/* ============================================
   KLAUSUR-TRAINER - Modern Quiz App Styles
   Inspired by Quizlet's clean design
   ============================================ */

/* CSS Variables */
:root {
    /* Colors - Modern Blue/Purple Gradient Theme */
    --primary-color: #6366f1;
    --primary-hover: #4f46e5;
    --primary-light: #e0e7ff;
    --secondary-color: #8b5cf6;

    --success-color: #10b981;
    --success-light: #d1fae5;
    --error-color: #ef4444;
    --error-light: #fee2e2;
    --warning-color: #f59e0b;
    --warning-light: #fef3c7;

    --bg-primary: #0f172a;
    --bg-secondary: #1e293b;
    --bg-card: #334155;
    --bg-hover: #475569;

    --text-primary: #f8fafc;
    --text-secondary: #94a3b8;
    --text-muted: #64748b;

    --border-color: #475569;
    --border-radius: 12px;
    --border-radius-lg: 16px;

    /* Shadows */
    --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.3);
    --shadow-md: 0 4px 6px rgba(0, 0, 0, 0.3);
    --shadow-lg: 0 10px 15px rgba(0, 0, 0, 0.4);

    /* Transitions */
    --transition-fast: 150ms ease;
    --transition-normal: 250ms ease;
}

/* Reset & Base */
*,
*::before,
*::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
    background: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.6;
    min-height: 100vh;
}

/* Container */
.container {
    max-width: 800px;
    margin: 0 auto;
    padding: 0 20px;
}

/* ============================================
   HEADER
   ============================================ */
.header {
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    padding: 16px 20px;
    position: sticky;
    top: 0;
    z-index: 100;
    box-shadow: var(--shadow-md);
}

.header-content {
    max-width: 800px;
    margin: 0 auto;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    font-size: 1.5rem;
    font-weight: 700;
    color: white;
}

.exam-countdown {
    background: rgba(255, 255, 255, 0.2);
    padding: 8px 16px;
    border-radius: 20px;
    font-size: 0.875rem;
    font-weight: 500;
    color: white;
    font-variant-numeric: tabular-nums;
    letter-spacing: 0.5px;
}

/* ============================================
   NAVIGATION
   ============================================ */
.main-nav {
    background: var(--bg-secondary);
    border-bottom: 1px solid var(--border-color);
    position: sticky;
    top: 60px;
    z-index: 99;
}

.nav-tabs {
    max-width: 800px;
    margin: 0 auto;
    display: flex;
    gap: 4px;
    padding: 8px 20px;
}

.nav-tab {
    flex: 1;
    padding: 12px 16px;
    border: none;
    background: transparent;
    color: var(--text-secondary);
    font-size: 0.9rem;
    font-weight: 500;
    cursor: pointer;
    border-radius: var(--border-radius);
    transition: var(--transition-fast);
}

.nav-tab:hover {
    background: var(--bg-hover);
    color: var(--text-primary);
}

.nav-tab.active {
    background: var(--primary-color);
    color: white;
}

/* ============================================
   VIEWS
   ============================================ */
.view {
    display: none;
    padding: 24px 0;
    min-height: calc(100vh - 120px);
}

.view.active {
    display: block;
    animation: fadeIn 0.3s ease;
}

@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(10px);
    }

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

.section-title {
    font-size: 1.5rem;
    font-weight: 600;
    margin-bottom: 24px;
    color: var(--text-primary);
}

.subsection-title {
    font-size: 1.1rem;
    font-weight: 600;
    margin: 24px 0 16px;
    color: var(--text-secondary);
}

/* ============================================
   TOPICS GRID
   ============================================ */
.topics-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 16px;
}

.topic-card {
    background: var(--bg-card);
    border-radius: var(--border-radius-lg);
    padding: 20px;
    cursor: pointer;
    transition: var(--transition-normal);
    border: 1px solid var(--border-color);
    position: relative;
    overflow: hidden;
}

.topic-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: linear-gradient(90deg, var(--primary-color), var(--secondary-color));
    opacity: 0;
    transition: var(--transition-normal);
}

.topic-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
    border-color: var(--primary-color);
}

.topic-card:hover::before {
    opacity: 1;
}

.topic-card-header {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    margin-bottom: 12px;
}

