body {
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100vh;
    margin: 0;
    font-family: sans-serif;
    background-color: #121212;
    color: white;
}

.container {
    text-align: center;
}

.speedometer {
    width: 200px;
    height: 200px;
    border: 10px solid #222;
    border-radius: 50%;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    margin-bottom: 2em;
    box-shadow: 0 0 20px rgba(0, 0, 0, 0.5);
}

.speed-display {
    font-size: 3em;
    font-weight: bold;
}

.unit {
    font-size: 0.5em;
}

.location-info {
    margin-top: 1em;
}

#action {
    padding: 1em 2em;
    border: none;
    border-radius: 5px;
    cursor: pointer;
    transition: background-color 0.3s;
}

#action.start {
    background-color: #4CAF50; /* Green */
    color: white;
}

#action.stop {
    background-color: #f44336; /* Red */
    color: white;
}

#status {
    margin-top: 1em;
    font-style: italic;
    color: #888;
}

@media (max-width: 600px) {
    .speedometer {
        width: 150px;
        height: 150px;
    }

    .speed-display {
        font-size: 2em;
    }

    .location-info {
        font-size: 0.9em;
    }
}