/* ── Tab-Navigation ── */
        .tab-nav {
            display: flex;
            gap: 0.5rem;
            background: var(--panel-bg);
            border: 1px solid var(--border-color);
            border-radius: var(--radius);
            padding: 0.5rem;
            margin-bottom: 2rem;
            flex-wrap: wrap;
        }

        .tab-btn {
            flex: 1;
            min-width: 140px;
            padding: 0.75rem 1.2rem;
            border: none;
            border-radius: 10px;
            cursor: pointer;
            font-size: 0.95rem;
            font-weight: 600;
            color: var(--clr-muted);
            background: transparent;
            transition: var(--transition-fast);
            display: flex;
            align-items: center;
            justify-content: center;
            gap: 0.5rem;
            font-family: inherit;
        }

        .tab-btn:hover {
            color: var(--clr-text);
            background: var(--box-bg);
        }

        .tab-btn.active {
            background: linear-gradient(135deg, var(--clr-accent), var(--clr-accent2));
            color: var(--clr-on-accent);
            box-shadow: 0 4px 12px rgba(52, 211, 153, 0.25);
        }

        .tab-content {
            display: none;
        }

        .tab-content.active {
            display: block;
            animation: fadeIn 0.3s ease;
        }

        /* ── Info-Karten ── */
        .info-grid {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
            gap: 1rem;
            margin-bottom: 1.5rem;
        }

        .info-card {
            background: var(--panel-bg);
            border: 1px solid var(--border-color);
            border-radius: var(--radius);
            padding: 1.4rem;
            border-left: 4px solid var(--clr-accent);
            transition: var(--transition-fast);
        }

        .info-card:hover {
            border-color: var(--clr-accent);
            box-shadow: var(--shadow);
        }

        .info-card.c-green {
            border-left-color: var(--success);
        }

        .info-card.c-blue {
            border-left-color: var(--clr-accent2);
        }

        .info-card.c-purple {
            border-left-color: #a78bfa;
        }

        .info-card.c-yellow {
            border-left-color: var(--warning);
        }

        .info-card.c-red {
            border-left-color: var(--danger);
        }

        .info-card h3 {
            font-size: 1rem;
            font-weight: 700;
            margin-bottom: 0.6rem;
            color: var(--clr-text);
        }

        .info-card p {
            font-size: 0.9rem;
            color: var(--clr-muted);
            line-height: 1.6;
        }

        /* ── Formel-Box ── */
        .formula-box {
            background: var(--box-bg);
            border: 1px dashed var(--clr-accent);
            border-radius: 8px;
            padding: 0.6rem 1rem;
            margin: 0.7rem 0;
            font-family: 'Courier New', monospace;
            font-size: 1rem;
            font-weight: 700;
            text-align: center;
            color: var(--clr-accent-text);
        }

        .formula-box.blue {
            border-color: var(--clr-accent2);
            color: var(--clr-accent2-text);
        }

        .formula-box.purple {
            border-color: #a78bfa;
            color: #a78bfa;
        }

        .formula-box.yellow {
            border-color: var(--warning);
            color: var(--warning-text);
        }

        .formula-box.red {
            border-color: var(--danger);
            color: var(--danger-text);
        }

        /* ── Merksatz ── */
        .merksatz {
            background: rgba(251, 191, 36, 0.08);
            border: 1px solid rgba(251, 191, 36, 0.4);
            border-left: 4px solid var(--warning);
            border-radius: 8px;
            padding: 0.9rem 1.2rem;
            margin: 0.8rem 0;
            font-weight: 600;
            color: var(--warning-text);
            font-size: 0.9rem;
        }

        .merksatz::before {
            content: "💡 Merksatz: ";
        }

        /* ── Beispiel-Box ── */
        .example-box {
            background: rgba(52, 211, 153, 0.06);
            border: 1px solid rgba(52, 211, 153, 0.2);
            border-left: 4px solid var(--success);
            border-radius: 8px;
            padding: 0.9rem 1.2rem;
            margin: 0.8rem 0;
            font-size: 0.9rem;
            color: var(--clr-muted);
            line-height: 1.6;
        }

