.wp-block-mia-favorite button {
    display: block;
    width: 1rem;
    height: 1rem;
    font-size: 1px;
    line-height: 1;
    background: #ddd;
    clip-path: shape(from 50% 91%, line to 90% 50%, arc to 50% 9% of 1%, arc to 10% 50% of 1%);
    outline: none;
    border: none;
    cursor: pointer;
}

.wp-block-mia-favorite button:hover {
    background: #bbb;
}

.wp-block-mia-favorite.active button,
.wp-block-mia-favorite.active button:hover {
    background: var(--preset--color--miamired, red);
}