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

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
    padding: 20px;
    display: flex;
    justify-content: center;
    align-items: center;
}

.container {
    max-width: 800px;
    width: 100%;
    background: white;
    border-radius: 20px;
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.3);
    overflow: hidden;
}

header {
    background: linear-gradient(135deg, #009246 0%, #ce2b37 100%);
    color: white;
    padding: 30px;
    text-align: center;
}

header h1 {
    font-size: 2.5rem;
    margin-bottom: 10px;
}

.subtitle {
    opacity: 0.9;
    font-size: 1.1rem;
}

.screen {
    display: none;
    padding: 40px;
}

.screen.active {
    display: block;
}

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

.setup-section h2 {
    color: #333;
    margin-bottom: 15px;
    font-size: 1.3rem;
}

.checkbox-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 12px;
}

.checkbox-grid label {
    display: flex;
    align-items: center;
    padding: 12px;
    background: #f5f5f5;
    border-radius: 8px;
    cursor: pointer;
    transition: all 0.2s;
}

.checkbox-grid label:hover {
    background: #e8e8e8;
    transform: translateY(-2px);
}

.checkbox-grid input[type="checkbox"] {
    margin-right: 10px;
    width: 20px;
    height: 20px;
    cursor: pointer;
}

.btn-primary, .btn-secondary {
    width: 100%;
    padding: 15px;
    font-size: 1.1rem;
    font-weight: bold;
    border: none;
    border-radius: 10px;
    cursor: pointer;
    transition: all 0.3s;
}

.btn-primary {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 5px 20px rgba(102, 126, 234, 0.4);
}

.btn-secondary {
    background: #6c757d;
    color: white;
    margin-top: 10px;
}

.btn-secondary:hover {
    background: #5a6268;
}

.quiz-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 30px;
}

.stats {
    display: flex;
    gap: 20px;
    font-size: 1.2rem;
}

.stats span {
    background: #f5f5f5;
    padding: 8px 15px;
    border-radius: 8px;
}

.question-card {
    background: #f9f9f9;
    padding: 30px;
    border-radius: 15px;
    margin-bottom: 20px;
}

.verb-info {
    text-align: center;
    margin-bottom: 30px;
}

.verb-info h2 {
    font-size: 2.5rem;
    color: #333;
    margin-bottom: 10px;
}

.verb-translation {
    color: #666;
    font-size: 1.2rem;
}

.conjugation-request {
    text-align: center;
    margin-bottom: 25px;
}

.conjugation-request p {
    color: #666;
    margin-bottom: 10px;
}

.request-details {
    display: flex;
    justify-content: center;
    gap: 15px;
}

.badge {
    display: inline-block;
    padding: 8px 20px;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    border-radius: 20px;
    font-weight: bold;
}

#answer-input {
    width: 100%;
    padding: 15px;
    font-size: 1.3rem;
    border: 3px solid #ddd;
    border-radius: 10px;
    margin-bottom: 15px;
    text-align: center;
    transition: border-color 0.3s;
}

#answer-input:focus {
    outline: none;
    border-color: #667eea;
}

.feedback {
    margin-top: 20px;
    padding: 15px;
    border-radius: 10px;
    font-size: 1.1rem;
    text-align: center;
    display: none;
}

.feedback.show {
    display: block;
}

.feedback.correct {
    background: #d4edda;
    color: #155724;
    border: 2px solid #c3e6cb;
}

.feedback.incorrect {
    background: #f8d7da;
    color: #721c24;
    border: 2px solid #f5c6cb;
}

.progress-bar {
    height: 8px;
    background: #e0e0e0;
    border-radius: 4px;
    overflow: hidden;
}

.progress-fill {
    height: 100%;
    background: linear-gradient(90deg, #009246 0%, #ce2b37 100%);
    width: 0%;
    transition: width 0.3s;
}

.results-stats {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
    gap: 20px;
    margin: 30px 0;
}

.stat-box {
    background: #f9f9f9;
    padding: 25px;
    border-radius: 15px;
    text-align: center;
}

.stat-value {
    font-size: 2.5rem;
    font-weight: bold;
    color: #667eea;
    margin-bottom: 10px;
}

.stat-label {
    color: #666;
    font-size: 1rem;
}

#results-screen h2 {
    text-align: center;
    color: #333;
    font-size: 2rem;
    margin-bottom: 20px;
}

@media (max-width: 600px) {
    header h1 {
        font-size: 1.8rem;
    }
    
    .verb-info h2 {
        font-size: 2rem;
    }
    
    .checkbox-grid {
        grid-template-columns: 1fr;
    }
    
    .quiz-header {
        flex-direction: column;
        gap: 15px;
    }
    
    .stats {
        flex-wrap: wrap;
        justify-content: center;
    }
}