element-web/res/welcome.html

<style type="text/css">
    /* we deliberately inline style here to avoid flash-of-CSS problems, and to avoid
 * voodoo where we have to set display: none by default
 */

    h1::after {
        content: "!";
    }

    .mx_Parent {
        display: -webkit-box;
        display: -webkit-flex;
        display: -ms-flexbox;
        display: flex;
        -webkit-box-orient: vertical;
        -webkit-box-direction: normal;
        -webkit-flex-direction: column;
        -ms-flex-direction: column;
        flex-direction: column;
        -webkit-box-pack: center;
        -webkit-justify-content: center;
        -ms-flex-pack: center;
        justify-content: center;
        -webkit-box-align: center;
        -webkit-align-items: center;
        -ms-flex-align: center;
        align-items: center;
        text-align: center;
        padding: 25px 35px;
        color: #2e2f32;
    }

    .mx_Logo {
        height: 54px;
        margin-top: 2px;
    }

    .mx_ButtonGroup {
        margin-top: 10px;
    }

    .mx_ButtonRow {
        display: -webkit-box;
        display: -webkit-flex;
        display: -ms-flexbox;
        display: flex;
        -webkit-justify-content: space-around;
        -ms-flex-pack: distribute;
        -webkit-box-align: center;
        -webkit-align-items: center;
        -ms-flex-align: center;
        align-items: center;
        justify-content: space-between;
        box-sizing: border-box;
        margin: 12px 0 0;
    }

    .mx_ButtonRow > * {
        margin: 0 10px;
    }

    .mx_ButtonRow > *:first-child {
        margin-left: 0;
    }

    .mx_ButtonRow > *:last-child {
        margin-right: 0;
    }

    .mx_ButtonParent {
        display: -webkit-box;
        display: -webkit-flex;
        display: -ms-flexbox;
        display: flex;
        padding: 10px 20px;
        -webkit-box-orient: horizontal;
        -webkit-box-direction: normal;
        -webkit-flex-direction: row;
        -ms-flex-direction: row;
        flex-direction: row;
        -webkit-box-pack: center;
        -webkit-justify-content: center;
        -ms-flex-pack: center;
        justify-content: center;
        -webkit-box-align: center;
        -webkit-align-items: center;
        -ms-flex-align: center;
        align-items: center;
        border-radius: 4px;
        width: 150px;
        background-repeat: no-repeat;
        background-position: 10px center;
        text-decoration: none;
        color: #2e2f32 !important;
    }

    .mx_ButtonLabel {
        margin-left: 20px;
    }

    .mx_Header_title {
        font-size: 24px;
        font-weight: 600;
        margin: 20px 0 0;
    }

    .mx_Header_subtitle {
        font-size: 12px;
        font-weight: normal;
        margin: 8px 0 0;
    }

    .mx_ButtonSignIn {
        background-color: #368bd6;
        color: white !important;
    }

    .mx_ButtonCreateAccount {
        background-color: #1161fe;
        color: white !important;
    }

    .mx_SecondaryButton {
        background-color: #ffffff;
        color: #2e2f32;
    }

    .mx_Button_iconSignIn {
        background-image: url("welcome/images/icon-sign-in.svg");
    }
    .mx_Button_iconCreateAccount {
        background-image: url("welcome/images/icon-create-account.svg");
    }
    .mx_Button_iconHelp {
        background-image: url("welcome/images/icon-help.svg");
    }
    .mx_Button_iconRoomDirectory {
        background-image: url("welcome/images/icon-room-directory.svg");
    }

    /*
.mx_WelcomePage_loggedIn is applied by EmbeddedPage from the Welcome component
If it is set on the page, we should show the buttons. Otherwise, we have to assume
we don't have an account and should hide them. No account == no guest account either.
 */
    .mx_WelcomePage:not(.mx_WelcomePage_loggedIn) .mx_WelcomePage_guestFunctions {
        display: none;
    }

    .mx_ButtonRow.mx_WelcomePage_guestFunctions {
        margin-top: 20px;
    }
    .mx_ButtonRow.mx_WelcomePage_guestFunctions > div {
        margin: 0 auto;
    }

    @media only screen and (max-width: 480px) {
        .mx_ButtonRow {
            flex-direction: column;
        }

        .mx_ButtonRow > * {
            margin: 0 0 10px 0;
        }
    }
</style>

<div class="mx_Parent">
    <a href="https://chat.superhero.com" target="_blank" rel="noopener">
        <img src="$logoUrl" alt="" class="mx_Logo" />
    </a>
    <h1 class="mx_Header_title">_t("welcome_to_superhero")</h1>
    <!-- XXX: Our translations system isn't smart enough to recognize variables in the HTML, so we manually do it -->
    <div class="mx_ButtonGroup">
        <div class="mx_ButtonRow">
            <a href="#/login" class="mx_ButtonParent mx_ButtonSignIn mx_Button_iconSignIn">
                <div class="mx_ButtonLabel">_t("action|sign_in")</div>
            </a>
            <a href="#/register" class="mx_ButtonParent mx_ButtonCreateAccount mx_Button_iconCreateAccount">
                <div class="mx_ButtonLabel">_t("action|create_account")</div>
            </a>
        </div>
        <div class="mx_ButtonRow mx_WelcomePage_guestFunctions">
            <div>
                <a href="#/directory" class="mx_ButtonParent mx_SecondaryButton mx_Button_iconRoomDirectory">
                    <div class="mx_ButtonLabel">_t("action|explore_rooms")</div>
                </a>
            </div>
        </div>
    </div>
</div>