:root {
            --primary: #6366f1;
            --primary-dark: #4f46e5;
            --primary-light: #818cf8;
            --primary-bg: #eef2ff;
            --success: #22c55e;
            --success-bg: #f0fdf4;
            --warning: #f59e0b;
            --warning-bg: #fffbeb;
            --danger: #ef4444;
            --danger-bg: #fef2f2;
            --info: #06b6d4;
            --text-dark: #1e293b;
            --text-muted: #64748b;
            --text-light: #94a3b8;
            --bg: #f8fafc;
            --card-bg: #ffffff;
            --border: #e2e8f0;
            --radius: 12px;
            --radius-sm: 8px;
            --radius-lg: 16px;
            --shadow-sm: 0 1px 2px rgba(0,0,0,.04);
            --shadow: 0 2px 8px rgba(0,0,0,.06);
            --shadow-md: 0 4px 16px rgba(0,0,0,.08);
            --shadow-lg: 0 8px 32px rgba(0,0,0,.10);
            --nav-h: 64px;
        }
        * { margin: 0; padding: 0; box-sizing: border-box; }
        body {
            font-family: 'Segoe UI', -apple-system, BlinkMacSystemFont, Roboto, 'Helvetica Neue', Arial, sans-serif;
            background: var(--bg); color: var(--text-dark); font-size: 15px; line-height: 1.6;
        }

        /* === Navigation === */
        .navbar {
            height: var(--nav-h); background: var(--card-bg);
            border-bottom: 1px solid var(--border);
            display: flex; align-items: center; justify-content: space-between;
            padding: 0 24px; position: sticky; top: 0; z-index: 999;
            box-shadow: var(--shadow-sm);
        }
        .nav-left { display: flex; align-items: center; gap: 16px; }
        .nav-logo {
            width: 40px; height: 40px; border-radius: 10px;
            background: linear-gradient(135deg, var(--primary), #8b5cf6);
            display: flex; align-items: center; justify-content: center;
            font-weight: 800; color: #fff; font-size: 18px;
        }
        .nav-brand { font-size: 18px; font-weight: 700; color: var(--text-dark); }
        .nav-brand small { font-size: 11px; font-weight: 500; color: var(--text-muted); display: block; }
        .mode-badge {
            font-size: 10px; font-weight: 700; padding: 3px 10px; border-radius: 20px;
            text-transform: uppercase; letter-spacing: .04em; white-space: nowrap;
        }
        .mode-testing { background: #fef3c7; color: #92400e; border: 1px solid #fde68a; }
        .nav-links { display: flex; gap: 4px; }
        .nav-link {
            padding: 8px 16px; border-radius: var(--radius-sm);
            color: var(--text-muted); text-decoration: none; font-weight: 600; font-size: 14px;
            transition: all .15s ease; display: flex; align-items: center; gap: 6px;
        }
        .nav-link:hover { background: var(--primary-bg); color: var(--primary-dark); }
        .nav-link.active { background: var(--primary); color: #fff; }
        .nav-link svg { width: 18px; height: 18px; }
        .nav-right { display: flex; align-items: center; gap: 12px; }
        .nav-user {
            display: flex; align-items: center; gap: 8px; padding: 4px 8px 4px 4px;
            border-radius: 24px; background: transparent; border: 1px solid transparent;
            cursor: pointer; transition: all .15s ease; position: relative;
        }
        .nav-user:hover { background: var(--bg); border-color: var(--border); }
        .nav-avatar {
            width: 32px; height: 32px; border-radius: 50%;
            background: linear-gradient(135deg, var(--primary), #8b5cf6);
            display: flex; align-items: center; justify-content: center;
            color: #fff; font-weight: 700; font-size: 14px; flex-shrink: 0;
        }
        .nav-user-info { font-size: 13px; line-height: 1.2; }
        .nav-user-info strong { display: block; color: var(--text-dark); font-size: 13px; max-width: 120px; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
        .nav-user-info span { color: var(--text-muted); font-size: 11px; }
        .nav-user-arrow { color: var(--text-muted); flex-shrink: 0; transition: transform .15s ease; }
        .nav-user.open .nav-user-arrow { transform: rotate(180deg); }

