/* ============================================
   GIF Frame Extractor - Modern Stylesheet
   Matching ConvertICO design system
   ============================================ */

/* CSS Variables */
:root {
    --primary: #8B5CF6;
    --primary-light: #DDD6FE;
    --primary-dark: #7C3AED;
    --accent: #10B981;
    --success: #10B981;
    --success-light: #D1FAE5;
    --warning: #F59E0B;
    --danger: #EF4444;
    
    /* Format colors */
    --png: #10B981;
    --webp: #3B82F6;
    --jpg: #F59E0B;
    
    --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: 1000px;
    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(139, 92, 246, 0.2);
    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);
}

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

.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(139, 92, 246, 0.05), rgba(124, 58, 237, 0.05));
    opacity: 0;
    transition: opacity 0.3s ease;
}

.upload-area:hover,
.upload-area.dragover,
.upload-area.active {
    border-color: var(--primary);
    background: linear-gradient(135deg, #f5f3ff 0%, #ede9fe 100%);
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.upload-area:hover::before,
.upload-area.dragover::before,
.upload-area.active::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-flex;
    align-items: center;
    gap: 0.5rem;
    background: var(--bg);
    color: var(--text-muted);
    padding: 0.5rem 1rem;
    border-radius: var(--radius-full);
    font-size: 0.875rem;
}

/* Progress Section */
.progress-section {
    margin-top: 2rem;
    padding: 1.5rem;
    background: var(--bg);
    border-radius: var(--radius-md);
}

.progress-bar-wrapper {
    height: 10px;
    background: var(--border);
    border-radius: var(--radius-full);
    overflow: hidden;
    margin-bottom: 0.75rem;
}

.progress-bar {
    height: 100%;
    background: linear-gradient(135deg, var(--primary), var(--success));
    border-radius: var(--radius-full);
    width: 0%;
    transition: width 0.3s ease;
}

.progress-text {
    text-align: center;
    font-size: 0.9rem;
    color: var(--text-secondary);
    margin: 0;
}

/* Editor Section */
.editor-section {
    padding: 0;
    animation: fadeIn 0.4s ease;
}

/* 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;
}

/* Editor Grid */
.editor-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 0;
}

/* Panels */
.preview-panel,
.controls-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);
}

/* Preview Container */
.preview-container {
    position: relative;
}

.preview-wrapper {
    background: 
        linear-gradient(45deg, #f0f0f0 25%, transparent 25%),
        linear-gradient(-45deg, #f0f0f0 25%, transparent 25%),
        linear-gradient(45deg, transparent 75%, #f0f0f0 75%),
        linear-gradient(-45deg, transparent 75%, #f0f0f0 75%);
    background-size: 20px 20px;
    background-position: 0 0, 0 10px, 10px -10px, -10px 0px;
    background-color: #fff;
    border-radius: var(--radius-lg);
    padding: 1.5rem;
    display: flex;
    align-items: center;
    justify-content: center;
    min-height: 280px;
    border: 1px solid var(--border);
}

.preview-wrapper img {
    max-width: 100%;
    max-height: 250px;
    border-radius: var(--radius-sm);
    box-shadow: var(--shadow-md);
}

/* Control Groups */
.control-group {
    margin-bottom: 1.5rem;
}

.control-label {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-size: 0.9rem;
    font-weight: 600;
    color: var(--text);
    margin-bottom: 0.75rem;
}

.control-label svg,
.control-label i {
    color: var(--primary);
}

/* Format Options */
.format-options {
    display: grid;
    gap: 0.75rem;
}

.format-option {
    cursor: pointer;
    display: block;
}

.format-option input {
    display: none;
}

.format-box {
    display: flex;
    flex-direction: column;
    padding: 1rem 1.25rem;
    border: 2px solid var(--border);
    border-radius: var(--radius-md);
    background: var(--bg);
    transition: all 0.2s ease;
}

.format-option:hover .format-box {
    border-color: var(--primary-light);
    background: #faf5ff;
}

