:root {
    --primary-color: #2563eb;
    --secondary-color: #64748b;
    --success-color: #10b981;
    --danger-color: #ef4444;
    --warning-color: #f59e0b;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    background-color: #f8fafc;
    padding-bottom: env(safe-area-inset-bottom);
}

.navbar {
    background: linear-gradient(135deg, var(--primary-color) 0%, #1d4ed8 100%);
    box-shadow: 0 2px 8px rgba(0,0,0,0.15);
    position: sticky;
    top: 0;
    z-index: 1030;
}

.navbar-brand {
    font-weight: 700;
    font-size: 1.25rem;
}

.nav-link {
    padding: 0.5rem 0.75rem;
    border-radius: 6px;
    transition: background-color 0.2s;
}

.nav-link:hover {
    background-color: rgba(255, 255, 255, 0.1);
}

.nav-link.active {
    background-color: rgba(255, 255, 255, 0.2);
}

.card {
    border: none;
    border-radius: 12px;
    box-shadow: 0 1px 3px rgba(0,0,0,0.1);
    margin-bottom: 1rem;
}

.card-header {
    background-color: transparent;
    border-bottom: 1px solid #e2e8f0;
    font-weight: 600;
    padding: 1rem 1.25rem;
}

.btn {
    border-radius: 8px;
    font-weight: 500;
    padding: 0.5rem 1rem;
}

.btn-primary {
    background-color: var(--primary-color);
    border-color: var(--primary-color);
}

.btn-primary:hover {
    background-color: #1d4ed8;
    border-color: #1d4ed8;
}

.fab-button {
    position: fixed;
    bottom: 20px;
    right: 20px;
    width: 60px;
    height: 60px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 24px;
    box-shadow: 0 4px 6px rgba(0,0,0,0.2);
    z-index: 1000;
}

.alert {
    border-radius: 8px;
    border: none;
}

.badge {
    padding: 0.35em 0.65em;
    border-radius: 6px;
}

.stat-card {
    background: white;
    border-radius: 12px;
    padding: 1.25rem;
    margin-bottom: 1rem;
    box-shadow: 0 1px 3px rgba(0,0,0,0.1);
}

.stat-card .stat-value {
    font-size: 2rem;
    font-weight: 700;
    color: var(--primary-color);
}

.stat-card .stat-label {
    font-size: 0.875rem;
    color: var(--secondary-color);
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.low-stock-alert {
    border-left: 4px solid var(--danger-color);
}

@media (max-width: 768px) {
    .container {
        padding-left: 0.75rem;
        padding-right: 0.75rem;
    }

    .card {
        border-radius: 8px;
    }

    .fab-button {
        bottom: 80px;
    }
}