/* ============================================
   PNG Analyzer - Modern Stylesheet
   Blue/Cyan Color Theme for ConvertICO
   ============================================ */

/* CSS Variables */
:root {
    --primary: #0891B2;
    --primary-light: #CFFAFE;
    --primary-dark: #0E7490;
    --accent: #06B6D4;
    --success: #10B981;
    --success-light: #D1FAE5;
    --warning: #F59E0B;
    --warning-light: #FEF3C7;
    --danger: #EF4444;
    --danger-light: #FEE2E2;
    
    --quality: #0891B2;
    --colortype: #06B6D4;
    --optimization: #22D3EE;
    
    --bg: #f8fafc;
    --bg-elevated: #ffffff;
    --text: #1e293b;
    --text-secondary: #64748b;
    --text-muted: #94a3b8;
    --border: #e2e8f0;
    
    --shadow-sm: 0 1px 3px rgba(0,0,0,0.1);
    --shadow-md: 0 4px 6px -1px rgba(0,0,0,0.1);
    --shadow-lg: 0 10px 15px -3px rgba(0,0,0,0.1);
    --shadow-xl: 0 20px 25px -5px rgba(0,0,0,0.1);
    
    --radius-sm: 6px;
    --radius-md: 12px;
    --radius-lg: 16px;
    --radius-xl: 24px;
    --radius-full: 9999px;
}

/* Base */
* {
    box-sizing: border-box;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    background: linear-gradient(135deg, var(--bg) 0%, #f1f5f9 100%);
    color: var(--text);
    line-height: 1.6;
    margin: 0;
    padding: 0;
}

/* Container */
.tool-container {
    max-width: 1100px;
    margin: 0 auto;
    padding: 2rem;
}

/* Header */
.tool-header {
    text-align: center;
    margin-bottom: 2rem;
}

.tool-title-row {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 1rem;
    margin-bottom: 1rem;
}

.tool-icon-wrapper {
    width: 64px;
    height: 64px;
    background: linear-gradient(135deg, var(--primary), var(--primary-dark));
    border-radius: var(--radius-lg);
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    box-shadow: var(--shadow-lg), 0 0 40px rgba(8, 145, 178, 0.25);
    flex-shrink: 0;
}

.tool-icon-wrapper svg,
.tool-icon-wrapper i {
    width: 28px;
    height: 28px;
}

.tool-title {
    font-size: clamp(1.75rem, 4vw, 2.5rem);
    font-weight: 700;
    margin: 0;
    background: linear-gradient(135deg, var(--primary), var(--primary-dark));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    letter-spacing: -0.02em;
}

.tool-description {
    font-size: 1.15rem;
    color: var(--text-secondary);
    max-width: 650px;
    margin: 0 auto;
    line-height: 1.7;
}

/* Main Tool Area */
.tool-main {
    background: var(--bg-elevated);
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-xl);
    overflow: hidden;
    border: 1px solid var(--border);
    position: relative;
}

/* Upload Section */
.upload-section {
    padding: 3rem;
    position: relative;
}

.upload-form {
    width: 100%;
}

.upload-area {
    border: 2px dashed var(--border);
    border-radius: var(--radius-lg);
    padding: 4rem 2rem;
    text-align: center;
    cursor: pointer;
    transition: all 0.3s ease;
    background: linear-gradient(135deg, #fafafa 0%, #f5f5f5 100%);
    position: relative;
    overflow: hidden;
}

.upload-area::before {
    content: '';
    position: absolute;
    inset: 0;
    background: linear-gradient(135deg, rgba(8, 145, 178, 0.05), rgba(14, 116, 144, 0.05));
    opacity: 0;
    transition: opacity 0.3s ease;
}

.upload-area:hover,
.upload-area.dragover,
.upload-area.highlight {
    border-color: var(--primary);
    background: linear-gradient(135deg, #ecfeff 0%, #cffafe 100%);
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.upload-area:hover::before,
.upload-area.dragover::before {
    opacity: 1;
}

.upload-content {
    position: relative;
    z-index: 1;
}

.upload-icon {
    color: var(--primary);
    margin-bottom: 1.5rem;
    transition: transform 0.3s ease;
}

.upload-area:hover .upload-icon {
    transform: translateY(-5px);
}

.upload-title {
    font-size: 1.5rem;
    font-weight: 600;
    color: var(--text);
    margin: 0 0 0.5rem;
}

.upload-subtitle {
    color: var(--text-secondary);
    margin: 0 0 1rem;
    font-size: 1rem;
}

