body {
    font-family: sans-serif;
    margin: 20px;
    background-color: #f4f4f9;
    color: #333;
}

h1, h2 {
    text-align: center;
    color: #2c3e50;
}

.upload-container {
    text-align: center;
    margin: 30px auto;
    padding: 20px;
    border: 2px dashed #ccc;
    border-radius: 10px;
    max-width: 500px;
}

.hidden {
    display: none;
}

.controls {
    display: flex;
    justify-content: center;
    align-items: center;
    flex-wrap: wrap;
    margin-bottom: 20px;
    gap: 20px;
}

.filter-group {
    display: flex;
    align-items: center;
    gap: 5px;
}

.controls label {
    font-size: 1em;
    margin-right: 5px;
}

.controls select {
    padding: 5px;
    border-radius: 5px;
    border: 1px solid #ccc;
}

.chart-container {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(400px, 1fr));
    gap: 20px;
    padding: 10px;
}

.chart-item {
    background-color: #fff;
    border: 1px solid #ddd;
    border-radius: 8px;
    padding: 20px;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

/* Responsive layout for smaller screens */
@media (max-width: 850px) {
    .chart-container {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 480px) {
    body {
        margin: 10px;
    }
    .controls {
        flex-direction: column;
        gap: 10px;
    }
    .chart-item {
        padding: 15px;
    }
}