* {
            box-sizing: border-box;
        }

        body {
            margin: 0;
            font-family: Arial, sans-serif;
            background: #f4f6f8;
            color: #222;
        }

        header {
            height: 100px;
            background: #2f5d8c;
            color: white;
            display: flex;
            align-items: center;
            padding: 0 30px;
            font-size: 32px;
            font-weight: bold;
        }

        .layout {
            display: flex;
            min-height: calc(100vh - 100px);
        }

        nav {
            width: 100px;
            background: #1f2a36;
            color: white;
            padding: 15px;
        }

        nav h2 {
            margin-top: 0;
            font-size: 20px;
        }

        nav ul {
            list-style: none;
            padding: 0;
            margin: 20px 0 0 0;
        }

        nav li {
            margin-bottom: 12px;
        }

        nav a {
            color: white;
            text-decoration: none;
        }

        nav a:hover {
            text-decoration: underline;
        }

        main {
            flex: 1;
            padding: 30px;
        }

        .card {
            background: white;
            border-radius: 10px;
            padding: 24px;
            max-width: 700px;
            box-shadow: 0 2px 10px rgba(0, 0, 0, 0.08);
        }

        label {
            display: block;
            margin-top: 16px;
            font-weight: bold;
        }

        input[type="text"],
        textarea {
            width: 100%;
            margin-top: 6px;
            padding: 10px;
            font-size: 14px;
        }

        textarea {
            min-height: 220px;
            resize: vertical;
            font-family: monospace;
        }

        button {
            margin-top: 10px;
            padding: 10px 16px;
            font-size: 14px;
            cursor: pointer;
        }

        .success {
            margin-bottom: 20px;
            color: green;
            font-weight: bold;
        }

        .error {
            margin-bottom: 20px;
            color: darkred;
            font-weight: bold;
        }

        .muted {
            color: #666;
        }

.module-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
    gap: 20px;
    margin-top: 20px;
}

.module-card {
    display: block;
    text-decoration: none;
    color: inherit;
    background: white;
    border-radius: 10px;
    padding: 20px;
    box-shadow: 0 2px 10px rgba(0,0,0,0.08);
    transition: transform 0.1s ease, box-shadow 0.1s ease;
}

.module-card:hover {
    transform: translateY(-4px);
    box-shadow: 0 6px 18px rgba(0,0,0,0.12);
}

.module-card h2 {
    margin-top: 0;
}

.module-card.disabled {
    opacity: 0.5;
    pointer-events: none;
}

nav li.active a {
    font-weight: bold;
    color: #4da3ff;
}

main h1 {
    margin-top: 0;
    margin-bottom: 0;
}

.primary-button {
    display: inline-block;
    margin-top: 12px;
    padding: 10px 16px;
    font-size: 14px;
    cursor: pointer;

    border: none;
    border-radius: 8px;
    background: #2f5d8c;
    color: white;
    text-decoration: none;
}

.primary-button:hover {
    background: #3d73a8;
}