.upload-hint {
    display: inline-block;
    background: var(--bg);
    color: var(--text-muted);
    padding: 0.5rem 1rem;
    border-radius: var(--radius-full);
    font-size: 0.875rem;
}

/* Processing Overlay */
.processing-overlay {
    position: absolute;
    inset: 0;
    background: rgba(255, 255, 255, 0.95);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 100;
    backdrop-filter: blur(4px);
}

.processing-content {
    text-align: center;
    padding: 3rem;
}

.processing-spinner {
    margin-bottom: 1.5rem;
    color: var(--primary);
}

.processing-spinner .spin {
    animation: spin 1s linear infinite;
}

@keyframes spin {
    from { transform: rotate(0deg); }
    to { transform: rotate(360deg); }
}

.processing-status {
    font-size: 1.1rem;
    font-weight: 600;
    color: var(--text);
    margin: 0;
}

/* Results Section */
.results-section {
    padding: 0;
}

/* File Info Bar */
.file-info-bar {
    display: flex;
    flex-wrap: wrap;
    gap: 1.5rem;
    padding: 1.25rem 2rem;
    background: linear-gradient(135deg, #f8fafc 0%, #f1f5f9 100%);
    border-bottom: 1px solid var(--border);
}

.file-info-item {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-size: 0.9rem;
    color: var(--text-secondary);
}

.file-info-item svg,
.file-info-item i {
    color: var(--primary);
    flex-shrink: 0;
}

/* Analysis Grid - Two Column Layout */
.analysis-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 0;
}

/* Panels */
.preview-panel,
.analysis-panel {
    padding: 2rem;
}

.preview-panel {
    background: #fafafa;
    border-right: 1px solid var(--border);
}

.panel-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1.5rem;
}

.panel-header h3 {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-size: 1.1rem;
    font-weight: 600;
    color: var(--text);
    margin: 0;
}

.panel-header h3 svg,
.panel-header h3 i {
    color: var(--primary);
}

/* PNG Display */
.png-display {
    background-color: #f8f9fa;
    border: 1px solid var(--border);
    border-radius: var(--radius-md);
    padding: 1.5rem;
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 300px;
    overflow: auto;
    transition: background 0.3s ease;
}

.png-display img {
    max-width: 100%;
    max-height: 300px;
    transition: transform 0.3s ease;
    border-radius: var(--radius-sm);
}

.png-display.checkerboard-bg {
    background-image: linear-gradient(45deg, #e0e0e0 25%, transparent 25%), 
                      linear-gradient(-45deg, #e0e0e0 25%, transparent 25%), 
                      linear-gradient(45deg, transparent 75%, #e0e0e0 75%), 
                      linear-gradient(-45deg, transparent 75%, #e0e0e0 75%);
    background-size: 20px 20px;
    background-position: 0 0, 0 10px, 10px -10px, -10px 0px;
}

.preview-unavailable {
    color: var(--text-muted);
    font-style: italic;
    padding: 2rem;
}

/* Background Toggle */
.bg-toggle {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.bg-toggle-label {
    font-size: 0.85rem;
    color: var(--text-secondary);
}

.toggle-switch {
    position: relative;
    display: inline-block;
    width: 44px;
    height: 24px;
}

.toggle-switch input {
    opacity: 0;
    width: 0;
    height: 0;
}

.toggle-slider {
    position: absolute;
    cursor: pointer;
    inset: 0;
    background-color: var(--border);
    transition: 0.3s;
    border-radius: var(--radius-full);
}

.toggle-slider:before {
    position: absolute;
    content: "";
    height: 18px;
    width: 18px;
    left: 3px;
    bottom: 3px;
    background-color: white;
    transition: 0.3s;
    border-radius: 50%;
    box-shadow: var(--shadow-sm);
}

input:checked + .toggle-slider {
    background: linear-gradient(135deg, var(--primary), var(--primary-dark));
}

input:checked + .toggle-slider:before {
    transform: translateX(20px);
}

/* PNG Viewer Controls */
.png-viewer-controls {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 0.75rem;
    margin-top: 1.25rem;
    padding-top: 1.25rem;
    border-top: 1px solid var(--border);
}

.control-button {
    display: inline-flex;
    align-items: center;
    gap: 0.4rem;
    padding: 0.5rem 0.875rem;
    background: var(--bg);
    border: 1px solid var(--border);
    border-radius: var(--radius-full);
    cursor: pointer;
    transition: all 0.2s ease;
    font-size: 0.85rem;
    font-weight: 500;
    color: var(--text-secondary);
    text-decoration: none;
}

