/* Container: Sticky Navigation */
.app-nav { 
    position: sticky; top: 0; z-index: 9999; background: #fafafa; padding: 7px; 
    margin: 0 -20px; display: flex; align-items: center; gap: 7px; 
    border-bottom: 1px solid #aaa; background-clip: padding-box; 
}

/* Items & Icons */
.nav-item { display: flex; align-items: center; justify-content: center; text-decoration: none; margin: 0; padding: 0; line-height: 0; }

.nav-item img { 
    display: block; width: 48px; height: 48px; object-fit: contain; 
    border: 0.5px solid #aaa; border-radius: 8px; background: #fff; 
    filter: grayscale(80%); opacity: 0.5; transition: all 0.2s ease-in-out; 
}

/* Zustände: Aktiv & Hover */
.nav-item.active img { filter: grayscale(0); opacity: 1; border: 0.5px solid #f06; box-shadow: 0 2px 6px rgba(0,0,0,0.15); }

@media (hover: hover) {
    .nav-item:hover img { filter: grayscale(0); opacity: 1; border: 0.5px solid #333; box-shadow: 3px 3px 5px rgba(0,0,0,0.75); }
    .nav-item.active:hover img { border-color: #f06; }
}

/* Mobile Anpassung */
@media (max-width: 600px) {
    .app-nav { margin: 0 -9px; border: none; border-bottom: 2px solid #ccc; }
    .nav-item img { width: 42px; height: 42px; }
}