body {
    margin: 0;
    font-family: Arial, sans-serif;
    background-color: #1a1a1a;
    color: #e0e0e0;
    display: flex;
    flex-direction: column;
    align-items: center;
    padding: 1.25rem;
}

.top-bar {
    display: flex;
    justify-content: space-between;
    margin-bottom: 1.8rem;
    flex-wrap: wrap;
    gap: 2rem;
    max-width: 38rem;
}

.activity-section,
.year-section {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

label {
    color: #b0b0b0;
    font-size: 14px;
}

select,
button {
    padding: 0.5rem 0.75rem;
    font-size: 14px;
    background-color: #393939;
    color: #e0e0e0;
    border: 1px solid #404040;
    border-radius: 0.25rem;
    cursor: pointer;
}

@media (hover: hover) {
    select:hover,
    button:hover {
        background-color: #4d4d4d;
    }
}

.calendar {
    display: grid;
    grid-template-columns: repeat(7, 1fr);
    gap: 0.3rem;
    width: 100%;
    max-width: 32rem;
}

.day-box {
    aspect-ratio: 1;
    background-color: #393939;
    border: 1px solid #404040;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    border-radius: 0.1rem;
    font-size: 16px;
    transition: background-color 0.2s;
    color: #b0b0b0;
    position: relative;
}

.day-box .month-label {
    position: absolute;
    top: 0.125rem;
    left: 0.125rem;
    font-size: 12px;
    color: #808080;
    font-weight: bold;
    line-height: 1;
}

@media (hover: hover) {
    .day-box:hover {
        border-color: #707070;
    }
}

.day-box.month-1,
.day-box.month-3,
.day-box.month-5,
.day-box.month-7,
.day-box.month-9,
.day-box.month-11 {
    background-color: #3f3f3f;
}

.day-box.month-2,
.day-box.month-4,
.day-box.month-6,
.day-box.month-8,
.day-box.month-10,
.day-box.month-12 {
    background-color: #323232;
}

.day-box.empty {
    background-color: transparent;
    border: none;
    cursor: default;
}

.day-box.completed {
    background-color: #2d5a2d;
    color: #90ee90;
    border-color: #4a7c4a;
}

.day-box.today::after {
    content: '';
    position: absolute;
    top: 0.125rem;
    right: 0.125rem;
    width: 0;
    height: 0;
    border-left: 0.54rem solid transparent;
    border-top: 0.54rem solid #e8e8e8;
}

.footer {
    margin-top: 1.8rem;
    display: flex;
    gap: 2rem;
}

@media (max-width: 600px) {
    .day-box {
        font-size: 12px;
    }
    .day-box .month-label {
        font-size: 8px;
    }
}