        .example-box strong {
            color: var(--success-text);
        }

        /* ── Dreisatz-Tabelle ── */
        .dreisatz-table {
            width: 100%;
            border-collapse: collapse;
            margin: 1rem 0;
            border-radius: 10px;
            overflow: hidden;
            font-size: 0.9rem;
        }

        .dreisatz-table th {
            background: linear-gradient(135deg, var(--clr-accent), var(--clr-accent2));
            color: var(--clr-on-accent);
            padding: 0.7rem 1rem;
            text-align: center;
            font-weight: 700;
        }

        .dreisatz-table td {
            padding: 0.6rem 1rem;
            text-align: center;
            border-bottom: 1px solid var(--border-color);
            color: var(--clr-muted);
            background: var(--box-bg);
        }

        .dreisatz-table tr:nth-child(even) td {
            background: var(--panel-bg);
        }

        .dreisatz-table td.hl {
            color: var(--clr-accent-text);
            font-weight: 700;
            background: rgba(52, 211, 153, 0.08);
        }

        /* ── Section-Divider ── */
        .section-divider {
            height: 2px;
            background: linear-gradient(90deg, var(--clr-accent), var(--clr-accent2), transparent);
            border-radius: 2px;
            margin: 1.8rem 0;
        }

        /* ── Übungs-Karten ── */
        .exercise-card {
            background: var(--panel-bg);
            border: 1px solid var(--border-color);
            border-radius: var(--radius);
            padding: 1.8rem;
            margin-bottom: 1.5rem;
            box-shadow: var(--shadow-sm);
            transition: var(--transition-fast);
        }

        .exercise-card:hover {
            box-shadow: var(--shadow);
        }

        .exercise-card.is-correct {
            border-color: var(--success);
            background: rgba(52, 211, 153, 0.04);
        }

        .exercise-card.is-wrong {
            border-color: var(--danger);
            background: rgba(248, 113, 113, 0.04);
        }

        .exercise-header {
            display: flex;
            justify-content: space-between;
            align-items: flex-start;
            margin-bottom: 1rem;
            flex-wrap: wrap;
            gap: 0.5rem;
        }

        .exercise-title {
            font-size: 1.05rem;
            font-weight: 700;
            color: var(--clr-text);
            display: flex;
            align-items: center;
            flex-wrap: wrap;
            gap: 0.5rem;
        }

        .diff-badge {
            padding: 0.2rem 0.7rem;
            border-radius: 999px;
            font-size: 0.75rem;
            font-weight: 700;
        }

        .diff-1 {
            background: rgba(52, 211, 153, 0.15);
            color: var(--success-text);
        }

        .diff-2 {
            background: rgba(251, 191, 36, 0.15);
            color: var(--warning-text);
        }

        .diff-3 {
            background: rgba(248, 113, 113, 0.15);
            color: var(--danger-text);
        }

        .topic-tag {
            display: inline-block;
            padding: 0.15rem 0.6rem;
            border-radius: 999px;
            font-size: 0.72rem;
            font-weight: 700;
            text-transform: uppercase;
            letter-spacing: 0.04em;
        }

        .tag-prozentsatz {
            background: rgba(56, 189, 248, 0.15);
            color: var(--clr-accent2-text);
        }

        .tag-prozentwert {
            background: rgba(52, 211, 153, 0.15);
            color: var(--success-text);
        }

        .tag-grundwert {
            background: rgba(167, 139, 250, 0.15);
            color: #a78bfa;
        }

        .tag-zins {
            background: rgba(251, 191, 36, 0.15);
            color: var(--warning-text);
        }

        .tag-zinseszins {
            background: rgba(248, 113, 113, 0.15);
            color: var(--danger-text);
        }

