.calendar {
    width: 100%;
}

.calendar-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 10px;
    background-color: #f0f0f0;
}

.calendar-body {
    display: flex;
    flex-wrap: wrap;
}

.calendar-day {
    width: calc(100% / 7);
    border: 1px solid #ddd;
    position: relative;
    padding: 10px;
    box-sizing: border-box;
}

.date-number {
    position: absolute;
    top: 10px;
    right: 10px;
    font-size: 1.5em;
    color: #aaa;
}

.note-text {
    width: 100%;
    height: 100px;
    border: none;
    background: transparent;
    resize: none;
}

.past {
    background-color: rgba(128, 0, 128, 0.2);
}

.today {
    background-color: rgba(0, 128, 0, 0.2);
}

.future {
    background-color: rgba(255, 165, 0, 0.2);
}

.calendar-day.empty {
    background-color: transparent;
}