/* ============================================================
   FRAME ENGINE - Stylesheet
   Modo oscuro nativo, responsive, CSS Grid/Flexbox
   ============================================================ */

/* === CSS Variables === */
:root {
    /* Colors - Dark Theme */
    --bg-primary: #0a0e1a;
    --bg-secondary: #111827;
    --bg-tertiary: #1a2236;
    --bg-card: #161d2e;
    --bg-hover: #1e293b;
    --bg-active: #243049;

    /* Accent - Cyan/Teal */
    --accent: #06b6d4;
    --accent-light: #22d3ee;
    --accent-dark: #0891b2;
    --accent-glow: rgba(6, 182, 212, 0.15);

    /* Success */
    --success: #10b981;
    --success-light: #34d399;
    --success-bg: rgba(16, 185, 129, 0.1);

    /* Danger */
    --danger: #ef4444;
    --danger-light: #f87171;
    --danger-bg: rgba(239, 68, 68, 0.1);

    /* Warning */
    --warning: #f59e0b;
    --warning-bg: rgba(245, 158, 11, 0.1);

    /* Text */
    --text-primary: #f1f5f9;
    --text-secondary: #94a3b8;
    --text-muted: #64748b;
    --text-inverse: #0f172a;

    /* Border */
    --border: #1e293b;
    --border-light: #334155;
    --border-focus: var(--accent);

    /* Gradients */
    --gradient-accent: linear-gradient(135deg, var(--accent), var(--accent-light));
    --gradient-glow: radial-gradient(ellipse at center, var(--accent-glow) 0%, transparent 70%);

    /* Shadows */
    --shadow-sm: 0 1px 2px rgba(0,0,0,0.3);
    --shadow-md: 0 4px 12px rgba(0,0,0,0.4);
    --shadow-lg: 0 8px 30px rgba(0,0,0,0.5);
    --shadow-glow: 0 0 20px var(--accent-glow);
    --shadow-accent: 0 4px 20px rgba(6, 182, 212, 0.2);

    /* Transitions */
    --transition-fast: 0.15s ease;
    --transition-base: 0.25s ease;
    --transition-slow: 0.4s ease;

    /* Radii */
    --radius-sm: 6px;
    --radius-md: 10px;
    --radius-lg: 14px;
    --radius-xl: 20px;

    /* Font */
    --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    --font-mono: 'JetBrains Mono', 'Fira Code', monospace;

    /* Layout */
    --header-height: 64px;
    --steps-height: 72px;
    --footer-height: 40px;
    --sidebar-width: 300px;
}

/* === Reset & Base === */
*, *::before, *::after {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    font-size: 16px;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

body {
    font-family: var(--font-sans);
    background: var(--bg-primary);
    color: var(--text-primary);
    min-height: 100vh;
    overflow-x: hidden;
    line-height: 1.5;
}

/* Background Effects */
.bg-grid {
    position: fixed;
    inset: 0;
    background-image:
        linear-gradient(rgba(6, 182, 212, 0.03) 1px, transparent 1px),
        linear-gradient(90deg, rgba(6, 182, 212, 0.03) 1px, transparent 1px);
    background-size: 40px 40px;
    pointer-events: none;
    z-index: 0;
}

.bg-glow {
    position: fixed;
    top: -50%;
    left: 50%;
    transform: translateX(-50%);
    width: 800px;
    height: 800px;
    background: var(--gradient-glow);
    border-radius: 50%;
    pointer-events: none;
    z-index: 0;
}

/* === App Container === */
#app {
    position: relative;
    z-index: 1;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

/* === Header === */
.app-header {
    height: var(--header-height);
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0 32px;
    background: rgba(10, 14, 26, 0.8);
    backdrop-filter: blur(20px);
    border-bottom: 1px solid var(--border);
    position: sticky;
    top: 0;
    z-index: 100;
}