        .exercise-text {
            font-size: 0.95rem;
            line-height: 1.7;
            color: var(--clr-muted);
            margin-bottom: 1.2rem;
        }

        /* ── Interaktive Tabelle ── */
        .input-table {
            width: 100%;
            border-collapse: collapse;
            margin: 0.8rem 0;
            border-radius: 10px;
            overflow: hidden;
            font-size: 0.9rem;
        }

        .input-table th {
            background: linear-gradient(135deg, rgba(52, 211, 153, 0.2), rgba(56, 189, 248, 0.2));
            color: var(--clr-text);
            padding: 0.7rem 1rem;
            text-align: center;
            font-weight: 700;
            border-bottom: 1px solid var(--border-color);
        }

        .input-table td {
            padding: 0.55rem 0.8rem;
            text-align: center;
            border-bottom: 1px solid var(--border-color);
            background: var(--box-bg);
        }

        .input-table tr:nth-child(even) td {
            background: var(--panel-bg);
        }

        .input-table input[type="text"] {
            width: 100%;
            padding: 0.45rem 0.7rem;
            border: 1px solid var(--border-color);
            border-radius: 8px;
            font-size: 0.9rem;
            text-align: center;
            transition: var(--transition-fast);
            background: var(--clr-bg);
            color: var(--clr-text);
            font-family: inherit;
        }

        .input-table input:focus {
            outline: none;
            border-color: var(--clr-accent);
            box-shadow: 0 0 0 3px rgba(52, 211, 153, 0.15);
        }

        .input-table input.inp-correct {
            border-color: var(--success);
            background: rgba(52, 211, 153, 0.08);
            color: var(--success-text);
        }

        .input-table input.inp-wrong {
            border-color: var(--danger);
            background: rgba(248, 113, 113, 0.08);
            color: var(--danger-text);
        }

        .filled-val {
            display: inline-block;
            background: rgba(52, 211, 153, 0.1);
            border: 1px solid rgba(52, 211, 153, 0.3);
            border-radius: 6px;
            padding: 0.3rem 0.7rem;
            font-weight: 700;
            color: var(--clr-accent-text);
            font-size: 0.9rem;
        }

        /* ── Haupt-Antwort-Feld ── */
        .main-answer-row {
            display: flex;
            align-items: center;
            gap: 1rem;
            flex-wrap: wrap;
            margin-top: 1.2rem;
        }

        .main-answer-row label {
            font-weight: 700;
            color: var(--clr-text);
            font-size: 0.95rem;
        }

        .main-answer-input {
            border: 2px solid var(--border-color);
            border-radius: 10px;
            padding: 0.55rem 1rem;
            font-size: 1.05rem;
            font-weight: 700;
            width: 140px;
            text-align: center;
            background: var(--clr-bg);
            color: var(--clr-text);
            font-family: inherit;
            transition: var(--transition-fast);
        }

        .main-answer-input:focus {
            outline: none;
            border-color: var(--clr-accent);
            box-shadow: 0 0 0 3px rgba(52, 211, 153, 0.15);
        }

        .main-answer-input.inp-correct {
            border-color: var(--success);
            background: rgba(52, 211, 153, 0.08);
            color: var(--success-text);
        }

        .main-answer-input.inp-wrong {
            border-color: var(--danger);
            background: rgba(248, 113, 113, 0.08);
            color: var(--danger-text);
        }

        .unit-label {
            font-weight: 600;
            color: var(--clr-muted);
        }

        /* ── Btn-Gruppe ── */
        .btn-group {
            display: flex;
            gap: 0.6rem;
            flex-wrap: wrap;
            margin-top: 1rem;
        }

        .zec-btn {
            padding: 0.55rem 1.2rem;
            border: 1px solid var(--border-color);
            border-radius: 8px;
            cursor: pointer;
            font-size: 0.88rem;
            font-weight: 600;
            transition: var(--transition-fast);
            display: inline-flex;
            align-items: center;
            gap: 0.4rem;
            font-family: inherit;
            background: var(--box-bg);
            color: var(--clr-muted);
        }

