/* German Tutor - Modern CSS Styles */

:root {
    --primary: #2563eb;
    --primary-dark: #1d4ed8;
    --secondary: #10b981;
    --accent: #f59e0b;
    --background: #f8fafc;
    --surface: #ffffff;
    --text: #1e293b;
    --text-light: #64748b;
    --border: #e2e8f0;
    --shadow: 0 1px 3px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 25px rgba(0, 0, 0, 0.1);
    --radius: 12px;
}

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

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    background: var(--background);
    color: var(--text);
    line-height: 1.6;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 20px;
}

/* Header */
.header {
    background: var(--surface);
    padding: 20px 30px;
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    margin-bottom: 20px;
}

.header-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.header-controls {
    display: flex;
    align-items: center;
    gap: 20px;
}

.german-toggle {
    display: flex;
    align-items: center;
}

.floating-german-toggle {
    position: fixed;
    bottom: 30px;
    right: 30px;
    z-index: 1000;
    background: var(--surface);
    padding: 12px 20px;
    border-radius: 30px;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.15);
    border: 2px solid var(--border);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.floating-german-toggle:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 25px rgba(0, 0, 0, 0.2);
}

.toggle-label {
    display: flex;
    align-items: center;
    gap: 10px;
    cursor: pointer;
    user-select: none;
}

.toggle-label input[type="checkbox"] {
    display: none;
}

.toggle-slider {
    width: 44px;
    height: 24px;
    background: #cbd5e1;
    border-radius: 12px;
    position: relative;
    transition: background 0.3s;
}

.toggle-slider::before {
    content: '';
    position: absolute;
    width: 20px;
    height: 20px;
    background: white;
    border-radius: 50%;
    top: 2px;
    left: 2px;
    transition: transform 0.3s;
    box-shadow: 0 2px 4px rgba(0,0,0,0.2);
}

.toggle-label input[type="checkbox"]:checked + .toggle-slider {
    background: var(--primary);
}

.toggle-label input[type="checkbox"]:checked + .toggle-slider::before {
    transform: translateX(20px);
}

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

.masked-german {
    color: transparent;
    text-shadow: 0 0 8px rgba(0,0,0,0.3);
    background: repeating-linear-gradient(
        45deg,
        #e2e8f0,
        #e2e8f0 2px,
        #f1f5f9 2px,
        #f1f5f9 4px
    );
    padding: 2px 4px;
    border-radius: 3px;
}

.logo {
    display: flex;
    align-items: center;
    gap: 15px;
}

.flag {
    font-size: 2.5rem;
}

.logo h1 {
    font-size: 1.8rem;
    font-weight: 700;
    color: var(--text);
}

.subtitle {
    font-size: 0.9rem;
    color: var(--text-light);
    display: block;
}

.progress-indicator {
    display: flex;
    gap: 10px;
}

.level-badge, .lesson-badge {
    padding: 8px 16px;
    border-radius: 20px;
    font-weight: 600;
    font-size: 0.9rem;
}

.level-badge {
    background: var(--primary);
    color: white;
}

.lesson-badge {
    background: var(--secondary);
    color: white;
}

/* Navigation */
.nav {
    display: flex;
    gap: 10px;
    margin-bottom: 20px;
    flex-wrap: wrap;
}

.nav-btn {
    flex: 1;
    min-width: 120px;
    padding: 15px 20px;
    border: 2px solid var(--border);
    background: var(--surface);
    border-radius: var(--radius);
    cursor: pointer;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 8px;
    transition: all 0.3s ease;
    font-size: 0.9rem;
    font-weight: 500;
}

.nav-btn:hover {
    border-color: var(--primary);
    background: #eff6ff;
}

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

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

/* Main Content */
.main-content {
    background: var(--surface);
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    padding: 30px;
    min-height: 600px;
}

.section {
    display: none;
}

.section.active {
    display: block;
}

/* Section Header */
.section-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 30px;
}

.section-header h2 {
    font-size: 1.8rem;
    color: var(--text);
}

.level-selector {
    padding: 10px 20px;
    border: 2px solid var(--border);
    border-radius: 8px;
    font-size: 1rem;
    background: var(--surface);
    cursor: pointer;
}

/* Welcome Card */
.welcome-card {
    text-align: center;
    padding: 40px;
    background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
    border-radius: var(--radius);
    color: white;
    margin-bottom: 30px;
}

.welcome-card h2 {
    font-size: 2.5rem;
    margin-bottom: 10px;
}

.welcome-card p {
    font-size: 1.2rem;
    opacity: 0.9;
    margin-bottom: 30px;
}

.stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
    gap: 20px;
    margin-bottom: 30px;
}

.stat-card {
    background: rgba(255, 255, 255, 0.2);
    padding: 20px;
    border-radius: var(--radius);
    backdrop-filter: blur(10px);
}