.topic-number {
    background: var(--primary-light);
    color: var(--primary-color);
    width: 32px;
    height: 32px;
    border-radius: 8px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 600;
    font-size: 0.875rem;
}

.topic-card h3 {
    font-size: 1rem;
    font-weight: 600;
    margin-bottom: 8px;
    color: var(--text-primary);
}

.topic-card p {
    font-size: 0.875rem;
    color: var(--text-secondary);
    margin-bottom: 16px;
}

.topic-stats {
    display: flex;
    gap: 16px;
    font-size: 0.8rem;
    color: var(--text-muted);
}

.topic-stat {
    display: flex;
    align-items: center;
    gap: 4px;
}

.topic-progress-bar {
    height: 4px;
    background: var(--bg-hover);
    border-radius: 2px;
    margin-top: 12px;
    overflow: hidden;
}

.topic-progress-fill {
    height: 100%;
    background: linear-gradient(90deg, var(--primary-color), var(--secondary-color));
    border-radius: 2px;
    transition: width 0.5s ease;
}

/* ============================================
   QUIZ VIEW
   ============================================ */
.quiz-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 16px;
}

.quiz-topic {
    font-size: 0.9rem;
    color: var(--text-secondary);
    font-weight: 500;
}

.quiz-progress {
    font-size: 0.9rem;
    color: var(--text-muted);
}

.progress-bar-container {
    height: 6px;
    background: var(--bg-card);
    border-radius: 3px;
    margin-bottom: 24px;
    overflow: hidden;
}

.progress-bar {
    height: 100%;
    background: linear-gradient(90deg, var(--primary-color), var(--secondary-color));
    border-radius: 3px;
    transition: width 0.3s ease;
    width: 0%;
}

/* Question Card */
.question-card {
    background: var(--bg-card);
    border-radius: var(--border-radius-lg);
    padding: 24px;
    box-shadow: var(--shadow-md);
}

.question-badge {
    display: flex;
    gap: 8px;
    margin-bottom: 16px;
}

.difficulty-badge,
.type-badge {
    padding: 4px 10px;
    border-radius: 20px;
    font-size: 0.75rem;
    font-weight: 500;
    text-transform: uppercase;
}

.difficulty-badge {
    background: var(--bg-hover);
    color: var(--text-secondary);
}

.difficulty-badge.easy {
    background: var(--success-light);
    color: var(--success-color);
}

.difficulty-badge.medium {
    background: var(--warning-light);
    color: var(--warning-color);
}

.difficulty-badge.hard {
    background: var(--error-light);
    color: var(--error-color);
}

.type-badge {
    background: var(--primary-light);
    color: var(--primary-color);
}

.source-badge {
    background: var(--bg-hover);
    color: var(--text-muted);
    font-size: 0.7rem;
}

.source-badge.student {
    background: rgba(16, 185, 129, 0.15);
    color: var(--success-color);
}

.source-badge.ai {
    background: rgba(139, 92, 246, 0.15);
    color: var(--secondary-color);
}

.question-text {
    font-size: 1.1rem;
    font-weight: 500;
    margin-bottom: 24px;
    line-height: 1.5;
}

/* Options */
.options-container {
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.option-btn {
    display: flex;
    align-items: flex-start;
    gap: 12px;
    padding: 16px;
    background: var(--bg-secondary);
    border: 2px solid var(--border-color);
    border-radius: var(--border-radius);
    cursor: pointer;
    transition: var(--transition-fast);
    text-align: left;
    width: 100%;
}

.option-btn:hover:not(.disabled) {
    border-color: var(--primary-color);
    background: var(--bg-hover);
}

.option-btn.selected {
    border-color: var(--primary-color);
    background: rgba(99, 102, 241, 0.1);
}

.option-btn.correct {
    border-color: var(--success-color);
    background: var(--success-light);
}

.option-btn.correct .option-text {
    color: var(--success-color);
}

.option-btn.incorrect {
    border-color: var(--error-color);
    background: var(--error-light);
}

.option-btn.incorrect .option-text {
    color: var(--error-color);
}

.option-btn.disabled {
    cursor: default;
    opacity: 0.7;
}

.option-indicator {
    width: 24px;
    height: 24px;
    border: 2px solid var(--border-color);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
    font-size: 0.75rem;
    font-weight: 600;
    color: var(--text-muted);
    transition: var(--transition-fast);
}