        .zec-btn:hover {
            transform: translateY(-1px);
            box-shadow: var(--shadow-sm);
            color: var(--clr-text);
            border-color: var(--clr-muted);
        }

        .zec-btn.btn-primary {
            background: linear-gradient(135deg, var(--clr-accent), var(--clr-accent2));
            color: var(--clr-on-accent);
            border: none;
            box-shadow: 0 3px 10px rgba(52, 211, 153, 0.2);
        }

        .zec-btn.btn-primary:hover {
            box-shadow: 0 6px 20px rgba(52, 211, 153, 0.35);
            color: var(--clr-on-accent);
        }

        .zec-btn.btn-tip {
            color: var(--warning-text);
            border-color: rgba(251, 191, 36, 0.3);
        }

        .zec-btn.btn-tip:hover {
            background: rgba(251, 191, 36, 0.08);
        }

        .zec-btn.btn-solution {
            color: var(--clr-accent2-text);
            border-color: rgba(56, 189, 248, 0.3);
        }

        .zec-btn.btn-solution:hover {
            background: rgba(56, 189, 248, 0.08);
        }

        .zec-btn.btn-reset-ex {
            color: var(--clr-muted);
        }

        .zec-btn.btn-reset-ex:hover {
            color: var(--clr-text);
        }

        /* ── Feedback ── */
        .ex-feedback {
            border-radius: 10px;
            padding: 0.9rem 1.2rem;
            margin-top: 1rem;
            font-weight: 600;
            font-size: 0.9rem;
            display: none;
            animation: fadeIn 0.3s ease;
        }

        .ex-feedback.show {
            display: block;
        }

        .ex-feedback.f-success {
            background: rgba(52, 211, 153, 0.08);
            border: 1px solid var(--success);
            color: var(--success-text);
        }

        .ex-feedback.f-error {
            background: rgba(248, 113, 113, 0.08);
            border: 1px solid var(--danger);
            color: var(--danger-text);
        }

        .ex-feedback.f-tip {
            background: rgba(251, 191, 36, 0.08);
            border: 1px solid var(--warning);
            color: var(--warning-text);
        }

        /* ── Lösung ── */
        .solution-box {
            background: rgba(56, 189, 248, 0.05);
            border: 1px solid rgba(56, 189, 248, 0.25);
            border-radius: 10px;
            padding: 1.1rem 1.3rem;
            margin-top: 1rem;
            display: none;
        }

        .solution-box.show {
            display: block;
            animation: fadeIn 0.3s ease;
        }

        .solution-box h4 {
            color: var(--clr-accent2-text);
            margin-bottom: 0.7rem;
            font-size: 0.95rem;
        }

        .solution-step {
            background: var(--box-bg);
            border: 1px solid var(--border-color);
            border-left: 3px solid var(--clr-accent2);
            border-radius: 6px;
            padding: 0.5rem 0.9rem;
            margin: 0.35rem 0;
            font-size: 0.88rem;
            color: var(--clr-muted);
        }

        .solution-formula {
            margin-top: 0.7rem;
            padding: 0.55rem 1rem;
            background: var(--box-bg);
            border-radius: 8px;
            font-family: 'Courier New', monospace;
            font-size: 0.88rem;
            font-weight: 700;
            color: var(--clr-accent-text);
            border: 1px solid rgba(52, 211, 153, 0.2);
        }

        /* ── Kategorie-Filter ── */
        .category-filter {
            display: flex;
            flex-wrap: wrap;
            gap: 0.5rem;
            margin-bottom: 1.5rem;
            padding: 1rem 1.2rem;
            background: var(--panel-bg);
            border: 1px solid var(--border-color);
            border-radius: var(--radius);
        }

