#calendar {
    max-width: 330px;
}

.custom-calendar {
    background: #fff;
    border: 2px solid #cfcfcf;
    border-radius: 15px;
    padding: 26px 20px 15px;
    font-family: Arial, "Hiragino Kaku Gothic ProN", "Yu Gothic", sans-serif;
    box-sizing: border-box;
}

.custom-calendar * {
    box-sizing: border-box;
}

.custom-calendar__header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: 18px;
}

.custom-calendar__title {
    display: flex;
    align-items: baseline;
    gap: 8px;
    line-height: 1;
}

.custom-calendar__month {
    font-size: 42px;
    font-weight: 700;
    color: #1f6b43;
    letter-spacing: -0.04em;
}

.custom-calendar__year {
    font-size: 25px;
    color: #9b9b9b;
    font-weight: 300;
}

.custom-calendar__nav {
    display: flex;
    align-items: center;
    gap: 16px;
}

.custom-calendar__arrow {
    border: none;
    background: transparent;
    font-size: 16px;
    color: #666;
    cursor: pointer;
    padding: 0;
    line-height: 1;
}

.custom-calendar__arrow:hover {
    opacity: 0.7;
}

.custom-calendar__week {
    display: grid;
    grid-template-columns: repeat(7, 1fr);
    border: 1.5px solid #d6d6d6;
    border-radius: 999px;
    background: #fff;
    margin-bottom: 15px;
}

.custom-calendar__week div {
    text-align: center;
    padding: 5px 0;
    font-size: 17px;
    color: #444;
    border-radius: 999px;
}

.custom-calendar__week .sun {
    color: #ff5d5d;
    border: 1px solid #ff7b7b;
}

.custom-calendar__grid {
    display: grid;
    grid-template-columns: repeat(7, 1fr);
    gap: 5px;
}

.custom-calendar__cell {
    height: 36px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 18px;
    font-weight: 300;
    color: #444;
    border-radius: 999px;
    cursor: pointer;
    user-select: none;
    transition: .2s;
}

.custom-calendar__cell:hover {
    background: rgba(31, 107, 67, 0.08);
}

.custom-calendar__cell.is-empty {
    cursor: default;
}

.custom-calendar__cell.is-empty:hover {
    background: transparent;
}

.custom-calendar__cell.is-sunday {
    color: #ff5d5d;
}

.custom-calendar__cell.is-saturday {
    color: #444;
}

.custom-calendar__cell.is-selected {
    background: #1f6b43;
    color: #fff;
    font-weight: 500;
}

.custom-calendar__cell.is-today:not(.is-selected) {
    background: 1px solid #1f6b43;
    color: #1f6b43;
}

@media screen and (max-width: 640px) {
    .custom-calendar__week div {
        font-size: 14px;
        padding: 3px 0;
    }
}