.option-btn.checkbox .option-indicator {
    border-radius: 4px;
}

.option-btn.selected .option-indicator {
    background: var(--primary-color);
    border-color: var(--primary-color);
    color: white;
}

.option-btn.correct .option-indicator {
    background: var(--success-color);
    border-color: var(--success-color);
    color: white;
}

.option-btn.incorrect .option-indicator {
    background: var(--error-color);
    border-color: var(--error-color);
    color: white;
}

.option-text {
    flex: 1;
    font-size: 0.95rem;
    color: var(--text-primary);
    line-height: 1.4;
}

/* Feedback */
.feedback-container {
    margin-top: 24px;
    padding: 20px;
    border-radius: var(--border-radius);
    animation: slideIn 0.3s ease;
}

@keyframes slideIn {
    from {
        opacity: 0;
        transform: translateY(-10px);
    }

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

.feedback-container.correct {
    background: var(--success-light);
    border: 1px solid var(--success-color);
}

.feedback-container.incorrect {
    background: var(--error-light);
    border: 1px solid var(--error-color);
}

.feedback-header {
    display: flex;
    align-items: center;
    gap: 8px;
    font-weight: 600;
    font-size: 1rem;
    margin-bottom: 12px;
}

.feedback-container.correct .feedback-header {
    color: var(--success-color);
}

.feedback-container.incorrect .feedback-header {
    color: var(--error-color);
}

.feedback-icon {
    font-size: 1.2rem;
}

.feedback-explanation {
    font-size: 0.9rem;
    color: var(--bg-primary);
    line-height: 1.6;
    white-space: pre-wrap;
    max-height: 400px;
    overflow-y: auto;
    padding-right: 8px;
}

/* Custom scrollbar for explanation */
.feedback-explanation::-webkit-scrollbar {
    width: 6px;
}

.feedback-explanation::-webkit-scrollbar-track {
    background: rgba(0, 0, 0, 0.1);
    border-radius: 3px;
}

.feedback-explanation::-webkit-scrollbar-thumb {
    background: rgba(0, 0, 0, 0.3);
    border-radius: 3px;
}

/* Question Actions */
.question-actions {
    display: flex;
    gap: 12px;
    margin-top: 24px;
    justify-content: center;
}

/* ============================================
   BUTTONS
   ============================================ */
.btn {
    padding: 12px 24px;
    border: none;
    border-radius: var(--border-radius);
    font-size: 1rem;
    font-weight: 500;
    cursor: pointer;
    transition: var(--transition-fast);
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
}

.btn-primary {
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    color: white;
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.btn-secondary {
    background: var(--bg-hover);
    color: var(--text-primary);
}

.btn-secondary:hover {
    background: var(--border-color);
}

.btn-large {
    padding: 16px 32px;
    font-size: 1.1rem;
}

.btn-icon {
    width: 36px;
    height: 36px;
    border: none;
    background: transparent;
    color: var(--text-secondary);
    font-size: 1.2rem;
    cursor: pointer;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: var(--transition-fast);
}

.btn-icon:hover {
    background: var(--bg-hover);
    color: var(--text-primary);
}

.hidden {
    display: none !important;
}

/* ============================================
   EXAM VIEW
   ============================================ */
.exam-intro {
    text-align: center;
    padding: 60px 20px;
}

.exam-icon {
    font-size: 4rem;
    margin-bottom: 24px;
}

.exam-intro h2 {
    font-size: 2rem;
    margin-bottom: 16px;
}

.exam-intro p {
    color: var(--text-secondary);
    margin-bottom: 24px;
}

.exam-details {
    list-style: none;
    margin-bottom: 32px;
}

.exam-details li {
    padding: 8px 0;
    color: var(--text-secondary);
}

.exam-details li::before {
    content: '✓ ';
    color: var(--success-color);
}

/* Results */
.exam-results {
    text-align: center;
    padding: 40px 20px;
}

.results-header h2 {
    margin-bottom: 24px;
}

.score-circle {
    width: 150px;
    height: 150px;
    border-radius: 50%;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 32px;
    box-shadow: var(--shadow-lg);
}

.score-value {
    font-size: 2.5rem;
    font-weight: 700;
    color: white;
}

.results-breakdown {
    display: flex;
    justify-content: center;
    gap: 40px;
    margin-bottom: 32px;
}