.stat-value {
    font-size: 2.5rem;
    font-weight: 700;
    display: block;
}

.stat-label {
    font-size: 0.9rem;
    opacity: 0.9;
}

.cta-button {
    padding: 15px 40px;
    background: white;
    color: var(--primary);
    border: none;
    border-radius: 30px;
    font-size: 1.1rem;
    font-weight: 600;
    cursor: pointer;
    transition: transform 0.3s ease;
}

.cta-button:hover {
    transform: translateY(-2px);
}

/* Levels Grid */
.levels-grid h3 {
    font-size: 1.5rem;
    margin-bottom: 20px;
}

.level-cards {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 20px;
}

.level-card {
    background: var(--background);
    padding: 25px;
    border-radius: var(--radius);
    border: 2px solid var(--border);
    cursor: pointer;
    transition: all 0.3s ease;
}

.level-card:hover {
    border-color: var(--primary);
    transform: translateY(-5px);
}

.level-card h4 {
    font-size: 1.3rem;
    margin-bottom: 10px;
    color: var(--primary);
}

.level-card p {
    color: var(--text-light);
    font-size: 0.9rem;
}

/* Lessons List */
.lessons-list {
    display: grid;
    gap: 15px;
}

.lesson-card {
    background: var(--background);
    padding: 20px;
    border-radius: var(--radius);
    border: 2px solid var(--border);
    cursor: pointer;
    transition: all 0.3s ease;
}

.lesson-card:hover {
    border-color: var(--primary);
    background: #eff6ff;
}

.lesson-card.completed {
    border-color: var(--secondary);
    background: #ecfdf5;
}

.lesson-card h4 {
    font-size: 1.1rem;
    margin-bottom: 8px;
}

.lesson-card p {
    color: var(--text-light);
    font-size: 0.9rem;
}

.lesson-card .lesson-meta {
    display: flex;
    gap: 15px;
    margin-top: 10px;
    font-size: 0.85rem;
    color: var(--text-light);
}

/* Lesson Content */
.back-button {
    padding: 10px 20px;
    background: var(--background);
    border: 2px solid var(--border);
    border-radius: 8px;
    cursor: pointer;
    margin-bottom: 20px;
    font-size: 0.9rem;
}

.back-button:hover {
    border-color: var(--primary);
}

.lesson-content {
    animation: fadeIn 0.3s ease;
}

.lesson-header {
    background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
    color: white;
    padding: 30px;
    border-radius: var(--radius);
    margin-bottom: 30px;
}

.lesson-header h2 {
    font-size: 2rem;
    margin-bottom: 10px;
}

.lesson-header p {
    opacity: 0.9;
}

.lesson-section {
    margin-bottom: 30px;
}

.lesson-section h3 {
    font-size: 1.4rem;
    margin-bottom: 15px;
    color: var(--primary);
}

.vocabulary-table {
    width: 100%;
    border-collapse: collapse;
    background: var(--background);
    border-radius: var(--radius);
    overflow: hidden;
}

.vocabulary-table th,
.vocabulary-table td {
    padding: 15px;
    text-align: left;
    border-bottom: 1px solid var(--border);
}

.vocabulary-table th {
    background: var(--primary);
    color: white;
    font-weight: 600;
}

.vocabulary-table tr:hover {
    background: #f1f5f9;
}

.dialogue-box {
    background: var(--background);
    padding: 20px;
    border-radius: var(--radius);
    margin-bottom: 15px;
}

.dialogue-line {
    margin-bottom: 15px;
    padding: 15px;
    background: var(--surface);
    border-radius: 8px;
    border-left: 4px solid var(--primary);
}

.dialogue-line.speaker-colleague {
    border-left-color: var(--secondary);
}

.dialogue-speaker {
    font-weight: 600;
    margin-bottom: 5px;
    color: var(--primary);
}

.dialogue-german {
    font-size: 1.1rem;
    margin-bottom: 5px;
}

.dialogue-english {
    color: var(--text-light);
    font-size: 0.9rem;
}

/* Speaker Button */
.speaker-button {
    background: var(--primary);
    color: white;
    border: none;
    border-radius: 50%;
    width: 40px;
    height: 40px;
    font-size: 1.2rem;
    cursor: pointer;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    transition: all 0.3s ease;
    flex-shrink: 0;
    vertical-align: middle;
    margin-left: 8px;
}

.speaker-button:hover {
    background: var(--primary-dark);
    transform: scale(1.1);
}

.speaker-button:active {
    transform: scale(0.95);
}

.speaker-button.speaking {
    background: var(--accent);
    animation: pulse 1s infinite;
}

@keyframes pulse {
    0%, 100% {
        opacity: 1;
    }
    50% {
        opacity: 0.7;
    }
}

/* Stop All Button */
.stop-all-button {
    background: #ef4444;
    color: white;
    border: none;
    border-radius: 8px;
    padding: 10px 20px;
    font-size: 0.9rem;
    cursor: pointer;
    transition: all 0.3s ease;
    white-space: nowrap;
}