.header-brand {
    display: flex;
    align-items: center;
    gap: 12px;
}

.logo {
    display: flex;
    align-items: center;
    gap: 12px;
}

.logo svg .logo-rect {
    fill: var(--bg-tertiary);
    stroke: var(--accent);
    stroke-width: 1.5;
    transition: fill var(--transition-fast);
}

.logo svg .logo-rect.accent {
    fill: var(--accent);
}

.logo:hover svg .logo-rect {
    fill: var(--accent-glow);
}

.logo-text {
    font-size: 1.25rem;
    font-weight: 700;
    letter-spacing: -0.02em;
}

.logo-text .accent {
    background: var(--gradient-accent);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.version {
    font-size: 0.7rem;
    font-family: var(--font-mono);
    color: var(--text-muted);
    padding: 2px 8px;
    background: var(--bg-tertiary);
    border-radius: 20px;
    border: 1px solid var(--border);
}

.header-actions {
    display: flex;
    gap: 8px;
}

/* === Steps Navigation === */
.steps-nav {
    height: var(--steps-height);
    display: flex;
    align-items: center;
    justify-content: center;
    background: rgba(17, 24, 39, 0.6);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--border);
    padding: 0 24px;
}

.steps-track {
    display: flex;
    align-items: center;
    gap: 0;
    max-width: 600px;
    width: 100%;
}

.step {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 6px;
    opacity: 0.4;
    transition: opacity var(--transition-base);
}

.step.active {
    opacity: 1;
}

.step.completed {
    opacity: 0.7;
}

.step.completed .step-number {
    background: var(--success);
    color: var(--text-inverse);
}

.step-number {
    width: 32px;
    height: 32px;
    border-radius: 50%;
    background: var(--bg-tertiary);
    border: 2px solid var(--border-light);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 0.875rem;
    font-weight: 600;
    transition: all var(--transition-base);
}

.step.active .step-number {
    background: var(--accent);
    border-color: var(--accent-light);
    color: var(--text-inverse);
    box-shadow: var(--shadow-glow);
}

.step-label {
    font-size: 0.7rem;
    font-weight: 500;
    color: var(--text-secondary);
    white-space: nowrap;
}

.step-connector {
    flex: 1;
    height: 2px;
    background: var(--border);
    margin: 0 12px;
    margin-bottom: 20px;
    position: relative;
    transition: background var(--transition-base);
}

.step-connector::after {
    content: '';
    position: absolute;
    left: 0;
    top: 0;
    height: 100%;
    width: 0;
    background: var(--accent);
    transition: width var(--transition-slow);
}

.step-connector.completed::after {
    width: 100%;
}

/* === Main Content === */
.main-content {
    flex: 1;
    padding: 32px;
    max-width: 1400px;
    width: 100%;
    margin: 0 auto;
}

/* === Step Panels === */
.step-panel {
    display: none;
    animation: fadeInUp 0.4s ease;
}

.step-panel.active {
    display: block;
}

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

.panel-header {
    text-align: center;
    margin-bottom: 32px;
}

.panel-header h2 {
    font-size: 1.75rem;
    font-weight: 700;
    margin-bottom: 8px;
    background: linear-gradient(135deg, var(--text-primary), var(--accent-light));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.panel-header p {
    color: var(--text-secondary);
    font-size: 0.95rem;
}

/* === Upload Zone === */
.upload-zone {
    position: relative;
    border: 2px dashed var(--border-light);
    border-radius: var(--radius-xl);
    padding: 48px 32px;
    text-align: center;
    background: var(--bg-card);
    transition: all var(--transition-base);
    cursor: pointer;
}

.upload-zone:hover {
    border-color: var(--accent);
    background: var(--accent-glow);
}

.upload-zone.drag-over {
    border-color: var(--accent);
    background: rgba(6, 182, 212, 0.08);
    transform: scale(1.01);
}

.upload-content {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 12px;
}

.upload-icon {
    color: var(--accent);
    margin-bottom: 8px;
}

.upload-content h3 {
    font-size: 1.25rem;
    font-weight: 600;
}

.upload-formats {
    color: var(--text-muted);
    font-size: 0.875rem;
    font-family: var(--font-mono);
}

