:root {
    /* März-Akademie Farbpalette */
    --bg-main: #F3F2EF;
    --card-bg: #FAF8F2;
    --math-bg: #FDE7D7; /* Soft Apricot für mathematische Ausdrücke */
    
    --text-main: #1E4349; /* Teal */
    --text-muted: #5a7b80; 
    
    --primary: #1E4349; /* Teal */
    --primary-hover: #132d31; 
    --accent: #F9A077; /* Apricot */
    --accent-hover: #e28a62;
    
    /* Semantische Feedback-Farben */
    --error: #e63946;
    --error-bg: #fdf0f1;
    --success: #2a9d8f;
    --success-bg: #f0fdfa;
    
    --border-color: #d6e0e2; 
}

* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

body {
    font-family: 'Geist', sans-serif;
    background: radial-gradient(circle at 85% 20%, #faece3 0%, var(--bg-main) 60%);
    background-color: var(--bg-main);
    background-attachment: fixed;
    color: var(--text-main);
    padding: 40px 20px;
    display: flex;
    flex-direction: column;
    align-items: center;
    min-height: 100vh;
}

/* ZURÜCK-BOX (Mit modernem Glaseffekt wie im Skilltree) */
.back-btn {
    /* Positionierung und Glaseffekt direkt auf dem interaktiven Element */
    position: fixed;
    top: 20px;
    left: 20px;
    background-color: rgba(250, 248, 242, 0.6);
    backdrop-filter: blur(10px);
    border: 1px solid rgba(255, 255, 255, 0.4);
    padding: 14px 20px;
    border-radius: 16px;
    box-shadow: 0 8px 30px rgba(30, 67, 73, 0.05);
    z-index: 100;

    /* Layout-Anpassung, damit das Padding Teil des Klickbereichs ist */
    display: inline-flex;
    align-items: center;
    gap: 8px; /* Abstand, falls du später ein Icon anstelle des Textpfeils einbaust */

    /* Typografie */
    font-size: 0.85rem;
    font-weight: 600;
    color: var(--text-muted);
    text-decoration: none;
    transition: color 0.2s ease, background-color 0.2s ease;
    cursor: pointer;
}

.back-btn:hover {
    color: var(--primary);
    background-color: rgba(250, 248, 242, 0.85); /* Optionales visuelles Feedback für den gesamten Button */
}

.container {
    max-width: 750px;
    width: 100%;
}

header {
    text-align: center;
    margin-bottom: 40px;
    margin-top: 60px; /* Platz wegen der fixierten Back-Box */
}

header h1 {
    font-family: 'Fraunces', serif;
    font-size: 2.2rem;
    font-weight: 800;
    color: var(--primary);
    margin-bottom: 12px;
    letter-spacing: -0.02em;
}

header p {
    color: var(--text-muted);
    font-size: 1.05rem;
    line-height: 1.6;
}

.section-title {
    font-family: 'Geist', sans-serif;
    font-size: 1.25rem;
    font-weight: 700;
    margin: 32px 0 16px 0;
    color: var(--primary);
    border-left: 4px solid var(--accent); /* Apricot Akzentbalken */
    padding-left: 12px;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.quiz-form {
    display: flex;
    flex-direction: column;
    gap: 20px;
}

#roundQuestions {
    display: flex;
    flex-direction: column;
    gap: 20px;
}

.question-card {
    position: relative;
    background-color: var(--card-bg);
    border: none;
    border-radius: 24px;
    padding: 32px;
    box-shadow: 0 8px 30px rgba(30, 67, 73, 0.06);
}

.question-card::before {
    content: "";
    position: absolute;
    top: 32px;
    bottom: 32px;
    left: 0;
    width: 4px;
    background-color: var(--primary);
    border-radius: 0 4px 4px 0;
}

.question-header {
    font-size: 0.78rem;
    text-transform: uppercase;
    letter-spacing: 0.07em;
    color: var(--text-muted);
    font-weight: 600;
    margin-bottom: 12px;
}

