.button {
    border-color: #000;
}

.modal-back-button {
    --button-dimensions: 1.5rem;
    --button-background-l: 0%;
    --button-background-alpha: 0.5;
    --button-color: var(--bulma-white);

    background-color: hsla(var(--bulma-scheme-h), var(--bulma-scheme-s), var(--button-background-l),
                           var(--button-background-alpha));
    border-radius: var(--bulma-radius-rounded);
    color: var(--button-color);
    cursor: pointer;
    display: inline-flex;
    justify-content: center;
    align-items: center;
    height: var(--button-dimensions);
    width: var(--button-dimensions);
}

.modal-back-button:hover,
.modal-back-button:focus {
    --button-background-alpha: 0.4;

    background-color: hsla(var(--bulma-scheme-h), var(--bulma-scheme-s), var(--button-background-l),
                           var(--button-background-alpha));
}