        .filter-chip {
            padding: 0.35rem 0.9rem;
            border-radius: 999px;
            border: 1px solid var(--border-color);
            background: var(--box-bg);
            cursor: pointer;
            font-size: 0.85rem;
            font-weight: 600;
            color: var(--clr-muted);
            transition: var(--transition-fast);
            font-family: inherit;
        }

        .filter-chip:hover {
            color: var(--clr-text);
            border-color: var(--clr-muted);
        }

        .filter-chip.active {
            background: linear-gradient(135deg, var(--clr-accent), var(--clr-accent2));
            color: var(--clr-on-accent);
            border-color: transparent;
        }

        /* ── Streak Banner ── */
        .streak-banner {
            display: flex;
            align-items: center;
            gap: 1.2rem;
            background: linear-gradient(135deg, rgba(251, 107, 53, 0.15), rgba(247, 197, 159, 0.1));
            border: 1px solid rgba(251, 107, 53, 0.3);
            border-radius: var(--radius);
            padding: 1rem 1.5rem;
            margin-bottom: 1.5rem;
        }

        .streak-number {
            font-size: 2.8rem;
            font-weight: 900;
            background: linear-gradient(135deg, #ff6b35, #fbbf24);
            -webkit-background-clip: text;
            -webkit-text-fill-color: transparent;
            background-clip: text;
            line-height: 1;
        }

        .streak-label {
            font-size: 1rem;
            font-weight: 700;
            color: var(--clr-text);
        }

        .streak-sub {
            font-size: 0.82rem;
            color: var(--clr-muted);
            margin-top: 0.2rem;
        }

        .streak-total {
            margin-left: auto;
            text-align: center;
        }

        .streak-total .num {
            font-size: 1.8rem;
            font-weight: 800;
            color: var(--clr-accent-text);
        }

        .streak-total .lbl {
            font-size: 0.75rem;
            color: var(--clr-muted);
        }

        /* ── Badges ── */
        .badges-grid {
            display: flex;
            flex-wrap: wrap;
            gap: 0.8rem;
        }

        .badge-item {
            display: flex;
            flex-direction: column;
            align-items: center;
            gap: 0.3rem;
            padding: 0.9rem 0.7rem;
            border-radius: 12px;
            border: 1px solid var(--border-color);
            background: var(--box-bg);
            width: 90px;
            text-align: center;
            transition: var(--transition-fast);
            cursor: default;
        }

        .badge-item.earned {
            border-color: var(--warning);
            background: rgba(251, 191, 36, 0.08);
            box-shadow: 0 0 15px rgba(251, 191, 36, 0.15);
        }

        .badge-item.locked {
            opacity: 0.35;
            filter: grayscale(1);
        }

        .badge-emoji {
            font-size: 1.8rem;
        }

        .badge-name {
            font-size: 0.7rem;
            font-weight: 700;
            color: var(--clr-muted);
        }

        .badge-item.earned .badge-name {
            color: var(--warning-text);
        }

        /* ── Statistik ── */
        .stats-grid {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(130px, 1fr));
            gap: 1rem;
            margin-bottom: 1.5rem;
        }

        .stat-card {
            background: var(--box-bg);
            border: 1px solid var(--border-color);
            border-radius: 12px;
            padding: 1.1rem;
            text-align: center;
            transition: var(--transition-fast);
        }

        .stat-card:hover {
            border-color: var(--clr-accent);
            box-shadow: var(--shadow-sm);
        }

        .stat-number {
            font-size: 2rem;
            font-weight: 800;
            background: linear-gradient(135deg, var(--clr-accent), var(--clr-accent2));
            -webkit-background-clip: text;
            -webkit-text-fill-color: transparent;
            background-clip: text;
        }

        .stat-label {
            font-size: 0.78rem;
            color: var(--clr-muted);
            margin-top: 0.25rem;
        }

        .progress-wrap {
            background: var(--box-bg);
            border: 1px solid var(--border-color);
            border-radius: 999px;
            height: 14px;
            overflow: hidden;
            margin: 0.5rem 0;
        }