.control-button:hover {
    background: var(--bg-elevated);
    border-color: var(--primary);
    color: var(--primary);
}

.control-button svg,
.control-button i {
    flex-shrink: 0;
}

.control-button.download-btn {
    background: linear-gradient(135deg, var(--success), #059669);
    color: white;
    border-color: transparent;
}

.control-button.download-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(16, 185, 129, 0.3);
}

/* Quality Score Card */
.quality-score-card {
    display: flex;
    align-items: center;
    gap: 1.25rem;
    padding: 1.25rem;
    border-radius: var(--radius-lg);
    margin-bottom: 1.5rem;
}

.quality-score-card.score-high {
    background: linear-gradient(135deg, rgba(16, 185, 129, 0.1), rgba(5, 150, 105, 0.05));
    border: 1px solid rgba(16, 185, 129, 0.3);
}

.quality-score-card.score-medium {
    background: linear-gradient(135deg, rgba(245, 158, 11, 0.1), rgba(217, 119, 6, 0.05));
    border: 1px solid rgba(245, 158, 11, 0.3);
}

.quality-score-card.score-low {
    background: linear-gradient(135deg, rgba(239, 68, 68, 0.1), rgba(220, 38, 38, 0.05));
    border: 1px solid rgba(239, 68, 68, 0.3);
}

.score-ring {
    width: 70px;
    height: 70px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
}

.score-high .score-ring {
    background: linear-gradient(135deg, var(--success), #059669);
    box-shadow: 0 4px 15px rgba(16, 185, 129, 0.3);
}

.score-medium .score-ring {
    background: linear-gradient(135deg, var(--warning), #D97706);
    box-shadow: 0 4px 15px rgba(245, 158, 11, 0.3);
}

.score-low .score-ring {
    background: linear-gradient(135deg, var(--danger), #DC2626);
    box-shadow: 0 4px 15px rgba(239, 68, 68, 0.3);
}

.score-ring .score-value {
    font-size: 1.75rem;
    font-weight: 700;
    color: white;
}

.score-details {
    display: flex;
    flex-direction: column;
}

.score-details .score-label {
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--text);
}

.score-details .score-hint {
    font-size: 0.85rem;
    color: var(--text-muted);
}

/* Stats Grid */
.stats-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 0.75rem;
    margin-bottom: 1.5rem;
}

.stat-card {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    padding: 1rem;
    background: var(--bg);
    border-radius: var(--radius-md);
    border: 1px solid var(--border);
    transition: all 0.2s ease;
}

.stat-card:hover {
    border-color: var(--primary-light);
    box-shadow: var(--shadow-sm);
}

.stat-card.opt-high {
    background: linear-gradient(135deg, rgba(239, 68, 68, 0.08), rgba(220, 38, 38, 0.04));
    border-color: rgba(239, 68, 68, 0.2);
}

.stat-card.opt-medium {
    background: linear-gradient(135deg, rgba(245, 158, 11, 0.08), rgba(217, 119, 6, 0.04));
    border-color: rgba(245, 158, 11, 0.2);
}

.stat-card.opt-low {
    background: linear-gradient(135deg, rgba(16, 185, 129, 0.08), rgba(5, 150, 105, 0.04));
    border-color: rgba(16, 185, 129, 0.2);
}

.stat-icon {
    width: 40px;
    height: 40px;
    border-radius: var(--radius-md);
    display: flex;
    align-items: center;
    justify-content: center;
    background: linear-gradient(135deg, var(--primary), var(--primary-dark));
    color: white;
    flex-shrink: 0;
}

.stat-info {
    display: flex;
    flex-direction: column;
    min-width: 0;
}

.stat-value {
    font-size: 1rem;
    font-weight: 600;
    color: var(--text);
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.stat-label {
    font-size: 0.75rem;
    color: var(--text-muted);
}

/* Accordion Sections */
.accordion-section {
    border: 1px solid var(--border);
    border-radius: var(--radius-md);
    margin-bottom: 0.75rem;
    overflow: hidden;
}

.accordion-trigger {
    width: 100%;
    padding: 1rem 1.25rem;
    background: var(--bg);
    border: none;
    text-align: left;
    font-size: 0.95rem;
    font-weight: 600;
    color: var(--text);
    cursor: pointer;
    display: flex;
    justify-content: space-between;
    align-items: center;
    transition: all 0.2s ease;
}

