body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    background-color: #f4f7f9;
    color: #333;
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    margin: 0;
    padding: 1rem;
    box-sizing: border-box;
}

#app {
    width: 100%;
    max-width: 600px;
    background: #fff;
    border-radius: 12px;
    box-shadow: 0 8px 24px rgba(0, 0, 0, 0.1);
    padding: 2rem;
    text-align: center;
}

h1 {
    color: #2c3e50;
    margin-bottom: 1rem;
}

#upload-container p {
    color: #7f8c8d;
    margin-bottom: 1.5rem;
}

#upload-button {
    background-color: #3498db;
    color: white;
    border: none;
    padding: 12px 24px;
    font-size: 1rem;
    border-radius: 8px;
    cursor: pointer;
    transition: background-color 0.3s;
}

#upload-button:hover {
    background-color: #2980b9;
}

.separator {
    margin-top: 2rem;
    margin-bottom: 1rem;
    font-size: 0.9rem;
    color: #95a5a6;
    text-align: center;
}

#manual-input-container {
    margin-top: 1rem;
}

.input-group {
    display: flex;
    flex-direction: column;
    gap: 10px;
    margin-bottom: 1rem;
}

.input-group textarea {
    width: 100%;
    padding: 12px;
    font-size: 1rem;
    border: 1px solid #ccc;
    border-radius: 8px;
    box-sizing: border-box;
    resize: vertical;
    min-height: 100px;
    font-family: inherit;
}

#manual-start-button {
    background-color: #27ae60;
    color: white;
    border: none;
    padding: 12px 24px;
    font-size: 1rem;
    border-radius: 8px;
    cursor: pointer;
    transition: background-color 0.3s;
    width: 100%;
}

#manual-start-button:hover {
    background-color: #229954;
}

#loading-container {
    margin-top: 1.5rem;
}

.hidden {
    display: none !important;
}

#quiz-container {
    text-align: left;
}

#progress {
    margin-bottom: 1rem;
    color: #7f8c8d;
    font-size: 0.9rem;
}

#question-card {
    border: 1px solid #e0e0e0;
    border-radius: 8px;
    padding: 1.5rem;
    margin-bottom: 1.5rem;
}

#question-text {
    font-size: 1.1rem;
    margin-bottom: 1.5rem;
    line-height: 1.6;
}

.option {
    display: block;
    width: 100%;
    padding: 12px;
    margin-bottom: 10px;
    background-color: #ecf0f1;
    border: 2px solid transparent;
    border-radius: 8px;
    cursor: pointer;
    text-align: left;
    font-size: 1rem;
    transition: all 0.2s;
}

.option:hover {
    background-color: #dfe6e9;
}

.option.selected {
    border-color: #3498db;
    background-color: #eaf5fc;
}

#result-container .analysis {
    margin-top: 1.5rem;
    padding: 1rem;
    border-radius: 8px;
    background-color: #f8f9fa;
    text-align: left;
}

#result-container h3 {
    margin-top: 0;
    font-size: 1.2rem;
    color: #2c3e50;
}

.analysis p {
    line-height: 1.6;
    font-size: 0.95rem;
}

.analysis p.correct {
    color: #2ecc71;
}

.analysis p.incorrect {
    color: #e74c3c;
}