body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    max-width: 800px;
    margin: 0 auto;
    padding: 20px;
    background-color: #f5f7fa;
    color: #333;
}
.container {
    background-color: white;
    border-radius: 10px;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
    padding: 30px;
    margin-bottom: 20px;
}
h1 {
    color: #2d3748;
    text-align: center;
    margin-bottom: 30px;
}
label {
    display: block;
    margin-bottom: 10px;
}
textarea {
    width: 100%;
    height: 200px;
    padding: 10px;
    border: 1px solid #ddd;
    border-radius: 5px;
    margin-bottom: 20px;
    font-family: monospace;
}
button {
    background-color: #4299e1;
    color: white;
    border: none;
    padding: 10px 20px;
    border-radius: 5px;
    cursor: pointer;
    font-size: 16px;
    transition: background-color 0.3s;
}
button:hover {
    background-color: #3182ce;
}
button:disabled {
    background-color: #cbd5e0;
    cursor: not-allowed;
}
#upload-container, #quiz-container, #results-container {
    display: none;
}
.option-label {
    display: block;
    padding: 10px;
    margin: 5px 0;
    border: 1px solid #ddd;
    border-radius: 4px;
    cursor: pointer;
    transition: all 0.3s ease;
}
.option-label:hover {
    background-color: #e2e8f0;
}
.option-label.correct {
    background-color: #d4edda;
    border-color: #c3e6cb;
    color: #155724;
    animation: fadeIn 0.5s;
}
.option-label.incorrect {
    background-color: #f8d7da;
    border-color: #f5c6cb;
    color: #721c24;
    animation: fadeIn 0.5s;
}
.option-radio {
    margin-right: 10px;
}
.current-question {
    font-size: 20px;
    margin-bottom: 20px;
}
.progress-bar {
    height: 10px;
    background-color: #edf2f7;
    border-radius: 5px;
    margin-bottom: 20px;
    overflow: hidden;
}
.progress-fill {
    height: 100%;
    background-color: #4299e1;
    width: 0%;
    transition: width 0.3s;
}
.score-display {
    text-align: center;
    font-size: 18px;
    margin-bottom: 20px;
}
.question-result {
    margin-bottom: 15px;
    padding: 15px;
    border-radius: 5px;
}
.correct {
    background-color: rgba(72, 187, 120, 0.2);
    border-left: 4px solid #48bb78;
}
.incorrect {
    background-color: rgba(245, 101, 101, 0.2);
    border-left: 4px solid #f56565;
}
.file-input-wrapper {
    position: relative;
    overflow: hidden;
    display: inline-block;
}
.file-input-wrapper input[type=file] {
    position: absolute;
    font-size: 100px;
    left: 0;
    top: 0;
    opacity: 0;
    cursor: pointer;
}
.file-input-button {
    background-color: #4299e1;
    color: white;
    border: none;
    padding: 10px 20px;
    border-radius: 5px;
    cursor: pointer;
    font-size: 16px;
    display: inline-block;
}
.topic-dropdown {
    padding: 10px;
    margin-bottom: 20px;
    border-radius: 5px;
    border: 1px solid #ddd;
    width: 100%;
}
.nav-buttons {
    display: flex;
    justify-content: space-between;
    margin-top: 20px;
}
.explanation {
    margin-top: 20px;
    padding: 15px;
    background-color: #f5f7fa;
    border-radius: 5px;
    border-left: 4px solid #4299e1;
}
.top-bar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 20px;
}
.restart-top {
    background-color: #ed8936;
    margin-left: auto;
}
.restart-top:hover {
    background-color: #dd6b20;
}
@keyframes fadeIn {
    from { opacity: 0.5; }
    to { opacity: 1; }
}
.quiz-stats {
    display: flex;
    gap: 20px;
    align-items: center;
}

.question-counter {
    color: #34495e;
}