:root {
    --primary-color: #e74c3c;
    --secondary-color: #3498db;
    --dark-color: #2c3e50;
    --light-color: #ecf0f1;
    --success-color: #2ecc71;
    --warning-color: #f39c12;
    --error-color: #e74c3c;
}

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

body {
    background-color: #f5f7fa;
    color: #333;
    line-height: 1.6;
}

.container {
    max-width: 900px;
    margin: 0 auto;
    padding: 20px;
}

header {
    text-align: center;
    margin-bottom: 30px;
}

header h1 {
    color: var(--primary-color);
    margin-bottom: 10px;
    font-size: 2.2rem;
}

header h1 i {
    margin-right: 10px;
}

header p {
    color: var(--dark-color);
    font-size: 1.1rem;
}

.upload-area {
    background-color: white;
    border: 2px dashed #ccc;
    border-radius: 10px;
    padding: 40px;
    text-align: center;
    margin-bottom: 30px;
    transition: all 0.3s ease;
    cursor: pointer;
}

.upload-area:hover, .upload-area.drag-over {
    border-color: var(--secondary-color);
    background-color: #f8f9fa;
}

.upload-area i {
    font-size: 48px;
    color: var(--secondary-color);
    margin-bottom: 15px;
}

.upload-area h2 {
    margin-bottom: 10px;
    color: var(--dark-color);
}

.upload-area p {
    margin: 10px 0;
    color: #666;
}

.btn {
    background-color: var(--secondary-color);
    color: white;
    border: none;
    padding: 12px 25px;
    border-radius: 5px;
    cursor: pointer;
    font-size: 1rem;
    transition: all 0.3s ease;
    display: inline-block;
}

.btn:hover {
    background-color: #2980b9;
    transform: translateY(-2px);
}

.convert-btn {
    background-color: var(--primary-color);
    width: 100%;
    padding: 15px;
    font-size: 1.1rem;
    margin-top: 20px;
}

.convert-btn:hover {
    background-color: #c0392b;
}

.convert-btn:disabled {
    background-color: #95a5a6;
    cursor: not-allowed;
    transform: none;
}

.download-btn {
    background-color: var(--success-color);
    width: 100%;
    padding: 15px;
    font-size: 1.1rem;
    margin-top: 15px;
}

.download-btn:hover {
    background-color: #27ae60;
}

.secondary-btn {
    background-color: var(--dark-color);
    width: 100%;
    padding: 15px;
    font-size: 1.1rem;
    margin-top: 10px;
}

.secondary-btn:hover {
    background-color: #1a252f;
}

.options-section {
    background-color: white;
    border-radius: 10px;
    padding: 25px;
    margin-bottom: 20px;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.05);
}

.options-section h3 {
    margin-bottom: 20px;
    color: var(--dark-color);
    border-bottom: 1px solid #eee;
    padding-bottom: 10px;
}

.options-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 20px;
}

.option {
    margin-bottom: 15px;
}

.option label {
    display: block;
    margin-bottom: 8px;
    font-weight: 500;
    color: #555;
}

.option select, .option input[type="text"] {
    width: 100%;
    padding: 10px 12px;
    border: 1px solid #ddd;
    border-radius: 4px;
    font-size: 0.95rem;
}

.option input[type="checkbox"] {
    margin-right: 10px;
    transform: scale(1.2);
}

.progress-container {
    margin: 25px 0;
    text-align: center;
}

.progress-bar {
    background-color: #e0e0e0;
    border-radius: 10px;
    height: 12px;
    margin-bottom: 10px;
    overflow: hidden;
}

.progress {
    background: linear-gradient(90deg, var(--secondary-color), var(--primary-color));
    height: 100%;
    width: 0%;
    transition: width 0.3s ease;
}

.progress-info {
    display: flex;
    justify-content: space-between;
    font-size: 0.95rem;
    color: #666;
    margin-top: 5px;
}

.result-section {
    text-align: center;
    background-color: white;
    padding: 25px;
    border-radius: 10px;
    margin-top: 25px;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.05);
}

.result-section h3 {
    color: var(--success-color);
    margin-bottom: 15px;
    font-size: 1.5rem;
}

.conversion-stats {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
    gap: 15px;
    margin: 20px 0;
    text-align: center;
}

.conversion-stats p {
    background-color: #f8f9fa;
    padding: 15px;
    border-radius: 5px;
    font-size: 0.95rem;
}

.conversion-stats i {
    margin-right: 8px;
    color: var(--secondary-color);
}

.conversion-stats span {
    font-weight: bold;
    color: var(--dark-color);
}

footer {
    margin-top: 40px;
    text-align: center;
    font-size: 0.9rem;
    color: #777;
    padding-top: 20px;
    border-top: 1px solid #eee;
}

footer .disclaimer {
    font-style: italic;
    margin-top: 10px;
    color: var(--warning-color);
}

@media (max-width: 768px) {
    .container {
        padding: 15px;
    }
    
    header h1 {
        font-size: 1.8rem;
    }
    
    .upload-area {
        padding: 30px 15px;
    }
    
    .options-grid {
        grid-template-columns: 1fr;
    }
    
    .conversion-stats {
        grid-template-columns: 1fr;
    }
}