Below python (v. 3.9.7) function is injecting CSS styles, that are loaded from a standard CSS file, into a selenium driver object. While in macOS (11.5.2, homebrew) the styles are applied correctly, in Linux (Ubuntu 20.04) the styles were not applied and this message is thrown out: javascript error: Invalid or unexpected token

So which part of the string is causing the issue and how do I have to preprocess the string before sending it?

def injectCSS(driver, file):
    css = Path(file).read_text()
    css = css.replace('\n', '')
    execute = rf'''
    var style = document.createElement('style');
    style.type = 'text/css';
    style.innerHTML = '{css}';
    document.head.appendChild(style);
    '''
    try:
        driver.execute_script(execute)
        time.sleep(1)
        print('CSS injection done')
    except Exception as e:
        print(str(e))

UPDATE: I narrowed down the problematic string: it's not the string in the Python variable, it's located inside the loaded CSS file itself and it's the line containing the src attribute in a @font-face rule:

@font-face {
    font-family: "myfont";
    src: url(http://my.font.com/font.woff2) format('woff2');
}

UPDATE 2: Well, thanks to @cruisepandey I figured out the problematic markup in the CSS: it's the single quotes inside the CSS file, e.g. font-family: 'serif';. Replacing them with double quotes fixes the problem. Why single quotationmarks in the variable are allowed, but not in the CSS file itself? Also: why does the issue occur in linux and not in macOS?