.stop-all-button:hover {
    background: #dc2626;
    transform: scale(1.05);
}

.stop-all-button:active {
    transform: scale(0.95);
}

/* Speech Control */
.speech-control {
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: 0.9rem;
    color: white;
}

.speech-control label {
    font-weight: 500;
}

.speech-control select {
    padding: 8px 12px;
    border: none;
    border-radius: 6px;
    font-size: 0.85rem;
    cursor: pointer;
    background: rgba(255, 255, 255, 0.2);
    color: white;
}

.speech-control select:hover {
    background: rgba(255, 255, 255, 0.3);
}

.exercise-box {
    background: var(--background);
    padding: 20px;
    border-radius: var(--radius);
    margin-bottom: 15px;
}

.exercise-question {
    font-size: 1.1rem;
    margin-bottom: 15px;
    font-weight: 500;
}

.exercise-options {
    display: grid;
    gap: 10px;
}

.exercise-option {
    padding: 12px 20px;
    background: var(--surface);
    border: 2px solid var(--border);
    border-radius: 8px;
    cursor: pointer;
    transition: all 0.3s ease;
}

.exercise-option:hover {
    border-color: var(--primary);
    background: #eff6ff;
}

.exercise-option.correct {
    border-color: var(--secondary);
    background: #ecfdf5;
}

.exercise-option.incorrect {
    border-color: #ef4444;
    background: #fef2f2;
}

/* Vocabulary Grid */
.vocabulary-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 15px;
}

.vocab-card {
    background: var(--background);
    padding: 20px;
    border-radius: var(--radius);
    border: 2px solid var(--border);
    transition: all 0.3s ease;
}

.vocab-card:hover {
    border-color: var(--primary);
    transform: translateY(-3px);
}

.vocab-german {
    font-size: 1.3rem;
    font-weight: 600;
    color: var(--primary);
    margin-bottom: 5px;
}

.vocab-english {
    font-size: 1.1rem;
    color: var(--text);
    margin-bottom: 8px;
}

.vocab-pronunciation {
    font-size: 0.9rem;
    color: var(--text-light);
    font-style: italic;
    margin-bottom: 10px;
}

.vocab-example {
    font-size: 0.85rem;
    color: var(--text-light);
    padding-top: 10px;
    border-top: 1px solid var(--border);
}

/* Practice Modes */
.practice-modes {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 20px;
    margin-bottom: 30px;
}

.practice-card {
    background: var(--background);
    padding: 30px;
    border-radius: var(--radius);
    border: 2px solid var(--border);
    cursor: pointer;
    transition: all 0.3s ease;
    text-align: center;
}

.practice-card:hover {
    border-color: var(--primary);
    transform: translateY(-5px);
}

.practice-icon {
    font-size: 3rem;
    display: block;
    margin-bottom: 15px;
}

.practice-card h3 {
    font-size: 1.2rem;
    margin-bottom: 10px;
}

.practice-card p {
    color: var(--text-light);
    font-size: 0.9rem;
}

.practice-area {
    background: var(--background);
    padding: 30px;
    border-radius: var(--radius);
    min-height: 300px;
}

/* Quiz */
.quiz-start {
    text-align: center;
    padding: 60px 30px;
}

.quiz-start h3 {
    font-size: 2rem;
    margin-bottom: 15px;
}

.quiz-start p {
    color: var(--text-light);
    margin-bottom: 30px;
}

.quiz-question {
    margin-bottom: 30px;
}

.quiz-question h4 {
    font-size: 1.3rem;
    margin-bottom: 20px;
}

.quiz-score {
    text-align: center;
    padding: 40px;
}

.quiz-score h3 {
    font-size: 2.5rem;
    margin-bottom: 10px;
}

/* Progress Details */
.progress-details {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 20px;
}

.progress-card {
    background: var(--background);
    padding: 25px;
    border-radius: var(--radius);
    border: 2px solid var(--border);
}

.progress-card h3 {
    font-size: 0.9rem;
    color: var(--text-light);
    margin-bottom: 10px;
}

.progress-value {
    font-size: 2rem;
    font-weight: 700;
    color: var(--primary);
}

.reset-button {
    padding: 10px 20px;
    background: #ef4444;
    color: white;
    border: none;
    border-radius: 8px;
    cursor: pointer;
    font-size: 0.9rem;
}

.reset-button:hover {
    background: #dc2626;
}

/* Animations */
@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(10px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* Responsive */
@media (max-width: 768px) {
    .header-content {
        flex-direction: column;
        gap: 15px;
    }

    .nav {
        flex-direction: column;
    }

    .nav-btn {
        min-width: 100%;
    }

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

    .level-cards {
        grid-template-columns: 1fr;
    }

    .practice-modes {
        grid-template-columns: 1fr;
    }

    .progress-details {
        grid-template-columns: 1fr;
    }
}