.upload-limit {
    color: var(--text-muted);
    font-size: 0.8rem;
}

.upload-drag-overlay {
    position: absolute;
    inset: 0;
    background: rgba(6, 182, 212, 0.1);
    border-radius: var(--radius-xl);
    display: flex;
    align-items: center;
    justify-content: center;
    opacity: 0;
    pointer-events: none;
    transition: opacity var(--transition-fast);
    backdrop-filter: blur(4px);
}

.upload-zone.drag-over .upload-drag-overlay {
    opacity: 1;
}

.upload-drag-overlay span {
    font-size: 1.5rem;
    font-weight: 600;
    color: var(--accent-light);
}

/* === Upload Progress === */
.upload-progress {
    margin-top: 24px;
    padding: 20px;
    background: var(--bg-card);
    border-radius: var(--radius-lg);
    border: 1px solid var(--border);
}

.progress-info {
    display: flex;
    justify-content: space-between;
    margin-bottom: 10px;
    font-size: 0.875rem;
}

.progress-filename {
    color: var(--text-secondary);
    font-family: var(--font-mono);
}

.progress-percent {
    font-weight: 600;
    color: var(--accent);
}

.progress-bar {
    height: 6px;
    background: var(--bg-tertiary);
    border-radius: 100px;
    overflow: hidden;
}

.progress-fill {
    height: 100%;
    width: 0%;
    background: var(--gradient-accent);
    border-radius: 100px;
    transition: width 0.3s ease;
}

.progress-details {
    display: flex;
    justify-content: space-between;
    margin-top: 8px;
    font-size: 0.75rem;
    color: var(--text-muted);
    font-family: var(--font-mono);
}

/* === Video Preview === */
.video-preview {
    margin-top: 24px;
    background: var(--bg-card);
    border-radius: var(--radius-lg);
    border: 1px solid var(--border);
    overflow: hidden;
}

.preview-container {
    background: #000;
    display: flex;
    align-items: center;
    justify-content: center;
    max-height: 400px;
    overflow: hidden;
}

.preview-container video {
    width: 100%;
    max-height: 400px;
    object-fit: contain;
}

.preview-info {
    padding: 24px;
}

.info-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
    gap: 16px;
    margin-bottom: 20px;
}

.info-item {
    display: flex;
    flex-direction: column;
    gap: 4px;
}

.info-label {
    font-size: 0.75rem;
    color: var(--text-muted);
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.info-value {
    font-size: 0.875rem;
    color: var(--text-primary);
    font-weight: 500;
    font-family: var(--font-mono);
}

/* === Extract Options === */
.extract-options {
    display: flex;
    flex-direction: column;
    gap: 16px;
    margin-bottom: 24px;
}

.extract-card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    padding: 20px 24px;
    transition: all var(--transition-base);
    cursor: pointer;
}

.extract-card:hover {
    border-color: var(--border-light);
}

.extract-card.active {
    border-color: var(--accent);
    background: var(--accent-glow);
    box-shadow: var(--shadow-glow);
}

.extract-card-header {
    margin-bottom: 12px;
}

.extract-desc {
    font-size: 0.85rem;
    color: var(--text-muted);
    margin-bottom: 16px;
}

/* Radio Custom */
.radio-custom {
    display: flex;
    align-items: center;
    gap: 12px;
    cursor: pointer;
    font-weight: 600;
    font-size: 1rem;
}

.radio-custom input {
    display: none;
}

.radio-check {
    width: 20px;
    height: 20px;
    border: 2px solid var(--border-light);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all var(--transition-fast);
    flex-shrink: 0;
}

.radio-check::after {
    content: '';
    width: 8px;
    height: 8px;
    border-radius: 50%;
    background: var(--accent);
    opacity: 0;
    transform: scale(0);
    transition: all var(--transition-fast);
}

