.entry-content h3.ff-history-heading { color: #315d42; }
.entry-content .ff-history-photo-bridge {
    border-inline-start: 2px solid #a2b7a2;
    padding-inline-start: clamp(.8rem, 2vw, 1.2rem);
    margin-block: 1.4rem;
    line-height: 1.95;
    font-family: "Yu Mincho", "Hiragino Mincho ProN", serif;
}
.entry-content .ff-history-sources {
    margin-block: 1.3rem 2.2rem;
    padding-block-start: .6rem;
    border-top: 1px solid #d9e0d6;
    color: #344638;
    font-size: .9rem;
    line-height: 1.8;
    min-width: 0;
    overflow-wrap: anywhere;
}
.entry-content .ff-history-sources summary {
    padding: .55rem .2rem;
    cursor: pointer;
}
.entry-content .ff-history-sources summary:focus-visible,
.entry-content .ff-history-sources a:focus-visible {
    outline: 2px solid #254d36;
    outline-offset: 3px;
}
.entry-content .ff-history-sources ul {
    padding-inline-start: 1.5rem;
    margin-block: .6rem 1rem;
}
.entry-content .ff-history-sources li { margin-block: .65rem; }