CSS样式:在位置之前?

在这里拉小提琴: https://jsfiddle.net/sgbotsford/d52zyp0t/72/

额外的第一行缩进是从哪里来的 <li> 使用=>:在满足之前?

问题是。我无法控制的情况将段落标记放在列表元素中。当我使用a:before时,它是一个负数左边,它在页边空白处,就像我想要的那样。但是文本缩进在我之前使用的地方增加了:before。这个额外的缩进是从哪里来的?

期望的行为是段落和列表项的样式相同,除了=>在左边空白处浮动。

我相信我最终可以做足够多的实验来破解一个解决方案,但现在我正试图从盒子模型的角度来理解这种行为。

一个答案建议从中删除文本缩进标记 <p> 这会导致一次冲水 < 还有一个较小的缩进 <李>

HTML

<html>
<head>

</head>
<body>

<div class=content>

<p>This is a paragraph. It has several sentences.  It goes on and on and on and on. It has several sentences.  It goes on and on and on and on. </p>

<ul class="c">
  <li><p>This is a list element that is long enough to wrap, I think. But it needs to be longer to check justification. It looks a lot like a paragraph.</p></li>
 <li><p>This is a list element that is long enough to wrap, I think. But it needs to be longer to check justification.</p></li>
 </ul>

<ul class="b">
  <li><p>This is a list element that is styled using ::before and outdenting the content. Where does the extra space come from? </p></li>
   <li><p>This is a list element that is long enough to wrap, I think.</p></li>
</ul>


</div>
</body>
</html>

CSS

body {
  text-align: justify;
  hyphens: auto;
  margin-left: 3rem;
}

.content {
  width: 40rem;
  background-color: yellow;
}

p   {
  width: 15rem;
  margin: auto;
  margin-top: 0.6rem;
  background-color: lightgreen;
  padding: 0;
  font-style: normal;
  font-size: 1.25rem;
  line-height: 1.4rem;
  text-indent: 1rem;
  text-align: justify;
  hyphens: auto;
  word-break: break-word;
    }


ul {
  list-style-type: none;
  margin: 1rem;
  padding: 0;
}

ul.b li p::before {
    content: "=>";
    font-weight: bold;
    position: relative;
    left: -2.5rem;
    }