:root {
    --primary-color: #4361ee;
    --secondary-color: #3f37c9;
    --success-color: #4cc9f0;
    --error-color: #f72585;
    --light-color: #f8f9fa;
    --dark-color: #212529;
    --gray-color: #6c757d;
    --border-radius: 8px;
    --box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
    --transition: all 0.3s ease;
}

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

body {
    background-color: #f5f7fa;
    color: var(--dark-color);
    line-height: 1.6;
}

.container {
    max-width: 800px;
    margin: 0 auto;
    padding: 2rem;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

header {
    text-align: center;
    margin-bottom: 2rem;
}

header h1 {
    font-size: 2.5rem;
    margin-bottom: 0.5rem;
    color: var(--primary-color);
}

header h1 i {
    margin-right: 0.5rem;
}

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

main {
    flex: 1;
    display: flex;
    flex-direction: column;
    justify-content: center;
}

.upload-area {
    border: 2px dashed var(--gray-color);
    border-radius: var(--border-radius);
    padding: 3rem 2rem;
    text-align: center;
    cursor: pointer;
    transition: var(--transition);
    background-color: white;
    margin-bottom: 1.5rem;
}

.upload-area:hover {
    border-color: var(--primary-color);
    box-shadow: var(--box-shadow);
}

.upload-area.drag-over {
    border-color: var(--primary-color);
    background-color: rgba(67, 97, 238, 0.05);
}

.upload-content i {
    font-size: 3rem;
    color: var(--primary-color);
    margin-bottom: 1rem;
}

.upload-content h3 {
    margin-bottom: 0.5rem;
    color: var(--dark-color);
}

.upload-content p {
    color: var(--gray-color);
    margin-bottom: 1rem;
}

.browse-btn {
    background-color: var(--primary-color);
    color: white;
    border: none;
    padding: 0.75rem 1.5rem;
    border-radius: var(--border-radius);
    font-size: 1rem;
    cursor: pointer;
    transition: var(--transition);
}

.browse-btn:hover {
    background-color: var(--secondary-color);
    transform: translateY(-2px);
}

.progress-container {
    background-color: white;
    border-radius: var(--border-radius);
    padding: 2rem;
    box-shadow: var(--box-shadow);
    margin-bottom: 1.5rem;
    text-align: center;
}

.progress-bar {
    height: 10px;
    background-color: #e9ecef;
    border-radius: 5px;
    margin-bottom: 1rem;
    overflow: hidden;
}

.progress-bar::after {
    content: '';
    display: block;
    height: 100%;
    width: 0;
    background-color: var(--primary-color);
    border-radius: 5px;
    transition: width 0.3s ease;
}

.progress-text {
    display: block;
    margin-bottom: 1rem;
    font-weight: bold;
    color: var(--primary-color);
}

.file-info {
    color: var(--gray-color);
    font-size: 0.9rem;
}

.result-container, .error-container {
    background-color: white;
    border-radius: var(--border-radius);
    padding: 2rem;
    box-shadow: var(--box-shadow);
    text-align: center;
    margin-bottom: 1.5rem;
}

.result-icon {
    font-size: 4rem;
    margin-bottom: 1rem;
}

.result-icon .success {
    color: var(--success-color);
}

.result-icon .error {
    color: var(--error-color);
}

.result-title {
    margin-bottom: 1rem;
    color: var(--dark-color);
}

.result-message {
    color: var(--gray-color);
    margin-bottom: 1.5rem;
}

.download-btn {
    background-color: var(--success-color);
    color: white;
    border: none;
    padding: 0.75rem 1.5rem;
    border-radius: var(--border-radius);
    font-size: 1rem;
    cursor: pointer;
    transition: var(--transition);
    margin-right: 1rem;
}

.download-btn:hover {
    background-color: #3aa8d8;
    transform: translateY(-2px);
}

.try-again-btn {
    background-color: var(--light-color);
    color: var(--dark-color);
    border: none;
    padding: 0.75rem 1.5rem;
    border-radius: var(--border-radius);
    font-size: 1rem;
    cursor: pointer;
    transition: var(--transition);
}

.try-again-btn:hover {
    background-color: #e2e6ea;
    transform: translateY(-2px);
}

footer {
    text-align: center;
    margin-top: 2rem;
    color: var(--gray-color);
    font-size: 0.9rem;
}

@media (max-width: 768px) {
    .container {
        padding: 1rem;
    }
    
    header h1 {
        font-size: 2rem;
    }
    
    .upload-area {
        padding: 2rem 1rem;
    }
    
    .download-btn, .try-again-btn {
        display: block;
        width: 100%;
        margin-bottom: 0.5rem;
    }
    
    .download-btn {
        margin-right: 0;
    }
}