body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    margin: 0;
    padding: 20px;
    background-color: #f4f4f9;
    color: #333;
}
h1 { text-align: center; }
.hub-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
    gap: 20px;
    max-width: 800px;
    margin: 0 auto;
}
.app-card {
    background: #fff;
    padding: 20px;
    border-radius: 8px;
    text-decoration: none;
    color: #333;
    box-shadow: 0 2px 5px rgba(0,0,0,0.1);
    transition: transform 0.2s;
}
.app-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 5px 15px rgba(0,0,0,0.2);
}
.app-card h2 { margin-top: 0; }
.back-btn {
    display: inline-block;
    padding: 10px 20px;
    background: #636e72;
    color: white;
    text-decoration: none;
    border-radius: 6px;
    font-weight: bold;
    margin-bottom: 20px;
    transition: background 0.2s;
}
.back-btn:hover { background: #2d3436; }