/* ── Fortschrittsbalken ── */
        #fortschritt-bar {
            position: sticky;
            top: 0;
            z-index: 200;
            height: 4px;
            background: var(--border-color);
        }

        #fortschritt-fill {
            height: 100%;
            width: 0%;
            background: linear-gradient(90deg, var(--clr-accent), var(--clr-accent2));
            transition: width .3s ease;
        }

        /* ── Zweispaltiges Layout ── */
        .lern-wrapper {
            display: grid;
            grid-template-columns: 220px 1fr;
            gap: 2rem;
            width: 100%;
            align-items: start;
        }

        /* ── Sidebar-Navigation ── */
        .lern-nav {
            position: sticky;
            top: 1.5rem;
            background: var(--panel-bg);
            border: 1px solid var(--border-color);
            border-radius: var(--radius);
            padding: 1rem;
            box-shadow: var(--shadow-sm);
        }

        .lern-nav h3 {
            font-size: .72rem;
            text-transform: uppercase;
            letter-spacing: .08em;
            font-weight: 700;
            color: var(--clr-muted);
            margin-bottom: .75rem;
            padding-left: .4rem;
        }

        .lern-nav a {
            display: flex;
            align-items: center;
            gap: .5rem;
            padding: .45rem .6rem;
            border-radius: 8px;
            color: var(--clr-muted);
            text-decoration: none;
            font-size: .88rem;
            transition: var(--transition-fast);
            font-weight: 500;
        }

        .lern-nav a:hover {
            color: var(--clr-text);
            background: var(--box-bg);
        }

        .lern-nav a.aktiv {
            background: rgba(52, 211, 153, 0.12);
            color: var(--clr-accent-text);
            font-weight: 700;
        }

        .lern-nav a .nav-num {
            width: 22px;
            height: 22px;
            border-radius: 50%;
            background: var(--box-bg);
            border: 1px solid var(--border-color);
            font-size: .72rem;
            text-align: center;
            line-height: 20px;
            font-weight: 700;
            flex-shrink: 0;
            transition: var(--transition-fast);
        }

        .lern-nav a.aktiv .nav-num {
            background: var(--clr-accent);
            color: var(--clr-on-accent);
            border-color: var(--clr-accent);
        }

        /* ── Kapitel-Karten ── */
        .kapitel {
            background: var(--panel-bg);
            border: 1px solid var(--border-color);
            border-radius: var(--radius);
            box-shadow: var(--shadow-sm);
            margin-bottom: 1.5rem;
            overflow: hidden;
            transition: var(--transition-fast);
        }

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

        .kapitel-header {
            display: flex;
            align-items: center;
            gap: .8rem;
            padding: 1rem 1.5rem;
            background: linear-gradient(90deg,
                    rgba(52, 211, 153, .15) 0%,
                    rgba(56, 189, 248, .08) 100%);
            border-bottom: 1px solid var(--border-color);
        }

        .kapitel-header .kap-num {
            width: 36px;
            height: 36px;
            border-radius: 50%;
            background: linear-gradient(135deg, var(--clr-accent), var(--clr-accent2));
            color: var(--clr-on-accent);
            display: flex;
            align-items: center;
            justify-content: center;
            font-weight: 800;
            font-size: 1rem;
            flex-shrink: 0;
        }

        .kapitel-header h2 {
            font-size: 1.15rem;
            font-weight: 700;
            color: var(--clr-text);
        }

        .kapitel-body {
            padding: 1.5rem;
        }

        .kapitel-body p {
            color: var(--clr-muted);
            margin-bottom: .85rem;
            font-size: .95rem;
            line-height: 1.7;
        }

        .kapitel-body h3 {
            font-size: .9rem;
            font-weight: 700;
            color: var(--clr-accent2-text);
            margin: 1.4rem 0 .6rem;
            display: flex;
            align-items: center;
            gap: .4rem;
        }

        .kapitel-body h3::before {
            content: '';
            display: block;
            width: 3px;
            height: 1em;
            background: var(--clr-accent2);
            border-radius: 2px;
        }

        .kapitel-body ul,
        .kapitel-body ol {
            margin: .4rem 0 .85rem 1.4rem;
            color: var(--clr-muted);
            font-size: .92rem;
        }

        .kapitel-body li {
            margin-bottom: .3rem;
            line-height: 1.6;
        }

        /* ── Inline Code ── */
        code {
            background: rgba(248, 113, 113, .12);
            color: var(--danger-text);
            border-radius: 4px;
            padding: .1em .35em;
            font-family: 'Fira Code', 'Consolas', monospace;
            font-size: .88em;
            font-weight: 600;
        }

        pre code {
            background: none;
            color: inherit;
            padding: 0;
            font-size: inherit;
            font-weight: normal;
        }

