/* Reset and base styles */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    line-height: 1.6;
    color: #333;
    background-color: #f8f9fa;
}

/* Header */
.header {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    padding: 1rem 0;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
}

.nav {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    font-size: 1.5rem;
    font-weight: bold;
}

.nav-links {
    display: flex;
    gap: 2rem;
}

.nav-link {
    color: white;
    text-decoration: none;
    padding: 0.5rem 1rem;
    border-radius: 5px;
    transition: background-color 0.3s;
}

.nav-link:hover {
    background-color: rgba(255,255,255,0.1);
}

/* Main content */
.main {
    max-width: 1200px;
    margin: 0 auto;
    padding: 2rem;
    min-height: calc(100vh - 120px);
}

/* Hero section */
.hero {
    text-align: center;
    margin-bottom: 3rem;
}

.hero h2 {
    font-size: 2.5rem;
    margin-bottom: 1rem;
    color: #2c3e50;
}

.hero p {
    font-size: 1.2rem;
    color: #666;
    margin-bottom: 3rem;
}

/* Learning methods grid */
.learning-methods {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
    margin-bottom: 3rem;
}

.method-card {
    background: white;
    padding: 2rem;
    border-radius: 10px;
    text-align: center;
    box-shadow: 0 4px 15px rgba(0,0,0,0.1);
    transition: transform 0.3s, box-shadow 0.3s;
    cursor: pointer;
}

.method-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 8px 25px rgba(0,0,0,0.15);
}

.method-icon {
    font-size: 3rem;
    margin-bottom: 1rem;
}

.method-card h3 {
    color: #2c3e50;
    margin-bottom: 1rem;
}

.method-card p {
    color: #666;
    font-size: 0.9rem;
}

/* CTA section */
.cta-section {
    margin-top: 3rem;
}

.cta-button {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    padding: 1rem 2rem;
    border-radius: 50px;
    text-decoration: none;
    font-size: 1.1rem;
    font-weight: bold;
    transition: transform 0.3s, box-shadow 0.3s;
    display: inline-block;
}

.cta-button:hover {
    transform: translateY(-2px);
    box-shadow: 0 5px 15px rgba(102, 126, 234, 0.4);
}

/* Topics page */
.topics-container {
    text-align: center;
}

.topics-container h2 {
    font-size: 2rem;
    margin-bottom: 1rem;
    color: #2c3e50;
}

.topics-container p {
    color: #666;
    margin-bottom: 2rem;
}

.subjects {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
    margin-top: 2rem;
}

.subject-card {
    background: white;
    padding: 2rem;
    border-radius: 10px;
    box-shadow: 0 4px 15px rgba(0,0,0,0.1);
    text-align: center;
}

.subject-card.active {
    border: 2px solid #667eea;
}

.subject-card.disabled {
    opacity: 0.5;
    cursor: not-allowed;
}

.subject-icon {
    font-size: 3rem;
    margin-bottom: 1rem;
}

.subject-card h3 {
    color: #2c3e50;
    margin-bottom: 0.5rem;
}

.topics-list {
    margin-top: 1.5rem;
    text-align: left;
}

.topic-item {
    background: #f8f9fa;
    padding: 1rem;
    border-radius: 5px;
    margin-bottom: 1rem;
    cursor: pointer;
    transition: background-color 0.3s;
    border-left: 4px solid #667eea;
}

.topic-item:hover {
    background: #e9ecef;
}

.topic-item.disabled {
    opacity: 0.5;
    cursor: not-allowed;
    border-left-color: #ccc;
}

.topic-item h4 {
    color: #2c3e50;
    margin-bottom: 0.5rem;
}

.topic-item p {
    color: #666;
    font-size: 0.9rem;
    margin-bottom: 0.5rem;
}

.difficulty {
    font-size: 0.8rem;
    color: #667eea;
    font-weight: bold;
}

/* Footer */
.footer {
    background: #2c3e50;
    color: white;
    text-align: center;
    padding: 1rem;
    margin-top: auto;
}

/* Learning Interface */
.learning-interface {
    max-width: 1000px;
    margin: 0 auto;
}

