具有“正确”边距行为的假“显示：磨合”

Question

之前关于“让我们不支持display: run-in，因为它很复杂，没有人真正使用或想要使用它”，StackOverflow 版……

• display: run-in dropped in Chrome?
• Style a definitition list as simple key value set
• CSS method instead of display:run-in; to position a block inline?

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我希望文档中的 h5 元素具有以下行为：

• 它的作用类似于run-in 后跟一个段落 (p)
• 后跟标题（h1、...、h6）或其他内容（ul 等）时，它的作用类似于 block

如果标题的内容被包裹在（或包含）一个块中，这本质上就是same behavior as run-in；即，将<h6>…</h6> 更改为<h6><div>…</div></h6> 或<h6>…<div /></h6>。

（但是，如果可能，我不希望修改 HTML：它是通过 pandoc 从 markdown 生成的。）

这是我目前使用的浮动内联块。注意 h5 和 h6 之间的边距是如何“折叠”的。

CSS

/* Just some basic styles to start off */
body { line-height: 1.5; }
h4,h5,h6 { font-size: 1em; margin: 1em 0; }
h4 { background: #fee; }
h5 { background: #eef; }
h6 { background: #dfd; font-style: italic; font-weight: normal; }

/* Now let’s try to emulate `display: run-in`... */
h4,h5,h6 {
    clear: both;
}
h5 {
    float: left;
    display: inline-block;
    margin: 0 1em 0 0;
}

HTML

<h4>Section</h4>

<h5>Heading</h5>
<p>Paragraph here. This is some text to fill out the line and make it wrap,
so you can get a feel for how a heading with <code>display: run-in;</code>
might look.</p>

<h5>Heading, but without immediately following text</h5>

<h6><div>Subheading</div></h6>
<p>There should be as much space between the &lt;h5> and &lt;h6> as there is
between the &lt;h4> and &lt;h5>, but it gets “collapsed” because the
&lt;h5> floats.</p>

<h5>Heading followed by a list</h5>
<ul><li>A list item</li></ul>

Here is a jsfiddle containing the HTML and CSS.
Here is one using run-in for browsers that still support it, like Safari.

这是 7 年前的 demo page，我发现有人尝试（未成功）伪造相同的行为。

Safari 截图

伪造：

使用run-in（预期行为，在 h5 和 h6 或 ul 之间有正确的边距）：

Answer 1

也许我有一个你想要的妥协：DEMO

/* Just some basic styles to start off */
body { line-height: 1.5; }
h4,h5,h6 { font-size: 1em; margin: 1em 0; }
h4 { background: #fee; }
h5 { background: #eef; }
h6 { background: #dfd; font-style: italic; font-weight: normal; }

/* Now let’s try to emulate `display: run-in`... */
* {
 clear:left;
}
h5 {
    float:left;
    display: run-in;
    margin: 0 1em 0 0;

}
h5:after {
    content:'.';
    position:absolute;
    background:inherit;
    width:100%;
    right:0;
    z-index:-1;
}
body {
    position:relative; /* to include defaut margin of body to draw h5:after element within body */
}
p /* + any other phrasing tag you wish */ {
    clear:none;
    background:white;
}