body {
    font-family: Arial, sans-serif;
    text-align: center;
    background-color: #f5f5f5;
    margin: 0;
    padding: 0;
}

h1 {
    color: #333;
    font-size: 2em;
    margin: 15px 0;
}

.container {
    display: flex;
    flex-direction: column;
    align-items: center;
    max-width: 1500px;
    margin: auto;
}

.controls {
    display: flex;
    flex-direction: column;
    align-items: center;
    margin-bottom: 20px;
}

.button-group {
    display: flex;
    gap: 10px; /* Adds space between the buttons */
}

#current-heart-rate {
    font-size: 1.5em;
    font-weight: bold;
    margin: 20px 0;
    color: #ff3333;
}

#connect-button, #export-button {
    padding: 10px 20px;
    font-size: 1em;
    margin: 10px 0;
    cursor: pointer;
}

#heart-rate-chart {
    width: 90%;
    max-width: 1200px;
    height: 450px; /* Increased height */
    background-color: #fff;
    border: 1px solid #ddd;
    padding: 10px;
}

/* Media query for smaller screens */
@media (max-width: 600px) {
    h1 {
        font-size: 1.5em;
    }

    #current-heart-rate {
        font-size: 1.2em;
    }

    #connect-button, #export-button {
        padding: 8px 16px;
        font-size: 0.9em;
    }

    #heart-rate-chart {
        width: 100%;
        max-width: 100%;
        height: 400px; /* Adjusted height for smaller screens */
        margin: 10px auto;
        padding: 5px;
    }
}