body {
    margin: 0;
    padding: 0;
}

.reference_item {
    padding: 0.5em;
    border: 1px solid #6d6c6c;
}

.main_ttl {
    font-size: 2.5em;
    text-align: center;
}

.plan_inner {
    width: 80%;
    text-align: center;
    margin: 30px auto;
    padding: 30px 0 50px;
    box-shadow: 0 3px 6px rgba(0, 0, 0, 0.1);
    border-radius: 8px;
    background-color: #ffffff;
}

.quick_reference {
    width: 80%;
    margin: 0 auto;
}

.paint_img {
    width: 140px;
    height: 170px;
}

.main_text {
    margin: 10px;
    padding: 10px;
    text-align: left;
	display: inline-block;
}

.plan_img {
    width: 80%;
}

.plan_list {
    display: flex;
    justify-content: center;
    flex-wrap: wrap;
    gap: 20px;
}

.planB, .planA, .planS, .planSS,
.silicon, .radical, .fluorine, .inorganic {
    background-color: #f9f9f9;
    width: 35%;
    margin: 5px;
    width: 20%;
    padding: 5px;
    border-radius: 8px;
}

.planB, .silicon { background-color: rgb(247, 255, 239); }
.planA, .radical { background-color: rgb(243, 254, 255); }
.planS, .fluorine { background-color: rgb(254, 255, 239); }
.planSS, .inorganic { background-color: rgb(255, 249, 249); }

.plan_ttl, .product {
    font-size: 1.5em;
}

.price_ttl {
    font-size: 1.2em;
    margin: 10px;
}

.sub_ttl {
    margin: 10px;
    font-size: 1.3em;
    font-weight: bold;
}

.topic {
    margin: 10px;
    font-size: 1.2em;
    font-weight: bold;
}

.price, .sale {
    height: 50px;
    line-height: 50px;
}

.del {
    position: relative;
    font-size: 1.8em;
}

.sale_price {
    font-size: 1.8em;
}

.del:after {
    content: '';
    display: block;
    width: 100%;
    height: 2px;
    margin-top: -2px;
    border-top: solid 2px #800000;
    border-bottom: solid 2px #800000;
    position: absolute;
    left: 0;
    top: 50%;
}

.total {
    font-size: 2em;
}

.price_breakdown {
    width: 80%;
    margin: 0 auto 30px;
}

.work_details {
    text-align: left;
}

.amount {
    text-align: right;
}

/* ===== レスポンシブ追加 ===== */
@media (max-width: 768px) {
    .plan_list {
        flex-direction: column;
        align-items: center;
    }

    .planA, .planB, .planS, .planSS,
    .silicon, .radical, .fluorine, .inorganic {
        width: 90%;
    }

    .paint_img {
        width: 70%;
        height: auto;
    }

    .main_ttl {
        font-size: 2em;
    }

    .main_text {
        font-size: 1em;
        margin: 10px;
    }

    .price_breakdown {
        width: 80%;
    }
}