async function saveSettings() {
    // MQTT
    const mqtt = {
        broker: document.getElementById('mqtt_broker').value,
        port: parseInt(document.getElementById('mqtt_port').value, 10),
        user: document.getElementById('mqtt_user').value || null,
        password: document.getElementById('mqtt_password').value || null,
        button_circulation: document.getElementById('mqtt_button_circulation').value || null
    };

    // InfluxDB
    const influxdb = {
        url: document.getElementById('influxdb_url').value,
        token: document.getElementById('influxdb_token').value,
        bucket: document.getElementById('influxdb_bucket').value,
        org: document.getElementById('influxdb_org').value,
        location: document.getElementById('influxdb_location').value || null,
        measurement: document.getElementById('influxdb_measurement').value || null
    };

    // Modbus
    const modbus = {
        host: document.getElementById('modbus_host').value,
        port: parseInt(document.getElementById('modbus_port').value, 10),
        max_coils_addr: parseInt(document.getElementById('modbus_max_coils_addr').value, 10) || null,
        max_input_addr: parseInt(document.getElementById('modbus_max_input_addr').value, 10) || null,
        max_holding_addr: parseInt(document.getElementById('modbus_max_holding_addr').value, 10) || null,
        modbus_coils: null,
        modbus_input_register: null,
        modbus_holding_register: null
    };

    // Default (für [default])
    const defaultConfig = {
        loglevel: document.getElementById('loglevel')?.value || null
    };

    const settings = {
        default: defaultConfig,
        mqtt,
        influxdb,
        modbus
    };

    try {
        const response = await fetch('/api/save-settings', {
            method: 'POST',
            headers: {
                'Content-Type': 'application/json',
            },
            body: JSON.stringify(settings)
        });

        const messageDiv = document.getElementById('message');
        if (response.ok) {
            messageDiv.className = 'message success';
            messageDiv.textContent = '✓ Einstellungen erfolgreich gespeichert!';
        } else {
            messageDiv.className = 'message error';
            messageDiv.textContent = '✗ Fehler beim Speichern der Einstellungen!';
        }

        setTimeout(() => {
            messageDiv.style.display = 'none';
        }, 3000);
    } catch (error) {
        const messageDiv = document.getElementById('message');
        messageDiv.className = 'message error';
        messageDiv.textContent = '✗ Verbindungsfehler!';
    }
}