.question-body {
    font-size: 1.05rem;
    line-height: 1.6;
    color: var(--text-main);
    margin-bottom: 20px;
    display: flex;
    flex-direction: column;
    gap: 10px;
}

.question-body p { margin: 0; }

.math-render-box {
    background: #fdfdfd;
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: 16px 20px;
    text-align: center;
    overflow-x: auto;
}

.input-wrapper {
    display: flex;
    flex-direction: column;
    gap: 10px;
}

.mc-container {
    display: flex;
    flex-direction: column;
    gap: 10px;
}

.mc-btn {
    width: 100%;
    padding: 14px 24px;
    border: 2px solid var(--border-color);
    border-radius: 16px;
    background: #ffffff;
    color: var(--text-main);
    font-weight: 600;
    font-size: 0.97rem;
    cursor: pointer;
    transition: all 0.2s ease;
    text-align: center;
    font-family: inherit;
    line-height: 1.5;
}

.mc-btn:hover:not(:disabled):not(.selected) {
    border-color: var(--primary);
    background: rgba(30, 67, 73, 0.03);
}

.mc-btn.selected {
    background: var(--primary);
    color: #ffffff;
    border-color: var(--primary);
}

.mc-btn:disabled { cursor: not-allowed; opacity: 0.75; }

.question-card.answer-correct  .mc-btn.selected { background: var(--success); border-color: var(--success); }
.question-card.answer-incorrect .mc-btn.selected { background: var(--error);   border-color: var(--error);   }

.question-text {
    font-size: 1.1rem;
    font-weight: 600;
    margin-bottom: 16px;
    color: var(--text-main);
    line-height: 1.5;
}

.math-expr {
    font-family: 'Fraunces', serif;
    font-style: italic;
    background: var(--math-bg);
    padding: 4px 8px;
    border-radius: 6px;
    color: var(--text-main);
}

.input-field {
    width: 100%;
    padding: 16px 24px;
    border: 2px solid var(--border-color);
    border-radius: 50px; /* Pill-Shape */
    font-size: 1rem;
    background-color: #ffffff;
    color: var(--text-main);
    font-weight: 500;
    outline: none;
    transition: border-color 0.2s, box-shadow 0.2s;
}

.input-field:focus {
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(30, 67, 73, 0.05);
}

.solution-toggle {
    display: inline-flex;
    align-items: center;
    margin-top: 14px;
    font-size: 0.85rem;
    font-weight: 600;
    color: var(--text-muted);
    cursor: pointer;
    user-select: none;
    transition: color 0.2s ease;
}

.solution-toggle:hover {
    color: var(--primary);
}

.solution-toggle.open {
    color: var(--primary);
}

.solution-box {
    max-height: 0;
    overflow: hidden;
    opacity: 0;
    margin-top: 0;
    padding: 0 18px;
    border-radius: 14px;
    background-color: var(--math-bg);
    font-size: 0.95rem;
    line-height: 1.6;
    color: var(--text-main);
    transition: max-height 0.35s ease, opacity 0.3s ease, padding 0.3s ease, margin-top 0.3s ease;
}

.solution-box.open {
    max-height: 600px;
    opacity: 1;
    margin-top: 12px;
    padding: 18px;
}

/* Antwort-Status nach Auswertung */
.question-card.answer-correct {
    border: 2px solid var(--success);
    background-color: var(--success-bg);
}

.question-card.answer-incorrect {
    border: 2px solid var(--error);
    background-color: var(--error-bg);
}

.question-card.answer-empty {
    border: 2px solid var(--border-color);
}

.question-card.answer-correct .input-field {
    border-color: var(--success);
}

.question-card.answer-incorrect .input-field {
    border-color: var(--error);
}

.input-field:disabled {
    background-color: #f5f5f3;
    cursor: not-allowed;
    opacity: 0.85;
}