        /* User dropdown menu */
        .nav-user-dropdown {
            display: none; position: absolute; top: calc(100% + 6px); right: 0;
            min-width: 220px; background: var(--card-bg);
            border: 1px solid var(--border); border-radius: var(--radius-sm);
            box-shadow: 0 8px 24px rgba(0,0,0,.12); z-index: 300; overflow: hidden;
        }
        .nav-user-dropdown.open { display: block; }
        .nav-user-dropdown-header {
            padding: 14px 16px; border-bottom: 1px solid var(--border);
            background: var(--bg);
        }
        .nav-user-dropdown-header strong { display: block; font-size: 14px; color: var(--text-dark); }
        .nav-user-dropdown-header span { font-size: 12px; color: var(--text-muted); }
        .nav-user-dropdown-item {
            display: flex; align-items: center; gap: 10px;
            padding: 11px 16px; font-size: 14px; font-weight: 500;
            color: var(--text-dark); text-decoration: none;
            transition: background .12s ease; border: none; width: 100%;
            cursor: pointer; background: transparent;
        }
        .nav-user-dropdown-item:hover { background: var(--bg); }
        .nav-user-dropdown-item svg { color: var(--text-muted); flex-shrink: 0; }
        .nav-user-dropdown-item.danger { color: var(--danger); }
        .nav-user-dropdown-item.danger svg { color: var(--danger); }
        .nav-user-dropdown-item.danger:hover { background: var(--danger-bg); }
        .nav-user-dropdown-divider { height: 1px; background: var(--border); }

        .nav-toggle { display: none; background: none; border: none; cursor: pointer; padding: 6px; }

        /* === Layout === */
        .container { max-width: 1200px; margin: 0 auto; padding: 32px 24px; }
        .page-header { margin-bottom: 28px; }
        .page-title { font-size: 28px; font-weight: 800; color: var(--text-dark); margin-bottom: 6px; }
        .page-subtitle { font-size: 15px; color: var(--text-muted); }

        /* === Cards === */
        .card {
            background: var(--card-bg); border: 1px solid var(--border);
            border-radius: var(--radius); padding: 24px; box-shadow: var(--shadow-sm);
        }
        .card-header {
            display: flex; align-items: center; justify-content: space-between;
            margin-bottom: 20px; padding-bottom: 16px; border-bottom: 1px solid var(--border);
        }
        .card-title { font-size: 18px; font-weight: 700; color: var(--text-dark); }

        /* === Stats Grid === */
        .stats-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 20px; margin-bottom: 32px; }
        .stat-card {
            background: var(--card-bg); border: 1px solid var(--border);
            border-radius: var(--radius); padding: 20px; box-shadow: var(--shadow-sm);
            transition: transform .15s ease, box-shadow .15s ease;
        }
        .stat-card:hover { transform: translateY(-2px); box-shadow: var(--shadow-md); }
        .stat-icon {
            width: 48px; height: 48px; border-radius: 12px;
            display: flex; align-items: center; justify-content: center;
            margin-bottom: 14px;
        }
        .stat-icon svg { width: 24px; height: 24px; }
        .stat-icon.blue { background: var(--primary-bg); color: var(--primary); }
        .stat-icon.green { background: var(--success-bg); color: var(--success); }
        .stat-icon.amber { background: var(--warning-bg); color: var(--warning); }
        .stat-icon.purple { background: #faf5ff; color: #a855f7; }
        .stat-value { font-size: 28px; font-weight: 800; color: var(--text-dark); line-height: 1; }
        .stat-label { font-size: 13px; color: var(--text-muted); margin-top: 6px; }

        /* === Grid === */
        .grid-2 { display: grid; grid-template-columns: 1fr 1fr; gap: 24px; }
        .grid-3 { display: grid; grid-template-columns: repeat(3, 1fr); gap: 20px; }

        /* === Table === */
        .table { width: 100%; border-collapse: collapse; }
        .table th {
            text-align: left; padding: 12px 16px; font-size: 12px; font-weight: 700;
            text-transform: uppercase; letter-spacing: .05em; color: var(--text-muted);
            border-bottom: 2px solid var(--border);
        }
        .table td { padding: 14px 16px; border-bottom: 1px solid var(--border); font-size: 14px; }
        .table tr:last-child td { border-bottom: none; }
        .table tr:hover td { background: var(--bg); }

