/* Target the very root of the page */
    html {
        background-color: #34495e;
    }

    body {
        background-color: #34495e;
        color: #fff;
        font-family: Arial, sans-serif;
        margin: 0;
        padding: 20px;
    }

    .container {
        max-width: 800px; /* Widened for the graph */
        margin: 40px auto;
        background: rgba(0,0,0,0.3); /* Slightly darker for contrast */
        padding: 30px;
        border-radius: 10px;
        box-shadow: 0 4px 15px rgba(0,0,0,0.3);
    }

    label, input { font-size: 1.1em; }

    input {
        background: #2c3e50;
        border: 1px solid #5d6d7e;
        color: white;
        padding: 8px;
        border-radius: 5px;
    }

    button {
        font-size: 1.1em; padding: 10px 25px;
        background: #2980b9; color: #fff;
        border: none; border-radius: 5px; cursor: pointer;
    }

    button:hover { background: #1abc9c; }

    .loading { pointer-events: none; opacity: 0.7; }
    .loading::after { content: " ..."; }