body {
    position: relative;
}

body::before {
    content: '';
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: url(../../images/grade-5th/bg.png);
    background-position: top center;
    background-size: cover;
    background-repeat: no-repeat;
    z-index: -1;
}

@media screen and (max-width: 768px) {
    body::before {
        background: url(../../images/grade-5th/bg_sp.png);
        background-size: cover;
        background-repeat: no-repeat;
    }
}

/* 春の色 */
body.spring .week-block {
    background-color: #6ead12 !important;
}
body.spring .week-date {
    border: 3px solid #6ead12 !important;
    color: #6ead12 !important;
}
/* 秋の色 */
body.autumn .week-block {
    background-color: #009834 !important;
}
body.autumn .week-date {
    border: 3px solid #009834 !important;
    color: #009834 !important;
}
/* 冬の色 */
body.winter .week-block {
    background-color: #016122 !important;
}
body.winter .week-date {
    border: 3px solid #016122 !important;
    color: #016122 !important;
}