Не видно контента при использовании Shadow DOM. Начальный код -
export const CustomHeader = () => {
customElements.define("custom-header", class extends HTMLElement {
connectedCallback() {
this.attachShadow({mode: "open"});
this.innerHTML =
`
<link rel="stylesheet" href="css/Base.css">
<link rel="stylesheet" href="components/Header/css/Header.css">
<header class="Header">
<div class="HeaderBody">
<a class="Logo waves-effect waves-teal" href="#" data-LogoText="{Finsweet"></a>
<input class="HeaderMobileMenuButton" type="checkbox" aria-label="Мобильное меню" data-ToolTip="Мобильное меню">
<div class="HeaderMenu">
<nav class="NavigationRow">
<ul class="ListRow">
<li class="ListRowItem">
<a href="#" class="HeaderLink waves-effect waves-light"><span class="HeaderLinkText">Home</span></a>
</li>
<li class="ListRowItem">
<a href="#" class="HeaderLink waves-effect waves-light"><span class="HeaderLinkText">Blog</span></a>
</li>
<li class="ListRowItem">
<a href="#" class="HeaderLink waves-effect waves-light"><span class="HeaderLinkText">About us</span></a>
</li>
<li class="ListRowItem">
<a href="#" class="HeaderLink waves-effect waves-light"><span class="HeaderLinkText">Contact us</span></a>
</li>
<li class="ListRowItem">
<button class="Button ButtonWhite waves-effect" type="button"><span class="ButtonText">Subscribe</span></button>
</li>
</ul>
</nav>
</div>
</div>
</header>
`;
};
});
};