:root {
    --primary-color: #4a90e2;
    --secondary-color: #f8f9fa;
    --header-height: 70px;
}

.tab-container {
    background: rgba(128, 128, 128, 0.1);
    border-radius: 12px;
    box-shadow: 0 5px 20px rgba(0, 0, 0, 0.05);
    padding: 20px;
}

.nav-tabs {
    border-bottom: 2px solid #e9ecef;
    margin-bottom: 20px;
}

.nav-tabs .nav-link {
    border: none;
    color: #6c757d;
    font-weight: 500;
    padding: 12px 20px;
    transition: all 0.3s ease;
}

.nav-tabs .nav-link:hover {
    color: var(--primary-color);
    border-color: transparent;
    transform: translateY(-2px);
}

.nav-tabs .nav-link.active {
    color: var(--primary-color);
    border: none;
    border-bottom: 2px solid var(--primary-color);
    background: transparent;
}

.nav-tabs .nav-link i {
    margin-right: 8px;
}

.content-card {
    padding: 20px;
    background: var(--secondary-color);
    border-radius: 8px;
    transition: all 0.3s ease;
}

.content-card:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.05);
}

.content-card h2 {
    color: #2c3e50;
    font-size: 1.5rem;
    margin-bottom: 1rem;
}

.content-card h2 i {
    margin-right: 10px;
    color: var(--primary-color);
}

.content-card p {
    color: #6c757d;
    line-height: 1.6;
}

.alert {
    margin-top: 1rem;
    border: none;
    border-radius: 8px;
}

.alert i {
    margin-right: 8px;
}

.tab-pane {
    animation: fadeIn 0.3s ease-in;
}

@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(10px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}