.header-menu button.menu-toggle,
.header-menu button.sublist-toggle {
    border: 0;
    font: inherit;
    -webkit-appearance: none;
    appearance: none;
}

.header-menu button.menu-toggle {
    width: 100%;
    text-align: left;
}

.header-menu a:focus,
.header-menu button:focus {
    outline: 2px solid currentColor;
    outline-offset: 2px;
}