.learning-header {
    text-align: center;
    margin-bottom: 2rem;
}

.learning-header h2 {
    color: #2c3e50;
    font-size: 2rem;
    margin-bottom: 0.5rem;
}

.learning-header p {
    color: #666;
    font-size: 1.1rem;
}

/* Learning Method Selector */
.learning-method-selector {
    text-align: center;
    margin-bottom: 2rem;
}

.learning-method-selector h3 {
    color: #2c3e50;
    margin-bottom: 1rem;
}

.method-buttons {
    display: flex;
    justify-content: center;
    gap: 1rem;
    flex-wrap: wrap;
}

.method-btn {
    background: white;
    border: 2px solid #667eea;
    color: #667eea;
    padding: 0.75rem 1.5rem;
    border-radius: 25px;
    cursor: pointer;
    transition: all 0.3s;
    font-size: 1rem;
    font-weight: bold;
}

.method-btn:hover {
    background: #667eea;
    color: white;
    transform: translateY(-2px);
}

.method-btn.active {
    background: #667eea;
    color: white;
}

/* Visual Learning - Flashcards */
.visual-learning {
    text-align: center;
}

.visual-learning h3 {
    color: #2c3e50;
    margin-bottom: 1.5rem;
}

.flashcards {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 1.5rem;
    margin-bottom: 2rem;
}

.flashcard {
    background: white;
    border-radius: 10px;
    box-shadow: 0 4px 15px rgba(0,0,0,0.1);
    cursor: pointer;
    perspective: 1000px;
    height: 200px;
    transition: transform 0.3s;
}

.flashcard:hover {
    transform: translateY(-5px);
}

.card-front, .card-back {
    position: absolute;
    width: 100%;
    height: 100%;
    backface-visibility: hidden;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    padding: 1rem;
    border-radius: 10px;
    transition: transform 0.6s;
}

.card-back {
    transform: rotateY(180deg);
    background: #f8f9fa;
}

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

.flashcard.flipped .card-back {
    transform: rotateY(0deg);
}

.card-front h4, .card-back h4 {
    color: #2c3e50;
    font-size: 1.5rem;
    margin-bottom: 0.5rem;
}

.pronunciation {
    color: #667eea;
    font-style: italic;
    margin-bottom: 1rem;
}

.conjugations {
    text-align: left;
}

.conjugation {
    line-height: 1.8;
}

.visual-controls {
    display: flex;
    justify-content: center;
    gap: 1rem;
    margin-top: 2rem;
}

.btn-primary, .btn-secondary {
    padding: 0.75rem 1.5rem;
    border: none;
    border-radius: 25px;
    cursor: pointer;
    font-weight: bold;
    transition: all 0.3s;
}

.btn-primary {
    background: #667eea;
    color: white;
}

.btn-primary:hover {
    background: #5a67d8;
    transform: translateY(-2px);
}

.btn-secondary {
    background: #e2e8f0;
    color: #4a5568;
}

.btn-secondary:hover {
    background: #cbd5e0;
    transform: translateY(-2px);
}

/* Auditory Learning */
.auditory-learning {
    text-align: center;
    padding: 2rem;
}

.auditory-learning h3 {
    color: #2c3e50;
    margin-bottom: 1rem;
}

.audio-card {
    background: white;
    padding: 2rem;
    border-radius: 10px;
    box-shadow: 0 4px 15px rgba(0,0,0,0.1);
    margin: 1rem auto;
    max-width: 400px;
}

.play-btn {
    background: #667eea;
    color: white;
    border: none;
    padding: 1rem 2rem;
    border-radius: 25px;
    cursor: pointer;
    font-size: 1.1rem;
    margin: 1rem 0;
    transition: all 0.3s;
}

.play-btn:hover {
    background: #5a67d8;
    transform: scale(1.05);
}

/* Kinesthetic Learning */
.kinesthetic-learning h3 {
    color: #2c3e50;
    text-align: center;
    margin-bottom: 1.5rem;
}

.drag-drop-exercise {
    display: flex;
    flex-direction: column;
    gap: 2rem;
    margin-top: 1rem;
}

