JS Modify CSS File

In doing self-change settings, inadvertently saw the JS modify CSS method, feel very useful, special to learn to share. Okay, here's the beginning: JS's document.stylesheets gets an array of objects that are introduced into the CSS. Such as:

Where Cssstylesheet expands as follows:

document.stylesheets[0] It is different to get the first cssrules and cssrules that you apply! Rules are the first few selectors; Cssrules is the rule document.stylesheets[0].cssrules to get all the CSS file lines document.stylesheets[  0].cssrules[0] CSS first document.stylesheets[0].cssrules[0]. style.background="Red"// Modify the background color of the first bar to be red

Instance:

Change the font color of Heading 1 to the CSS introduced in red:

. wode{    Color: #000;    font-size:36px;}. article{    color: #333;} h1,h2,h3{    color: #0D9BF2;}

<! DOCTYPE html>
　
Before modification:
After modification:
　
JS Modify CSS File