.result-item {
    text-align: center;
}

.result-value {
    font-size: 1.5rem;
    font-weight: 600;
}

.result-label {
    font-size: 0.875rem;
    color: var(--text-secondary);
}

/* ============================================
   PROGRESS VIEW
   ============================================ */
.stats-overview {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 16px;
    margin-bottom: 32px;
}

.stat-card {
    background: var(--bg-card);
    padding: 24px;
    border-radius: var(--border-radius-lg);
    text-align: center;
}

.stat-value {
    font-size: 2rem;
    font-weight: 700;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.stat-label {
    font-size: 0.875rem;
    color: var(--text-secondary);
    margin-top: 4px;
}

.topic-progress-list {
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.topic-progress-item {
    background: var(--bg-card);
    padding: 16px;
    border-radius: var(--border-radius);
    display: flex;
    align-items: center;
    gap: 16px;
}

.topic-progress-info {
    flex: 1;
}

.topic-progress-name {
    font-weight: 500;
    margin-bottom: 8px;
}

.topic-progress-bar-bg {
    height: 8px;
    background: var(--bg-hover);
    border-radius: 4px;
    overflow: hidden;
}

.topic-progress-bar-fill {
    height: 100%;
    background: linear-gradient(90deg, var(--primary-color), var(--secondary-color));
    border-radius: 4px;
}

.topic-progress-percent {
    font-weight: 600;
    color: var(--primary-color);
    min-width: 50px;
    text-align: right;
}

.weak-topics {
    margin-top: 32px;
    padding: 20px;
    background: var(--bg-card);
    border-radius: var(--border-radius-lg);
    border: 1px solid var(--warning-color);
}

.weak-topics-list {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
    margin-top: 12px;
}

.weak-topic-tag {
    padding: 8px 16px;
    background: var(--warning-light);
    color: var(--warning-color);
    border-radius: 20px;
    font-size: 0.875rem;
    font-weight: 500;
    cursor: pointer;
    transition: var(--transition-fast);
}

.weak-topic-tag:hover {
    transform: scale(1.05);
}

/* ============================================
   MODAL
   ============================================ */
.modal {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.7);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 1000;
    padding: 20px;
}

.modal-content {
    background: var(--bg-secondary);
    border-radius: var(--border-radius-lg);
    max-width: 600px;
    width: 100%;
    max-height: 90vh;
    overflow-y: auto;
}

.modal-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 20px;
    border-bottom: 1px solid var(--border-color);
}

.modal-header h3 {
    font-size: 1.25rem;
}

.modal-body {
    padding: 20px;
}

.modal-body textarea {
    width: 100%;
    padding: 16px;
    border: 2px solid var(--border-color);
    border-radius: var(--border-radius);
    background: var(--bg-card);
    color: var(--text-primary);
    font-family: inherit;
    font-size: 1rem;
    resize: vertical;
    margin-top: 16px;
}

.modal-body textarea:focus {
    outline: none;
    border-color: var(--primary-color);
}

.model-answer {
    margin-top: 24px;
    padding: 16px;
    background: var(--bg-card);
    border-radius: var(--border-radius);
    border-left: 4px solid var(--success-color);
}

.model-answer h4 {
    color: var(--success-color);
    margin-bottom: 8px;
    font-size: 0.9rem;
}

.model-answer p {
    color: var(--text-secondary);
    font-size: 0.95rem;
    line-height: 1.6;
}

.model-answer ul {
    margin-top: 12px;
    padding-left: 20px;
}

.model-answer li {
    color: var(--text-secondary);
    margin-bottom: 4px;
}

.modal-actions {
    display: flex;
    gap: 12px;
    padding: 20px;
    border-top: 1px solid var(--border-color);
    justify-content: flex-end;
}

/* ============================================
   RESPONSIVE
   ============================================ */
@media (max-width: 640px) {
    .header-content {
        flex-direction: column;
        gap: 8px;
    }

    .nav-tabs {
        padding: 8px 12px;
    }

    .nav-tab {
        padding: 10px 8px;
        font-size: 0.8rem;
    }

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

    .stats-overview {
        grid-template-columns: 1fr;
    }

    .question-card {
        padding: 16px;
    }

    .option-btn {
        padding: 12px;
    }

    .results-breakdown {
        flex-direction: column;
        gap: 16px;
    }
}

/* ============================================
   FLASHCARDS
   ============================================ */
.flashcard-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 24px;
    flex-wrap: wrap;
    gap: 16px;
}

