.content {
    display: flex;
    flex-direction: column;
    align-items: center;
}

.content ul {
    display: flex;
    justify-content: space-around;
    margin: 10px 0;
    padding: 10px 0;
    width: 100%;
    border-top: 1px solid #ededed;
    border-bottom: 1px solid #ededed;
}

.content h1 {
    margin: 10px 0;
}

.text_box {
    display: flex;
    flex-direction: column;
    width: 100%;
    font-size: 18px;
    color: #000000;
    line-height: 3;
    text-align: justify;
    text-indent: 2em;
}

.text_box span {
    width: 100%;
}

.unit_box {
    margin: 10px 0;
}

.unit_box .last,
.unit_box .next {
    margin: 10px 0;
}

@media screen and (max-width: 768px) {
    .content_box {
        padding: 0 20px;
    }
    .unit_box {
        text-align: center;
    }
}