.av-873-container {
    width: 100%;
    display: flex;
    gap: 30px;
    align-items: flex-start;
}
.av-873-img-col {
    flex: 0 0 50%;
    position: relative;
    min-height: 300px; /* Gives some space for absolute images */
}
.av-873-img-item {
    max-width: 100%;
    height: auto;
    border-radius: 4px;
    position: absolute;
    top: 0;
    left: 0;
    opacity: 0;
    transition: opacity 0.4s ease;
    z-index: 1;
}
.av-873-img-item.active {
    opacity: 1;
    z-index: 2;
    position: relative; /* Let the active one dictate height if needed, or keep absolute and rely on min-height */
}
.av-873-text-col {
    flex: 1;
}
.av-873-item {
    border: 1px solid transparent; /* default for transition */
    margin-bottom: 10px;
    border-radius: 4px;
    background: transparent;
    transition: box-shadow 0.3s ease;
}
.av-873-item:hover {
    box-shadow: 0 4px 10px rgba(0,0,0,0.05);
}
.av-873-header {
    background-color: #f7f7f7;
    padding: 15px 20px;
    cursor: pointer;
    font-weight: 600;
    border-radius: 4px;
    transition: background-color 0.3s ease;
}
.av-873-header:hover {
    background-color: #eeeeee;
}
.av-873-desc {
    padding: 15px 20px;
    color: #555;
    line-height: 1.6;
    border-top: 1px solid #eee;
}

@media (max-width: 767px) {
    .av-873-container {
        flex-direction: column;
    }
    .av-873-img-col {
        flex: 1 1 100%;
        width: 100%;
        min-height: auto;
        margin-bottom: 20px;
    }
    .av-873-img-item {
        position: relative;
        display: none;
    }
    .av-873-img-item.active {
        display: block;
    }
}