var cssId = 'main';  // you could encode the css path itself to generate id..

 if (!document.getElementById(cssId))

    var head  = document.getElementsByTagName('head')[0];
    var link  = document.createElement('link');
    {
        if (localStorage.getItem('siteTheme') == "Light") {
            link.href = "https://alusunlocker.gq/css/light/proxies.css"
        } else {
            link.href = 'https://alusunblocker.gq/css/dark/proxies.css';
        }
    link.type = 'text/css';
    link.id   = cssId;
    link.rel  = 'stylesheet';
    head.appendChild(link);
}
var cssId = 'boilerplate';  // you could encode the css path itself to generate id..

 if (!document.getElementById(cssId))

    var head  = document.getElementsByTagName('head')[0];
    var link  = document.createElement('link');
    {
        if (localStorage.getItem('siteTheme') == "Light") {
            link.href = "https://alusunblocker.gq/css/light/boilerplate.css"
        } else {
            link.href = 'http://alusunblocker.gq/css/dark/boilerplate.css';
        }
    link.type = 'text/css';
    link.id   = cssId;
    link.rel  = 'stylesheet';
    head.appendChild(link);
}