.accordion-trigger:hover {
    background: var(--bg-elevated);
}

.accordion-trigger span {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.accordion-trigger span svg,
.accordion-trigger span i {
    color: var(--primary);
}

.accordion-icon {
    color: var(--text-muted);
    transition: transform 0.3s ease;
}

.accordion-section.open .accordion-icon {
    transform: rotate(180deg);
}

.accordion-content {
    display: none;
    padding: 0 1.25rem 1.25rem;
    background: var(--bg-elevated);
}

.accordion-section.open .accordion-content {
    display: block;
}

/* Details List */
.details-list {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.detail-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0.625rem 0.875rem;
    background: var(--bg);
    border-radius: var(--radius-sm);
    font-size: 0.875rem;
}

.detail-name {
    font-weight: 500;
    color: var(--text-secondary);
}

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

.detail-value.has-feature {
    color: var(--success);
}

.detail-value.has-metadata {
    color: var(--warning);
}

/* Chunks Grid */
.chunks-grid {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
    margin-bottom: 0.75rem;
}

.chunk-tag {
    font-family: 'Monaco', 'Menlo', monospace;
    font-size: 0.8rem;
    padding: 0.35rem 0.75rem;
    background: linear-gradient(135deg, var(--primary-light), #e0f2fe);
    color: var(--primary-dark);
    border-radius: var(--radius-full);
    font-weight: 600;
}

.chunks-hint {
    font-size: 0.8rem;
    color: var(--text-muted);
    margin: 0;
    font-style: italic;
}

/* Recommendations Section */
.recommendations-section {
    padding: 2rem;
    background: linear-gradient(135deg, #ecfeff 0%, #cffafe 100%);
    border-top: 1px solid var(--border);
}

.recommendations-list {
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
    margin-bottom: 2rem;
}

.recommendation-item {
    display: flex;
    align-items: flex-start;
    gap: 0.75rem;
    padding: 0.875rem 1rem;
    background: var(--bg-elevated);
    border-radius: var(--radius-md);
    font-size: 0.95rem;
    color: var(--text-secondary);
    box-shadow: var(--shadow-sm);
}

.rec-icon {
    width: 32px;
    height: 32px;
    border-radius: var(--radius-sm);
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--primary-light);
    color: var(--primary);
    flex-shrink: 0;
}

/* Recommended Tools */
.recommended-tools h4 {
    font-size: 1rem;
    font-weight: 600;
    color: var(--text);
    margin: 0 0 1rem;
}

.tools-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 0.75rem;
}

.tool-card-link {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    padding: 1rem;
    background: var(--bg-elevated);
    border-radius: var(--radius-md);
    text-decoration: none;
    transition: all 0.2s ease;
    border: 1px solid var(--border);
}

.tool-card-link:hover {
    border-color: var(--primary);
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.tool-icon-small {
    width: 40px;
    height: 40px;
    border-radius: var(--radius-md);
    display: flex;
    align-items: center;
    justify-content: center;
    background: linear-gradient(135deg, var(--primary), var(--primary-dark));
    color: white;
    flex-shrink: 0;
}

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

.tool-info .tool-name {
    font-weight: 600;
    color: var(--text);
    font-size: 0.9rem;
}

.tool-info .tool-desc {
    font-size: 0.8rem;
    color: var(--text-muted);
}

/* Action Bar */
.action-bar {
    display: flex;
    justify-content: center;
    gap: 1rem;
    padding: 2rem;
    background: linear-gradient(135deg, #f8fafc 0%, #f1f5f9 100%);
    border-top: 1px solid var(--border);
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    padding: 0.875rem 1.5rem;
    font-size: 1rem;
    font-weight: 600;
    border-radius: var(--radius-full);
    border: none;
    cursor: pointer;
    transition: all 0.3s ease;
    text-decoration: none;
}

.btn svg,
.btn i {
    flex-shrink: 0;
}

.btn-primary {
    background: linear-gradient(135deg, var(--primary), var(--primary-dark));
    color: white;
    box-shadow: 0 4px 15px rgba(8, 145, 178, 0.3);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(8, 145, 178, 0.4);
}

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

.btn-secondary:hover {
    background: var(--bg-elevated);
    border-color: var(--text-muted);
}

/* Error Message */
.error-message {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    margin: 2rem;
    padding: 1rem 1.5rem;
    background: var(--danger-light);
    border: 1px solid #FECACA;
    border-left: 4px solid var(--danger);
    border-radius: var(--radius-md);
    color: var(--danger);
    font-weight: 500;
}