.format-option input:checked + .format-box {
    border-color: var(--primary);
    background: linear-gradient(135deg, #faf5ff 0%, #f3e8ff 100%);
    box-shadow: 0 0 0 3px rgba(139, 92, 246, 0.1);
}

.format-name {
    font-weight: 700;
    font-size: 0.95rem;
    color: var(--text);
}

.format-desc {
    font-size: 0.8rem;
    color: var(--text-muted);
    margin-top: 0.25rem;
}

/* Checkbox Option */
.checkbox-option {
    display: flex;
    align-items: flex-start;
    gap: 0.75rem;
    padding: 1rem;
    background: var(--bg);
    border: 1px solid var(--border);
    border-radius: var(--radius-md);
    cursor: pointer;
    transition: all 0.2s ease;
}

.checkbox-option:hover {
    background: #faf5ff;
    border-color: var(--primary-light);
}

.checkbox-option input {
    display: none;
}

.checkbox-mark {
    width: 22px;
    height: 22px;
    border: 2px solid var(--border);
    border-radius: var(--radius-sm);
    background: white;
    flex-shrink: 0;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.2s ease;
    margin-top: 2px;
}

.checkbox-option input:checked + .checkbox-mark {
    background: linear-gradient(135deg, var(--primary), var(--primary-dark));
    border-color: var(--primary);
}

.checkbox-option input:checked + .checkbox-mark::after {
    content: '';
    width: 6px;
    height: 10px;
    border: solid white;
    border-width: 0 2px 2px 0;
    transform: rotate(45deg);
    margin-bottom: 2px;
}

.checkbox-content {
    flex: 1;
}

.checkbox-label {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-weight: 600;
    color: var(--text);
    font-size: 0.95rem;
}

.checkbox-label svg,
.checkbox-label i {
    color: var(--primary);
}

.checkbox-hint {
    display: block;
    font-size: 0.8rem;
    color: var(--text-muted);
    margin-top: 0.25rem;
}

.checkbox-option.disabled {
    opacity: 0.5;
    pointer-events: none;
}

/* Options Info */
.options-info {
    display: flex;
    gap: 0.75rem;
    padding: 1rem;
    background: linear-gradient(135deg, #fefce8 0%, #fef9c3 100%);
    border-radius: var(--radius-md);
    font-size: 0.875rem;
    color: #854d0e;
    margin-top: 1.5rem;
}

.options-info svg,
.options-info i {
    flex-shrink: 0;
    color: #ca8a04;
}

.options-info strong {
    color: #713f12;
}

/* Action Bar */
.action-bar {
    display: flex;
    gap: 1rem;
    padding: 1.5rem 2rem;
    background: linear-gradient(135deg, #f8fafc 0%, #f1f5f9 100%);
    border-top: 1px solid var(--border);
    justify-content: center;
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    padding: 0.875rem 1.75rem;
    border-radius: var(--radius-full);
    font-weight: 600;
    font-size: 1rem;
    cursor: pointer;
    transition: all 0.2s ease;
    border: none;
    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(139, 92, 246, 0.3);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(139, 92, 246, 0.4);
}

.btn-primary:disabled {
    background: var(--border);
    color: var(--text-muted);
    cursor: not-allowed;
    transform: none;
    box-shadow: none;
}

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

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

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

.btn-success:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(16, 185, 129, 0.4);
}

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

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

/* Results Section */
.results-section {
    padding: 2rem;
    animation: fadeIn 0.4s ease;
}

.results-header {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.75rem;
    margin-bottom: 1.5rem;
}

.results-icon {
    width: 48px;
    height: 48px;
    background: linear-gradient(135deg, var(--success), #059669);
    border-radius: var(--radius-full);
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
}

.results-title {
    font-size: 1.35rem;
    font-weight: 700;
    color: var(--success);
    margin: 0;
}

/* Output Summary */
.output-summary {
    display: flex;
    flex-wrap: wrap;
    gap: 1rem;
    justify-content: center;
    margin-bottom: 2rem;
    padding: 1.25rem;
    background: var(--bg);
    border-radius: var(--radius-lg);
}

