:root {
  --bg: #0a0a0f;
  --bg-elevated: #12121a;
  --surface: rgba(255, 255, 255, 0.04);
  --surface-hover: rgba(255, 255, 255, 0.07);
  --surface-active: rgba(255, 255, 255, 0.1);
  --border: rgba(255, 255, 255, 0.08);
  --border-hover: rgba(255, 255, 255, 0.15);
  --text: #e8e8ed;
  --text-secondary: rgba(255, 255, 255, 0.5);
  --text-tertiary: rgba(255, 255, 255, 0.3);
  --accent: #6366f1;
  --accent-hover: #818cf8;
  --accent-glow: rgba(99, 102, 241, 0.25);
  --purple: #a855f7;
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 16px;
  --radius-xl: 20px;
  --transition: 200ms cubic-bezier(0.4, 0, 0.2, 1);
  --topbar-bg: rgba(10, 10, 15, 0.8);
  --card-shadow: 0 12px 32px rgba(0, 0, 0, 0.3);
  --preview-bg: rgba(0, 0, 0, 0.2);
  --gradient-a: rgba(99, 102, 241, 0.12);
  --gradient-b: rgba(168, 85, 247, 0.06);
  --upload-accent-bg: rgba(99, 102, 241, 0.05);
  --remove-btn-bg: rgba(0, 0, 0, 0.7);
}

[data-theme="light"] {
  --bg: #f5f5f7;
  --bg-elevated: #ffffff;
  --surface: rgba(0, 0, 0, 0.03);
  --surface-hover: rgba(0, 0, 0, 0.06);
  --surface-active: rgba(0, 0, 0, 0.09);
  --border: rgba(0, 0, 0, 0.1);
  --border-hover: rgba(0, 0, 0, 0.2);
  --text: #1a1a2e;
  --text-secondary: rgba(0, 0, 0, 0.55);
  --text-tertiary: rgba(0, 0, 0, 0.35);
  --accent: #6366f1;
  --accent-hover: #4f46e5;
  --accent-glow: rgba(99, 102, 241, 0.2);
  --purple: #9333ea;
  --topbar-bg: rgba(245, 245, 247, 0.85);
  --card-shadow: 0 8px 24px rgba(0, 0, 0, 0.08);
  --preview-bg: rgba(0, 0, 0, 0.03);
  --gradient-a: rgba(99, 102, 241, 0.06);
  --gradient-b: rgba(168, 85, 247, 0.03);
  --upload-accent-bg: rgba(99, 102, 241, 0.04);
  --remove-btn-bg: rgba(0, 0, 0, 0.6);
}

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

html { scroll-behavior: smooth; }

body {
  min-height: 100vh;
  color: var(--text);
  font-family: "Inter", "Noto Sans SC", -apple-system, BlinkMacSystemFont, sans-serif;
  line-height: 1.6;
  background: var(--bg);
  -webkit-font-smoothing: antialiased;
}

body::before {
  content: "";
  position: fixed;
  inset: 0;
  background:
    radial-gradient(ellipse 80% 60% at 50% -20%, var(--gradient-a), transparent),
    radial-gradient(ellipse 60% 40% at 80% 50%, var(--gradient-b), transparent);
  pointer-events: none;
  z-index: 0;
}

img { display: block; max-width: 100%; }
button, a, textarea, input { font: inherit; color: inherit; }
button, a { cursor: pointer; }

button:focus-visible, a:focus-visible, textarea:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
}

/* Top Bar */
.top-bar {
  position: sticky;
  top: 0;
  z-index: 100;
  background: var(--topbar-bg);
  backdrop-filter: blur(20px) saturate(1.2);
  border-bottom: 1px solid var(--border);
}

.top-bar-inner {
  max-width: 1280px;
  margin: 0 auto;
  padding: 0 24px;
  height: 56px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

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

.logo-text {
  font-size: 1rem;
  font-weight: 700;
  letter-spacing: -0.02em;
  color: var(--text);
}

.status-badge {
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 4px 12px;
  border-radius: 999px;
  background: var(--surface);
  border: 1px solid var(--border);
  font-size: 0.8rem;
  color: var(--text-secondary);
}

.status-dot {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: #22c55e;
  box-shadow: 0 0 6px rgba(34, 197, 94, 0.5);
}

.top-bar-right {
  display: flex;
  align-items: center;
  gap: 10px;
}

.theme-toggle {
  display: grid;
  place-items: center;
  width: 36px;
  height: 36px;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  background: var(--surface);
  color: var(--text-secondary);
  transition: color var(--transition), background var(--transition), border-color var(--transition);
}

.theme-toggle:hover {
  color: var(--text);
  background: var(--surface-hover);
  border-color: var(--border-hover);
}