.btn-submit {
    background-color: var(--primary);
    color: #ffffff;
    border: none;
    border-radius: 50px; /* Pill-Shape */
    padding: 16px 32px;
    font-size: 1.1rem;
    font-weight: 600;
    cursor: pointer;
    transition: background-color 0.2s, transform 0.1s;
    width: 100%;
    text-align: center;
    margin-top: 24px;
    box-shadow: 0 4px 12px rgba(30, 67, 73, 0.1);
}

.btn-submit:hover {
    background-color: var(--primary-hover);
    transform: translateY(-1px);
}

.btn-submit:active {
    transform: scale(0.99);
}

.btn-submit:disabled,
.btn-skip:disabled {
    opacity: 0.4;
    cursor: not-allowed;
    pointer-events: none;
    transform: none;
    box-shadow: none;
}

/* Einstufungs-Ergebnisbereich */
.result-section {
    display: none;
    background-color: var(--card-bg);
    border: 2px solid var(--accent);
    border-radius: 24px;
    padding: 32px;
    margin-top: 40px;
    box-shadow: 0 10px 30px rgba(30, 67, 73, 0.08);
    animation: fadeIn 0.6s ease-out forwards;
}

@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.result-title {
    font-family: 'Fraunces', serif;
    font-size: 1.6rem;
    font-weight: 800;
    color: var(--accent);
    margin-bottom: 24px;
    text-align: center;
}

.level-display {
    font-size: 1.2rem;
    font-weight: 600;
    margin-bottom: 16px;
    display: flex;
    justify-content: space-between;
}

.level-value {
    color: var(--accent);
    font-weight: 700;
}

/* Progress Bar */
.progress-container {
    background-color: var(--border-color);
    border-radius: 50px; /* Sauberes Pill-Design */
    height: 24px;
    width: 100%;
    overflow: hidden;
    margin-bottom: 24px;
    position: relative;
    box-shadow: inset 0 2px 5px rgba(0, 0, 0, 0.05);
}

.progress-bar {
    background-color: var(--accent);
    height: 100%;
    width: 0%;
    transition: width 1.5s cubic-bezier(0.1, 1, 0.1, 1);
    display: flex;
    align-items: center;
    justify-content: flex-end;
    padding-right: 12px;
}

.progress-text {
    color: #ffffff;
    font-size: 0.85rem;
    font-weight: 700;
}

.advice-box {
    background-color: #faece3; /* Weicher Apricot-Hintergrund */
    border-left: 4px solid var(--accent);
    padding: 24px;
    border-radius: 0 16px 16px 0;
    font-size: 1.05rem;
    line-height: 1.6;
    color: var(--text-main);
    display: flex;
    flex-direction: column;
    gap: 8px;
}

/* Button für die Navigation zum Lernmodul */
.btn-module {
    background-color: var(--accent);
    color: #ffffff;
    border: none;
    border-radius: 50px; /* Pill-Shape */
    padding: 12px 28px;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: background-color 0.2s, transform 0.1s;
    text-align: center;
    align-self: flex-start;
    text-decoration: none;
    box-shadow: 0 4px 12px rgba(249, 160, 119, 0.2);
}

.btn-module:hover {
    background-color: var(--accent-hover);
    transform: translateY(-1px);
}

@media (max-width: 480px) {
    .btn-module {
        width: 100%;
        align-self: center;
    }
}

/* ============================================================
   NEU: Styling für Multiple-Choice Optionen & Toggles
   ============================================================ */

.solution-toggle {
    display: none; /* Initial verstecken, wird per JS nach Abgabe sichtbar */
}

.options-container {
    display: flex;
    flex-direction: column;
    gap: 12px;
    margin-top: 14px;
}

.option-label {
    display: flex;
    align-items: center;
    gap: 14px;
    background-color: #ffffff;
    border: 2px solid var(--border-color);
    padding: 14px 24px;
    border-radius: 50px; /* Integriert sich nahtlos ins Pill-Design */
    cursor: pointer;
    font-size: 1rem;
    font-weight: 500;
    transition: background-color 0.2s, border-color 0.2s, box-shadow 0.2s;
    user-select: none;
}

