insertRule() 不插入规则但不给出任何错误

Question

我正在尝试将样式规则直接插入到文档的头部。

它插入样式元素而不是代码本身。没有错误或任何错误。

var thumbStyles = document.createElement("style"); 
    document.head.appendChild(thumbStyles);
    thumbStyles.sheet.insertRule(
    "figure#styleThumbs { \
    position: absolute; \
    left: 0px; \
    bottom: 0px; \
    } \
    ")
    thumbStyles.sheet.insertRule(
    "figure#styleThumbs img { \
    outline: 1px solid black; \
    cursor: pointer; \
    opacity: 0.75; \
    } \
    ")
    thumbStyles.sheet.insertRule(
    "figure#styleThumbs img:hover { \
    outline: 1px solid red; \
    opacity: 1.0; \
    } \
    ");

Picture of HTML Head with style but no style code

I also asked this question on FCC but have no answers

Answer 1

插入的 CSS 没有显示在 DOM 中，但确实有效。

var thumbStyles = document.createElement("style"); 
document.head.appendChild(thumbStyles);
thumbStyles.sheet.insertRule(`#test{
background-color: dodgerblue;
}`);

<div id="test">
This is a test
</div>

insertRule() 不插入规则但不给出任何错误

insertRule() not inserting rule but not giving any errors

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