createStyleSheet function
Creates or retrieves a cached web.CSSStyleSheet from the given CSS string.
This function uses the constructable stylesheets API which is more
efficient than creating <style> elements. Stylesheets are cached
so the same CSS content always returns the same instance.
Implementation
web.CSSStyleSheet createStyleSheet(String cssText) {
return _stylesheetCache.putIfAbsent(cssText, () {
final sheet = web.createCSSStyleSheet();
sheet.replaceSync(cssText);
return sheet;
});
}