.option-label:hover {
    border-color: var(--primary);
    background-color: rgba(30, 67, 73, 0.02);
}

/* Styling des nativen Radio-Buttons */
.option-label input[type="radio"] {
    accent-color: var(--primary);
    width: 20px;
    height: 20px;
    cursor: pointer;
}

/* Visuelles Feedback bei inaktiven (disabled) Elementen */
.option-label input[type="radio"]:disabled {
    cursor: not-allowed;
    opacity: 0.7;
}

.question-card.answer-correct .option-label {
    background-color: #ffffff;
}

.question-card.answer-incorrect .option-label {
    background-color: #ffffff;
}

.btn-skip {
    background: transparent;
    color: var(--text-muted);
    border: 2px solid var(--border-color);
    border-radius: 50px;
    padding: 16px;
    width: 100%;
    font-size: 1.1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s;
    margin-top: 12px;
    text-align: center;
}

.btn-skip:hover {
    color: var(--primary);
    border-color: var(--primary);
}

/* ============================================================
   Farbige Abschnitt-Titel je Kategorie
   ============================================================ */

.section-uebergang { border-left-color: #6dbf96; }
.section-analysis  { border-left-color: #7aaee0; }
.section-linalg    { border-left-color: #d97a7a; }
.section-advanced  { border-left-color: var(--accent); }

/* ============================================================
   Kategorie-Aufschlüsselung im Ergebnisbereich
   ============================================================ */

.cat-breakdown {
    display: flex;
    flex-direction: column;
    gap: 14px;
    margin-bottom: 28px;
}

.cat-row {
    display: grid;
    grid-template-columns: minmax(0, 1fr) 52px 120px;
    align-items: center;
    gap: 12px;
}

@media (max-width: 520px) {
    .cat-row {
        grid-template-columns: minmax(0, 1fr) 44px 80px;
        gap: 8px;
    }
}

.cat-label {
    display: flex;
    align-items: center;
    gap: 8px;
    min-width: 0;
    font-size: 0.88rem;
    font-weight: 600;
    color: var(--text-main);
    overflow-wrap: anywhere;
}

.cat-dot {
    width: 10px;
    height: 10px;
    border-radius: 50%;
    flex-shrink: 0;
}

.cat-dot-uebergang { background: #6dbf96; }
.cat-dot-analysis  { background: #7aaee0; }
.cat-dot-linalg    { background: #d97a7a; }
.cat-dot-advanced  { background: var(--accent); }

.cat-score {
    font-size: 0.82rem;
    font-weight: 700;
    color: var(--text-muted);
    text-align: right;
    white-space: nowrap;
}

.cat-bar-wrap {
    background: var(--border-color);
    border-radius: 50px;
    height: 8px;
    overflow: hidden;
}

.cat-bar-fill {
    height: 100%;
    border-radius: 50px;
    width: 0%;
    transition: width 0.8s cubic-bezier(0.1, 1, 0.1, 1);
}

.cat-fill-uebergang { background: #6dbf96; }
.cat-fill-analysis  { background: #7aaee0; }
.cat-fill-linalg    { background: #d97a7a; }
.cat-fill-advanced  { background: var(--accent); }

/* ============================================================
   Zusammenfassung im Ergebnisbereich
   ============================================================ */

.result-summary {
    margin: 4px 0 20px;
}

/* ============================================================
   Freigeschaltete Knoten-Box
   ============================================================ */

.unlocked-box {
    display: none;
    background: rgba(109, 191, 150, 0.10);
    border: 1.5px solid #6dbf96;
    border-radius: 14px;
    padding: 14px 18px;
    font-size: 0.88rem;
    color: var(--text-main);
    margin-bottom: 16px;
    line-height: 1.6;
}

/* ============================================================
   Skip-Bestätigungs-Modal
   ============================================================ */

