body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background-color: #f5f7fa;
    margin: 0;
    padding: 0;
    color: #333;
}

.container {
    max-width: 800px;
    margin: 40px auto;
    padding: 20px;
    background-color: white;
    border-radius: 10px;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
}

h1 {
    text-align: center;
    color: #2c3e50;
    margin-bottom: 30px;
}

.converter-box {
    border: 1px solid #e0e0e0;
    padding: 25px;
    border-radius: 8px;
    background-color: #f9f9f9;
}

.file-input-section {
    margin-bottom: 25px;
    text-align: center;
}

.file-input-section input[type="file"] {
    display: none;
}

.file-label {
    display: inline-block;
    padding: 12px 20px;
    background-color: #3498db;
    color: white;
    border-radius: 5px;
    cursor: pointer;
    transition: background-color 0.3s;
}

.file-label:hover {
    background-color: #2980b9;
}

#fileName {
    display: block;
    margin-top: 10px;
    font-size: 14px;
    color: #666;
}

.options-section {
    margin: 25px 0;
    padding: 20px;
    background-color: white;
    border-radius: 8px;
    border: 1px solid #e0e0e0;
}

.options-section h3 {
    margin-top: 0;
    color: #2c3e50;
    border-bottom: 1px solid #eee;
    padding-bottom: 10px;
}

.option-group {
    margin-bottom: 15px;
}

.option-group label {
    display: block;
    margin-bottom: 5px;
    font-weight: 500;
}

.option-group select, .option-group input[type="number"] {
    width: 100%;
    padding: 8px 12px;
    border: 1px solid #ddd;
    border-radius: 4px;
    font-size: 14px;
}

.checkbox-group {
    display: flex;
    align-items: center;
}

.checkbox-group input {
    margin-right: 10px;
}

.convert-btn {
    display: block;
    width: 100%;
    padding: 12px;
    background-color: #27ae60;
    color: white;
    border: none;
    border-radius: 5px;
    font-size: 16px;
    cursor: pointer;
    transition: background-color 0.3s;
}

.convert-btn:hover {
    background-color: #219653;
}

#status {
    margin-top: 15px;
    text-align: center;
    font-size: 14px;
    color: #666;
    min-height: 20px;
}