/* ===== CSS Variables / Design Tokens ===== */
:root {
  /* Light Theme (Default) - Black/Gray/White */
  --bg-primary: #ffffff;
  --bg-secondary: #f5f5f5;
  --bg-card: #ffffff;
  --bg-card-hover: #fafafa;
  --bg-input: #f0f0f0;
  
  --border-subtle: #e0e0e0;
  --border-hover: #c0c0c0;
  --border-accent: #000000;
  
  --text-primary: #000000;
  --text-secondary: #666666;
  --text-muted: #999999;
  --text-accent: #000000;
  
  --accent: #000000;
  --accent-light: #333333;
  --accent-glow: rgba(0, 0, 0, 0.08);
  
  --success: #10b981;
  --error: #ef4444;
  --warning: #f59e0b;
  
  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 14px;
  --radius-xl: 18px;
  
  --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.08);
  --shadow-md: 0 2px 8px rgba(0, 0, 0, 0.1);
  --shadow-lg: 0 4px 20px rgba(0, 0, 0, 0.12);
  --shadow-glow: 0 0 20px rgba(0, 0, 0, 0.08);
  
  --font: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --transition: 0.2s cubic-bezier(0.4, 0, 0.2, 1);
}

/* Dark Theme */
[data-theme="dark"] {
  --bg-primary: #0a0a0a;
  --bg-secondary: #141414;
  --bg-card: #1a1a1a;
  --bg-card-hover: #222222;
  --bg-input: #1f1f1f;
  
  --border-subtle: #2a2a2a;
  --border-hover: #404040;
  --border-accent: #ffffff;
  
  --text-primary: #ffffff;
  --text-secondary: #a0a0a0;
  --text-muted: #666666;
  --text-accent: #ffffff;
  
  --accent: #ffffff;
  --accent-light: #cccccc;
  --accent-glow: rgba(255, 255, 255, 0.1);
  
  --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.3);
  --shadow-md: 0 2px 8px rgba(0, 0, 0, 0.4);
  --shadow-lg: 0 4px 20px rgba(0, 0, 0, 0.5);
  --shadow-glow: 0 0 20px rgba(255, 255, 255, 0.05);
}

/* ===== Reset ===== */
*, *::before, *::after {
  margin: 0; padding: 0; box-sizing: border-box;
}
html {
  font-size: 16px;
  scroll-behavior: smooth;
}
body {
  font-family: var(--font);
  background: var(--bg-primary);
  color: var(--text-primary);
  min-height: 100vh;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
  transition: background 0.3s ease, color 0.3s ease;
}

/* ===== Background Pattern ===== */
.bg-pattern {
  position: fixed; inset: 0; z-index: -1;
  background-image: 
    linear-gradient(rgba(128,128,128,0.03) 1px, transparent 1px),
    linear-gradient(90deg, rgba(128,128,128,0.03) 1px, transparent 1px);
  background-size: 40px 40px;
}
[data-theme="dark"] .bg-pattern {
  background-image: 
    linear-gradient(rgba(255,255,255,0.02) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255,255,255,0.02) 1px, transparent 1px);
}

/* ===== Scrollbar ===== */
::-webkit-scrollbar { width: 6px; }
::-webkit-scrollbar-track { background: transparent; }
::-webkit-scrollbar-thumb { background: rgba(128,128,128,0.3); border-radius: 3px; }
::-webkit-scrollbar-thumb:hover { background: rgba(128,128,128,0.5); }

/* ===== Navbar ===== */
.navbar {
  position: sticky; top: 0; z-index: 100;
  display: flex; align-items: center; justify-content: space-between;
  padding: 0 32px; height: 64px;
  background: var(--bg-primary);
  border-bottom: 1px solid var(--border-subtle);
  transition: background 0.3s ease, border-color 0.3s ease;
}
.nav-brand {
  display: flex; align-items: center; gap: 10px;
}
.nav-logo { font-size: 1.5rem; }
.nav-title {
  font-size: 1.1rem; font-weight: 700; letter-spacing: -0.02em;
  color: var(--text-primary);
}
.nav-right {
  display: flex; align-items: center; gap: 16px;
}
.nav-tabs { display: flex; gap: 4px; }
.nav-tab {
  display: flex; align-items: center; gap: 6px;
  padding: 8px 16px; border: none; border-radius: var(--radius-md);
  background: transparent; color: var(--text-secondary);
  font-family: var(--font); font-size: 0.875rem; font-weight: 500;
  cursor: pointer; transition: var(--transition);
}
.nav-tab:hover { color: var(--text-primary); background: var(--bg-secondary); }
.nav-tab.active {
  color: var(--text-primary);
  background: var(--bg-secondary);
}
.nav-tab svg { opacity: 0.7; }
.nav-tab.active svg { opacity: 1; }