.error-message svg,
.error-message i {
    flex-shrink: 0;
}

/* Related Tools */
.related-tools {
    display: flex;
    align-items: center;
    gap: 1rem;
    margin: 2rem 0;
    padding: 1.25rem 1.5rem;
    background: var(--bg-elevated);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-sm);
    flex-wrap: wrap;
}

.related-label {
    font-weight: 600;
    color: var(--text);
    font-size: 0.9rem;
}

.related-links {
    display: flex;
    gap: 0.75rem;
    flex-wrap: wrap;
}

.related-link {
    display: inline-flex;
    align-items: center;
    gap: 0.4rem;
    padding: 0.5rem 1rem;
    background: var(--bg);
    color: var(--text-secondary);
    text-decoration: none;
    border-radius: var(--radius-full);
    font-size: 0.875rem;
    font-weight: 500;
    transition: all 0.2s ease;
    border: 1px solid var(--border);
}

.related-link:hover {
    background: var(--primary);
    color: white;
    border-color: var(--primary);
    transform: translateY(-2px);
}

.related-link svg,
.related-link i {
    flex-shrink: 0;
}

/* Info Sections */
.info-sections {
    display: grid;
    gap: 2rem;
    margin-top: 3rem;
}

.info-card {
    background: var(--bg-elevated);
    border-radius: var(--radius-xl);
    padding: 2rem;
    box-shadow: var(--shadow-md);
    border: 1px solid var(--border);
}

.info-card h2 {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    font-size: 1.35rem;
    color: var(--text);
    margin: 0 0 1.5rem;
}

.info-card h2 svg,
.info-card h2 i {
    color: var(--primary);
    flex-shrink: 0;
}

.info-card p {
    color: var(--text-secondary);
    line-height: 1.7;
    margin: 0 0 1rem;
}

.info-card p:last-child {
    margin-bottom: 0;
}

.info-card p a {
    color: var(--primary);
    text-decoration: none;
    font-weight: 500;
    border-bottom: 1px dotted var(--primary);
    transition: all 0.2s ease;
}

.info-card p a:hover {
    border-bottom-style: solid;
}

/* Steps List */
.steps-list {
    list-style: none;
    padding: 0;
    margin: 0;
    counter-reset: step;
}

.steps-list li {
    position: relative;
    padding-left: 3.5rem;
    padding-bottom: 1.25rem;
    counter-increment: step;
    color: var(--text-secondary);
    line-height: 1.6;
}

.steps-list li:not(:last-child)::after {
    content: '';
    position: absolute;
    left: calc(1rem - 1px);
    top: 2rem;
    bottom: 0;
    width: 2px;
    background: var(--primary-light);
}

.steps-list li::before {
    content: counter(step);
    position: absolute;
    left: 0;
    top: 0;
    width: 2rem;
    height: 2rem;
    background: linear-gradient(135deg, var(--primary), var(--primary-dark));
    color: white;
    border-radius: var(--radius-full);
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    font-size: 0.875rem;
    z-index: 1;
}

/* Mode Explanations */
.mode-explanations {
    display: grid;
    gap: 1rem;
}

.mode-explain {
    display: flex;
    gap: 1rem;
    align-items: flex-start;
}

.mode-tag {
    flex-shrink: 0;
    padding: 0.35rem 0.85rem;
    border-radius: var(--radius-full);
    font-size: 0.8rem;
    font-weight: 600;
    color: white;
}

.mode-tag.quality {
    background: linear-gradient(135deg, var(--quality), #0E7490);
}

.mode-tag.colortype {
    background: linear-gradient(135deg, var(--colortype), #0891B2);
}

.mode-tag.optimization {
    background: linear-gradient(135deg, var(--optimization), #06B6D4);
}

.mode-explain p {
    margin: 0;
    color: var(--text-secondary);
    font-size: 0.95rem;
    line-height: 1.6;
}

/* Use Cases Grid */
.use-cases-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 1.25rem;
    margin-bottom: 1.5rem;
}

.use-case {
    display: flex;
    gap: 1rem;
    padding: 1.25rem;
    background: var(--bg);
    border-radius: var(--radius-md);
    border: 1px solid var(--border);
    transition: all 0.2s ease;
}

.use-case:hover {
    border-color: var(--primary-light);
    box-shadow: var(--shadow-sm);
}

.use-case-icon {
    width: 48px;
    height: 48px;
    background: linear-gradient(135deg, var(--primary), var(--primary-dark));
    border-radius: var(--radius-md);
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    flex-shrink: 0;
}

