因为info-sec不是info-container的同级。

据我所知，css中没有适合你的选择器。因此，您必须使用javascript来实现这一点。