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

:root {
  --bg-base: #0a0a0f;
  --bg-surface: rgba(20, 20, 29, 0.65);
  --bg-surface-hover: rgba(28, 28, 40, 0.8);
  --bg-elevated: rgba(30, 30, 45, 0.6);
  --bg-input: rgba(14, 14, 22, 0.8);
  --border: rgba(255, 255, 255, 0.08);
  --border-hover: rgba(99, 102, 241, 0.35);
  --border-focus: #6366f1;
  --text-primary: #f1f3f9;
  --text-secondary: #94a3b8;
  --text-muted: #64748b;
  --accent: #6366f1;
  --accent-hover: #818cf8;
  --accent-glow: rgba(99, 102, 241, 0.3);
  --accent-gradient: linear-gradient(135deg, #6366f1 0%, #8b5cf6 50%, #ec4899 100%);
  --success: #34d399;
  --success-glow: rgba(52, 211, 153, 0.3);
  --warning: #fbbf24;
  --danger: #f87171;
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 20px;
  --transition: 220ms cubic-bezier(0.16, 1, 0.3, 1);
  --glass-blur: blur(20px);
}

body {
  font-family: 'Inter', system-ui, -apple-system, sans-serif;
  background-color: var(--bg-base);
  background-image: 
    radial-gradient(circle at 15% 15%, rgba(99, 102, 241, 0.12) 0%, transparent 40%),
    radial-gradient(circle at 85% 75%, rgba(139, 92, 246, 0.1) 0%, transparent 40%),
    radial-gradient(circle at 50% 50%, rgba(236, 72, 153, 0.05) 0%, transparent 60%);
  background-attachment: fixed;
  color: var(--text-primary);
  min-height: 100vh;
  line-height: 1.5;
  -webkit-font-smoothing: antialiased;
}

/* ── Layout ───────────────────────────────────────── */
.app {
  max-width: 1050px;
  margin: 0 auto;
  padding: 48px 24px 80px;
}

header {
  text-align: center;
  margin-bottom: 48px;
  position: relative;
}

.header-badge {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 4px 14px;
  border-radius: 999px;
  background: rgba(99, 102, 241, 0.12);
  border: 1px solid rgba(99, 102, 241, 0.25);
  color: #a5b4fc;
  font-size: 0.75rem;
  font-weight: 600;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  margin-bottom: 16px;
  box-shadow: 0 0 20px rgba(99, 102, 241, 0.15);
}

.header-badge-dot {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: #6366f1;
  box-shadow: 0 0 8px #6366f1;
}

header h1 {
  font-size: 2.5rem;
  font-weight: 800;
  letter-spacing: -0.03em;
  background: var(--accent-gradient);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  filter: drop-shadow(0 4px 24px rgba(99, 102, 241, 0.2));
  line-height: 1.15;
}

header p {
  color: var(--text-secondary);
  font-size: 0.95rem;
  margin-top: 10px;
  max-width: 540px;
  margin-left: auto;
  margin-right: auto;
}

/* ── Navigation Tabs ──────────────────────────────── */
.nav-tabs {
  display: inline-flex;
  gap: 8px;
  background: rgba(14, 14, 22, 0.7);
  padding: 6px;
  border-radius: 999px;
  border: 1px solid var(--border);
  margin-top: 24px;
}

.nav-tab {
  background: transparent;
  border: none;
  color: var(--text-secondary);
  font-size: 0.85rem;
  font-weight: 600;
  font-family: inherit;
  padding: 8px 20px;
  border-radius: 999px;
  cursor: pointer;
  transition: all var(--transition);
}

.nav-tab:hover {
  color: var(--text-primary);
  background: rgba(255, 255, 255, 0.05);
}

.nav-tab.active {
  color: #fff;
  background: var(--accent);
  box-shadow: 0 0 16px var(--accent-glow);
}

/* ── View Sections ────────────────────────────────── */
.view-section {
  display: block;
}

.view-section.hidden {
  display: none !important;
}

/* ── Custom Color Input ───────────────────────────── */
.color-picker-wrapper {
  display: flex;
  align-items: center;
  gap: 12px;
}

.control-group input[type="color"] {
  -webkit-appearance: none;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  width: 44px;
  height: 44px;
  cursor: pointer;
  background: none;
  padding: 2px;
}

.control-group input[type="color"]::-webkit-color-swatch-wrapper {
  padding: 0;
}

.control-group input[type="color"]::-webkit-color-swatch {
  border: none;
  border-radius: 6px;
}


/* ── Card ─────────────────────────────────────────── */
.card {
  background: var(--bg-surface);
  backdrop-filter: var(--glass-blur);
  -webkit-backdrop-filter: var(--glass-blur);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 28px;
  margin-bottom: 24px;
  box-shadow: 0 12px 32px -4px rgba(0, 0, 0, 0.3), inset 0 1px 0 rgba(255, 255, 255, 0.05);
  transition: all var(--transition);
}

