body {
    background: linear-gradient(to bottom, #f8f9fa, #e9ecef);
    font-family: 'Arial', sans-serif;
}

.logo {
    max-width: 250px;
    transition: transform 0.5s ease;
}

.site-subtitle {
    font-size: 1.5rem;
    color: #333;
    font-weight: 300;
}

.category-btn {
    transition: all 0.3s;
    position: relative;
}

.category-btn::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0;
    height: 2px;
    background-color: #007bff;
    transition: width 0.3s ease;
}

.category-btn:hover::after {
    width: 100%;
}

.category-btn.selected {
    background-color: #007bff;
    color: white;
}

.card-item {
    opacity: 0;
    transition: opacity 0.5s ease, transform 0.5s ease;
}

.card-item.visible {
    opacity: 1;
    animation: cardEntrance 0.5s ease forwards;
}

@keyframes cardEntrance {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.card {
    box-shadow: 0 4px 8px rgba(0,0,0,0.1);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.card:hover {
    transform: translateY(-5px);
    box-shadow: 0 8px 16px rgba(0,0,0,0.2);
}

footer {
    background: linear-gradient(to bottom, #343a40, #495057);
    color: white;
    padding: 20px 0;
}

footer a {
    text-decoration: none;
}

.social-icon {
    font-size: 1.5rem;
    transition: transform 0.3s ease, color 0.3s ease;
}

.social-icon:hover {
    transform: scale(1.2);
    color: #007bff;
}