        /* === Buttons === */
        .btn {
            display: inline-flex; align-items: center; justify-content: center; gap: 8px;
            padding: 10px 20px; border-radius: var(--radius-sm); border: none;
            font-size: 14px; font-weight: 600; cursor: pointer;
            transition: all .15s ease; text-decoration: none; white-space: nowrap;
        }
        .btn-primary { background: var(--primary); color: #fff; }
        .btn-primary:hover { background: var(--primary-dark); }
        .btn-secondary { background: var(--bg); color: var(--text-dark); border: 1px solid var(--border); }
        .btn-secondary:hover { background: var(--border); }
        .btn-danger { background: var(--danger); color: #fff; }
        .btn-danger:hover { background: #dc2626; }
        .btn-success { background: var(--success); color: #fff; }
        .btn-success:hover { background: #16a34a; }
        .btn-lg { padding: 14px 28px; font-size: 16px; }
        .btn-sm { padding: 6px 12px; font-size: 13px; }
        .btn-block { width: 100%; }
        .btn-icon {
            width: 32px; height: 32px; padding: 0; border-radius: 8px;
            background: transparent; border: 1px solid var(--border);
            display: inline-flex; align-items: center; justify-content: center;
            cursor: pointer; transition: all .15s ease;
        }
        .btn-icon:hover { background: var(--bg); }
        .btn-icon.danger:hover { border-color: var(--danger); color: var(--danger); background: var(--danger-bg); }

        /* === Forms === */
        .form-group { margin-bottom: 20px; }
        .form-label { display: block; font-size: 14px; font-weight: 600; color: var(--text-dark); margin-bottom: 6px; }
        .form-label .req { color: var(--danger); }
        .form-input, .form-select, .form-textarea {
            width: 100%; padding: 12px 16px; border: 1px solid var(--border);
            border-radius: var(--radius-sm); font-size: 15px; color: var(--text-dark);
            background: var(--card-bg); transition: all .15s ease; font-family: inherit;
        }
        .form-input:focus, .form-select:focus, .form-textarea:focus {
            outline: none; border-color: var(--primary); box-shadow: 0 0 0 3px var(--primary-bg);
        }
        .form-textarea { min-height: 120px; resize: vertical; }
        .form-error { font-size: 13px; color: var(--danger); margin-top: 4px; }
        .form-hint { font-size: 13px; color: var(--text-muted); margin-top: 4px; }
        .form-radio-group { display: flex; gap: 16px; }
        .form-radio {
            display: flex; align-items: center; gap: 8px; padding: 10px 16px;
            border: 1px solid var(--border); border-radius: var(--radius-sm); cursor: pointer;
            transition: all .15s ease; flex: 1;
        }
        .form-radio:hover { border-color: var(--primary); }
        .form-radio input { accent-color: var(--primary); }
        .form-radio.selected { border-color: var(--primary); background: var(--primary-bg); }

        /* === Alerts === */
        .alert {
            padding: 14px 18px; border-radius: var(--radius-sm); margin-bottom: 20px;
            display: flex; align-items: center; gap: 10px; font-size: 14px; font-weight: 500;
        }
        .alert-success { background: var(--success-bg); color: #15803d; border: 1px solid #bbf7d0; }
        .alert-danger { background: var(--danger-bg); color: #b91c1c; border: 1px solid #fecaca; }
        .alert-info { background: #f0f9ff; color: #0369a1; border: 1px solid #bae6fd; }
        .alert-warning { background: var(--warning-bg); color: #b45309; border: 1px solid #fde68a; }

        /* === Badges === */
        .badge {
            display: inline-flex; align-items: center; gap: 4px;
            padding: 4px 10px; border-radius: 20px; font-size: 12px; font-weight: 600;
        }
        .badge-success { background: var(--success-bg); color: var(--success); }
        .badge-warning { background: var(--warning-bg); color: var(--warning); }
        .badge-danger { background: var(--danger-bg); color: var(--danger); }
        .badge-info { background: #f0f9ff; color: var(--info); }
        .badge-muted { background: var(--bg); color: var(--text-muted); }

        /* === Empty State === */
        .empty-state { text-align: center; padding: 48px 24px; }
        .empty-state-icon {
            width: 64px; height: 64px; border-radius: 50%;
            background: var(--primary-bg); color: var(--primary);
            display: flex; align-items: center; justify-content: center;
            margin: 0 auto 16px;
        }
        .empty-state-icon svg { width: 32px; height: 32px; }
        .empty-state-title { font-size: 18px; font-weight: 700; color: var(--text-dark); margin-bottom: 6px; }
        .empty-state-text { font-size: 14px; color: var(--text-muted); margin-bottom: 20px; }