.drag-source {
    background: #f8f9fa;
    padding: 1rem;
    border-radius: 10px;
    min-height: 150px;
    order: 2;
}

.drag-source h4 {
    color: #2c3e50;
    margin-bottom: 1rem;
    text-align: center;
}

.draggable-items-container {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
    justify-content: center;
}

.drop-targets {
    order: 1;
}


.drop-zone {
    background: white;
    border: 2px dashed #ddd;
    padding: 1rem;
    border-radius: 10px;
    margin-bottom: 1rem;
}

.drop-zone h5 {
    color: #2c3e50;
    margin-bottom: 0.5rem;
}

.conjugation-slots {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.drop-slot {
    background: #f8f9fa;
    padding: 0.75rem;
    border-radius: 5px;
    border: 2px dashed #ccc;
    min-height: 40px;
    display: flex;
    align-items: center;
    transition: all 0.3s ease;
    font-weight: bold;
}

.drop-slot:hover {
    border-color: #667eea;
    background: #f0f7ff;
}

.draggable-item {
    background: #667eea;
    color: white;
    padding: 0.5rem 1rem;
    border-radius: 20px;
    margin: 0.25rem;
    cursor: move;
    transition: all 0.3s;
    user-select: none;
    font-weight: bold;
    box-shadow: 0 2px 5px rgba(0,0,0,0.1);
}

.draggable-item:hover {
    background: #5a67d8;
    transform: scale(1.05);
    box-shadow: 0 4px 10px rgba(0,0,0,0.2);
}

/* Reading Learning */
.reading-learning h3 {
    color: #2c3e50;
    text-align: center;
    margin-bottom: 1.5rem;
}

.study-guide {
    background: white;
    padding: 2rem;
    border-radius: 10px;
    box-shadow: 0 4px 15px rgba(0,0,0,0.1);
}

.verb-entry {
    border-bottom: 1px solid #eee;
    padding: 1.5rem 0;
}

.verb-entry:last-child {
    border-bottom: none;
}

.verb-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1rem;
}

.verb-header h5 {
    color: #2c3e50;
    font-size: 1.2rem;
}

.conjugation-table table {
    width: 100%;
    border-collapse: collapse;
    margin-bottom: 1rem;
}

.conjugation-table td {
    padding: 0.5rem;
    border: 1px solid #eee;
}

.conjugation-table td:first-child {
    background: #f8f9fa;
    font-weight: bold;
    width: 100px;
}

.example-sentence {
    background: #f0f7ff;
    padding: 1rem;
    border-radius: 5px;
    border-left: 4px solid #667eea;
}

.study-notes {
    margin-top: 2rem;
    padding-top: 2rem;
    border-top: 2px solid #eee;
}

.study-notes h4 {
    color: #2c3e50;
    margin-bottom: 1rem;
}

.notes-area {
    width: 100%;
    min-height: 120px;
    padding: 1rem;
    border: 2px solid #ddd;
    border-radius: 5px;
    font-family: inherit;
    resize: vertical;
    margin-bottom: 1rem;
}

.notes-area:focus {
    border-color: #667eea;
    outline: none;
}

/* Progress Bar */
.learning-progress {
    text-align: center;
    margin-top: 2rem;
}

.progress-bar {
    background: #e2e8f0;
    border-radius: 10px;
    height: 10px;
    margin: 1rem 0;
    overflow: hidden;
}

.progress-fill {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    height: 100%;
    transition: width 0.3s ease;
}

/* Responsive design */
@media (max-width: 768px) {
    .nav {
        flex-direction: column;
        gap: 1rem;
    }
    
    .hero h2 {
        font-size: 2rem;
    }
    
    .learning-methods {
        grid-template-columns: 1fr;
    }
    
    .subjects {
        grid-template-columns: 1fr;
    }
    
    .method-buttons {
        flex-direction: column;
        align-items: center;
    }
    
    .flashcards {
        grid-template-columns: 1fr;
    }
    
    .drag-drop-exercise {
        grid-template-columns: 1fr;
    }
    
    .visual-controls {
        flex-direction: column;
        align-items: center;
    }
}