:root {
    --primary-color: #4361ee;
    --primary-dark: #3a56d4;
    --secondary-color: #7209b7;
    --success-color: #4cc9f0;
    --warning-color: #f72585;
    --light-color: #f8f9fa;
    --dark-color: #212529;
    --gray-color: #6c757d;
    --gray-light: #e9ecef;
    --border-radius: 12px;
    --box-shadow: 0 8px 25px rgba(0, 0, 0, 0.1);
    --transition: all 0.3s ease;
}

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

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    line-height: 1.6;
    color: var(--dark-color);
    background: linear-gradient(135deg, #f5f7fa 0%, #c3cfe2 100%);
    min-height: 100vh;
    padding: 20px;
}

.container {
    max-width: 1000px;
    margin: 0 auto;
}

/* Header */
.header {
    text-align: center;
    margin-bottom: 30px;
}

.header h1 {
    color: var(--primary-color);
    font-size: 2.5rem;
    margin-bottom: 10px;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 15px;
}

.subtitle {
    font-size: 1.1rem;
    color: var(--gray-color);
    max-width: 600px;
    margin: 0 auto;
}

/* Note Box */
.note-box {
    background-color: #e3f2fd;
    border-left: 4px solid var(--primary-color);
    padding: 15px 20px;
    border-radius: var(--border-radius);
    margin-bottom: 30px;
    display: flex;
    align-items: center;
    gap: 15px;
}

.note-box i {
    color: var(--primary-color);
    font-size: 1.5rem;
}

/* Cards */
.card {
    background: white;
    border-radius: var(--border-radius);
    box-shadow: var(--box-shadow);
    padding: 30px;
    margin-bottom: 30px;
    transition: var(--transition);
}

/* Upload Section */
.upload-area {
    text-align: center;
    padding: 60px 20px;
    border: 3px dashed var(--gray-light);
    border-radius: var(--border-radius);
    transition: var(--transition);
    cursor: pointer;
}

.upload-area:hover {
    border-color: var(--primary-color);
    background-color: rgba(67, 97, 238, 0.02);
}

.upload-icon {
    font-size: 4rem;
    color: var(--primary-color);
    margin-bottom: 20px;
}

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

.upload-area p {
    color: var(--gray-color);
    margin-bottom: 25px;
}

.file-requirements {
    font-size: 0.9rem;
    margin-top: 20px;
    color: var(--gray-color);
}

/* File Info */
.file-info {
    display: flex;
    justify-content: space-between;
    background-color: var(--gray-light);
    padding: 20px;
    border-radius: var(--border-radius);
    margin-bottom: 30px;
    flex-wrap: wrap;
    gap: 15px;
}

.info-item {
    display: flex;
    flex-direction: column;
}

.info-label {
    font-weight: 600;
    color: var(--gray-color);
    font-size: 0.9rem;
    margin-bottom: 5px;
}

.info-value {
    font-weight: 700;
    color: var(--dark-color);
    word-break: break-all;
}

/* Compression Options */
.compression-options {
    margin-bottom: 30px;
}

.compression-options h3 {
    margin-bottom: 20px;
    color: var(--dark-color);
}

.option-group {
    display: flex;
    flex-direction: column;
    gap: 15px;
    margin-bottom: 25px;
}

.option {
    display: flex;
    align-items: flex-start;
}

.option input[type="radio"] {
    margin-top: 5px;
    margin-right: 15px;
    accent-color: var(--primary-color);
}

.option label {
    flex: 1;
    cursor: pointer;
    padding: 15px;
    border: 2px solid var(--gray-light);
    border-radius: var(--border-radius);
    transition: var(--transition);
}

.option label:hover {
    border-color: var(--primary-color);
    background-color: rgba(67, 97, 238, 0.03);
}

.option input[type="radio"]:checked + label {
    border-color: var(--primary-color);
    background-color: rgba(67, 97, 238, 0.05);
}

.option-title {
    display: block;
    font-weight: 700;
    font-size: 1.1rem;
    color: var(--dark-color);
    margin-bottom: 5px;
}