.topic-select {
    padding: 10px 16px;
    border-radius: var(--border-radius);
    border: 2px solid var(--border-color);
    background: var(--bg-card);
    color: var(--text-primary);
    font-size: 0.9rem;
    cursor: pointer;
}

.topic-select:focus {
    outline: none;
    border-color: var(--primary-color);
}

.flashcard-container {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 24px;
}

.flashcard {
    width: 100%;
    max-width: 500px;
    height: 350px;
    perspective: 1000px;
    cursor: pointer;
}

.flashcard-inner {
    position: relative;
    width: 100%;
    height: 100%;
    transition: transform 0.6s cubic-bezier(0.4, 0, 0.2, 1);
    transform-style: preserve-3d;
}

.flashcard-inner.flipped {
    transform: rotateY(180deg);
}

.flashcard-front,
.flashcard-back {
    position: absolute;
    width: 100%;
    height: 100%;
    backface-visibility: hidden;
    border-radius: var(--border-radius-lg);
    padding: 32px;
    display: flex;
    flex-direction: column;
    justify-content: center;
    box-shadow: var(--shadow-lg);
    overflow-y: auto;
    scrollbar-width: thin;
    /* Firefox */
    scrollbar-color: rgba(255, 255, 255, 0.3) transparent;
    /* Firefox */
}

/* Custom scrollbar for flashcards */
.flashcard-front::-webkit-scrollbar,
.flashcard-back::-webkit-scrollbar {
    width: 6px;
}

.flashcard-front::-webkit-scrollbar-track,
.flashcard-back::-webkit-scrollbar-track {
    background: transparent;
    margin: 8px 0;
    /* Add margin to top/bottom of track */
}

.flashcard-front::-webkit-scrollbar-thumb,
.flashcard-back::-webkit-scrollbar-thumb {
    background: rgba(255, 255, 255, 0.3);
    border-radius: 3px;
    border: 1px solid transparent;
}

.flashcard-front::-webkit-scrollbar-thumb:hover,
.flashcard-back::-webkit-scrollbar-thumb:hover {
    background: rgba(255, 255, 255, 0.5);
}

.flashcard-front {
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    color: white;
}

.flashcard-front p {
    font-size: 1.3rem;
    font-weight: 600;
    text-align: center;
    line-height: 1.5;
}

.flashcard-back {
    background: var(--bg-card);
    color: var(--text-primary);
    transform: rotateY(180deg);
    border: 2px solid var(--primary-color);
}

.flashcard-back p {
    font-size: 1rem;
    line-height: 1.7;
}

.flashcard-topic {
    font-size: 0.8rem;
    text-transform: uppercase;
    letter-spacing: 1px;
    opacity: 0.8;
    margin-bottom: 16px;
    text-align: center;
}

.flashcard-source {
    margin-top: 16px;
    font-size: 0.8rem;
    color: var(--text-muted);
    border-top: 1px solid var(--border-color);
    padding-top: 12px;
}

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

.flashcard-progress {
    font-size: 0.9rem;
    color: var(--text-secondary);
}

.flashcard-actions {
    display: flex;
    gap: 16px;
}

@media (max-width: 640px) {
    .flashcard {
        height: 300px;
    }

    .flashcard-front p {
        font-size: 1.1rem;
    }

    .flashcard-back p {
        font-size: 0.9rem;
    }
}

/* ============================================
   FLASHCARDS - ERWEITERT
   ============================================ */
.flashcard-controls {
    display: flex;
    gap: 16px;
    align-items: center;
    flex-wrap: wrap;
}

.mode-toggle {
    display: flex;
    background: var(--bg-card);
    border-radius: var(--border-radius);
    padding: 4px;
}

.mode-btn {
    padding: 8px 16px;
    border: none;
    background: transparent;
    color: var(--text-secondary);
    font-size: 0.9rem;
    cursor: pointer;
    border-radius: var(--border-radius);
    transition: var(--transition-fast);
}

