:root {
    --primary-color: #667eea;
    --secondary-color: #764ba2;
    --success-color: #28a745;
    --danger-color: #dc3545;
    --warning-color: #ffc107;
    --info-color: #17a2b8;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    background-color: #f8f9fa;
}

.navbar-brand {
    font-weight: 600;
}

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

.card:hover {
    box-shadow: 0 4px 12px rgba(0,0,0,0.1) !important;
}

.table-hover tbody tr:hover {
    background-color: rgba(0,0,0,0.02);
}

.btn {
    transition: background-color 0.2s, border-color 0.2s, color 0.2s;
}

.badge {
    font-weight: 500;
}

.form-control:focus,
.form-select:focus {
    border-color: var(--primary-color);
    box-shadow: 0 0 0 0.2rem rgba(102, 126, 234, 0.25);
}

.alert {
    border-left: 4px solid;
}

.alert-success {
    border-left-color: var(--success-color);
}

.alert-danger {
    border-left-color: var(--danger-color);
}

.alert-warning {
    border-left-color: var(--warning-color);
}

.alert-info {
    border-left-color: var(--info-color);
}

.contact-avatar {
    width: 40px;
    height: 40px;
    border-radius: 50%;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    font-weight: 600;
    color: white;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
}

.contact-avatar-lg {
    width: 80px;
    height: 80px;
    font-size: 1.5rem;
}

.pagination {
    margin-top: 1.5rem;
}

.search-box {
    max-width: 500px;
}

.stat-card {
    border-left: 4px solid;
}

.stat-card.primary {
    border-left-color: var(--primary-color);
}

.stat-card.success {
    border-left-color: var(--success-color);
}

.stat-card.info {
    border-left-color: var(--info-color);
}

.stat-card.warning {
    border-left-color: var(--warning-color);
}

footer {
    margin-top: auto;
}

.loading-spinner {
    display: inline-block;
    width: 1rem;
    height: 1rem;
    border: 2px solid currentColor;
    border-right-color: transparent;
    border-radius: 50%;
    animation: spinner-border 0.75s linear infinite;
}

@keyframes spinner-border {
    to { transform: rotate(360deg); }
}

@media (max-width: 768px) {
    .table-responsive {
        font-size: 0.875rem;
    }
    
    .btn-sm {
        padding: 0.25rem 0.5rem;
        font-size: 0.75rem;
    }
}