/* Theme Toggle */
.theme-toggle {
  width: 40px; height: 40px;
  display: flex; align-items: center; justify-content: center;
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  background: transparent;
  color: var(--text-secondary);
  cursor: pointer;
  transition: var(--transition);
}
.theme-toggle:hover {
  color: var(--text-primary);
  border-color: var(--border-hover);
  background: var(--bg-secondary);
}
.theme-toggle .sun-icon { display: none; }
.theme-toggle .moon-icon { display: block; }
[data-theme="dark"] .theme-toggle .sun-icon { display: block; }
[data-theme="dark"] .theme-toggle .moon-icon { display: none; }

/* ===== Main Content ===== */
.main-content {
  max-width: 1400px; margin: 0 auto;
  padding: 32px 32px 64px;
}
.page { display: none; }
.page.active { display: block; animation: fadeIn 0.3s ease; }

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(8px); }
  to { opacity: 1; transform: translateY(0); }
}

.page-header {
  margin-bottom: 32px;
}
.page-header h1 {
  font-size: 1.5rem; font-weight: 700; letter-spacing: -0.02em;
  margin-bottom: 6px;
}
.page-subtitle {
  color: var(--text-secondary); font-size: 0.9rem;
}

/* ===== Category Filters ===== */
.category-filters {
  display: flex; gap: 8px; margin-top: 16px; flex-wrap: wrap;
}
.cat-filter {
  padding: 6px 16px; border: 1px solid var(--border-subtle);
  border-radius: 100px; background: transparent;
  color: var(--text-secondary); font-family: var(--font);
  font-size: 0.8rem; font-weight: 500; cursor: pointer;
  transition: var(--transition);
}
.cat-filter:hover { border-color: var(--border-hover); color: var(--text-primary); }
.cat-filter.active {
  background: var(--accent); border-color: var(--accent);
  color: #fff;
}
[data-theme="dark"] .cat-filter.active {
  color: #000;
}

/* ===== Workflow Grid ===== */
.workflow-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 16px;
}
.workflow-card {
  position: relative;
  padding: 20px;
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg);
  cursor: pointer;
  transition: all 0.2s ease;
  overflow: hidden;
}
.workflow-card:hover {
  border-color: var(--border-hover);
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

.workflow-card-content { position: relative; z-index: 1; }
.wf-card-header {
  display: flex; align-items: center; gap: 12px; margin-bottom: 10px;
}
.wf-icon {
  font-size: 1.8rem;
  width: 48px; height: 48px;
  display: flex; align-items: center; justify-content: center;
  background: var(--bg-secondary);
  border-radius: var(--radius-md);
}
.wf-name {
  font-size: 1rem; font-weight: 600;
}
.wf-desc {
  color: var(--text-secondary); font-size: 0.82rem; line-height: 1.5;
  margin-bottom: 12px;
}
.wf-tags {
  display: flex; gap: 6px; flex-wrap: wrap;
}
.wf-tag {
  padding: 3px 10px; border-radius: 100px;
  font-size: 0.7rem; font-weight: 500;
  background: var(--bg-secondary); color: var(--text-secondary);
  border: 1px solid var(--border-subtle);
}
.wf-tag.img { 
  background: var(--text-primary); 
  color: var(--bg-primary);
  border-color: var(--text-primary);
}
[data-theme="dark"] .wf-tag.img {
  background: var(--bg-primary);
  color: var(--text-primary);
  border-color: var(--border-hover);
}

/* ===== Generate Panel ===== */
.generate-container { max-width: 1200px; margin: 0 auto; }

