:root {
    --primary: #2563eb;
    --secondary: #6c757d;
    --success: #198754;
    --info: #0dcaf0;
    --warning: #ffc107;
    --danger: #dc3545;
    --light: #f8f9fa;
    --dark: #212529;
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background-color: #f8f9fa;
}

.sidebar {
    min-height: 100vh;
    background: linear-gradient(180deg, #1a1a2e 0%, #2d3748 100%);
}

.nav-link {
    color: rgba(255, 255, 255, 0.5);
    border-radius: 0.375rem;
    padding: 0.5rem 1rem;
    margin: 0.125rem 0;
}

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

    .nav-link.active {
    background-color: var(--primary);
    color: white;
}

.card {
    transition: transform 0.2s ease, box-shadow 0.2s ease;
}

    .card:hover {
    transform: translateY(-2px);
    box-shadow: 0 0.5rem 1rem rgba(0, 0, 0, 0.1) !important;
}

.table th {
    font-weight: 600;
    text-transform: uppercase;
    font-size: 0.75rem;
    letter-spacing: 0.05em;
    color: #6c757d;
    border-bottom-width: 2px;
}

.btn {
    font-weight: 500;
    transition: all 0.2s ease;
}

    .btn:hover {
        transform: translateY(-1px);
    }

.breadcrumb-item a {
    color: var(--primary);
    text-decoration: none;
}

    .breadcrumb-item a:hover {
        text-decoration: underline;
    }

code {
    background-color: #f1f1f1;
    padding: 0.125rem 0.375rem;
    border-radius: 0.25rem;
    font-size: 0.875em;
}

.badge {
    font-weight: 500;
}

.spinner-border {
    width: 3rem;
    height: 3rem;
}

.validation-message {
    color: var(--danger);
    font-size: 0.875rem;
    margin-top: 0.25rem;
}

input:focus,
select:focus,
textarea:focus {
    border-color: var(--primary);
    box-shadow: 0 0 0 0.2rem rgba(37, 99, 235, 0.25);
}

.dropdown-menu {
    box-shadow: 0 0.5rem 1rem rgba(0, 0, 0, 0.15);
}

.alert {
    border: none;
    border-radius: 0.5rem;
}