        /* ── Infoboxen ── */
        .infobox {
            display: flex;
            gap: .7rem;
            align-items: flex-start;
            border-radius: 8px;
            padding: .85rem 1rem;
            margin: .85rem 0;
            font-size: .9rem;
            line-height: 1.6;
        }

        .infobox-icon {
            font-size: 1.1rem;
            flex-shrink: 0;
            margin-top: .1rem;
        }

        .infobox.info {
            background: rgba(56, 189, 248, .08);
            border-left: 3px solid var(--clr-accent2);
            color: var(--clr-muted);
        }

        .infobox.warn {
            background: rgba(251, 191, 36, .08);
            border-left: 3px solid var(--warning);
            color: var(--clr-muted);
        }

        .infobox.tipp {
            background: rgba(52, 211, 153, .08);
            border-left: 3px solid var(--clr-accent);
            color: var(--clr-muted);
        }

        .infobox.aufgabe {
            background: rgba(251, 191, 36, .07);
            border-left: 3px solid var(--warning);
            color: var(--clr-muted);
        }

        /* ── Aufgaben-Badge ── */
        .aufgabe-badge {
            display: inline-flex;
            align-items: center;
            gap: .35rem;
            background: rgba(251, 191, 36, .15);
            color: var(--warning-text);
            border-radius: 999px;
            padding: .2rem .75rem;
            font-size: .75rem;
            font-weight: 700;
            text-transform: uppercase;
            letter-spacing: .05em;
            margin-bottom: .6rem;
        }

        /* ── Tabellen ── */
        .tabelle-wrap {
            overflow-x: auto;
            margin: .75rem 0;
        }

        table {
            width: 100%;
            border-collapse: collapse;
            font-size: .88rem;
        }

        th {
            background: rgba(52, 211, 153, .12);
            color: var(--clr-accent-text);
            padding: .55rem .85rem;
            text-align: left;
            font-weight: 700;
            font-size: .8rem;
            text-transform: uppercase;
            letter-spacing: .04em;
        }

        td {
            padding: .5rem .85rem;
            border-bottom: 1px solid var(--border-color);
            color: var(--clr-muted);
        }

        tr:last-child td {
            border-bottom: none;
        }

        tr:hover td {
            background: var(--box-bg);
        }

        /* ── Vergleich Java ↔ Python ── */
        .vergleich {
            display: grid;
            grid-template-columns: 1fr 1fr;
            gap: .85rem;
            margin: .85rem 0;
        }

        .vergleich>div {
            border-radius: 8px;
            overflow: hidden;
        }

        .vergleich-label {
            padding: .35rem .75rem;
            font-size: .75rem;
            font-weight: 700;
            letter-spacing: .05em;
            text-transform: uppercase;
        }

        .java-label {
            background: rgba(232, 113, 26, .25);
            color: #f59a45;
        }

        .py-label {
            background: rgba(55, 118, 171, .25);
            color: #7ec8e3;
        }

        .vergleich pre {
            margin: 0;
            border-radius: 0;
        }

        /* ── Code-Block ── */
        .code-block {
            margin: .85rem 0;
            border-radius: 10px;
            overflow: hidden;
            border: 1px solid var(--border-color);
            transition: border-color .2s;
        }

        .code-block:focus-within {
            border-color: var(--clr-accent);
        }

        .code-toolbar {
            background: #1a1e2e;
            display: flex;
            align-items: center;
            justify-content: space-between;
            padding: .4rem .75rem;
            border-bottom: 1px solid rgba(255, 255, 255, .06);
        }

        .code-toolbar .dots {
            display: flex;
            gap: .35rem;
        }

        .code-toolbar .dot {
            width: 11px;
            height: 11px;
            border-radius: 50%;
        }

        .dot-r {
            background: #ff5f57;
        }

        .dot-y {
            background: #febc2e;
        }

        .dot-g {
            background: #28c840;
        }

        .lang-badge {
            font-size: .72rem;
            color: var(--clr-muted);
            font-family: monospace;
            letter-spacing: .5px;
        }

        .shortcut-hint {
            font-size: .7rem;
            color: var(--clr-muted);
            font-family: monospace;
            opacity: .6;
        }

        textarea.code-input {
            width: 100%;
            background: #0d1117;
            color: #c9d1d9;
            border: none;
            outline: none;
            font-family: 'Fira Code', 'Consolas', monospace;
            font-size: .88rem;
            line-height: 1.65;
            padding: 1rem;
            resize: vertical;
            min-height: 70px;
            tab-size: 4;
            box-sizing: border-box;
        }