.summary-item {
    text-align: center;
    padding: 0 1.5rem;
    border-right: 1px solid var(--border);
}

.summary-item:last-child {
    border-right: none;
}

.summary-label {
    font-size: 0.8rem;
    color: var(--text-muted);
    text-transform: uppercase;
    letter-spacing: 0.05em;
    margin-bottom: 0.25rem;
}

.summary-value {
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--text);
}

/* Results Actions */
.results-actions {
    display: flex;
    flex-wrap: wrap;
    gap: 1rem;
    justify-content: center;
    margin-bottom: 2rem;
}

.secondary-actions {
    display: flex;
    flex-wrap: wrap;
    gap: 0.75rem;
    justify-content: center;
    padding-top: 1.5rem;
    border-top: 1px solid var(--border);
}

/* Frames Grid */
.frames-section {
    margin-top: 2rem;
    padding-top: 2rem;
    border-top: 1px solid var(--border);
}

.frames-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: 1rem;
}

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

.frames-title svg,
.frames-title i {
    color: var(--primary);
}

.frames-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(120px, 1fr));
    gap: 1rem;
}

.frame-item {
    background: var(--bg-elevated);
    border: 1px solid var(--border);
    border-radius: var(--radius-md);
    overflow: hidden;
    transition: all 0.2s ease;
    position: relative;
}

.frame-item:hover {
    transform: translateY(-3px);
    box-shadow: var(--shadow-md);
    border-color: var(--primary-light);
}

.frame-preview {
    height: 100px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: 
        linear-gradient(45deg, #f0f0f0 25%, transparent 25%),
        linear-gradient(-45deg, #f0f0f0 25%, transparent 25%),
        linear-gradient(45deg, transparent 75%, #f0f0f0 75%),
        linear-gradient(-45deg, transparent 75%, #f0f0f0 75%);
    background-size: 10px 10px;
    background-position: 0 0, 0 5px, 5px -5px, -5px 0px;
    background-color: #fff;
    position: relative;
}

.frame-preview img {
    max-width: 90%;
    max-height: 90%;
    object-fit: contain;
}

.frame-download {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    width: 36px;
    height: 36px;
    background: rgba(139, 92, 246, 0.9);
    border-radius: var(--radius-full);
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    text-decoration: none;
    opacity: 0;
    transition: all 0.2s ease;
    box-shadow: var(--shadow-md);
}

.frame-item:hover .frame-download {
    opacity: 1;
}

.frame-download:hover {
    background: var(--primary);
    transform: translate(-50%, -50%) scale(1.1);
}

.frame-info {
    padding: 0.75rem;
    text-align: center;
    background: var(--bg);
    border-top: 1px solid var(--border);
}

.frame-number {
    font-weight: 600;
    font-size: 0.85rem;
    color: var(--text);
}

.frame-timing {
    font-size: 0.75rem;
    color: var(--text-muted);
    margin-top: 0.15rem;
}

/* More Frames Link */
.more-frames {
    grid-column: 1 / -1;
    text-align: center;
    padding: 1rem;
    background: var(--bg);
    border-radius: var(--radius-md);
    border: 1px dashed var(--border);
}

.more-frames-link {
    color: var(--primary);
    text-decoration: none;
    font-weight: 600;
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    transition: all 0.2s ease;
}

.more-frames-link:hover {
    color: var(--primary-dark);
}

/* Error Message */
.error-message {
    display: none;
    align-items: center;
    gap: 0.75rem;
    padding: 1rem 1.5rem;
    margin: 1.5rem 2rem;
    background: #FEF2F2;
    border: 1px solid #FECACA;
    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);
}

/* 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;
}

/* 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;
}

.steps-list li a {
    color: var(--primary);
    text-decoration: none;
}

.steps-list li a:hover {
    text-decoration: underline;
}

/* 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.png {
    background: linear-gradient(135deg, var(--png), #059669);
}

.mode-tag.webp {
    background: linear-gradient(135deg, var(--webp), #2563EB);
}