.skip-overlay {
    display: none;
    position: fixed;
    inset: 0;
    background: rgba(30, 67, 73, 0.45);
    backdrop-filter: blur(6px);
    -webkit-backdrop-filter: blur(6px);
    z-index: 1000;
    align-items: center;
    justify-content: center;
    padding: 24px;
}

.skip-modal {
    background: var(--card-bg);
    border-radius: 24px;
    padding: 40px 36px;
    max-width: 420px;
    width: 100%;
    box-shadow: 0 24px 60px rgba(30, 67, 73, 0.18);
    border: 1px solid var(--border-color);
    text-align: center;
}

.skip-modal-title {
    font-family: 'Fraunces', serif;
    font-size: 1.4rem;
    font-weight: 800;
    color: var(--text-main);
    margin-bottom: 14px;
}

.skip-modal-text {
    font-size: 0.95rem;
    color: var(--text-muted);
    line-height: 1.65;
    margin-bottom: 28px;
}

.skip-modal-text strong {
    color: var(--text-main);
}

.skip-confirm-btn {
    display: block;
    width: 100%;
    padding: 14px 24px;
    background: var(--primary);
    color: #fff;
    border: none;
    border-radius: 50px;
    font-size: 0.95rem;
    font-weight: 600;
    text-align: center;
    text-decoration: none;
    margin-bottom: 12px;
    cursor: pointer;
    transition: background 0.2s, transform 0.1s;
    box-shadow: 0 4px 12px rgba(30, 67, 73, 0.15);
}

.skip-confirm-btn:hover {
    background: var(--primary-hover);
    transform: translateY(-1px);
}

.skip-cancel-btn {
    display: block;
    width: 100%;
    padding: 14px 24px;
    background: transparent;
    color: var(--text-muted);
    border: 2px solid var(--border-color);
    border-radius: 50px;
    font-size: 0.95rem;
    font-weight: 600;
    cursor: pointer;
    transition: border-color 0.2s, color 0.2s;
}

.skip-cancel-btn:hover {
    border-color: var(--text-main);
    color: var(--text-main);
}

/* ============================================================
   Adaptive Test – Round UI
   ============================================================ */

.adaptive-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: 20px;
    gap: 12px;
}

.round-badge {
    display: inline-flex;
    align-items: center;
    background: var(--primary);
    color: #fff;
    font-size: 0.82rem;
    font-weight: 700;
    letter-spacing: 0.05em;
    padding: 6px 16px;
    border-radius: 50px;
}

.nodes-stat {
    font-size: 0.85rem;
    font-weight: 600;
    color: var(--text-muted);
}

/* Submit-Bar: vertical stack of actions */
.submit-bar {
    display: flex;
    flex-direction: column;
    gap: 10px;
    margin-top: 24px;
}

.btn-end {
    background: transparent;
    color: var(--text-muted);
    border: 2px solid var(--border-color);
    border-radius: 50px;
    padding: 14px 32px;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: border-color 0.2s, color 0.2s;
    text-align: center;
}

.btn-end:hover {
    border-color: var(--error);
    color: var(--error);
}

/* Round Result Card */
.round-result-section {
    margin-top: 28px;
}

.round-result-card {
    background: var(--card-bg);
    border: 2px solid var(--accent);
    border-radius: 24px;
    padding: 28px 32px;
    box-shadow: 0 8px 30px rgba(30, 67, 73, 0.06);
    animation: fadeIn 0.4s ease-out forwards;
}

.rr-title {
    font-family: 'Fraunces', serif;
    font-size: 1.3rem;
    font-weight: 800;
    color: var(--primary);
    margin-bottom: 14px;
}

.rr-stats {
    display: flex;
    align-items: center;
    gap: 10px;
    font-size: 1rem;
    font-weight: 700;
    margin-bottom: 10px;
}

.rr-correct { color: var(--success); }
.rr-wrong   { color: var(--error); }
.rr-sep     { color: var(--text-muted); }

.rr-next-info {
    font-size: 0.9rem;
    color: var(--text-muted);
    margin-bottom: 20px;
    line-height: 1.5;
}

