div.is-style-half figure, figure.is-style-half, #editor figure.is-style-half {
    width: 50%;
    max-width: 555px;
}
figure.is-style-half.alignright {
    margin-right: auto;
}
figure.is-style-half.alignleft {
    margin-left: auto;
}
figure.is-style-half:not(.alignleft):not(.alignright) {
    margin-right: auto;
    margin-left: auto;
}