body {
    background: #f5f7fa;
    font-family: 'Segoe UI', sans-serif;
}

.card {
    border-radius: 15px;
}

#chart_div {
    margin-top: 20px;
    min-height: 400px;
}

footer {
    position: relative;
    bottom: 0;
    width: 100%;
}