body {
}
.picture_list {
    display: flex;
    flex-wrap: wrap;
    width: 84%;
    margin: auto;
}

.list_item {
    width: 100%;
    margin-bottom: 10%;
}

.item_content {
    margin-top: 5%;
    font-size: 16px;
    font-weight: bold;
    line-height: 1.5em;
    color: #000000;
}

.content_date {
    font-size: 19.5px;
}

.list_pic {
    aspect-ratio: 4/3;
    overflow: hidden;
}

.list_pic img {
    background-size: contain;
    background-repeat: no-repeat;
}

@media screen and (min-width: 769px) {
    .list_item {
        width: 32%;
    }

    .list_item {
        margin: 0 2% 5% 0;
    }

    .list_item:nth-child(3n) {
        margin-right: 0;
    }

    .item_content {
        font-size: 18px;
    }

    .content_date {
        font-size: 20px;
    }
}