        /* === Child Card === */
        .child-card {
            background: var(--card-bg); border: 1px solid var(--border);
            border-radius: var(--radius); padding: 20px; box-shadow: var(--shadow-sm);
            transition: all .15s ease; cursor: pointer; text-decoration: none; color: inherit;
            display: block;
        }
        .child-card:hover { border-color: var(--primary); box-shadow: var(--shadow-md); transform: translateY(-2px); }
        .child-card-head { display: flex; align-items: center; gap: 14px; margin-bottom: 14px; }
        .child-avatar {
            width: 56px; height: 56px; border-radius: 50%;
            background: linear-gradient(135deg, var(--primary), #8b5cf6);
            display: flex; align-items: center; justify-content: center;
            color: #fff; font-weight: 700; font-size: 22px;
        }
        .child-avatar.green { background: linear-gradient(135deg, #22c55e, #16a34a); }
        .child-avatar.amber { background: linear-gradient(135deg, #f59e0b, #d97706); }
        .child-avatar.pink { background: linear-gradient(135deg, #ec4899, #db2777); }
        .child-name { font-size: 17px; font-weight: 700; color: var(--text-dark); }
        .child-meta { font-size: 13px; color: var(--text-muted); }
        .child-card-body { display: flex; gap: 16px; flex-wrap: wrap; }
        .child-info { font-size: 13px; color: var(--text-muted); }
        .child-info strong { color: var(--text-dark); display: block; font-size: 15px; }

        /* === Test Subtest Card === */
        .subtest-card {
            background: var(--card-bg); border: 1px solid var(--border);
            border-radius: var(--radius); padding: 24px; box-shadow: var(--shadow-sm);
            margin-bottom: 16px; transition: all .15s ease;
        }
        .subtest-card:hover { box-shadow: var(--shadow-md); }
        .subtest-card-head { display: flex; align-items: center; justify-content: space-between; margin-bottom: 12px; }
        .subtest-num {
            width: 36px; height: 36px; border-radius: 50%;
            background: var(--primary-bg); color: var(--primary);
            display: flex; align-items: center; justify-content: center;
            font-weight: 700; font-size: 16px; flex-shrink: 0;
        }
        .subtest-num.done { background: var(--success-bg); color: var(--success); }
        .subtest-num.active { background: var(--primary); color: #fff; }
        .subtest-info { flex: 1; padding: 0 16px; }
        .subtest-title { font-size: 17px; font-weight: 700; color: var(--text-dark); }
        .subtest-meta { font-size: 13px; color: var(--text-muted); display: flex; gap: 12px; flex-wrap: wrap; }
        .subtest-meta span { display: flex; align-items: center; gap: 4px; }
        .subtest-meta svg { width: 14px; height: 14px; }

        /* === Responsive === */
        @media (max-width: 1024px) {
            .stats-grid { grid-template-columns: repeat(2, 1fr); }
            .grid-3 { grid-template-columns: 1fr 1fr; }
        }
        @media (max-width: 768px) {
            .nav-links { display: none; }
            .nav-links.open {
                display: flex; position: absolute; top: var(--nav-h); left: 0; right: 0;
                background: var(--card-bg); flex-direction: column; padding: 12px;
                border-bottom: 1px solid var(--border); box-shadow: var(--shadow-md);
                max-height: calc(100vh - var(--nav-h)); overflow-y: auto;
            }
            .nav-links.open .nav-link { padding: 12px 16px; }
            .nav-toggle { display: flex; }
            .nav-user-info { display: none; }
            .nav-user { padding: 4px; }
            .stats-grid { grid-template-columns: 1fr; }
            .grid-2, .grid-3 { grid-template-columns: 1fr; }
            .container { padding: 20px 16px; }
            .page-title { font-size: 22px; }
        }
        @media (max-width: 1024px) and (min-width: 769px) {
            .nav-link { padding: 8px 10px; font-size: 13px; }
            .nav-link svg { width: 16px; height: 16px; }
            .nav-brand { font-size: 16px; }
            .nav-brand small { font-size: 10px; }
        }