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

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background: linear-gradient(135deg, #74b9ff, #0dbc79);
    min-height: 100vh;
    color: #333;
}

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

header {
    text-align: center;
    margin-bottom: 30px;
    background: white;
    padding: 30px;
    border-radius: 20px;
    box-shadow: 0 10px 30px rgba(0,0,0,0.1);
}

header h1 {
    font-size: 2.5em;
    color: #2d3436;
    margin-bottom: 10px;
}

header p {
    font-size: 1.2em;
    color: #636e72;
}

.quiz-container {
    background: white;
    border-radius: 20px;
    padding: 30px;
    box-shadow: 0 10px 30px rgba(0,0,0,0.1);
    margin-bottom: 20px;
}

.loading {
    text-align: center;
    padding: 50px 0;
}

.spinner {
    width: 50px;
    height: 50px;
    border: 5px solid #f3f3f3;
    border-top: 5px solid #74b9ff;
    border-radius: 50%;
    animation: spin 1s linear infinite;
    margin: 0 auto 20px;
}

@keyframes spin {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}

.quiz-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 30px;
    padding-bottom: 15px;
    border-bottom: 2px solid #ddd;
}

.quiz-number {
    font-size: 1.2em;
    font-weight: bold;
    color: #74b9ff;
}

.score {
    font-size: 1.2em;
    font-weight: bold;
    color: #00b894;
}

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

.question-section h2 {
    font-size: 1.5em;
    line-height: 1.6;
    color: #2d3436;
    background: #f8f9fa;
    padding: 20px;
    border-radius: 15px;
    border-left: 5px solid #74b9ff;
}

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

.option {
    background: #f8f9fa;
    border: 2px solid #ddd;
    border-radius: 15px;
    padding: 15px 20px;
    margin-bottom: 15px;
    cursor: pointer;
    transition: all 0.3s ease;
    font-size: 1.1em;
}

.option:hover {
    background: #e9ecef;
    border-color: #74b9ff;
    transform: translateY(-2px);
}

.option.selected {
    background: #74b9ff;
    color: white;
    border-color: #74b9ff;
}

.option.correct {
    background: #00b894;
    color: white;
    border-color: #00b894;
}

.option.incorrect {
    background: #e17055;
    color: white;
    border-color: #e17055;
}

.option.disabled {
    cursor: not-allowed;
    opacity: 0.7;
}

.explanation {
    background: #fff3cd;
    border: 1px solid #ffeaa7;
    border-radius: 15px;
    padding: 20px;
    margin-bottom: 30px;
}

.explanation h3 {
    color: #e17055;
    margin-bottom: 10px;
}

.explanation p {
    line-height: 1.6;
    color: #2d3436;
}

.quiz-controls {
    text-align: center;
}

.quiz-controls button {
    background: #74b9ff;
    color: white;
    border: none;
    padding: 15px 30px;
    border-radius: 25px;
    font-size: 1.1em;
    cursor: pointer;
    margin: 0 10px;
    transition: all 0.3s ease;
}

.quiz-controls button:hover {
    background: #0984e3;
    transform: translateY(-2px);
}

.result-section {
    text-align: center;
    padding: 50px 0;
}

.result-section h2 {
    font-size: 2.5em;
    color: #00b894;
    margin-bottom: 30px;
}

.final-score {
    background: #f8f9fa;
    border-radius: 15px;
    padding: 30px;
    margin-bottom: 30px;
}

.final-score p {
    font-size: 2em;
    font-weight: bold;
    color: #2d3436;
    margin-bottom: 15px;
}

.score-message {
    font-size: 1.3em;
    color: #636e72;
}

.info-section {
    background: white;
    border-radius: 20px;
    padding: 25px;
    box-shadow: 0 10px 30px rgba(0,0,0,0.1);
    text-align: center;
}

.info-section h3 {
    color: #74b9ff;
    margin-bottom: 15px;
    font-size: 1.5em;
}

.info-section p {
    line-height: 1.6;
    color: #636e72;
    font-size: 1.1em;
}

@media (max-width: 768px) {
    .container {
        padding: 10px;
    }
    
    header h1 {
        font-size: 2em;
    }
    
    .quiz-container {
        padding: 20px;
    }
    
    .question-section h2 {
        font-size: 1.3em;
    }
    
    .quiz-controls button {
        padding: 12px 25px;
        font-size: 1em;
    }
}