#concept .main {
    display: flex;
    flex-direction: column;
    column-gap: 32px;
}

h2 {
    font-size: 4.8rem;
    margin-bottom: 24px;
    font-family: var(--font-en);
}

h2 span {
    font-size: small;
    margin-left: 8px;
    font-family: var(--font-en);
}

h3 {
    font-size: 3.2rem;
    font-family: var(--font-en);
}

#concept a {
    display: block;
    text-align: end;
    color: red;
}

article {
    margin-bottom: 48px;
    padding: 16px;
}

article:last-child {
    margin-bottom: 0;
}

.font16 {
    font-size: 1.6rem;
}

.font14 {
    font-size: 1.4rem;
}

.font20 {
    font-size: 2.0rem;
}

/* -----------------concept-history----------------- */

.history-container {
    display: flex;
    flex-direction: column;
    row-gap: 32px;
}

.history-container section:nth-child(2) {
    display: flex;
    column-gap: 20px;
    margin-left: 40px;
}

.history-container section:nth-child(3) {
    display: flex;
    justify-content: end;
    column-gap: 20px;
}

/* -----------------concept-concept----------------- */
#concept-concept h2 {
    color: rgb(186, 85, 211);
}

#concept-concept h3 {
    position: relative;
    left: -32px;
    color: rgb(186, 85, 211);
}

#concept-concept .font14 {
    font-size: 1.4rem;
    padding-left: 64px;
    margin-top: -12px;
}


#concept-concept {
    background-color: thistle;
    display: flex;
    justify-content: space-between;
}

.white-circle {
    width: 64px;
    height: 64px;
    background-color: #fff;
    border-radius: 50%;
}

.concept-container {
    display: flex;
    flex-direction: column;
    justify-content: space-around;
}

.concept-container-left {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    grid-template-rows: repeat(2, 1fr);
    grid-row-gap: 24px;
    margin-bottom: 40px;
}

.concept-container-left div:last-child {
    grid-area: 2 / 1 / 3 / 3;
    width: fit-content;
    margin: 0 auto;
}

.concept-container-right {
    display: flex;
    flex-direction: column;
    row-gap: 20px;
}

.left-div-min-container {
    display: flex;
}

/* -----------------concept-history----------------- */
.policy-container {
    display: flex;
    align-items: center;
    justify-content: space-around;
    column-gap: 16px;
}

.policy-container-left {
    display: flex;
    flex-direction: column;
}

#concept-policy h2 {
    color: #008b00;
}

.policy-container-left section p:first-child {
    padding: 24px;
    border: 2px solid #008b00;
    margin-bottom: 40px;
}


/* ----------------------------------------------------------------------------------------- */
.sp-on {
    display: none;
}

@media screen and (max-width: 767px) {
    article {
        margin: 0 auto;
        padding: 8px 4px;
    }

    h2 {
        font-size: 4rem;
    }

    h3 {
        font-size: 2.4rem;
    }

    #concept-concept h3 {
        font-size: 1.8rem;
    }

    .font20 {
        font-size: 1.6rem;
    }

    .font16 {
        font-size: 1.3rem;
    }

    .font14,
    #concept-concept .font14 {
        font-size: 1.0rem;
    }

    #concept-concept .font14 {
        padding-left: 0;
    }

    .history-container section:nth-child(2),
    .history-container section:nth-child(3) {
        flex-direction: column;
        margin: 0 auto;
        row-gap: 20px;
    }

    .history-container img {
        margin: 0 auto;
    }

    #concept-concept {
        flex-direction: column;
    }

    .concept-container-left {
        display: flex;
        flex-direction: column;
    }

    .container-left-div {
        display: grid;
        grid-template-columns: repeat(3, 1fr);
        grid-template-rows: 1fr;
    }

    .left-div-min-container {
        grid-area: 1 / 1 / 2 / 2;
    }

    .container-left-div .font14 {
        grid-area: 1 / 2 / 2 / 4;
    }

    .concept-container-left div:last-child {
        margin: 0;
    }

    .concept-container-right {
        align-items: center;
    }


    .policy-container {
        flex-direction: column;
        margin: 0 auto;
    }

    .white-circle {
        width: 40px;
        height: 40px;
    }

    .policy-container-left section p:first-child {
        padding: 10px;
        margin-bottom: 24px;
    }

    .policy-container-left,
    .concept-container {
        margin-bottom: 24px;
    }

    .left-div-first {
        margin-right: 1.7rem;
    }

    .sp-on {
        display: block;
    }

    .sp-off {
        display: none;
    }

    .l-container {
        padding-left: 1.4rem;
        padding-right: 1.4rem;
    }