body {
    margin: 0;
    font-family: 'Helvetica Neue', Arial, sans-serif;
    background-color: #f5f5f5;
}

h1{
    margin: 0;
    padding: 0;
    font-weight: 700;
}

#head {
    background-color: #fff;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
    padding: 1rem 0;
}

#head_div {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

#head_title {
    color: #333;
    font-size: 32px;
    margin-bottom: 1rem;
}

/* 新規：メインのカード配置 */
main {
    display: flex;
    align-items: center;
    justify-content: center;
    min-height: calc(100vh - 120px); /* ヘッダー分を除いた中央寄せ */
    padding: 2rem 1rem;
}

.subjects {
    display: flex;
    gap: 2rem;
    align-items: center;
    justify-content: center;
    flex-wrap: wrap;
}

/* カード共通スタイル */
.card {
    display: block;
    width: 260px;
    text-align: center;
    background: #fff;
    border-radius: 10px;
    overflow: hidden;
    box-shadow: 0 6px 18px rgba(0,0,0,0.08);
    transition: transform 0.25s ease, box-shadow 0.25s ease;
    text-decoration: none;
    color: inherit;
    border: 1px solid rgba(0,0,0,0.06);
}

.card img {
    width: 100%;
    height: 170px;
    object-fit: cover;
    /* display: block; */
}
img {
    max-width: 50%;
    height: auto;
    /* display: flex; */
}

/* キャプション */
.caption {
    display: block;
    padding: 14px 12px;
    font-size: 18px;
    font-weight: 600;
    background: linear-gradient(180deg, #fff 0%, #fafafa 100%);
}

/* ホバー効果 */
.card:hover {
    transform: translateY(-6px) scale(1.02);
    box-shadow: 0 14px 30px rgba(0,0,0,0.12);
}

.suugaku_img {
    max-width: 70%;
    height: 70%;
    margin-top: 1rem;
}
/* レスポンシブ */
/* @media (max-width: 320px) {
    .subjects {
        gap: 1rem;
    }
    .card {
        width: 220px;
    }
}

@media (max-width: 520px) {
    main {
        min-height: auto;
        padding-bottom: 2rem;
    }
    .subjects {
        flex-direction: column;
        gap:0.5rem;
    }
    .card {
        width: 90%;
        margin:0 auto;
    }
}

@media (min-width: 320px) {
    main{
        width: 100dvh;
    }
    .card{
        width: 40dvh;
    }
    img{
        max-width: 30dvh;
        height: auto;
    }
} */