:root {
    --primary-color: #1a73e8;
    --primary-dark: #0d47a1;
    --primary-light: #63a4ff;
    --secondary-color: #f5f5f5;
    --correct-color: #4caf50;
    --wrong-color: #f44336;
    --text-color: #333;
    --light-text: #fff;
}

* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
}

body {
    background-color: #f0f2f5;
    color: var(--text-color);
    line-height: 1.6;
    padding: 20px;
}

.quiz-container {
    max-width: 800px;
    margin: 0 auto;
    background-color: white;
    border-radius: 10px;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.1);
    overflow: hidden;
}

.quiz-header {
    background-color: var(--primary-color);
    color: var(--light-text);
    padding: 20px;
    text-align: center;
}

.quiz-header h1 {
    margin-bottom: 15px;
    font-size: 24px;
}

.quiz-info {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-top: 15px;
    font-size: 16px;
    background-color: var(--primary-dark);
    padding: 10px 15px;
    border-radius: 5px;
}

.timer, .score {
    display: flex;
    align-items: center;
}

.progress-container {
    flex-grow: 1;
    margin: 0 15px;
    height: 10px;
    background-color: rgba(255, 255, 255, 0.3);
    border-radius: 5px;
    overflow: hidden;
}

.progress-bar {
    height: 100%;
    background-color: white;
    width: 0%;
    transition: width 0.3s ease;
}

.quiz-section {
    padding: 25px;
}

.hidden {
    display: none;
}

.question-container {
    margin-bottom: 25px;
}

.question-number {
    font-weight: bold;
    color: var(--primary-dark);
    margin-bottom: 10px;
}

.question-text {
    font-size: 18px;
    margin-bottom: 20px;
    line-height: 1.5;
}

.options {
    display: grid;
    grid-template-columns: 1fr;
    gap: 12px;
}

.option {
    padding: 12px 15px;
    background-color: var(--secondary-color);
    border-radius: 5px;
    cursor: pointer;
    transition: all 0.2s ease;
}

.option:hover {
    background-color: #e0e0e0;
}

.option.correct {
    background-color: var(--correct-color);
    color: white;
}

.option.wrong {
    background-color: var(--wrong-color);
    color: white;
}

.option.selected {
    border: 2px solid var(--primary-color);
}

.btn {
    background-color: var(--primary-color);
    color: white;
    border: none;
    padding: 12px 25px;
    border-radius: 5px;
    cursor: pointer;
    font-size: 16px;
    transition: background-color 0.3s;
    display: block;
    margin: 0 auto;
}

.btn:hover {
    background-color: var(--primary-dark);
}

.result-stats {
    text-align: center;
    margin-bottom: 30px;
}

.result-stats p {
    font-size: 18px;
    margin: 10px 0;
}

#final-score {
    font-weight: bold;
    font-size: 24px;
    color: var(--primary-dark);
}

.answer-key {
    margin-top: 30px;
    border-top: 1px solid #eee;
    padding-top: 20px;
}

.key-entry {
    margin-bottom: 15px;
    padding: 15px;
    background-color: #f9f9f9;
    border-radius: 5px;
}

.key-entry.correct {
    border-left: 4px solid var(--correct-color);
}

.key-entry.incorrect {
    border-left: 4px solid var(--wrong-color);
}

.key-question {
    font-weight: bold;
    margin-bottom: 5px;
}

.key-answer {
    margin-top: 5px;
    font-style: italic;
}

.key-explanation {
    margin-top: 5px;
    font-size: 14px;
    color: #666;
}

@media (max-width: 600px) {
    .quiz-info {
        flex-direction: column;
        gap: 10px;
    }
    
    .progress-container {
        width: 100%;
        margin: 10px 0;
    }
}