/* ... existing styles ... */

.nav-btn {
    background: #000;
    color: #008800;
    border: 1px solid #008800;
    padding: 0.5rem 1rem;
    font-family: 'Courier New', Courier, monospace;
    cursor: pointer;
    font-weight: bold;
    text-transform: uppercase;
    transition: all 0.2s;
}

.nav-btn:hover {
    background: #002200;
    color: #00ff00;
    border-color: #00ff00;
}

.nav-btn.active {
    background: #00ff00;
    color: #000;
    border-color: #00ff00;
}

@media (max-width: 600px) {
    .nav-btn {
        flex: 1 1 auto; /* Grow to fill space */
        text-align: center;
        padding: 0.8rem 0.5rem; /* Larger touch target */
        font-size: 0.9rem;
    }
}