:root {
    --primary-bg: #0d1a26; /* Darker blue-grey for main background */
    --secondary-bg: #152b3e; /* Slightly lighter dark blue for secondary elements */
    --navbar-bg: #0a131b; /* Very dark blue for navbar background */
    --primary-text: #e0e6eb; /* Lighter text for better contrast */
    --accent-color: #3f7eab; /* A more subdued, sophisticated blue */
    --disabled-color: #718096;
    --health-good: #48bb78;
    --health-bad: #f56565;
    --border-color: #2a415a; /* Dark blue-grey border */
}

* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, 'Open Sans', 'Helvetica Neue', sans-serif;
    color: var(--primary-text);
    margin: 0; /* Ensure no default margin */
    min-height: 100vh; /* Ensure full viewport height */
    display: flex; /* Use flexbox for layout */
    flex-direction: column; /* Stack children vertically */
    align-items: center; /* Center children horizontally */
}

#app {
    width: 100%;
    max-width: 800px;
    margin: 20px;
    padding: 20px;
    background-color: var(--secondary-bg);
    border-radius: 8px;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.4);
}

h1, h2, h3 {
    text-align: center;
    margin-bottom: 20px;
}

h1 {
    font-size: 2.5rem;
    color: var(--accent-color);
}