.radio-custom input:checked + .radio-check {
    border-color: var(--accent);
}

.radio-custom input:checked + .radio-check::after {
    opacity: 1;
    transform: scale(1);
}

/* === Input Groups === */
.input-group {
    display: flex;
    flex-direction: column;
    gap: 6px;
}

.input-group label {
    font-size: 0.8rem;
    color: var(--text-secondary);
    font-weight: 500;
}

.input-group input,
.input-group select {
    padding: 10px 14px;
    background: var(--bg-tertiary);
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    color: var(--text-primary);
    font-family: var(--font-sans);
    font-size: 0.9rem;
    transition: all var(--transition-fast);
}

.input-group input:focus,
.input-group select:focus {
    outline: none;
    border-color: var(--accent);
    box-shadow: 0 0 0 3px var(--accent-glow);
}

.input-group input::placeholder {
    color: var(--text-muted);
}

.input-group.small input {
    padding: 8px 10px;
    font-size: 0.85rem;
}

.input-with-slider {
    display: flex;
    gap: 12px;
    align-items: center;
}

.input-with-slider input[type="number"] {
    width: 80px;
    flex-shrink: 0;
}

.input-with-slider input[type="range"] {
    flex: 1;
}

.input-hint {
    font-size: 0.75rem;
    color: var(--text-muted);
    font-family: var(--font-mono);
}

.input-row {
    display: flex;
    gap: 12px;
}

.input-row .input-group {
    flex: 1;
}

/* === Range Sliders === */
input[type="range"] {
    -webkit-appearance: none;
    appearance: none;
    height: 6px;
    background: var(--bg-tertiary);
    border-radius: 100px;
    outline: none;
    cursor: pointer;
}

input[type="range"]::-webkit-slider-thumb {
    -webkit-appearance: none;
    appearance: none;
    width: 16px;
    height: 16px;
    border-radius: 50%;
    background: var(--accent);
    cursor: pointer;
    border: 2px solid var(--accent-light);
    box-shadow: 0 0 10px rgba(6, 182, 212, 0.3);
    transition: transform var(--transition-fast);
}

input[type="range"]::-webkit-slider-thumb:hover {
    transform: scale(1.2);
}

input[type="range"]::-moz-range-thumb {
    width: 16px;
    height: 16px;
    border-radius: 50%;
    background: var(--accent);
    cursor: pointer;
    border: 2px solid var(--accent-light);
}

.range-value {
    font-size: 0.85rem;
    color: var(--accent);
    font-family: var(--font-mono);
    font-weight: 500;
    min-width: 40px;
    text-align: right;
}

/* === Buttons === */
.btn-primary {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    padding: 10px 20px;
    background: var(--gradient-accent);
    color: var(--text-inverse);
    border: none;
    border-radius: var(--radius-sm);
    font-family: var(--font-sans);
    font-size: 0.875rem;
    font-weight: 600;
    cursor: pointer;
    transition: all var(--transition-fast);
    box-shadow: var(--shadow-accent);
}

.btn-primary:hover {
    transform: translateY(-1px);
    box-shadow: 0 6px 24px rgba(6, 182, 212, 0.3);
}

.btn-primary:active {
    transform: translateY(0);
}

.btn-primary:disabled {
    opacity: 0.5;
    cursor: not-allowed;
    transform: none;
}

.btn-accent {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    padding: 10px 20px;
    background: var(--success);
    color: var(--text-inverse);
    border: none;
    border-radius: var(--radius-sm);
    font-family: var(--font-sans);
    font-size: 0.875rem;
    font-weight: 600;
    cursor: pointer;
    transition: all var(--transition-fast);
}

.btn-accent:hover {
    background: var(--success-light);
    transform: translateY(-1px);
}

.btn-secondary {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    padding: 10px 20px;
    background: transparent;
    color: var(--text-secondary);
    border: 1px solid var(--border-light);
    border-radius: var(--radius-sm);
    font-family: var(--font-sans);
    font-size: 0.875rem;
    font-weight: 500;
    cursor: pointer;
    transition: all var(--transition-fast);
}

