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

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background: linear-gradient(135deg, #757885 0%, #6513b8 100%);
    min-height: 100vh;
    color: #333;
    
}

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

header {
    text-align: center;
    margin-bottom: 40px;
    color: white;
}

header h1 {
    font-size: 2.5rem;
    margin-bottom: 10px;
    text-shadow: 2px 2px 4px rgba(0,0,0,0.3);
}

header p {
    font-size: 1.2rem;
    opacity: 0.9;
}

.topics-grid {
    display: flex;
    flex-direction: column;
    gap: 15px;
    margin-bottom: 30px;
    max-width: 600px;
    margin-left: auto;
    margin-right: auto;
}

.topic-btn {
    background: white;
    border: none;
    padding: 20px;
    border-radius: 15px;
    font-size: 1.1rem;
    font-weight: 600;
    color: #333;
    cursor: pointer;
    transition: all 0.3s ease;
    box-shadow: 0 4px 15px rgba(0,0,0,0.1);
    text-align: left;
}

.topic-btn:hover {
    transform: translateY(-5px);
    box-shadow: 0 8px 25px rgba(0,0,0,0.2);
    background: #f8f9fa;
}

.modules-grid {
    display: flex;
    flex-direction: column;
    gap: 15px;
    margin-bottom: 30px;
    max-width: 600px;
    margin-left: auto;
    margin-right: auto;
}

.module-btn {
    background: white;
    color: #333;
    border: none;
    padding: 20px;
    border-radius: 15px;
    font-size: 1.1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    box-shadow: 0 4px 15px rgba(0,0,0,0.1);
    text-align: left;
}

.module-btn:hover {
    transform: translateY(-5px);
    box-shadow: 0 8px 25px rgba(0,0,0,0.2);
    background: #f8f9fa;
}

.back-btn {
    background: #2196F3;
    color: white;
    border: none;
    padding: 12px 24px;
    border-radius: 8px;
    font-size: 1rem;
    cursor: pointer;
    transition: all 0.3s ease;
    margin-bottom: 20px;
}

.back-btn:hover {
    background: #1976D2;
    transform: translateY(-2px);
}

.quiz-container {
    background: white;
    border-radius: 15px;
    padding: 30px;
    box-shadow: 0 8px 25px rgba(0,0,0,0.1);
    margin-bottom: 20px;
}

.question {
    font-size: 1.3rem;
    font-weight: 600;
    margin-bottom: 25px;
    color: #333;
}

.options {
    display: flex;
    flex-direction: column;
    gap: 15px;
    margin-bottom: 25px;
}

.option {
    display: flex;
    align-items: center;
    padding: 15px;
    border: 2px solid #e0e0e0;
    border-radius: 10px;
    cursor: pointer;
    transition: all 0.3s ease;
    background: #f9f9f9;
}

.option:hover {
    border-color: #2196F3;
    background: #f0f8ff;
}

.option.selected {
    border-color: #2196F3;
    background: #e3f2fd;
}

.option input[type="radio"] {
    margin-right: 15px;
    transform: scale(1.2);
}

.check-btn {
    background: #FF9800;
    color: white;
    border: none;
    padding: 12px 30px;
    border-radius: 8px;
    font-size: 1rem;
    cursor: pointer;
    transition: all 0.3s ease;
    margin-bottom: 20px;
}

.check-btn:hover {
    background: #F57C00;
}

.result {
    margin-top: 20px;
    padding: 20px;
    border-radius: 10px;
    border-left: 5px solid;
}

.result.correct {
    background: #e8f5e8;
    border-color: #4CAF50;
}

.result.incorrect {
    background: #ffebee;
    border-color: #f44336;
}

.result h4 {
    margin-bottom: 15px;
    font-size: 1.2rem;
}

.explanation {
    margin-top: 15px;
}

.explanation p {
    margin-bottom: 10px;
    padding: 8px;
    border-radius: 5px;
}

.explanation .correct-option {
    background: #e8f5e8;
    color: #2e7d32;
}

.explanation .incorrect-option {
    background: #ffebee;
    color: #c62828;
}

.next-btn {
    background: #4CAF50;
    color: white;
    border: none;
    padding: 12px 30px;
    border-radius: 8px;
    font-size: 1rem;
    cursor: pointer;
    transition: all 0.3s ease;
    margin-top: 20px;
}

.next-btn:hover {
    background: #45a049;
}

.final-result {
    text-align: center;
    background: white;
    border-radius: 15px;
    padding: 40px;
    box-shadow: 0 8px 25px rgba(0,0,0,0.1);
}

.final-result h2 {
    color: #333;
    margin-bottom: 20px;
    font-size: 2rem;
}

.score {
    font-size: 1.5rem;
    margin-bottom: 30px;
    color: #666;
}

.percentage {
    font-size: 3rem;
    font-weight: bold;
    color: #4CAF50;
    margin-bottom: 30px;
}

.home-btn {
    background: #2196F3;
    color: white;
    border: none;
    padding: 15px 40px;
    border-radius: 10px;
    font-size: 1.1rem;
    cursor: pointer;
    transition: all 0.3s ease;
}

.home-btn:hover {
    background: #1976D2;
    transform: translateY(-2px);
}

.topics-to-study {
    margin-top: 30px;
    padding: 20px;
    background: #fff3cd;
    border: 1px solid #ffeaa7;
    border-radius: 10px;
    text-align: left;
}

.topics-to-study h3 {
    color: #856404;
    margin-bottom: 15px;
    font-size: 1.3rem;
}

.topics-list {
    list-style: none;
    padding: 0;
    margin: 0;
}

.topics-list li {
    padding: 8px 0;
    border-bottom: 1px solid #ffeaa7;
    color: #856404;
    font-weight: 500;
}

.topics-list li:last-child {
    border-bottom: none;
}

.topics-list li:before {
    content: "📚 ";
    margin-right: 8px;
}

.hidden {
    display: none;
}

@media (max-width: 768px) {
    .topics-grid {
        max-width: 100%;
    }
    
    .modules-grid {
        max-width: 100%;
    }
    
    .quiz-container {
        padding: 20px;
    }
    
    .question {
        font-size: 1.1rem;
    }
}