.card:hover {
  border-color: var(--border-hover);
  box-shadow: 0 16px 40px -4px rgba(0, 0, 0, 0.4), 0 0 24px rgba(99, 102, 241, 0.1);
}

.card-title {
  font-size: 0.75rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--text-muted);
  margin-bottom: 20px;
  display: flex;
  align-items: center;
  gap: 8px;
}

.card-title::before {
  content: '';
  width: 8px;
  height: 8px;
  border-radius: 2px;
  background: var(--accent);
  display: inline-block;
}

/* ── File Drop Zone ───────────────────────────────── */
.drop-zone {
  border: 2px dashed rgba(255, 255, 255, 0.12);
  background: rgba(14, 14, 22, 0.4);
  border-radius: var(--radius-md);
  padding: 44px 24px;
  text-align: center;
  cursor: pointer;
  transition: all var(--transition);
  position: relative;
  overflow: hidden;
}

.drop-zone::before {
  content: '';
  position: absolute;
  inset: 0;
  background: radial-gradient(circle at center, var(--accent-glow) 0%, transparent 70%);
  opacity: 0;
  transition: opacity var(--transition);
}

.drop-zone:hover, .drop-zone.drag-over {
  border-color: var(--accent);
  background: rgba(99, 102, 241, 0.05);
  transform: translateY(-2px);
}

.drop-zone:hover::before, .drop-zone.drag-over::before {
  opacity: 1;
}

.drop-zone.has-file {
  border-color: var(--success);
  border-style: solid;
  background: rgba(52, 211, 153, 0.04);
  padding: 20px 24px;
  transform: none;
}

.drop-zone-icon {
  font-size: 2.5rem;
  margin-bottom: 12px;
  display: inline-block;
  transition: transform var(--transition);
  filter: drop-shadow(0 4px 12px rgba(99, 102, 241, 0.3));
}

.drop-zone:hover .drop-zone-icon {
  transform: scale(1.1) translateY(-4px);
}

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

.drop-zone-text strong {
  color: var(--accent-hover);
  font-weight: 600;
}

.file-info {
  display: flex;
  align-items: center;
  gap: 14px;
  font-size: 0.9rem;
}

.file-info-icon {
  font-size: 1.4rem;
}

.file-info-name {
  font-weight: 600;
  color: var(--text-primary);
}

.file-info-meta {
  color: var(--text-muted);
  font-size: 0.8rem;
  background: rgba(255, 255, 255, 0.06);
  padding: 2px 8px;
  border-radius: 4px;
}

.file-info-remove {
  margin-left: auto;
  background: rgba(248, 113, 113, 0.1);
  border: 1px solid rgba(248, 113, 113, 0.2);
  color: var(--danger);
  border-radius: var(--radius-sm);
  width: 28px;
  height: 28px;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  font-size: 0.85rem;
  transition: all var(--transition);
}

.file-info-remove:hover {
  background: var(--danger);
  color: #fff;
  transform: scale(1.05);
}

#videoFileInput { display: none; }

/* ── Controls Grid ────────────────────────────────── */
.controls-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(210px, 1fr));
  gap: 20px;
}

.control-group {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.control-group label {
  font-size: 0.75rem;
  font-weight: 600;
  color: var(--text-secondary);
  text-transform: uppercase;
  letter-spacing: 0.06em;
}

.control-group input[type="number"] {
  background: var(--bg-input);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  color: var(--text-primary);
  padding: 12px 14px;
  font-size: 0.9rem;
  font-weight: 500;
  font-family: inherit;
  outline: none;
  transition: all var(--transition);
  width: 100%;
  -moz-appearance: textfield;
  appearance: textfield;
}

.control-group input[type="number"]::-webkit-outer-spin-button,
.control-group input[type="number"]::-webkit-inner-spin-button {
  -webkit-appearance: none;
  margin: 0;
}

.control-group input[type="number"]:focus {
  border-color: var(--border-focus);
  box-shadow: 0 0 0 4px var(--accent-glow);
  background: rgba(18, 18, 28, 0.9);
}

/* ── Range Slider ─────────────────────────────────── */
.range-wrapper {
  display: flex;
  align-items: center;
  gap: 14px;
}

.range-wrapper input[type="range"] {
  flex: 1;
  -webkit-appearance: none;
  appearance: none;
  height: 6px;
  background: rgba(255, 255, 255, 0.1);
  border-radius: 3px;
  outline: none;
}