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

.btn-danger {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    padding: 10px 20px;
    background: transparent;
    color: var(--danger);
    border: 1px solid var(--danger);
    border-radius: var(--radius-sm);
    font-family: var(--font-sans);
    font-size: 0.875rem;
    font-weight: 500;
    cursor: pointer;
    transition: all var(--transition-fast);
}

.btn-danger:hover {
    background: var(--danger-bg);
    color: var(--danger-light);
}

.btn-large {
    padding: 14px 28px;
    font-size: 1rem;
}

.btn-small {
    padding: 6px 14px;
    font-size: 0.8rem;
    background: var(--bg-tertiary);
    color: var(--text-secondary);
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    font-family: var(--font-sans);
    font-weight: 500;
    cursor: pointer;
    transition: all var(--transition-fast);
}

.btn-small:hover {
    background: var(--bg-hover);
    color: var(--text-primary);
}

.btn-icon {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 36px;
    height: 36px;
    background: transparent;
    color: var(--text-secondary);
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    cursor: pointer;
    transition: all var(--transition-fast);
}

.btn-icon:hover {
    background: var(--bg-hover);
    color: var(--text-primary);
    border-color: var(--border-light);
}

.extract-actions,
.editor-actions,
.export-actions {
    display: flex;
    gap: 12px;
    justify-content: center;
    margin-top: 24px;
    padding-top: 24px;
    border-top: 1px solid var(--border);
}

.btn-export {
    width: 100%;
    padding: 12px;
    margin-top: 12px;
    background: var(--gradient-accent);
    color: var(--text-inverse);
    border: none;
    border-radius: var(--radius-sm);
    font-family: var(--font-sans);
    font-size: 0.875rem;
    font-weight: 600;
    cursor: pointer;
    transition: all var(--transition-fast);
}

.btn-export:hover {
    transform: translateY(-1px);
    box-shadow: var(--shadow-accent);
}

/* === Checkbox === */
.checkbox-label {
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: 0.85rem;
    color: var(--text-secondary);
    cursor: pointer;
}

.checkbox-label input {
    width: 16px;
    height: 16px;
    accent-color: var(--accent);
}

/* === Editor Layout === */
.editor-layout {
    display: grid;
    grid-template-columns: var(--sidebar-width) 1fr;
    gap: 24px;
    min-height: 600px;
}

/* Sidebar */
.editor-sidebar {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    padding: 20px;
    display: flex;
    flex-direction: column;
    gap: 16px;
    height: fit-content;
    position: sticky;
    top: calc(var(--header-height) + 16px);
}

.sidebar-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding-bottom: 12px;
    border-bottom: 1px solid var(--border);
}

.sidebar-header h3 {
    font-size: 1rem;
    font-weight: 600;
}

.badge {
    font-size: 0.7rem;
    font-family: var(--font-mono);
    padding: 2px 8px;
    background: var(--accent-glow);
    color: var(--accent);
    border-radius: 20px;
    border: 1px solid var(--accent-dark);
}

/* Accordion */
.accordion {
    display: flex;
    flex-direction: column;
    gap: 4px;
}

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

.accordion-trigger {
    width: 100%;
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 10px 12px;
    background: var(--bg-tertiary);
    color: var(--text-secondary);
    border: none;
    font-family: var(--font-sans);
    font-size: 0.85rem;
    font-weight: 500;
    cursor: pointer;
    transition: all var(--transition-fast);
    text-align: left;
}

.accordion-trigger:hover {
    background: var(--bg-hover);
    color: var(--text-primary);
}

.accordion-trigger.active {
    background: var(--accent-glow);
    color: var(--accent);
}

.accordion-panel {
    max-height: 0;
    overflow: hidden;
    transition: max-height var(--transition-slow);
}