.theme-icon--light { display: none; }
[data-theme="light"] .theme-icon--dark { display: none; }
[data-theme="light"] .theme-icon--light { display: block; }

/* App Shell */
.app-shell {
  position: relative;
  z-index: 1;
  max-width: 1280px;
  margin: 0 auto;
  padding: 24px;
}

/* Studio Layout */
.studio {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 20px;
  margin-bottom: 32px;
}

/* Panel */
.panel {
  background: var(--bg-elevated);
  border: 1px solid var(--border);
  border-radius: var(--radius-xl);
  overflow: hidden;
}

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

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

.panel-badge {
  font-size: 0.7rem;
  font-weight: 600;
  padding: 3px 8px;
  border-radius: 999px;
  background: linear-gradient(135deg, var(--accent), var(--purple));
  color: white;
  letter-spacing: 0.02em;
}

/* Composer */
.composer-form {
  padding: 20px;
  display: flex;
  flex-direction: column;
  gap: 16px;
}

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

.field-label {
  display: flex;
  align-items: center;
  gap: 6px;
  font-size: 0.82rem;
  font-weight: 500;
  color: var(--text-secondary);
}

.optional-tag {
  font-size: 0.7rem;
  padding: 1px 6px;
  border-radius: 4px;
  background: var(--surface);
  color: var(--text-tertiary);
}

textarea {
  width: 100%;
  min-height: 120px;
  resize: vertical;
  padding: 14px 16px;
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  background: var(--surface);
  color: var(--text);
  font-size: 0.92rem;
  line-height: 1.7;
  transition: border-color var(--transition), box-shadow var(--transition);
}

textarea::placeholder { color: var(--text-tertiary); }

textarea:focus {
  border-color: var(--accent);
  box-shadow: 0 0 0 3px var(--accent-glow);
  outline: none;
}

.char-count {
  text-align: right;
  font-size: 0.75rem;
  color: var(--text-tertiary);
  font-variant-numeric: tabular-nums;
}

/* Upload Zone */
.upload-zone {
  border: 1.5px dashed var(--border);
  border-radius: var(--radius-md);
  background: var(--surface);
  transition: border-color var(--transition), background var(--transition);
  cursor: pointer;
  position: relative;
  overflow: hidden;
}

.upload-zone:hover, .upload-zone.drag-over {
  border-color: var(--accent);
  background: var(--upload-accent-bg);
}

.upload-placeholder {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
  padding: 28px 16px;
  color: var(--text-tertiary);
  text-align: center;
}

.upload-placeholder p {
  font-size: 0.85rem;
  color: var(--text-secondary);
}

.upload-hint {
  font-size: 0.75rem;
}

.upload-preview {
  position: relative;
  padding: 8px;
}

.upload-preview img {
  width: 100%;
  max-height: 200px;
  object-fit: contain;
  border-radius: var(--radius-sm);
}

.edit-mode-hint {
  font-size: 0.78rem;
  line-height: 1.6;
  color: var(--accent-hover);
}

.remove-image-btn {
  position: absolute;
  top: 12px;
  right: 12px;
  width: 28px;
  height: 28px;
  display: grid;
  place-items: center;
  border: none;
  border-radius: 50%;
  background: var(--remove-btn-bg);
  color: white;
  backdrop-filter: blur(8px);
  transition: background var(--transition);
}

.remove-image-btn:hover { background: rgba(239, 68, 68, 0.8); }

/* Generate Button */
.generate-btn {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  width: 100%;
  height: 48px;
  border: none;
  border-radius: var(--radius-md);
  background: linear-gradient(135deg, var(--accent), var(--purple));
  color: white;
  font-size: 0.95rem;
  font-weight: 600;
  letter-spacing: -0.01em;
  transition: transform var(--transition), box-shadow var(--transition), opacity var(--transition);
  position: relative;
  overflow: hidden;
}

.generate-btn::before {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(135deg, transparent, rgba(255,255,255,0.1));
  opacity: 0;
  transition: opacity var(--transition);
}

.generate-btn:hover:not([disabled]) {
  transform: translateY(-1px);
  box-shadow: 0 8px 24px var(--accent-glow);
}

.generate-btn:hover:not([disabled])::before { opacity: 1; }

.generate-btn[disabled] {
  opacity: 0.6;
  cursor: not-allowed;
  transform: none;
}

.generate-btn .btn-icon { flex-shrink: 0; }

/* Preview Panel */
.preview-panel {
  display: flex;
  flex-direction: column;
}

.preview-stage {
  position: relative;
  flex: 1;
  min-height: 400px;
  background: linear-gradient(180deg, rgba(255,255,255,0.02), rgba(255,255,255,0.01));
  display: grid;
  place-items: center;
}