.rr-buttons {
    display: flex;
    flex-direction: column;
    gap: 10px;
}

/* Final Result */
.final-result-section {
    background: var(--card-bg);
    border: 2px solid var(--accent);
    border-radius: 24px;
    padding: 32px;
    margin-top: 32px;
    box-shadow: 0 10px 30px rgba(30, 67, 73, 0.08);
    animation: fadeIn 0.5s ease-out forwards;
}

.result-summary {
    font-size: 1.05rem;
    font-weight: 600;
    color: var(--text-main);
    text-align: center;
    margin: 16px 0 24px;
}

.final-buttons {
    display: flex;
    flex-direction: column;
    gap: 10px;
    margin-top: 20px;
}

/* ============================================================
   Multi-Input-Felder (λ1/λ2, x1/x2, Eigenwerte, NZSF)
   ============================================================ */

.multi-input-group {
    display: flex;
    align-items: center;
    gap: 14px;
}

.multi-label {
    font-weight: 600;
    font-size: 1rem;
    flex-shrink: 0;
    color: var(--text-main);
}

.multi-input {
    flex: 1;
    min-width: 0;
    padding: 14px 24px;
    border: 2px solid var(--border-color);
    border-radius: 50px;
    font-size: 1rem;
    background: #ffffff;
    color: var(--text-main);
    font-weight: 500;
    outline: none;
    font-family: inherit;
    transition: border-color 0.2s, box-shadow 0.2s;
}

.multi-input:focus {
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(30, 67, 73, 0.05);
}

.multi-input:disabled {
    background: #f5f5f3;
    cursor: not-allowed;
    opacity: 0.85;
}

.question-card.answer-correct   .multi-input { border-color: var(--success); }
.question-card.answer-incorrect .multi-input { border-color: var(--error); }

/* ============================================================
   Multi-Input-Felder (λ1/λ2, x1/x2, Eigenwerte, NZSF)
   ============================================================ */

.multi-input-group {
    display: flex;
    align-items: center;
    gap: 14px;
}

.multi-label {
    font-weight: 600;
    font-size: 1rem;
    flex-shrink: 0;
    color: var(--text-main);
}

.multi-input {
    flex: 1;
    min-width: 0;
    padding: 14px 24px;
    border: 2px solid var(--border-color);
    border-radius: 50px;
    font-size: 1rem;
    background: #ffffff;
    color: var(--text-main);
    font-weight: 500;
    outline: none;
    font-family: inherit;
    transition: border-color 0.2s, box-shadow 0.2s;
}

.multi-input:focus {
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(30, 67, 73, 0.05);
}

.multi-input:disabled {
    background: #f5f5f3;
    cursor: not-allowed;
    opacity: 0.85;
}

.question-card.answer-correct .multi-input  { border-color: var(--success); }
.question-card.answer-incorrect .multi-input { border-color: var(--error); }

/* ============================================================
   Intro-Section
   ============================================================ */

#introSection {
    width: 100%;
}

.intro-card {
    background: var(--card-bg);
    border-radius: 24px;
    padding: 40px 36px;
    box-shadow: 0 8px 30px rgba(30, 67, 73, 0.06);
    border: 2px solid var(--border-color);
}

.intro-title {
    font-family: 'Fraunces', serif;
    font-size: 1.6rem;
    font-weight: 800;
    color: var(--primary);
    margin-bottom: 24px;
}

.intro-list {
    list-style: none;
    display: flex;
    flex-direction: column;
    gap: 14px;
    margin-bottom: 32px;
    padding: 0;
}

.intro-list li {
    position: relative;
    padding-left: 1.5em;
    font-size: 1rem;
    line-height: 1.6;
    color: var(--text-muted);
}

.intro-list li::before {
    content: "→";
    position: absolute;
    left: 0;
    top: 0;
    color: var(--accent);
    font-weight: 700;
}

.intro-buttons {
    display: flex;
    flex-direction: column;
    gap: 10px;
}