.option-desc {
    display: block;
    font-size: 0.9rem;
    color: var(--gray-color);
}

/* Custom Settings */
.custom-settings {
    background-color: rgba(67, 97, 238, 0.03);
    border: 1px solid rgba(67, 97, 238, 0.1);
    border-radius: var(--border-radius);
    padding: 25px;
    margin-top: 20px;
    animation: fadeIn 0.3s ease;
}

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(-10px); }
    to { opacity: 1; transform: translateY(0); }
}

.custom-settings h4 {
    margin-bottom: 20px;
    color: var(--primary-color);
}

.slider-group {
    display: flex;
    flex-direction: column;
    gap: 25px;
}

.slider-container {
    display: flex;
    flex-direction: column;
    gap: 10px;
}

.slider-container label {
    display: flex;
    justify-content: space-between;
    align-items: center;
    font-weight: 600;
    color: var(--dark-color);
}

.slider-container span:first-child {
    color: var(--gray-color);
}

.slider-container input[type="range"] {
    width: 100%;
    height: 8px;
    -webkit-appearance: none;
    background: var(--gray-light);
    border-radius: 4px;
    outline: none;
}

.slider-container input[type="range"]::-webkit-slider-thumb {
    -webkit-appearance: none;
    width: 22px;
    height: 22px;
    background: var(--primary-color);
    border-radius: 50%;
    cursor: pointer;
    transition: var(--transition);
}

.slider-container input[type="range"]::-webkit-slider-thumb:hover {
    background: var(--primary-dark);
    transform: scale(1.1);
}

.slider-container input[type="range"]::-moz-range-thumb {
    width: 22px;
    height: 22px;
    background: var(--primary-color);
    border-radius: 50%;
    cursor: pointer;
    border: none;
}

.slider-labels {
    display: flex;
    justify-content: space-between;
    font-size: 0.85rem;
    color: var(--gray-color);
    margin-top: 5px;
}

.checkbox-group {
    display: flex;
    flex-direction: column;
    gap: 15px;
    margin-top: 10px;
}

.checkbox-label {
    display: flex;
    align-items: center;
    gap: 10px;
    cursor: pointer;
    font-size: 0.95rem;
    color: var(--dark-color);
}

.checkbox-label input[type="checkbox"] {
    accent-color: var(--primary-color);
    width: 18px;
    height: 18px;
    cursor: pointer;
}

/* Compression Preview */
.compression-preview {
    background-color: rgba(76, 201, 240, 0.05);
    border: 1px solid rgba(76, 201, 240, 0.2);
    border-radius: var(--border-radius);
    padding: 20px;
    margin-bottom: 25px;
}

.compression-preview h4 {
    margin-bottom: 15px;
    color: var(--success-color);
}

.preview-info {
    display: flex;
    justify-content: space-between;
    flex-wrap: wrap;
    gap: 15px;
}

.preview-item {
    display: flex;
    flex-direction: column;
}

.preview-label {
    font-size: 0.9rem;
    color: var(--gray-color);
    margin-bottom: 5px;
}

.preview-value {
    font-weight: 700;
    color: var(--dark-color);
}

/* Progress Section */
.progress-container {
    margin: 30px 0;
}

.progress-bar {
    height: 20px;
    background-color: var(--gray-light);
    border-radius: 10px;
    overflow: hidden;
    margin-bottom: 15px;
}

.progress-fill {
    height: 100%;
    background: linear-gradient(90deg, var(--primary-color), var(--secondary-color));
    width: 0%;
    border-radius: 10px;
    transition: width 0.5s ease;
}

.progress-text {
    text-align: center;
    font-weight: 700;
    font-size: 1.2rem;
    color: var(--dark-color);
    margin-bottom: 5px;
}

.progress-message {
    text-align: center;
    color: var(--gray-color);
    font-style: italic;
    margin-bottom: 20px;
}

.compression-details {
    background-color: var(--gray-light);
    border-radius: var(--border-radius);
    padding: 15px;
    margin-top: 20px;
}

.detail-item {
    display: flex;
    justify-content: space-between;
    margin-bottom: 10px;
}

