:root {
    --primary: #2c3e50;
    --secondary: #3f87a6;
}

body {
    background: linear-gradient(135deg, #f8f9fa 0%, #e9ecef 100%);
    font-family: 'Segoe UI', system-ui;
}

.calculator-card {
    max-width: 900px;
    margin: 2rem auto;
    box-shadow: 0 8px 30px rgba(0,0,0,0.12);
    border-radius: 1rem;
    overflow: hidden;
}

.rate-tier {
    border-left: 4px solid var(--primary);
    padding: 1rem;
    margin: 1rem 0;
    background: rgba(255,255,255,0.9);
    backdrop-filter: blur(8px);
}

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

.hidden {
    display: none;
}

.table th, .table td {
    vertical-align: middle;
}

.pagination .page-link {
    color: var(--primary);
}

.pagination .page-item.active .page-link {
    background-color: var(--primary);
    border-color: var(--primary);
    color: white;
}