.back-btn {
  display: inline-flex; align-items: center; gap: 6px;
  padding: 8px 16px; margin-bottom: 24px;
  border: 1px solid var(--border-subtle); border-radius: var(--radius-md);
  background: transparent; color: var(--text-secondary);
  font-family: var(--font); font-size: 0.85rem; cursor: pointer;
  transition: var(--transition);
}
.back-btn:hover { color: var(--text-primary); border-color: var(--border-hover); background: var(--bg-secondary); }

.generate-layout {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 24px;
}

.gen-input-panel, .gen-output-panel {
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-xl);
  padding: 24px;
  transition: background 0.3s ease, border-color 0.3s ease;
}

.gen-workflow-info {
  display: flex; align-items: center; gap: 14px;
  margin-bottom: 24px; padding-bottom: 20px;
  border-bottom: 1px solid var(--border-subtle);
}
.gen-workflow-icon { font-size: 2rem; }
.gen-workflow-info h2 { font-size: 1.1rem; font-weight: 700; }
.gen-workflow-info p { color: var(--text-secondary); font-size: 0.82rem; margin-top: 2px; }

.gen-section { margin-bottom: 20px; }
.gen-label {
  display: block; font-size: 0.85rem; font-weight: 600;
  margin-bottom: 8px; color: var(--text-primary);
}
.label-hint { color: var(--text-muted); font-weight: 400; font-size: 0.8rem; }

/* Upload Zone */
.upload-zone {
  border: 2px dashed var(--border-subtle);
  border-radius: var(--radius-lg);
  padding: 24px;
  text-align: center;
  cursor: pointer;
  transition: var(--transition);
  min-height: 160px;
  display: flex; align-items: center; justify-content: center;
  flex-direction: column;
  position: relative;
}
.upload-zone:hover, .upload-zone.dragover {
  border-color: var(--text-primary);
  background: var(--bg-secondary);
}
.upload-placeholder {
  display: flex; flex-direction: column; align-items: center; gap: 10px;
  color: var(--text-muted);
}
.upload-placeholder svg { opacity: 0.4; }
.upload-placeholder span { font-size: 0.85rem; }
.upload-hint { font-size: 0.75rem !important; opacity: 0.6; }

.upload-previews {
  display: flex; gap: 12px; flex-wrap: wrap; justify-content: center;
}
.upload-preview {
  position: relative; width: 120px; height: 120px;
  border-radius: var(--radius-md); overflow: hidden;
  border: 1px solid var(--border-subtle);
}
.upload-preview img {
  width: 100%; height: 100%; object-fit: cover;
}
.upload-preview-remove {
  position: absolute; top: 4px; right: 4px;
  width: 22px; height: 22px;
  background: rgba(0,0,0,0.7); border: none;
  border-radius: 50%; color: #fff;
  display: flex; align-items: center; justify-content: center;
  cursor: pointer; font-size: 14px; line-height: 1;
}

/* Textarea */
.gen-textarea {
  width: 100%; padding: 14px; min-height: 100px;
  background: var(--bg-input); border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  color: var(--text-primary); font-family: var(--font);
  font-size: 0.9rem; resize: vertical;
  transition: var(--transition);
}
.gen-textarea:focus {
  outline: none; border-color: var(--text-primary);
  box-shadow: 0 0 0 3px var(--accent-glow);
}
.gen-textarea::placeholder { color: var(--text-muted); }

/* Submit Button */
.gen-submit-btn {
  width: 100%; padding: 14px 24px;
  display: flex; align-items: center; justify-content: center; gap: 8px;
  background: var(--accent);
  border: none; border-radius: var(--radius-md);
  color: #fff; font-family: var(--font);
  font-size: 0.95rem; font-weight: 600;
  cursor: pointer;
  transition: all 0.2s ease;
}
[data-theme="dark"] .gen-submit-btn {
  color: #000;
}
.gen-submit-btn:hover {
  transform: translateY(-1px);
  opacity: 0.9;
  box-shadow: var(--shadow-md);
}
.gen-submit-btn:active { transform: translateY(0); }
.gen-submit-btn:disabled {
  opacity: 0.4; cursor: not-allowed; transform: none !important;
  box-shadow: none !important;
}

