:root {
    --primary-color: #4361ee;
    --primary-dark: #3a56d4;
    --secondary-color: #3f37c9;
    --accent-color: #4895ef;
    --light-color: #f8f9fa;
    --dark-color: #212529;
    --gray-color: #6c757d;
    --success-color: #4bb543;
    --error-color: #ff3333;
    --border-radius: 8px;
    --box-shadow: 0 4px 20px rgba(0, 0, 0, 0.1);
    --transition: all 0.3s ease;
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Poppins', sans-serif;
    background-color: #f5f7ff;
    color: var(--dark-color);
    line-height: 1.6;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 2rem 1rem;
}

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

header h1 {
    font-size: 2.5rem;
    color: var(--primary-color);
    margin-bottom: 0.5rem;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
}

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

.upload-section {
    margin-bottom: 2rem;
}

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

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

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

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

.upload-box p {
    color: var(--gray-color);
    margin: 0.5rem 0;
}

.upload-box .formats {
    font-size: 0.9rem;
    margin-top: 1rem;
}

#fileInput {
    display: none;
}

.btn-primary {
    background-color: var(--primary-color);
    color: white;
    border: none;
    padding: 0.75rem 1.5rem;
    border-radius: var(--border-radius);
    font-size: 1rem;
    font-weight: 500;
    cursor: pointer;
    transition: var(--transition);
    display: inline-block;
}

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

.btn-secondary {
    background-color: white;
    color: var(--primary-color);
    border: 1px solid var(--primary-color);
    padding: 0.75rem 1.5rem;
    border-radius: var(--border-radius);
    font-size: 1rem;
    font-weight: 500;
    cursor: pointer;
    transition: var(--transition);
}

.btn-secondary:hover {
    background-color: #f0f4ff;
}

.controls-section {
    background-color: white;
    border-radius: var(--border-radius);
    padding: 2rem;
    margin-bottom: 2rem;
    box-shadow: var(--box-shadow);
}

.enhance-options h3 {
    margin-bottom: 1.5rem;
    color: var(--primary-color);
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.option-group {
    margin-bottom: 1.5rem;
}

.option-group label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: 500;
}

.option-group input[type="range"] {
    width: 100%;
    height: 8px;
    -webkit-appearance: none;
    background: #e9ecef;
    border-radius: 4px;
    outline: none;
    margin-bottom: 0.5rem;
}

.option-group input[type="range"]::-webkit-slider-thumb {
    -webkit-appearance: none;
    width: 20px;
    height: 20px;
    background: var(--primary-color);
    border-radius: 50%;
    cursor: pointer;
    transition: var(--transition);
}

.option-group input[type="range"]::-webkit-slider-thumb:hover {
    transform: scale(1.1);
}

.option-group span {
    display: inline-block;
    width: 40px;
    text-align: right;
    font-weight: 500;
}

.preset-buttons {
    display: flex;
    flex-wrap: wrap;
    gap: 0.75rem;
    margin: 1.5rem 0;
}

.btn-preset {
    background-color: #f0f4ff;
    color: var(--primary-color);
    border: none;
    padding: 0.5rem 1rem;
    border-radius: 20px;
    font-size: 0.9rem;
    cursor: pointer;
    transition: var(--transition);
}

.btn-preset:hover {
    background-color: #e1e8ff;
}

.action-buttons {
    display: flex;
    gap: 1rem;
    margin-top: 2rem;
}

.result-section {
    background-color: white;
    border-radius: var(--border-radius);
    padding: 2rem;
    margin-bottom: 2rem;
    box-shadow: var(--box-shadow);
}

.comparison-container {
    position: relative;
    margin-bottom: 2rem;
}

.before-after {
    display: flex;
    position: relative;
    border-radius: var(--border-radius);
    overflow: hidden;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.1);
}

.before, .after {
    flex: 1;
    position: relative;
}

.before h3, .after h3 {
    position: absolute;
    top: 1rem;
    padding: 0.25rem 0.75rem;
    border-radius: 4px;
    font-size: 0.9rem;
    z-index: 2;
}

.before h3 {
    left: 1rem;
    background-color: rgba(0, 0, 0, 0.7);
    color: white;
}

.after h3 {
    right: 1rem;
    background-color: var(--primary-color);
    color: white;
}

.before img, .after img {
    width: 100%;
    height: auto;
    display: block;
}

.slider-container {
    position: relative;
    height: 30px;
    margin-top: 1rem;
}

.slider-container input[type="range"] {
    position: absolute;
    width: 100%;
    height: 100%;
    -webkit-appearance: none;
    background: transparent;
    z-index: 2;
    margin: 0;
}

.slider-container input[type="range"]::-webkit-slider-thumb {
    -webkit-appearance: none;
    width: 40px;
    height: 40px;
    background: white;
    border-radius: 50%;
    cursor: pointer;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.2);
    border: 2px solid var(--primary-color);
    transition: var(--transition);
}

.slider-container input[type="range"]::-webkit-slider-thumb:hover {
    transform: scale(1.05);
}

.slider-button {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    width: 40px;
    height: 40px;
    background: white;
    border-radius: 50%;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.2);
    border: 2px solid var(--primary-color);
    z-index: 1;
    pointer-events: none;
}

.download-options h3 {
    margin-bottom: 1.5rem;
    color: var(--primary-color);
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.format-options {
    display: flex;
    gap: 0.75rem;
    margin-bottom: 1.5rem;
}

.btn-download {
    background-color: #f0f4ff;
    color: var(--primary-color);
    border: none;
    padding: 0.5rem 1.5rem;
    border-radius: var(--border-radius);
    font-size: 0.9rem;
    cursor: pointer;
    transition: var(--transition);
}

.btn-download:hover {
    background-color: #e1e8ff;
}

.quality-option {
    display: flex;
    align-items: center;
    gap: 1rem;
    margin-bottom: 1.5rem;
}

.quality-option label {
    font-weight: 500;
}

.quality-option input[type="range"] {
    flex: 1;
    height: 8px;
    -webkit-appearance: none;
    background: #e9ecef;
    border-radius: 4px;
    outline: none;
}

.quality-option input[type="range"]::-webkit-slider-thumb {
    -webkit-appearance: none;
    width: 20px;
    height: 20px;
    background: var(--primary-color);
    border-radius: 50%;
    cursor: pointer;
}

#downloadBtn {
    width: 100%;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
}

.loading-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(255, 255, 255, 0.9);
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    z-index: 1000;
}

.spinner {
    width: 50px;
    height: 50px;
    border: 5px solid #f0f0f0;
    border-top: 5px solid var(--primary-color);
    border-radius: 50%;
    animation: spin 1s linear infinite;
    margin-bottom: 1rem;
}

@keyframes spin {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}

footer {
    text-align: center;
    padding: 1.5rem;
    color: var(--gray-color);
    font-size: 0.9rem;
}

.social-links {
    display: flex;
    justify-content: center;
    gap: 1rem;
    margin-top: 0.5rem;
}

.social-links a {
    color: var(--gray-color);
    font-size: 1.2rem;
    transition: var(--transition);
}

.social-links a:hover {
    color: var(--primary-color);
}

/* Responsive styles */
@media (max-width: 768px) {
    .before-after {
        flex-direction: column;
    }
    
    .preset-buttons {
        flex-direction: column;
    }
    
    .action-buttons {
        flex-direction: column;
    }
    
    .format-options {
        flex-wrap: wrap;
    }
}