.use-case-content h4 {
    margin: 0 0 0.375rem;
    font-size: 1rem;
    font-weight: 600;
    color: var(--text);
}

.use-case-content p {
    margin: 0;
    font-size: 0.875rem;
    color: var(--text-secondary);
    line-height: 1.5;
}

.use-cases-tip {
    display: flex;
    align-items: flex-start;
    gap: 0.625rem;
    padding: 1rem 1.25rem;
    background: linear-gradient(135deg, #ecfeff 0%, #cffafe 100%);
    border-radius: var(--radius-md);
    border: 1px solid var(--primary);
    margin-top: 0;
}

.use-cases-tip svg,
.use-cases-tip i {
    color: var(--primary);
    flex-shrink: 0;
    margin-top: 2px;
}

.use-cases-tip span {
    font-size: 0.9rem;
    color: var(--text-secondary);
    line-height: 1.5;
}

.use-cases-tip a {
    color: var(--primary);
    text-decoration: none;
    font-weight: 500;
}

.use-cases-tip a:hover {
    text-decoration: underline;
}

/* FAQ */
.faq-list {
    display: grid;
    gap: 0.75rem;
}

.faq-item {
    border: 1px solid var(--border);
    border-radius: var(--radius-md);
    overflow: hidden;
}

.faq-question {
    width: 100%;
    padding: 1rem 1.25rem;
    background: var(--bg);
    border: none;
    text-align: left;
    font-size: 1rem;
    font-weight: 600;
    color: var(--text);
    cursor: pointer;
    display: flex;
    justify-content: space-between;
    align-items: center;
    transition: all 0.2s ease;
}

.faq-question:hover {
    background: var(--bg-elevated);
}

.faq-question svg,
.faq-question i {
    color: var(--primary);
    transition: transform 0.3s ease;
    flex-shrink: 0;
}

.faq-item.open .faq-question svg,
.faq-item.open .faq-question i {
    transform: rotate(180deg);
}

.faq-answer {
    display: none;
    padding: 0 1.25rem 1rem;
    background: var(--bg-elevated);
}

.faq-item.open .faq-answer {
    display: block;
}

.faq-answer p {
    margin: 0;
    color: var(--text-secondary);
    line-height: 1.7;
}

/* Responsive */
@media (max-width: 900px) {
    .analysis-grid {
        grid-template-columns: 1fr;
    }
    
    .preview-panel {
        border-right: none;
        border-bottom: 1px solid var(--border);
    }
    
    .file-info-bar {
        justify-content: center;
    }
    
    .tools-grid {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 768px) {
    .tool-container {
        padding: 1rem;
    }
    
    .tool-title-row {
        flex-direction: row;
        gap: 0.75rem;
    }
    
    .tool-icon-wrapper {
        width: 48px;
        height: 48px;
    }
    
    .tool-icon-wrapper svg,
    .tool-icon-wrapper i {
        width: 24px;
        height: 24px;
    }
    
    .upload-section {
        padding: 2rem 1.5rem;
    }
    
    .preview-panel,
    .analysis-panel {
        padding: 1.5rem;
    }
    
    .stats-grid {
        grid-template-columns: 1fr;
    }
    
    .action-bar {
        flex-direction: column;
        padding: 1.5rem;
    }
    
    .btn {
        width: 100%;
    }
    
    .related-tools {
        flex-direction: column;
        text-align: center;
    }
    
    .related-links {
        justify-content: center;
    }
    
    .mode-explain {
        flex-direction: column;
    }
    
    .use-cases-grid {
        grid-template-columns: 1fr;
    }
    
    .use-case {
        padding: 1rem;
    }
    
    .quality-score-card {
        flex-direction: column;
        text-align: center;
    }
}

@media (max-width: 480px) {
    .tool-title {
        font-size: 1.5rem;
    }
    
    .file-info-bar {
        flex-direction: column;
        gap: 0.75rem;
        align-items: flex-start;
    }
    
    .steps-list li {
        padding-left: 3rem;
    }
    
    .png-viewer-controls {
        flex-direction: column;
        align-items: stretch;
    }
    
    .control-button {
        justify-content: center;
    }
}

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

.results-section {
    animation: fadeIn 0.4s ease;
}

/* Reduced Motion */
@media (prefers-reduced-motion: reduce) {
    *,
    *::before,
    *::after {
        animation-duration: 0.01ms !important;
        transition-duration: 0.01ms !important;
    }
}