        .code-actions {
            background: #1a1e2e;
            padding: .45rem .75rem;
            display: flex;
            gap: .5rem;
            align-items: center;
            flex-wrap: wrap;
            border-top: 1px solid rgba(255, 255, 255, .06);
        }

        /* ── Buttons ── */
        .btn {
            padding: .4rem .9rem;
            border: 1px solid var(--border-color);
            border-radius: 999px;
            cursor: pointer;
            font-size: .8rem;
            font-weight: 700;
            transition: var(--transition-fast);
            display: inline-flex;
            align-items: center;
            gap: .35rem;
            font-family: inherit;
            background: var(--box-bg);
            color: var(--clr-muted);
        }

        .btn:hover {
            transform: translateY(-1px);
            box-shadow: var(--shadow-sm);
        }

        .btn:active {
            transform: translateY(0);
        }

        .btn-run {
            background: rgba(52, 211, 153, .15);
            /* Code-Bereich ist in beiden Themes dunkel → helles Grün */
            color: #34d399;
            border-color: rgba(52, 211, 153, .3);
        }

        .btn-run:hover {
            background: var(--clr-accent);
            color: var(--clr-on-accent);
            border-color: var(--clr-accent);
        }

        .btn-reset-code {
            background: var(--box-bg);
            color: var(--clr-muted);
        }

        .btn-reset-code:hover {
            color: var(--clr-text);
            border-color: var(--clr-muted);
        }

        .btn-clear {
            background: rgba(248, 113, 113, .1);
            color: var(--danger-text);
            border-color: rgba(248, 113, 113, .25);
        }

        .btn-clear:hover {
            background: var(--danger);
            color: #fff;
            border-color: var(--danger);
        }

        .btn-test {
            background: rgba(167, 139, 250, .15);
            color: #a78bfa;
            border-color: rgba(167, 139, 250, .3);
        }

        .btn-test:hover {
            background: #a78bfa;
            color: #fff;
            border-color: #a78bfa;
        }

        .btn-test:disabled {
            opacity: .4;
            cursor: not-allowed;
            transform: none;
        }

        /* ── Ausgabe-Bereich ── */
        .output-area {
            background: #070d19;
            color: #c9d1d9;
            font-family: 'Fira Code', 'Consolas', monospace;
            font-size: .83rem;
            padding: .75rem 1rem;
            min-height: 36px;
            max-height: 280px;
            overflow-y: auto;
            white-space: pre-wrap;
            word-break: break-all;
            display: none;
            border-top: 1px solid rgba(255, 255, 255, .06);
        }

        .output-area.aktiv {
            display: block;
        }

        .out-error {
            color: var(--danger-text);
        }

        .out-info {
            color: rgba(56, 189, 248, .7);
            font-style: italic;
            font-size: .78rem;
        }

        /* ── Input-Simulation ── */
        .input-simuliert {
            background: #070d19;
            border-top: 1px solid rgba(56, 189, 248, .2);
            padding: .55rem 1rem;
            display: none;
            align-items: center;
            gap: .6rem;
        }

        .input-simuliert.aktiv {
            display: flex;
        }

        .input-simuliert label {
            color: var(--clr-accent2-text);
            font-size: .82rem;
            font-family: monospace;
            white-space: nowrap;
        }

        .input-simuliert input {
            flex: 1;
            background: transparent;
            border: none;
            border-bottom: 1px solid var(--clr-accent2);
            color: var(--clr-text);
            font-family: monospace;
            font-size: .82rem;
            outline: none;
            padding: .2rem;
        }

        .input-simuliert button {
            background: rgba(56, 189, 248, .15);
            border: 1px solid rgba(56, 189, 248, .3);
            color: var(--clr-accent2-text);
            border-radius: 999px;
            padding: .25rem .7rem;
            cursor: pointer;
            font-size: .78rem;
            font-weight: 700;
            font-family: inherit;
            transition: var(--transition-fast);
        }

        .input-simuliert button:hover {
            background: var(--clr-accent2);
            color: var(--clr-on-accent);
        }

        /* ── Quiz ── */
        .quiz-box {
            background: var(--box-bg);
            border: 1px solid var(--border-color);
            border-radius: 10px;
            padding: 1rem 1.1rem;
            margin: 1rem 0;
        }

        .quiz-frage {
            font-weight: 700;
            margin-bottom: .65rem;
            font-size: .92rem;
            color: var(--clr-text);
        }

