Shadow dom css override

shadow-dom-css-override.js

(function shadowLoop () {
    var host = document.getElementsByTagName('host-element-containing-shadow-root)[0];
    if (!host) {
        setTimeout(shadowLoop, 500);
    } else {
        var style = document.createElement('style');
        style.innerHTML = '#SomeID {display: none !important}';
        host.shadowRoot.appendChild(style);
    }
} ());