body {
    margin: 0;
    background: #0f0f0f;
    color: white;
    font-family: Arial;
}

.container {
    width: 95%;
    margin: 20px auto;
}

#chart {
    width: 100%;
    height: 500px;
}

.controls {
    margin-top: 15px;
}

button, select {
    padding: 8px 12px;
    margin-right: 10px;
    background: #1c1c1c;
    color: white;
    border: 1px solid #333;
    cursor: pointer;
}

button:hover {
    background: #333;
}