        .quiz-optionen {
            display: flex;
            flex-direction: column;
            gap: .4rem;
        }

        .quiz-option {
            background: var(--panel-bg);
            border: 1px solid var(--border-color);
            border-radius: 7px;
            padding: .55rem .85rem;
            cursor: pointer;
            transition: var(--transition-fast);
            font-size: .88rem;
            color: var(--clr-muted);
        }

        .quiz-option:hover {
            border-color: var(--clr-accent2);
            color: var(--clr-text);
            background: rgba(56, 189, 248, .06);
        }

        .quiz-option.richtig {
            border-color: var(--clr-accent);
            background: rgba(52, 211, 153, .12);
            color: var(--clr-accent-text);
            font-weight: 700;
        }

        .quiz-option.falsch {
            border-color: var(--danger);
            background: rgba(248, 113, 113, .1);
            color: var(--danger-text);
        }

        .quiz-feedback {
            margin-top: .6rem;
            font-size: .88rem;
            display: none;
            padding: .5rem .75rem;
            border-radius: 7px;
        }

        .quiz-feedback.richtig {
            display: block;
            background: rgba(52, 211, 153, .1);
            color: var(--clr-accent-text);
            border-left: 3px solid var(--clr-accent);
        }

        .quiz-feedback.falsch {
            display: block;
            background: rgba(248, 113, 113, .1);
            color: var(--danger-text);
            border-left: 3px solid var(--danger);
        }

        /* ── Test-Panel ── */
        .test-panel {
            display: none;
            border-top: 1px dashed rgba(167, 139, 250, .4);
            background: rgba(167, 139, 250, .05);
            padding: 1rem 1.2rem;
        }

        .test-panel.aktiv {
            display: block;
        }

        .test-panel-header {
            display: flex;
            align-items: center;
            gap: .6rem;
            margin-bottom: .75rem;
        }

        .test-panel-header h4 {
            font-size: .9rem;
            color: #a78bfa;
            font-weight: 700;
            flex: 1;
        }

        .test-summary {
            font-size: .78rem;
            font-weight: 700;
            padding: .25rem .75rem;
            border-radius: 999px;
        }

        .test-summary.alle-ok {
            background: rgba(52, 211, 153, .15);
            color: var(--clr-accent-text);
            border: 1px solid rgba(52, 211, 153, .3);
        }

        .test-summary.teils-ok {
            background: rgba(251, 191, 36, .15);
            color: var(--warning-text);
            border: 1px solid rgba(251, 191, 36, .3);
        }

        .test-summary.alle-fail {
            background: rgba(248, 113, 113, .15);
            color: var(--danger-text);
            border: 1px solid rgba(248, 113, 113, .3);
        }

        .test-gesamt-hinweis {
            font-size: .85rem;
            padding: .6rem .85rem;
            border-radius: 8px;
            margin-bottom: .75rem;
            font-weight: 600;
        }

        .test-gesamt-hinweis.ok {
            background: rgba(52, 211, 153, .1);
            color: var(--clr-accent-text);
            border-left: 3px solid var(--clr-accent);
        }

        .test-gesamt-hinweis.warn {
            background: rgba(251, 191, 36, .1);
            color: var(--warning-text);
            border-left: 3px solid var(--warning);
        }

        .test-gesamt-hinweis.fail {
            background: rgba(248, 113, 113, .1);
            color: var(--danger-text);
            border-left: 3px solid var(--danger);
        }

        .test-liste {
            display: flex;
            flex-direction: column;
            gap: .4rem;
        }

        .test-item {
            border-radius: 8px;
            overflow: hidden;
            border: 1px solid var(--border-color);
            background: var(--panel-bg);
        }

        .test-item-header {
            display: flex;
            align-items: center;
            gap: .55rem;
            padding: .5rem .75rem;
            cursor: pointer;
            user-select: none;
            transition: background .15s;
        }

        .test-item-header:hover {
            background: var(--box-bg);
        }

        .test-status-icon {
            font-size: 1rem;
            flex-shrink: 0;
        }

        .test-titel {
            font-size: .83rem;
            font-weight: 600;
            flex: 1;
            color: var(--clr-text);
        }

        .test-chevron {
            font-size: .7rem;
            color: var(--clr-muted);
            transition: transform .2s;
        }

        .test-item.open .test-chevron {
            transform: rotate(90deg);
        }

        .test-item-body {
            display: none;
            padding: .55rem .85rem .75rem;
            border-top: 1px solid var(--border-color);
            font-size: .83rem;
        }

