.pb-intro {
    margin-bottom: 1.5rem;
}

.pb-columns {
    display: flex;
    gap: 3rem;
    align-items: flex-start;
}

.pb-col {
    flex: 1;
    min-width: 0;
}

.pb-letter {
    font-weight: bold;
    font-size: 1.1rem;
    margin-top: 0.25rem;
    margin-bottom: 0.2rem;
    border-bottom: 1px solid #ccc;
    padding-bottom: 0.1rem;
}

.pb-gap {
    height: 0.4rem;
}

.pb-item {
    font-size: 0.875rem;
    line-height: 1.4;
    padding: 0.1rem 0;
}

.pb-author {
    color: #555;
}

@media (max-width: 640px) {
    .pb-columns {
        flex-direction: column;
    }
}