        .progress-fill {
            height: 100%;
            border-radius: 999px;
            background: linear-gradient(90deg, var(--clr-accent), var(--clr-accent2));
            transition: width 0.6s ease;
        }

        .progress-fill.f-warn {
            background: linear-gradient(90deg, var(--warning), #f59e0b);
        }

        .progress-fill.f-danger {
            background: linear-gradient(90deg, var(--danger), #f87171);
        }

        /* ── History ── */
        .history-item {
            display: flex;
            justify-content: space-between;
            align-items: center;
            padding: 0.6rem 0.9rem;
            border-radius: 8px;
            margin: 0.2rem 0;
            border: 1px solid var(--border-color);
            background: var(--box-bg);
            font-size: 0.88rem;
        }

        .history-item.h-correct {
            border-left: 3px solid var(--success);
        }

        .history-item.h-wrong {
            border-left: 3px solid var(--danger);
        }

        .history-item .h-title {
            color: var(--clr-text);
            font-weight: 600;
        }

        .history-item .h-time {
            color: var(--clr-muted);
            font-size: 0.78rem;
        }

        /* ── Notification ── */
        .notification {
            position: fixed;
            top: 5rem;
            right: 1.5rem;
            background: var(--panel-bg);
            border: 1px solid var(--border-color);
            border-left: 4px solid var(--success);
            border-radius: var(--radius);
            padding: 1rem 1.4rem;
            box-shadow: var(--shadow-lg);
            z-index: 3000;
            max-width: 300px;
            display: none;
            animation: slideIn 0.3s ease;
        }

        .notification.show {
            display: block;
        }

        .notification.n-badge {
            border-left-color: var(--warning);
        }

        .notification.n-error {
            border-left-color: var(--danger);
        }

        .notif-title {
            font-weight: 700;
            font-size: 0.95rem;
            color: var(--clr-text);
            margin-bottom: 0.2rem;
        }

        .notif-text {
            font-size: 0.85rem;
            color: var(--clr-muted);
        }

        @keyframes slideIn {
            from {
                transform: translateX(80px);
                opacity: 0;
            }

            to {
                transform: translateX(0);
                opacity: 1;
            }
        }

        /* ── Confetti ── */
        .confetti-container {
            position: fixed;
            top: 0;
            left: 0;
            width: 100%;
            height: 100%;
            pointer-events: none;
            z-index: 9999;
        }

        /* ── Reset-Button ── */
        .danger-btn {
            background: transparent;
            border: 1px solid rgba(248, 113, 113, 0.3);
            color: var(--danger-text);
            padding: 0.45rem 0.9rem;
            border-radius: 8px;
            cursor: pointer;
            font-size: 0.85rem;
            font-weight: 600;
            transition: var(--transition-fast);
            font-family: inherit;
        }

        .danger-btn:hover {
            background: rgba(248, 113, 113, 0.1);
        }

        /* ── Kategorie-Stats ── */
        .cat-stat-row {
            margin: 0.8rem 0;
        }

        .cat-stat-header {
            display: flex;
            justify-content: space-between;
            margin-bottom: 0.3rem;
            font-size: 0.9rem;
        }

        .cat-stat-header span:first-child {
            font-weight: 600;
            color: var(--clr-text);
        }

        .cat-stat-header span:last-child {
            color: var(--clr-muted);
        }

        /* ── Responsive ── */
        @media (max-width: 600px) {
            .tab-btn {
                font-size: 0.82rem;
                padding: 0.6rem 0.8rem;
            }

            .streak-number {
                font-size: 2rem;
            }

            .info-grid {
                grid-template-columns: 1fr;
            }
        }
    
        /* Kontrast-Korrekturen (WCAG AA, 2026-10-07): gleiche Farbtöne, nur dunkler bzw. heller */
        html[data-theme="light"] .formula-box.purple { color: #774bf7; }  /* statt #a78bfa */