存在替换<details>元素的展开宏的可能性，这在例如Can I replace The expand icon中进行了描述(▶)<详细信息>要素以及答案https://stackoverflow.com/a/10813665/1657886
通常，<details>元素中会有一个<summary>，并且一切都很好，但当<summary>元素丢失时，浏览器将返回到默认文本"；细节"；和默认图标。
CSS代码在存在<summary>元素的情况下工作：
details>summary {
list-style-type: none;
}
details > summary::-webkit-details-marker {
display: none;
}
details>summary::before {
content: "25ba";
padding-right:4px;
font-size: 80%;
}
details[open]>summary::before {
content: "25bc";
padding-right:4px;
font-size: 80%;
}
问题是，如果<summary>元素丢失，如何设置图标？
编辑完整示例(文件名：aa.html(：
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "https://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" lang="en-US">
<head>
<meta http-equiv="Content-Type" content="text/xhtml;charset=UTF-8"/>
<meta http-equiv="X-UA-Compatible" content="IE=11"/>
<title>My Project</title>
<style>
details>summary {
list-style-type: none;
}
details > summary::-webkit-details-marker {
display: none;
}
details>summary::before {
content: "25ba";
padding-right:4px;
font-size: 80%;
}
details[open]>summary::before {
content: "25bc";
padding-right:4px;
font-size: 80%;
}
</style>
</head>
<body>
<details >
<summary> The summary 1</summary> The details 1
</details>
<details >
The details no own summary
</details>
</body>
</html>
details {
position: relative;
}
/* details>summary {
list-style-type: none;
}
details > summary::-webkit-details-marker {
display: none;
} */
details::before,
details[open]::before {
display: inline-block;
transform: translate(2px, 1px);
position: absolute;
z-index: 1;
top: 0;
left: 0;
font-weight: 900;
}
details::after,
details[open]::after {
display: inline-block;
transform: translate(-3px, -2px);
position: absolute;
content: "";
width: 15px;
height: 22px;
background: #fff;
top: 0;
left: 0;
}
details::before {
content: " 02b";
}
details[open]::before {
content: " 02d";
}<details>
<!-- <summary>Click to expand</summary> -->
With some example text shown when expanded.
</details>由于一旦删除summary元素(或者至少我找不到(，就无法获取公开小部件，因此解决方案必须有点麻烦。