.x-logo {
    display: inline-block;
    width: 1em;
    height: 1em;
    font-size: inherit;
    font-weight: bold;
    text-align: center;
    line-height: 1;
}

.x-logo::before {
    content: "𝕏";
    font-family: serif;
    font-weight: bold;
}