/* Output Panel */
.gen-output-panel {
  display: flex; align-items: center; justify-content: center;
  min-height: 400px;
}
.output-empty {
  text-align: center; color: var(--text-muted);
  display: flex; flex-direction: column; align-items: center; gap: 12px;
}
.output-empty svg { opacity: 0.2; }
.output-empty p { font-size: 0.9rem; }

/* Progress */
.output-progress {
  text-align: center; width: 100%;
  display: flex; flex-direction: column; align-items: center; gap: 20px;
}
.progress-spinner {
  width: 48px; height: 48px;
  border: 3px solid var(--border-subtle);
  border-top-color: var(--text-primary);
  border-radius: 50%;
  animation: spin 0.8s linear infinite;
}
@keyframes spin { to { transform: rotate(360deg); } }

.progress-bar-container {
  width: 80%; height: 4px;
  background: var(--border-subtle);
  border-radius: 2px;
  overflow: hidden;
}
.progress-bar {
  height: 100%; width: 0%;
  background: var(--text-primary);
  border-radius: 2px;
  transition: width 0.5s ease;
}
.progress-text { color: var(--text-secondary); font-size: 0.85rem; }

/* Result */
.output-result {
  width: 100%; text-align: center;
  display: flex; flex-direction: column; align-items: center; gap: 16px;
}
.output-result img {
  max-width: 100%; max-height: 500px;
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-lg);
  cursor: pointer;
  transition: transform 0.3s ease;
}
.output-result img:hover { transform: scale(1.01); }
.output-actions {
  display: flex; gap: 10px; flex-wrap: wrap; justify-content: center;
}
.action-btn {
  display: flex; align-items: center; gap: 6px;
  padding: 8px 16px;
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  background: var(--bg-secondary); color: var(--text-secondary);
  font-family: var(--font); font-size: 0.8rem;
  cursor: pointer; transition: var(--transition);
}
.action-btn:hover {
  color: var(--text-primary); border-color: var(--border-hover);
  background: var(--bg-input);
}

/* ===== History ===== */
.history-actions { margin-top: 16px; }
.btn-outline {
  display: inline-flex; align-items: center; gap: 6px;
  padding: 8px 16px;
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  background: transparent; color: var(--text-secondary);
  font-family: var(--font); font-size: 0.82rem;
  cursor: pointer; transition: var(--transition);
}
.btn-outline:hover {
  background: var(--bg-secondary); border-color: var(--border-hover);
  color: var(--text-primary);
}
.btn-outline.export-btn:hover {
  border-color: var(--text-primary);
}
.history-actions { display: flex; gap: 8px; }

.history-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: 16px;
}
.history-card {
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg);
  overflow: hidden;
  transition: all 0.2s ease;
}
.history-card:hover {
  border-color: var(--border-hover);
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}
.history-thumb {
  width: 100%; aspect-ratio: 4/3;
  background: var(--bg-secondary);
  display: flex; align-items: center; justify-content: center;
  overflow: hidden; cursor: pointer;
}
.history-thumb img {
  width: 100%; height: 100%; object-fit: cover;
  transition: transform 0.3s ease;
}
.history-thumb:hover img { transform: scale(1.03); }
.history-thumb-failed {
  color: var(--error); font-size: 0.85rem;
  display: flex; flex-direction: column; align-items: center; gap: 8px;
}
.history-info {
  padding: 14px;
}
.history-meta {
  display: flex; align-items: center; gap: 8px; margin-bottom: 6px;
}
.history-wf-icon { font-size: 1.2rem; }
.history-wf-name { font-size: 0.85rem; font-weight: 600; }
.history-prompt {
  color: var(--text-secondary); font-size: 0.78rem;
  line-height: 1.4;
  display: -webkit-box; -webkit-line-clamp: 2;
  -webkit-box-orient: vertical; overflow: hidden;
  margin-bottom: 8px;
}
.history-footer {
  display: flex; justify-content: space-between; align-items: center;
}
.history-time {
  color: var(--text-muted); font-size: 0.72rem;
}
.history-duration {
  color: var(--text-muted); font-size: 0.72rem;
  background: var(--bg-secondary); padding: 2px 8px;
  border-radius: 100px;
}
.history-status-badge {
  font-size: 0.7rem; font-weight: 600;
  padding: 2px 8px; border-radius: 100px;
}
.history-status-badge.success { background: rgba(16,185,129,0.1); color: var(--success); }
.history-status-badge.failed { background: rgba(239,68,68,0.1); color: var(--error); }

