body {
    font-family: Arial, sans-serif;
    background-color: #f4f4f4;
}

h1 {
    margin-top: 20px;
}

.card {
    background-color: #fff;
    border-radius: 8px;
    box-shadow: 0 0 10px rgba(0, 0, 0, 0.1);
}

.chart-container {
    width: 150px;
    height: 150px;
    display: flex;
    align-items: center;
    justify-content: center;
}

canvas {
    max-width: 100%;
    max-height: 100%;
}

@media (max-width: 768px) {
    .d-flex {
        flex-direction: column;
        align-items: center;
    }

    .mr-4 {
        margin-right: 0 !important;
        margin-bottom: 20px;
    }
}