feat: support extra content which will be added to style tag from svg

README.md

@@ -279,6 +279,14 @@ html2Image.toSVG(element1, { fontEmbedCss });
 html2Image.toSVG(element2, { fontEmbedCss });
 ```
 
+### extraStyleContent
+
+When supplied, the library will add the given css definitions to the style tag from resulting svg.
+For example the following code will change the color from scrollbars to green:
+```javascript
+htmlToImage.toPng(node, { extraStyleContent: '*::-webkit-scrollbar {background-color: green;}'});
+```
+
 ### skipAutoScale
 
 When supplied, the library will skip the process of scaling extra large doms into the canvas object.

src/embed-webfonts.ts

@@ -228,9 +228,14 @@ export async function embedWebFonts<T extends HTMLElement>(
       ? null
       : await getWebFontCSS(clonedNode, options)
 
-  if (cssText) {
+  const finalCssText =
+    options.extraStyleContent != null
+      ? options.extraStyleContent.concat(cssText || '')
+      : cssText
+
+  if (finalCssText) {
     const styleNode = document.createElement('style')
-    const sytleContent = document.createTextNode(cssText)
+    const sytleContent = document.createTextNode(finalCssText)
 
     styleNode.appendChild(sytleContent)
 

src/types.ts

@@ -76,6 +76,11 @@ export interface Options {
    * create embed CSS for use across multiple calls to library functions.
    */
   fontEmbedCSS?: string
+  /**
+   * A CSS string to specify additional custom style content. It will be
+   * added to the style-tag.
+   */
+  extraStyleContent?: string
   /**
    * A boolean to turn off auto scaling for truly massive images..
    */