.calendar-container {
    margin: 20px;
    display: inline-block;
}

.calendar {
    border-collapse: collapse;
    border: 2px solid #333;
    font-size: 16px;
}

.calendar th,
.calendar td {
    border: 1px solid #333;
    padding: 8px;
    text-align: center;
    width: 40px;
    height: 40px;
}

.calendar th {
    font-weight: bold;
}

.calendar .header {
    font-size: 20px;
    font-weight: bold;
    text-align: center;
    padding: 8px;
}

.calendar .weekdays th {
    font-weight: bold;
    padding: 8px;
}

.calendar .weekdays th:nth-child(6),
.calendar .weekdays th:nth-child(7) {
    color: red;
}

.calendar td {
    position: relative;
}

.calendar td:nth-child(6),
.calendar td:nth-child(7) {
    color: red;
}

.calendar td.empty {
    background-color: transparent;
    border: none;
    padding: 0;
}