.accordion-panel.open {
    max-height: 500px;
}

.panel-content {
    padding: 12px;
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.sidebar-actions {
    display: flex;
    flex-direction: column;
    gap: 8px;
    margin-top: auto;
}

/* Filter Grid */
.filter-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 8px;
}

.filter-btn {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 4px;
    padding: 12px 8px;
    background: var(--bg-tertiary);
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    color: var(--text-secondary);
    cursor: pointer;
    transition: all var(--transition-fast);
}

.filter-btn:hover {
    border-color: var(--accent);
    color: var(--text-primary);
}

.filter-btn.active {
    background: var(--accent-glow);
    border-color: var(--accent);
    color: var(--accent);
}

.filter-name {
    font-size: 0.8rem;
    font-weight: 500;
}

.filter-desc {
    font-size: 0.65rem;
    color: var(--text-muted);
}

/* Watermark Tabs */
.watermark-tabs {
    display: flex;
    gap: 4px;
    background: var(--bg-tertiary);
    padding: 4px;
    border-radius: var(--radius-sm);
}

.tab-btn {
    flex: 1;
    padding: 6px;
    background: transparent;
    border: none;
    border-radius: 4px;
    color: var(--text-muted);
    font-family: var(--font-sans);
    font-size: 0.8rem;
    cursor: pointer;
    transition: all var(--transition-fast);
}

.tab-btn.active {
    background: var(--bg-card);
    color: var(--text-primary);
    font-weight: 500;
}

.tab-content {
    display: none;
}

.tab-content.active {
    display: flex;
    flex-direction: column;
    gap: 12px;
}

/* Format Options */
.format-options {
    display: flex;
    gap: 8px;
}

.format-radio {
    flex: 1;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 8px;
    background: var(--bg-tertiary);
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    cursor: pointer;
    transition: all var(--transition-fast);
    font-size: 0.8rem;
    color: var(--text-secondary);
}

.format-radio input {
    display: none;
}

.format-radio.active,
.format-radio:has(input:checked) {
    background: var(--accent-glow);
    border-color: var(--accent);
    color: var(--accent);
    font-weight: 500;
}

/* === Editor Main === */
.editor-main {
    display: flex;
    flex-direction: column;
    gap: 20px;
}

/* Gallery Toolbar */
.gallery-toolbar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 12px 16px;
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
}

.toolbar-left {
    display: flex;
    gap: 8px;
}

.toolbar-right {
    font-size: 0.8rem;
    color: var(--text-muted);
    font-family: var(--font-mono);
}

/* Gallery Grid */
.gallery-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(120px, 1fr));
    gap: 8px;
    max-height: 500px;
    overflow-y: auto;
    padding: 12px;
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
}

.gallery-placeholder {
    grid-column: 1 / -1;
    display: flex;
    align-items: center;
    justify-content: center;
    min-height: 200px;
    color: var(--text-muted);
    font-size: 0.9rem;
}

.frame-item {
    position: relative;
    aspect-ratio: 1;
    border-radius: var(--radius-sm);
    overflow: hidden;
    cursor: pointer;
    border: 2px solid transparent;
    transition: all var(--transition-fast);
    background: var(--bg-tertiary);
    user-select: none;
}

.frame-item:hover {
    border-color: var(--border-light);
    transform: scale(1.02);
}

.frame-item.selected {
    border-color: var(--accent);
    box-shadow: var(--shadow-glow);
}

.frame-item.selected::after {
    content: '';
    position: absolute;
    inset: 0;
    background: var(--accent-glow);
    pointer-events: none;
}

.frame-item img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.frame-item .frame-number {
    position: absolute;
    bottom: 4px;
    left: 4px;
    font-size: 0.65rem;
    font-family: var(--font-mono);
    color: var(--text-primary);
    background: rgba(0,0,0,0.6);
    padding: 1px 6px;
    border-radius: 4px;
    z-index: 2;
}