.mode-btn:hover {
    color: var(--text-primary);
}

.mode-btn.active {
    background: var(--primary-color);
    color: white;
}

/* Flashcard Stats */
.flashcard-stats {
    display: flex;
    justify-content: center;
    gap: 24px;
    margin-bottom: 24px;
}

.flashcard-stat {
    text-align: center;
    padding: 8px 16px;
    background: var(--bg-card);
    border-radius: var(--border-radius);
    min-width: 80px;
}

.flashcard-stat .stat-count {
    font-size: 1.5rem;
    font-weight: 700;
    display: block;
}

.flashcard-stat.new .stat-count {
    color: var(--text-secondary);
}

.flashcard-stat.learning .stat-count {
    color: var(--warning-color);
}

.flashcard-stat.mastered .stat-count {
    color: var(--success-color);
}

.flashcard-stat .stat-label {
    font-size: 0.75rem;
    color: var(--text-muted);
    text-transform: uppercase;
}

/* Confidence Area */
.confidence-area {
    text-align: center;
    margin-top: 16px;
}

.confidence-question {
    color: var(--text-secondary);
    margin-bottom: 16px;
    font-size: 0.95rem;
}

.confidence-buttons {
    display: flex;
    gap: 8px;
    justify-content: center;
    flex-wrap: wrap;
}

.confidence-btn {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 4px;
    padding: 12px 16px;
    border: 2px solid var(--border-color);
    background: var(--bg-card);
    border-radius: var(--border-radius);
    cursor: pointer;
    transition: var(--transition-fast);
    min-width: 70px;
}

.confidence-btn:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.confidence-btn .conf-icon {
    font-size: 1.5rem;
}

.confidence-btn .conf-text {
    font-size: 0.75rem;
    color: var(--text-secondary);
}

/* Confidence Button Colors */
.confidence-btn.conf-1:hover {
    border-color: var(--error-color);
    background: var(--error-light);
}

.confidence-btn.conf-2:hover {
    border-color: var(--warning-color);
    background: var(--warning-light);
}

.confidence-btn.conf-3:hover {
    border-color: #fbbf24;
    background: rgba(251, 191, 36, 0.2);
}

.confidence-btn.conf-4:hover {
    border-color: var(--success-color);
    background: var(--success-light);
}

.confidence-btn.conf-5:hover {
    border-color: var(--primary-color);
    background: var(--primary-light);
}

.confidence-hint {
    font-size: 0.75rem;
    color: var(--text-muted);
    margin-top: 12px;
}

/* Confidence Indicator on Card */
.flashcard-confidence-indicator {
    margin-top: 16px;
    padding: 6px 12px;
    border-radius: 20px;
    font-size: 0.8rem;
    font-weight: 500;
    display: inline-block;
}

.flashcard-confidence-indicator.conf-low {
    background: var(--error-light);
    color: var(--error-color);
}

.flashcard-confidence-indicator.conf-medium {
    background: var(--warning-light);
    color: var(--warning-color);
}

.flashcard-confidence-indicator.conf-high {
    background: var(--success-light);
    color: var(--success-color);
}

/* Flashcard Animation on Rating */
.flashcard.rated {
    animation: rateFlash 0.3s ease;
}

@keyframes rateFlash {
    0% {
        transform: scale(1);
    }

    50% {
        transform: scale(0.95);
    }

    100% {
        transform: scale(1);
    }
}

/* Learning Complete */
.learning-complete {
    text-align: center;
    padding: 40px 20px;
}

.learning-complete .complete-icon {
    font-size: 4rem;
    margin-bottom: 16px;
}

.learning-complete h3 {
    font-size: 1.5rem;
    margin-bottom: 24px;
}

.session-stats {
    display: flex;
    justify-content: center;
    gap: 32px;
    margin-bottom: 32px;
}

.session-stat .stat-value {
    font-size: 2rem;
    font-weight: 700;
    display: block;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.session-stat .stat-label {
    font-size: 0.85rem;
    color: var(--text-secondary);
}

.learning-complete .btn {
    margin: 8px;
}

@media (max-width: 640px) {
    .flashcard-controls {
        flex-direction: column;
        align-items: stretch;
    }

    .confidence-buttons {
        gap: 6px;
    }

    .confidence-btn {
        padding: 10px 12px;
        min-width: 60px;
    }

    .confidence-btn .conf-icon {
        font-size: 1.2rem;
    }
}