@import url('https://fonts.googleapis.com/css2?family=Roboto:wght@400;700&display=swap');

body {
    background-color: #f4f7f6; /* Lighter background */
    color: #333; /* Darker text for contrast */
    font-family: 'Roboto', sans-serif; /* Modern font */
    min-height: 100vh; /* Use min-height for flexibility */
    margin: 0;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center; /* Center content vertically */
    padding: 20px; /* Add some padding */
    box-sizing: border-box; /* Include padding in width/height calculations */
}

h1 {
    color: #2c3e50; /* Dark blue for heading */
    margin-bottom: 40px; /* Space below heading */
    font-size: 2.5em; /* Responsive font size */
}

#content {
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    width: 100%;
    max-width: 600px; /* Max width for content area */
    text-align: center; /* Center text within content */
}

#speed { /* Renamed from 'p' to be more specific, assuming this is the ID of the speed display */
    font-size: 2em; /* Default font size */
    color: #2c3e50; /* Consistent text color */
    margin-bottom: 30px; /* Space below speed display */
    font-weight: 700; /* Bolder speed reading */
}

#btnContainer {
    display: flex;
    justify-content: center; /* Center buttons */
    gap: 20px; /* Space between buttons */
    width: 100%; /* Full width to allow centering */
    margin-top: 20px; /* Space above button container */
}

button {
    background-color: #3498db; /* Primary button color (blue) */
    border: none;
    border-radius: 8px; /* Rounded corners */
    color: #fff;
    padding: 12px 25px; /* Adjusted padding */
    text-align: center;
    text-decoration: none;
    display: inline-block; /* Ensure it's an inline-block for proper display */
    font-size: 1em; /* Relative font size */
    cursor: pointer;
    transition: background-color 0.3s ease, transform 0.2s ease; /* Smooth transitions */
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1); /* Subtle shadow */
}

button:hover:not(:disabled) {
    background-color: #2980b9; /* Darker blue on hover */
    transform: translateY(-2px); /* Slight lift on hover */
}

button:disabled {
    background-color: #bdc3c7; /* Lighter grey for disabled */
    color: #7f8c8d; /* Muted text color for disabled */
    cursor: not-allowed;
    box-shadow: none; /* No shadow for disabled buttons */
}

button#startTracking {
    background-color: #2ecc71; /* Green for start button */
    /* display is handled by JS, so no need to repeat 'display: inline-block' here if it's always shown initially or JS handles it */
}

button#startTracking:hover:not(:disabled) {
    background-color: #27ae60; /* Darker green on hover */
}

/* Responsive adjustments */
@media (max-width: 768px) {
    h1 {
        font-size: 2em;
    }

    #speed {
        font-size: 1.8em; /* Adjusted for view on smaller screens */
        /* The font-size: 10vw from JS will override this when location access is granted.
           This style here is for the initial state or if JS controlled font-size is removed. */
    }

    button {
        padding: 10px 20px;
        font-size: 0.9em;
    }

    #btnContainer {
        flex-direction: column; /* Stack buttons vertically on small screens */
        gap: 15px;
    }
}

@media (max-width: 480px) {
    h1 {
        font-size: 1.8em;
    }

    #speed {
        font-size: 1.5em; /* Further adjust for very small screens */
    }

    button {
        width: 100%; /* Make buttons full width */
        padding: 12px; /* Adjust padding for full width */
        font-size: 1em; /* Ensure text is readable */
    }

    #btnContainer {
        gap: 10px; /* Reduce gap for stacked buttons */
    }
}