.frame-item .frame-check {
    position: absolute;
    top: 6px;
    right: 6px;
    width: 18px;
    height: 18px;
    border-radius: 50%;
    background: var(--accent);
    color: var(--text-inverse);
    display: none;
    align-items: center;
    justify-content: center;
    font-size: 0.7rem;
    z-index: 2;
}

.frame-item.selected .frame-check {
    display: flex;
}

.frame-item.dragging {
    opacity: 0.5;
    transform: scale(1.05);
    z-index: 10;
}

.frame-item.drag-over {
    border-color: var(--success);
    border-style: dashed;
}

/* Scrollbar */
.gallery-grid::-webkit-scrollbar {
    width: 6px;
}

.gallery-grid::-webkit-scrollbar-track {
    background: var(--bg-tertiary);
    border-radius: 100px;
}

.gallery-grid::-webkit-scrollbar-thumb {
    background: var(--border-light);
    border-radius: 100px;
}

.gallery-grid::-webkit-scrollbar-thumb:hover {
    background: var(--text-muted);
}

/* === Previewer === */
.previewer-section {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    overflow: hidden;
}

.previewer-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 12px 16px;
    border-bottom: 1px solid var(--border);
}

.previewer-header h4 {
    font-size: 0.9rem;
    font-weight: 600;
}

.previewer-controls {
    display: flex;
    align-items: center;
    gap: 12px;
}

.fps-control {
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: 0.8rem;
}

.fps-control label {
    color: var(--text-muted);
}

.fps-control input[type="range"] {
    width: 80px;
}

.fps-control span {
    font-family: var(--font-mono);
    color: var(--accent);
    min-width: 24px;
}

.previewer-canvas {
    position: relative;
    height: 200px;
    background: #000;
    display: flex;
    align-items: center;
    justify-content: center;
    overflow: hidden;
}

.previewer-canvas img {
    max-width: 100%;
    max-height: 100%;
    object-fit: contain;
}

.previewer-placeholder {
    color: var(--text-muted);
    font-size: 0.85rem;
}

/* === Export Grid === */
.export-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
    gap: 20px;
    margin-bottom: 24px;
}

.export-card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    padding: 28px 24px;
    text-align: center;
    transition: all var(--transition-base);
}

.export-card:hover {
    border-color: var(--accent);
    box-shadow: var(--shadow-glow);
    transform: translateY(-2px);
}

.export-icon {
    color: var(--accent);
    margin-bottom: 16px;
    display: flex;
    justify-content: center;
}

.export-card h3 {
    font-size: 1.1rem;
    font-weight: 600;
    margin-bottom: 8px;
}

.export-card p {
    font-size: 0.8rem;
    color: var(--text-muted);
    margin-bottom: 16px;
    line-height: 1.4;
}

.export-card .input-group {
    text-align: left;
    margin-bottom: 12px;
}

/* === Progress / Spinner === */
.extract-progress,
.export-progress {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 16px;
    padding: 32px;
    flex-direction: column;
}

.spinner,
.progress-spinner {
    width: 40px;
    height: 40px;
    border: 3px solid var(--border);
    border-top-color: var(--accent);
    border-radius: 50%;
    animation: spin 0.8s linear infinite;
}

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

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

/* === Toast Notifications === */
#toast-container {
    position: fixed;
    top: 20px;
    right: 20px;
    z-index: 1000;
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.toast {
    padding: 12px 20px;
    border-radius: var(--radius-sm);
    font-size: 0.875rem;
    font-weight: 500;
    animation: slideIn 0.3s ease, fadeOut 0.3s ease 4.7s;
    max-width: 320px;
    box-shadow: var(--shadow-lg);
}

.toast.success {
    background: var(--success-bg);
    color: var(--success);
    border: 1px solid var(--success);
}

.toast.error {
    background: var(--danger-bg);
    color: var(--danger);
    border: 1px solid var(--danger);
}

.toast.warning {
    background: var(--warning-bg);
    color: var(--warning);
    border: 1px solid var(--warning);
}