.range-wrapper input[type="range"]::-webkit-slider-thumb {
  -webkit-appearance: none;
  appearance: none;
  width: 20px;
  height: 20px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--accent), #8b5cf6);
  cursor: pointer;
  border: 2px solid var(--bg-base);
  box-shadow: 0 0 12px var(--accent-glow);
  transition: transform var(--transition);
}

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

.range-value {
  font-size: 0.9rem;
  font-weight: 700;
  color: #a5b4fc;
  min-width: 34px;
  text-align: right;
  font-variant-numeric: tabular-nums;
}

/* ── Stats Bar ────────────────────────────────────── */
.stats-bar {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 20px;
  padding-top: 20px;
  border-top: 1px solid var(--border);
}

.stat {
  background: rgba(255, 255, 255, 0.03);
  border: 1px solid rgba(255, 255, 255, 0.05);
  border-radius: var(--radius-sm);
  padding: 8px 14px;
  font-size: 0.8rem;
  display: flex;
  align-items: center;
  gap: 8px;
  transition: all var(--transition);
}

.stat:hover {
  background: rgba(255, 255, 255, 0.06);
  border-color: rgba(255, 255, 255, 0.1);
}

.stat-label {
  color: var(--text-muted);
  font-weight: 500;
}

.stat-value {
  font-weight: 700;
  color: var(--text-primary);
  font-variant-numeric: tabular-nums;
}

.stat-value.highlight {
  color: #a5b4fc;
  background: rgba(99, 102, 241, 0.15);
  padding: 2px 8px;
  border-radius: 4px;
}

/* ── Process Button ───────────────────────────────── */
.action-row {
  display: flex;
  align-items: center;
  gap: 16px;
  flex-wrap: wrap;
}

.btn-primary {
  position: relative;
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 14px 32px;
  font-size: 0.9rem;
  font-weight: 700;
  font-family: inherit;
  color: #fff;
  background: var(--accent-gradient);
  border: none;
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: all var(--transition);
  box-shadow: 0 4px 20px var(--accent-glow);
  overflow: hidden;
}

.btn-primary::before {
  content: '';
  position: absolute;
  top: 0;
  left: -100%;
  width: 100%;
  height: 100%;
  background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.25), transparent);
  transition: left 600ms ease;
}

.btn-primary:hover:not(:disabled)::before {
  left: 100%;
}

.btn-primary:hover:not(:disabled) {
  transform: translateY(-2px);
  box-shadow: 0 8px 28px rgba(99, 102, 241, 0.45);
}

.btn-primary:active:not(:disabled) {
  transform: translateY(0);
}

.btn-primary:disabled {
  opacity: 0.35;
  cursor: not-allowed;
  transform: none;
  box-shadow: none;
}

.btn-download {
  display: none;
  align-items: center;
  gap: 10px;
  padding: 14px 32px;
  font-size: 0.9rem;
  font-weight: 700;
  font-family: inherit;
  color: #052e16;
  background: linear-gradient(135deg, var(--success), #2dd4bf);
  border: none;
  border-radius: var(--radius-md);
  cursor: pointer;
  text-decoration: none;
  transition: all var(--transition);
  box-shadow: 0 4px 20px var(--success-glow);
}

.btn-download:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 28px rgba(52, 211, 153, 0.45);
}

.btn-download.visible { display: inline-flex; }

/* ── Progress Bar ─────────────────────────────────── */
.progress-container {
  display: none;
  flex-direction: column;
  gap: 8px;
  flex: 1;
  min-width: 220px;
}

.progress-container.visible { display: flex; }

.progress-bar-track {
  height: 10px;
  background: rgba(255, 255, 255, 0.08);
  border-radius: 999px;
  overflow: hidden;
  box-shadow: inset 0 1px 3px rgba(0, 0, 0, 0.4);
}

.progress-bar-fill {
  height: 100%;
  width: 0%;
  background: var(--accent-gradient);
  border-radius: 999px;
  transition: width 100ms linear;
  box-shadow: 0 0 12px var(--accent-glow);
}

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

/* ── Output Canvas ────────────────────────────────── */
.output-section {
  display: none;
}

.output-section.visible { display: block; }

.canvas-wrapper {
  overflow: auto;
  max-height: 600px;
  border-radius: var(--radius-md);
  border: 1px solid var(--border);
  box-shadow: inset 0 0 20px rgba(0, 0, 0, 0.5);
}

#outputCanvas {
  display: block;
  max-width: 100%;
  background-image:
    linear-gradient(45deg, #181824 25%, transparent 25%),
    linear-gradient(-45deg, #181824 25%, transparent 25%),
    linear-gradient(45deg, transparent 75%, #181824 75%),
    linear-gradient(-45deg, transparent 75%, #181824 75%);
  background-size: 24px 24px;
  background-position: 0 0, 0 12px, 12px -12px, -12px 0;
  background-color: #0f0f17;
}