.history-card-actions {
  display: flex; gap: 6px; padding: 0 14px 14px;
}
.history-card-actions .action-btn {
  flex: 1; font-size: 0.75rem; padding: 6px 10px;
  justify-content: center;
}

.history-empty {
  text-align: center; color: var(--text-muted);
  display: flex; flex-direction: column; align-items: center; gap: 12px;
  padding: 60px 0;
}
.history-empty svg { opacity: 0.2; }

/* ===== Settings ===== */
.settings-form {
  max-width: 560px;
}
.setting-group { margin-bottom: 24px; }
.setting-label {
  display: block; font-size: 0.85rem; font-weight: 600;
  margin-bottom: 8px;
}
.setting-input-wrap {
  position: relative; display: flex; align-items: center;
}
.setting-input {
  width: 100%; padding: 12px 14px;
  background: var(--bg-input); border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  color: var(--text-primary); font-family: var(--font);
  font-size: 0.9rem; transition: var(--transition);
}
.setting-input:focus {
  outline: none; border-color: var(--text-primary);
  box-shadow: 0 0 0 3px var(--accent-glow);
}
.setting-input::placeholder { color: var(--text-muted); }
.setting-toggle-vis {
  position: absolute; right: 10px;
  background: transparent; border: none;
  color: var(--text-muted); cursor: pointer;
  padding: 4px; transition: var(--transition);
}
.setting-toggle-vis:hover { color: var(--text-primary); }
.setting-hint {
  margin-top: 6px; font-size: 0.78rem; color: var(--text-muted);
}
.settings-save { max-width: 200px; }

/* ===== Lightbox ===== */
.lightbox {
  position: fixed; inset: 0; z-index: 1000;
  background: rgba(0, 0, 0, 0.95);
  display: none; align-items: center; justify-content: center;
  padding: 40px;
  opacity: 0;
  transition: opacity 0.3s ease;
}
.lightbox.active {
  display: flex; opacity: 1;
}
.lightbox-close {
  position: absolute; top: 20px; right: 20px;
  background: rgba(255,255,255,0.1); border: none;
  border-radius: 50%; width: 44px; height: 44px;
  display: flex; align-items: center; justify-content: center;
  color: #fff; cursor: pointer; transition: var(--transition);
}
.lightbox-close:hover { background: rgba(255,255,255,0.2); }
.lightbox img {
  max-width: 90vw; max-height: 90vh;
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-lg);
}

/* ===== Toast ===== */
.toast-container {
  position: fixed; bottom: 24px; right: 24px;
  z-index: 2000; display: flex; flex-direction: column; gap: 8px;
}
.toast {
  padding: 12px 20px;
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  color: var(--text-primary);
  font-size: 0.85rem;
  box-shadow: var(--shadow-lg);
  animation: toastIn 0.3s ease, toastOut 0.3s ease 2.7s forwards;
  display: flex; align-items: center; gap: 8px;
}
.toast.success { border-left: 3px solid var(--success); }
.toast.error { border-left: 3px solid var(--error); }
.toast.info { border-left: 3px solid var(--text-primary); }

@keyframes toastIn {
  from { opacity: 0; transform: translateY(20px) scale(0.95); }
  to { opacity: 1; transform: translateY(0) scale(1); }
}
@keyframes toastOut {
  to { opacity: 0; transform: translateY(-10px) scale(0.95); }
}

/* ===== Responsive ===== */
@media (max-width: 900px) {
  .navbar { padding: 0 16px; }
  .nav-title { display: none; }
  .main-content { padding: 20px 16px 48px; }
  .generate-layout {
    grid-template-columns: 1fr;
  }
  .workflow-grid {
    grid-template-columns: repeat(auto-fill, minmax(220px, 1fr));
  }
}
@media (max-width: 600px) {
  .nav-tab span { display: none; }
  .nav-tab { padding: 8px 12px; }
  .workflow-grid {
    grid-template-columns: 1fr;
  }
  .history-grid {
    grid-template-columns: 1fr;
  }
  .theme-toggle { width: 36px; height: 36px; }
}