.toast.info {
    background: rgba(6, 182, 212, 0.1);
    color: var(--accent);
    border: 1px solid var(--accent);
}

@keyframes slideIn {
    from {
        transform: translateX(100%);
        opacity: 0;
    }
    to {
        transform: translateX(0);
        opacity: 1;
    }
}

@keyframes fadeOut {
    from { opacity: 1; }
    to { opacity: 0; }
}

/* === Modal === */
.modal {
    position: fixed;
    inset: 0;
    z-index: 1000;
    display: flex;
    align-items: center;
    justify-content: center;
}

.modal.hidden {
    display: none;
}

.modal-overlay {
    position: absolute;
    inset: 0;
    background: rgba(0, 0, 0, 0.7);
    backdrop-filter: blur(4px);
}

.modal-content {
    position: relative;
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    width: 90%;
    max-width: 520px;
    box-shadow: var(--shadow-lg);
    animation: modalIn 0.3s ease;
    overflow: hidden;
}

@keyframes modalIn {
    from {
        transform: scale(0.9);
        opacity: 0;
    }
    to {
        transform: scale(1);
        opacity: 1;
    }
}

.modal-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 16px 20px;
    border-bottom: 1px solid var(--border);
}

.modal-header h3 {
    font-size: 1.1rem;
    font-weight: 600;
}

.modal-close {
    background: none;
    border: none;
    color: var(--text-muted);
    font-size: 1.5rem;
    cursor: pointer;
    transition: color var(--transition-fast);
    width: 32px;
    height: 32px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: var(--radius-sm);
}

.modal-close:hover {
    color: var(--text-primary);
    background: var(--bg-hover);
}

.modal-body {
    padding: 20px;
    max-height: 400px;
    overflow-y: auto;
}

.modal-footer {
    padding: 12px 20px;
    border-top: 1px solid var(--border);
    display: flex;
    justify-content: flex-end;
    gap: 8px;
}

/* === Footer === */
.app-footer {
    height: var(--footer-height);
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 12px;
    background: var(--bg-secondary);
    border-top: 1px solid var(--border);
    font-size: 0.75rem;
    color: var(--text-muted);
    font-family: var(--font-mono);
}

.footer-sep {
    opacity: 0.3;
}

.status-online {
    color: var(--success);
}

/* === Utilities === */
.hidden {
    display: none !important;
}

.sr-only {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border-width: 0;
}

/* === Responsive === */
@media (max-width: 1024px) {
    .editor-layout {
        grid-template-columns: 1fr;
    }

    .editor-sidebar {
        position: static;
    }
}

@media (max-width: 768px) {
    .main-content {
        padding: 16px;
    }

    .app-header {
        padding: 0 16px;
    }

    .logo-text {
        font-size: 1rem;
    }

    .panel-header h2 {
        font-size: 1.4rem;
    }

    .upload-zone {
        padding: 32px 16px;
    }

    .gallery-grid {
        grid-template-columns: repeat(auto-fill, minmax(90px, 1fr));
    }

    .export-grid {
        grid-template-columns: 1fr;
    }

    .info-grid {
        grid-template-columns: repeat(2, 1fr);
    }

    .extract-actions,
    .editor-actions,
    .export-actions {
        flex-direction: column;
    }

    .extract-actions button,
    .editor-actions button,
    .export-actions button {
        width: 100%;
    }

    .gallery-toolbar {
        flex-direction: column;
        gap: 8px;
        align-items: stretch;
    }

    .toolbar-left {
        justify-content: center;
    }

    .toolbar-right {
        text-align: center;
    }
}

@media (max-width: 480px) {
    .steps-nav {
        padding: 0 8px;
    }

    .step-label {
        display: none;
    }

    .step-connector {
        margin: 0 4px 0;
    }

    .upload-zone {
        padding: 24px 12px;
    }

    .upload-content h3 {
        font-size: 1rem;
    }

    .panel-header h2 {
        font-size: 1.2rem;
    }
}