/* ── Hidden Video ─────────────────────────────────── */
#hiddenVideo { display: none; }

/* ── Animations ───────────────────────────────────── */
@keyframes pulse {
  0%, 100% { opacity: 1; }
  50% { opacity: 0.6; }
}

.processing .btn-primary { animation: pulse 1.5s ease-in-out infinite; }

/* ── Tooltip ──────────────────────────────────────── */
.label-with-tip {
  display: inline-flex;
  align-items: center;
  gap: 6px;
}

.info-icon {
  position: relative;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 18px;
  height: 18px;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.08);
  border: 1px solid rgba(255, 255, 255, 0.15);
  color: var(--text-secondary);
  font-size: 0.65rem;
  font-weight: 700;
  font-style: italic;
  cursor: help;
  flex-shrink: 0;
  transition: all var(--transition);
}

.info-icon:hover {
  background: var(--accent);
  border-color: var(--accent);
  color: #fff;
  box-shadow: 0 0 12px var(--accent-glow);
}

.info-icon .tooltip {
  position: absolute;
  bottom: calc(100% + 10px);
  left: 50%;
  transform: translateX(-50%);
  background: #181824;
  border: 1px solid var(--border-hover);
  border-radius: var(--radius-sm);
  padding: 12px 16px;
  font-size: 0.78rem;
  font-style: normal;
  font-weight: 400;
  color: var(--text-primary);
  line-height: 1.5;
  width: 270px;
  white-space: normal;
  text-transform: none;
  letter-spacing: normal;
  pointer-events: none;
  opacity: 0;
  transition: opacity var(--transition), transform var(--transition);
  box-shadow: 0 12px 32px rgba(0, 0, 0, 0.6);
  z-index: 100;
}

.info-icon .tooltip::after {
  content: '';
  position: absolute;
  top: 100%;
  left: 50%;
  transform: translateX(-50%);
  border: 6px solid transparent;
  border-top-color: var(--border-hover);
}

.info-icon:hover .tooltip {
  opacity: 1;
}

/* ── Animation Preview ────────────────────────────── */
.preview-section { display: none; }
.preview-section.visible { display: block; }

.preview-layout {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 20px;
}

.preview-canvas-wrap {
  border-radius: var(--radius-md);
  border: 1px solid var(--border);
  overflow: hidden;
  background-image:
    linear-gradient(45deg, #181824 25%, transparent 25%),
    linear-gradient(-45deg, #181824 25%, transparent 25%),
    linear-gradient(45deg, transparent 75%, #181824 75%),
    linear-gradient(-45deg, transparent 75%, #181824 75%);
  background-size: 20px 20px;
  background-position: 0 0, 0 10px, 10px -10px, -10px 0;
  background-color: #0f0f17;
  display: inline-block;
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.4);
}

#previewCanvas {
  display: block;
  max-width: 320px;
  max-height: 320px;
  image-rendering: pixelated;
}

.preview-controls {
  display: flex;
  align-items: center;
  gap: 14px;
  flex-wrap: wrap;
  justify-content: center;
  background: rgba(14, 14, 22, 0.6);
  padding: 8px 18px;
  border-radius: 999px;
  border: 1px solid var(--border);
}

.btn-icon {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
  border: 1px solid var(--border);
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.05);
  color: var(--text-primary);
  font-size: 1rem;
  cursor: pointer;
  transition: all var(--transition);
}

.btn-icon:hover {
  border-color: var(--accent);
  background: var(--accent-glow);
  transform: scale(1.08);
}

.btn-icon.active {
  border-color: var(--accent);
  background: var(--accent);
  color: #fff;
  box-shadow: 0 0 16px var(--accent-glow);
}

.preview-frame-info {
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--text-secondary);
  min-width: 90px;
  text-align: center;
  font-variant-numeric: tabular-nums;
}

.speed-select {
  background: rgba(255, 255, 255, 0.06);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  color: var(--text-primary);
  padding: 6px 12px;
  font-size: 0.85rem;
  font-weight: 600;
  font-family: inherit;
  cursor: pointer;
  outline: none;
  transition: all var(--transition);
}

.speed-select:focus, .speed-select:hover {
  border-color: var(--accent);
  background: rgba(99, 102, 241, 0.1);
}

/* ── Responsive ───────────────────────────────────── */
@media (max-width: 600px) {
  .app { padding: 24px 14px 48px; }
  header h1 { font-size: 1.8rem; }
  .card { padding: 20px; }
  .controls-grid { grid-template-columns: 1fr 1fr; }
  .stats-bar { gap: 8px; }
  .stat { padding: 6px 10px; font-size: 0.75rem; }
  .info-icon .tooltip { width: 220px; }
  #previewCanvas { max-width: 240px; max-height: 240px; }
}