.mode-tag.jpg {
    background: linear-gradient(135deg, var(--jpg), #D97706);
}

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

/* Notes Grid */
.notes-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 1.5rem;
}

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

.note-item:hover {
    background: #faf5ff;
}

.note-icon {
    width: 48px;
    height: 48px;
    background: linear-gradient(135deg, var(--primary-light), #ede9fe);
    border-radius: var(--radius-md);
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
    color: var(--primary);
}

.note-content h4 {
    font-size: 1rem;
    font-weight: 600;
    color: var(--text);
    margin: 0 0 0.25rem;
}

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

/* 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;
}

.faq-answer a {
    color: var(--primary);
    text-decoration: none;
}

.faq-answer a:hover {
    text-decoration: underline;
}

/* Responsive */
@media (max-width: 1000px) {
    .editor-grid {
        grid-template-columns: 1fr;
    }
    
    .preview-panel {
        border-right: none;
        border-bottom: 1px solid var(--border);
    }
    
    .file-info-bar {
        justify-content: center;
    }
}

@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,
    .results-section {
        padding: 2rem 1.5rem;
    }
    
    .preview-panel,
    .controls-panel {
        padding: 1.5rem;
    }
    
    .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;
    }
    
    .output-summary {
        flex-direction: column;
        gap: 1rem;
    }
    
    .summary-item {
        border-right: none;
        border-bottom: 1px solid var(--border);
        padding: 0.75rem 0;
    }
    
    .summary-item:last-child {
        border-bottom: none;
    }
    
    .notes-grid {
        grid-template-columns: 1fr;
    }
    
    .results-actions,
    .secondary-actions {
        flex-direction: column;
    }
}

@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;
    }
    
    .frames-grid {
        grid-template-columns: repeat(auto-fill, minmax(90px, 1fr));
    }
    
    .frame-preview {
        height: 80px;
    }
}

/* ============================================
   PROCESSING OVERLAY
   ============================================ */
.processing-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.75);
    display: none;
    justify-content: center;
    align-items: center;
    z-index: 9999;
    backdrop-filter: blur(4px);
}

.processing-overlay.active {
    display: flex;
}

.processing-content {
    background: white;
    border-radius: 16px;
    padding: 40px 50px;
    text-align: center;
    max-width: 400px;
    width: 90%;
    box-shadow: 0 25px 50px rgba(0, 0, 0, 0.3);
    animation: slideUp 0.3s ease;
}

@keyframes slideUp {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.processing-animation {
    width: 80px;
    height: 80px;
    margin: 0 auto 25px;
    position: relative;
}

.processing-spinner {
    width: 80px;
    height: 80px;
    border: 4px solid #f0f0f0;
    border-top-color: var(--primary);
    border-radius: 50%;
    animation: spin 1s linear infinite;
}

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

.processing-icon {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    color: var(--primary);
    animation: pulse 1.5s ease-in-out infinite;
}

@keyframes pulse {
    0%, 100% {
        opacity: 1;
        transform: translate(-50%, -50%) scale(1);
    }
    50% {
        opacity: 0.7;
        transform: translate(-50%, -50%) scale(0.9);
    }
}

.processing-title {
    font-size: 20px;
    font-weight: 600;
    color: var(--text-dark);
    margin: 0 0 8px 0;
}

.processing-message {
    font-size: 14px;
    color: var(--text-muted);
    margin: 0 0 20px 0;
}

.processing-progress {
    background: #f0f0f0;
    border-radius: 10px;
    height: 8px;
    overflow: hidden;
    margin-bottom: 10px;
}

.processing-progress-bar {
    height: 100%;
    background: linear-gradient(90deg, var(--primary), var(--primary-dark));
    border-radius: 10px;
    width: 0%;
    transition: width 0.3s ease;
}

.processing-percent {
    font-size: 13px;
    color: var(--text-muted);
    font-weight: 500;
}

.processing-frames-info {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    margin-top: 15px;
    padding-top: 15px;
    border-top: 1px solid #eee;
    font-size: 13px;
    color: var(--text-muted);
}

.processing-frames-info i {
    color: var(--primary);
}

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

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