.preview-placeholder {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 12px;
  color: var(--text-tertiary);
  text-align: center;
  padding: 24px;
}

.preview-placeholder p { font-size: 0.88rem; }

#preview-image {
  width: 100%;
  height: 100%;
  min-height: 400px;
  object-fit: contain;
  background: var(--preview-bg);
}

.preview-info {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  padding: 14px 20px;
  border-top: 1px solid var(--border);
}

.preview-meta h3 {
  font-size: 0.88rem;
  font-weight: 600;
  line-height: 1.4;
  display: -webkit-box;
  -webkit-line-clamp: 1;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.preview-subtitle {
  font-size: 0.78rem;
  color: var(--text-secondary);
  margin-top: 2px;
}

.preview-actions { flex-shrink: 0; }

.action-btn {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 7px 14px;
  border-radius: var(--radius-sm);
  font-size: 0.82rem;
  font-weight: 500;
  text-decoration: none;
  transition: background var(--transition), border-color var(--transition);
}

.action-btn--primary {
  background: var(--surface);
  border: 1px solid var(--border);
}

.action-btn--primary:hover {
  background: var(--surface-hover);
  border-color: var(--border-hover);
}

/* History Section */
.history-section { margin-bottom: 48px; }

.section-header {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-bottom: 16px;
}

.section-title {
  font-size: 1rem;
  font-weight: 600;
}

.count-badge {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 24px;
  height: 24px;
  padding: 0 8px;
  border-radius: 999px;
  background: var(--surface);
  border: 1px solid var(--border);
  font-size: 0.75rem;
  color: var(--text-secondary);
  font-variant-numeric: tabular-nums;
}

.history-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(240px, 1fr));
  gap: 16px;
}

/* History Card */
.history-card {
  background: var(--bg-elevated);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  overflow: hidden;
  transition: border-color var(--transition), transform var(--transition), box-shadow var(--transition);
}

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

.history-image-btn {
  width: 100%;
  padding: 0;
  border: none;
  background: transparent;
  position: relative;
  overflow: hidden;
}

.history-img {
  width: 100%;
  aspect-ratio: 1;
  object-fit: cover;
  background: rgba(255, 255, 255, 0.02);
  transition: transform 400ms cubic-bezier(0.4, 0, 0.2, 1);
}

.history-card:hover .history-img { transform: scale(1.04); }

.history-overlay {
  position: absolute;
  inset: 0;
  display: grid;
  place-items: center;
  background: rgba(0, 0, 0, 0.4);
  opacity: 0;
  transition: opacity var(--transition);
  color: white;
}

.history-card:hover .history-overlay { opacity: 1; }

.history-body { padding: 12px 14px; }

.history-prompt {
  font-size: 0.82rem;
  line-height: 1.5;
  color: var(--text);
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
  margin-bottom: 8px;
}

.history-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
}

.history-time {
  font-size: 0.75rem;
  color: var(--text-tertiary);
}

.history-actions {
  display: flex;
  align-items: center;
  gap: 6px;
}

.history-delete,
.history-download {
  display: grid;
  place-items: center;
  width: 28px;
  height: 28px;
  padding: 0;
  border: none;
  border-radius: var(--radius-sm);
  background: transparent;
  color: var(--text-tertiary);
  text-decoration: none;
  transition: color var(--transition), background var(--transition), opacity var(--transition);
}

.history-delete:hover {
  color: #ef4444;
  background: rgba(239, 68, 68, 0.1);
}

.history-download:hover {
  color: var(--text);
  background: var(--surface);
}

.history-delete:disabled {
  opacity: 0.5;
  cursor: not-allowed;
}

/* Empty State */
.empty-state {
  display: none;
  flex-direction: column;
  align-items: center;
  gap: 12px;
  padding: 48px 24px;
  text-align: center;
  color: var(--text-tertiary);
  border: 1px dashed var(--border);
  border-radius: var(--radius-lg);
}

.empty-state.visible { display: flex; }
.empty-state p { font-size: 0.88rem; }

/* Loading Spinner */
@keyframes spin {
  to { transform: rotate(360deg); }
}

.generate-btn[disabled] .btn-icon {
  animation: spin 1s linear infinite;
}

/* Responsive */
@media (max-width: 768px) {
  .studio {
    grid-template-columns: 1fr;
  }

  .app-shell { padding: 16px; }

  .top-bar-inner { padding: 0 16px; }

  .preview-stage, #preview-image { min-height: 300px; }

  .history-grid {
    grid-template-columns: repeat(auto-fill, minmax(160px, 1fr));
    gap: 12px;
  }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after {
    animation: none !important;
    transition-duration: 0.01ms !important;
  }
}