.detail-item:last-child {
    margin-bottom: 0;
}

.detail-label {
    color: var(--gray-color);
}

.detail-value {
    font-weight: 600;
    color: var(--dark-color);
}

/* Results Section */
.results-comparison {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin: 30px 0;
    flex-wrap: wrap;
    gap: 30px;
}

.result {
    flex: 1;
    min-width: 250px;
    text-align: center;
    padding: 30px 20px;
    border-radius: var(--border-radius);
}

.result.original {
    background-color: var(--gray-light);
}

.result.compressed {
    background-color: rgba(76, 201, 240, 0.1);
    border: 2px solid var(--success-color);
}

.result h3 {
    margin-bottom: 20px;
    color: var(--dark-color);
}

.result-size {
    font-size: 2rem;
    font-weight: 800;
    margin-bottom: 10px;
}

.result.original .result-size {
    color: var(--gray-color);
}

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

.result-pages {
    font-size: 1.1rem;
    color: var(--gray-color);
}

.savings {
    font-size: 1.2rem;
    font-weight: 700;
    color: var(--success-color);
    margin-top: 15px;
    padding: 8px 15px;
    background-color: white;
    border-radius: 20px;
    display: inline-block;
}

.compression-stats {
    display: flex;
    justify-content: space-around;
    background-color: var(--gray-light);
    border-radius: var(--border-radius);
    padding: 20px;
    margin: 30px 0;
    flex-wrap: wrap;
    gap: 20px;
}

.stat {
    display: flex;
    align-items: center;
    gap: 10px;
}

.stat i {
    font-size: 1.2rem;
    color: var(--primary-color);
}

.stat-label {
    font-weight: 600;
    color: var(--gray-color);
}

.stat-value {
    font-weight: 700;
    color: var(--dark-color);
}

.download-section {
    display: flex;
    justify-content: center;
    gap: 15px;
    margin-top: 30px;
    flex-wrap: wrap;
}

/* Error Section */
.error-section {
    text-align: center;
}

.error-section i {
    font-size: 3rem;
    color: var(--warning-color);
    margin-bottom: 20px;
}

#error-message {
    margin: 25px 0;
    font-size: 1.1rem;
    color: var(--dark-color);
}

/* Buttons */
.btn {
    padding: 15px 30px;
    border: none;
    border-radius: var(--border-radius);
    font-weight: 600;
    font-size: 1rem;
    cursor: pointer;
    transition: var(--transition);
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 10px;
    min-width: 200px;
}

.btn-primary {
    background-color: var(--primary-color);
    color: white;
}

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

.btn-secondary {
    background-color: white;
    color: var(--primary-color);
    border: 2px solid var(--primary-color);
}

.btn-secondary:hover {
    background-color: rgba(67, 97, 238, 0.05);
    transform: translateY(-2px);
}

.btn-success {
    background-color: var(--success-color);
    color: white;
}

.btn-success:hover {
    background-color: #3db8df;
    transform: translateY(-2px);
}

/* Footer */
.footer {
    text-align: center;
    color: var(--gray-color);
    font-size: 0.9rem;
    margin-top: 30px;
    padding-top: 20px;
    border-top: 1px solid var(--gray-light);
}

/* Utility Classes */
.hidden {
    display: none !important;
}

/* Responsive */
@media (max-width: 768px) {
    .header h1 {
        font-size: 2rem;
        flex-direction: column;
        gap: 10px;
    }
    
    .card {
        padding: 20px;
    }
    
    .upload-area {
        padding: 40px 15px;
    }
    
    .file-info, .preview-info {
        flex-direction: column;
        gap: 15px;
    }
    
    .results-comparison {
        flex-direction: column;
    }
    
    .result-arrow {
        transform: rotate(90deg);
    }
    
    .compression-stats {
        flex-direction: column;
        align-items: flex-start;
    }
    
    .btn {
        min-width: 100%;
    }
    
    .action-buttons, .download-section {
        flex-direction: column;
    }
    
    .slider-labels {
        font-size: 0.75rem;
    }
}