.card {
            background: #ffffff;
            border: 1px solid #e5e7eb;
            border-radius: 12px;
            box-shadow: 0 8px 16px rgba(15, 23, 42, 0.06);
        }
        .stat-label {
            color: #64748b;
            font-size: 12px;
            text-transform: uppercase;
            letter-spacing: 0.04em;
        }
        .stat-value {
            color: #0f172a;
            font-size: 24px;
            font-weight: 700;
        }
        .chart-sidebar {
            position: fixed;
            right: 16px;
            top: 96px;
            z-index: 40;
            width: 220px;
            background: #ffffff;
            border: 1px solid #e5e7eb;
            border-radius: 12px;
            box-shadow: 0 12px 24px rgba(15, 23, 42, 0.12);
        }
        .column-sidebar {
            position: fixed;
            left: 16px;
            top: 96px;
            z-index: 40;
            width: 240px;
            background: #ffffff;
            border: 1px solid #e5e7eb;
            border-radius: 12px;
            box-shadow: 0 12px 24px rgba(15, 23, 42, 0.12);
        }
        .toggle-row {
            display: flex;
            align-items: center;
            justify-content: space-between;
            gap: 12px;
            padding: 6px 0;
        }
        .toggle-input {
            appearance: none;
            width: 38px;
            height: 22px;
            border-radius: 999px;
            background: #e2e8f0;
            position: relative;
            transition: background 0.2s ease;
            cursor: pointer;
        }
        .toggle-input::after {
            content: '';
            position: absolute;
            top: 3px;
            left: 3px;
            width: 16px;
            height: 16px;
            border-radius: 999px;
            background: #ffffff;
            box-shadow: 0 2px 6px rgba(15, 23, 42, 0.2);
            transition: transform 0.2s ease;
        }
        .toggle-input:checked {
            background: #6366f1;
        }
        .toggle-input:checked::after {
            transform: translateX(16px);
        }
        .airtime-wrap {
            position: sticky;
            left: 0;
            width: 100%;
            box-sizing: border-box;
        }
        #usageTable {
            position: relative;
        }
        .airtime-detail {
            position: relative;
        }
        .airtime-detail td[data-role="airtime-detail"] {
            padding-left: 1.5rem;
            padding-right: 1.5rem;
            position: relative;
        }
        .airtime-breakout {
            width: 100%;
            max-width: 100%;
            margin: 0;
            padding: 0;
            box-sizing: border-box;
        }
        .airtime-grid {
            display: grid;
            width: 100%;
            grid-template-columns: repeat(auto-fit, minmax(160px, 160px));
            gap: 12px;
            justify-content: space-between;
            align-items: stretch;
            justify-items: stretch;
        }
        .airtime-grid > div {
            width: 100%;
            height: 100%;
        }
        .airtime-nested {
            border-top: 1px solid #e2e8f0;
            padding-top: 16px;
        }
        .airtime-nested-title {
            font-size: 0.75rem;
            text-transform: uppercase;
            letter-spacing: 0.08em;
            color: #64748b;
        }
        .airtime-chart-grid {
            display: grid;
            grid-template-columns: 1fr;
            gap: 16px;
        }
        @media (min-width: 1024px) {
            .airtime-chart-grid {
                grid-template-columns: 1fr 1fr;
            }
        }
        .row-toggle {
            width: 24px;
            height: 24px;
            border-radius: 6px;
            display: inline-flex;
            align-items: center;
            justify-content: center;
            transition: background 0.15s ease;
        }
        .row-toggle:hover {
            background: #e2e8f0;
        }
        .row-toggle .chevron {
            width: 8px;
            height: 8px;
            border-right: 2px solid #64748b;
            border-bottom: 2px solid #64748b;
            transform: rotate(-45deg);
            transition: transform 0.2s ease;
        }
        .row-toggle[aria-expanded="true"] .chevron {
            transform: rotate(45deg);
        }
        .department-header .dept-toggle {
            width: 24px;
            height: 24px;
            border-radius: 6px;
            display: inline-flex;
            align-items: center;
            justify-content: center;
            transition: background 0.15s ease;
        }
        .department-header .dept-toggle:hover {
            background: #e2e8f0;
        }
        .department-header .dept-chevron {
            width: 8px;
            height: 8px;
            border-right: 2px solid #64748b;
            border-bottom: 2px solid #64748b;
            transform: rotate(45deg);
            transition: transform 0.2s ease;
            display: inline-block;
        }
        .department-header.is-collapsed .dept-chevron {
            transform: rotate(-45deg);
        }
        .chart-modal {
            position: fixed;
            right: 24px;
            top: 120px;
            width: 420px;
            min-width: 280px;
            max-width: 90vw;
            min-height: 240px;
            max-height: 70vh;
            overflow: hidden;
            background: #ffffff;
            border: 1px solid #e5e7eb;
            border-radius: 14px;
            box-shadow: 0 18px 40px rgba(15, 23, 42, 0.18);
            z-index: 60;
        }
        .chart-modal.hidden {
            display: none;
        }
        .chart-modal-header {
            cursor: move;
            user-select: none;
        }
        .chart-modal-body {
            overflow: auto;
            height: calc(100% - 48px);
        }
        .chart-action {
            font-size: 12px;
            font-weight: 600;
            color: #475569;
        }
        .chart-resize-handle {
            position: absolute;
            right: 6px;
            bottom: 6px;
            width: 14px;
            height: 14px;
            border-right: 2px solid #94a3b8;
            border-bottom: 2px solid #94a3b8;
            cursor: se-resize;
        }
        @media (max-width: 768px) {
            .column-sidebar {
                position: static;
                width: auto;
                margin-bottom: 16px;
            }
            .chart-sidebar {
                position: static;
                width: auto;
                margin-bottom: 16px;
            }
            .chart-modal {
                width: 92vw;
                left: 4vw;
                right: auto;
                top: 90px;
            }
        }