userContent.css

  
@-moz-document url(about:newtab), url(about:home) {
    .outer-wrapper::before {
        /* I don't know what I'm doing here but this works */
        content: "";
        position: absolute;
        top: 0;
        right: 0;
        bottom: 0;
        left: 0;

        /* Adjust this to your needs. */
        backdrop-filter: blur(15px) brightness(90%);
    }

    .outer-wrapper {
        background-size: cover !important;
        background-repeat: no-repeat !important;
        /* Change the below to your background path,
		       or place your background image with file
		       name "newTabBG.png" in the img folder in "chrome". */
        background-image: url(img/newTabBG.png) !important;
        background-position: 0% 0 !important;
        transition: background-position 1s ease-in-out !important;
    }

    /* hacks */
    :root[lwt-newtab-brighttext] {
        --newtab-background-color: #fff0 !important;
        --newtab-background-color-secondary: #ffffff00 !important;
    }

    :root {
        --newtab-background-color: #fff0 !important;
        --newtab-background-color-secondary: #fff0 !important;
        --newtab-overlay-color: #fff0 !important;
    }

    /* salvage readability */
    .section-title {
        text-shadow: 1px 1px 1px #222;
    }

    .personalize-button {
        z-index: 1;
    }

    .card {
        backdrop-filter: brightness(70%);
    }

    .modal-overlay {
        backdrop-filter: blur(15px) brightness(80%);
    }

    .modal {
        backdrop-filter: blur(15px) brightness(80%);
    }
    .section-empty-state {
        backdrop-filter: brightness(80%);
    }
    
    .top-site-outer .context-menu-button {
        backdrop-filter: blur(15px);
    }
    
    .card-outer {
        border: 2px solid #ffffff1f;
    }
    
    .top-site-outer .tile {
        /*! background-color: var(--newtab-background-color-secondary); */
        backdrop-filter: blur(15px) brightness(80%);
        border: 2px solid #ffffff1f;
    }

    .customize-menu {
        backdrop-filter: blur(15px) brightness(90%);
    }

    .modalOverlayOuter {
        backdrop-filter: blur(15px) brightness(69%);
    }

    .context-menu {
        /*! background: var(--newtab-background-color-secondary); */
        z-index: 10;
        backdrop-filter: blur(15px) brightness(90%);
    }

    .logo-and-wordmark {
        width: 512px;

        margin-left: auto;
        margin-right: auto;

        border: 2px solid #ffffff0f;
        border-radius: 12px;
        backdrop-filter: blur(32px);

        padding-top: 50px;
        padding-bottom: 50px;
    }
    .search-handoff-button {
        display: none !important;
    }

    .click-target-container *,
    .top-sites-list * {
        color: #fff !important ;
        text-shadow: 2px 2px 2px #222 !important ;
    }
}