        .test-item.open .test-item-body {
            display: block;
        }

        .test-row {
            display: grid;
            grid-template-columns: 120px 1fr;
            gap: .2rem .5rem;
            margin-bottom: .3rem;
            align-items: start;
        }

        .test-label {
            color: var(--clr-muted);
            font-size: .78rem;
            font-weight: 700;
            text-transform: uppercase;
            letter-spacing: .04em;
            padding-top: .2rem;
        }

        .test-val {
            font-family: 'Fira Code', monospace;
            font-size: .8rem;
            background: var(--box-bg);
            border-radius: 4px;
            padding: .15rem .4rem;
            word-break: break-all;
            color: var(--clr-muted);
        }

        .test-val.ok {
            background: rgba(52, 211, 153, .1);
            color: var(--clr-accent-text);
        }

        .test-val.fail {
            background: rgba(248, 113, 113, .1);
            color: var(--danger-text);
        }

        .test-hinweis {
            margin-top: .55rem;
            padding: .55rem .75rem;
            border-radius: 7px;
            font-size: .83rem;
            line-height: 1.55;
        }

        .test-hinweis.ok {
            background: rgba(52, 211, 153, .08);
            color: #6ee7b7;
            border-left: 3px solid var(--clr-accent);
        }

        .test-hinweis.fail {
            background: rgba(251, 191, 36, .08);
            color: #fcd34d;
            border-left: 3px solid var(--warning);
        }

        .test-hinweis.err {
            background: rgba(248, 113, 113, .08);
            color: var(--danger-text);
            border-left: 3px solid var(--danger);
        }

        /* ── Spinner ── */
        @keyframes spin {
            to {
                transform: rotate(360deg);
            }
        }

        .spinner {
            width: 14px;
            height: 14px;
            border: 2px solid rgba(167, 139, 250, .3);
            border-top-color: #a78bfa;
            border-radius: 50%;
            animation: spin .65s linear infinite;
            display: inline-block;
        }

        /* ── Responsive ── */
        @media (max-width: 860px) {
            .lern-wrapper {
                grid-template-columns: 1fr;
            }

            .lern-nav {
                position: static;
            }

            .vergleich {
                grid-template-columns: 1fr;
            }

            .test-row {
                grid-template-columns: 1fr;
            }
        }

        .hljs {
            border-radius: 0;
        }

        html[data-theme="light"] .kapitel-header {
            background: linear-gradient(90deg, rgba(16, 185, 129, .08) 0%, rgba(14, 165, 233, .05) 100%);
        }

        html[data-theme="light"] .kapitel-header h2 {
            color: var(--clr-text);
        }

        html[data-theme="light"] textarea.code-input {
            background: #1c2333;
        }

        html[data-theme="light"] .code-toolbar {
            background: #1a1e2e;
        }

        html[data-theme="light"] .code-actions {
            background: #1a1e2e;
        }

        html[data-theme="light"] .output-area {
            background: #0d1117;
        }

        html[data-theme="light"] .input-simuliert {
            background: #0d1117;
        }

        ::-webkit-scrollbar {
            width: 5px;
            height: 5px;
        }

        ::-webkit-scrollbar-track {
            background: var(--clr-bg);
        }

        ::-webkit-scrollbar-thumb {
            background: var(--border-color);
            border-radius: 3px;
        }

        /* ── Barrierefreiheit: Kontraste (WCAG AA) ──
           Code-Editor (Kopf- und Aktionsleiste) ist in beiden Themes dunkel →
           feste helle Schriftfarben statt Theme-Farben */
        .code-toolbar .lang-badge,
        .code-toolbar .shortcut-hint {
            color: #94a3b8;
            opacity: 1;
        }

        .code-actions .btn.btn-run {
            color: #34d399;
        }

        .code-actions .btn.btn-reset-code {
            color: #94a3b8;
        }

        .code-actions .btn.btn-clear {
            color: #fca5a5;
        }

        .code-actions .btn.btn-test {
            color: #c4b5fd;
        }

        /* Kommentarfarbe aus atom-one-dark (#5c6370) ist zu kontrastarm */
        .hljs-comment,
        .hljs-quote {
            color: #9ca3af;
        }

        /* Codebeispiele bleiben im hellen Theme dunkel hinterlegt – die
           Inline-code-Regel darf pre code nicht rosa einfärben */
        html[data-theme="light"] pre code.hljs {
            background: #282c34;
            color: #abb2bf;
        }

        html[data-theme="light"] .java-label {
            color: #9a3412;
        }

        html[data-theme="light"] .py-label {
            color: #1e3a8a;
        }