/* ============================================
   FLUX — Developer Toolkit
   Design System & Styles
   ============================================ */

/* --- Google Font --- */
@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700&family=JetBrains+Mono:wght@400;500&display=swap');

/* --- Design Tokens --- */
:root {
  /* Colors */
  --bg-primary: #06060b;
  --bg-secondary: #0c0c14;
  --bg-surface: rgba(15, 15, 25, 0.7);
  --bg-surface-hover: rgba(25, 25, 40, 0.8);
  --bg-elevated: rgba(20, 20, 35, 0.85);
  --bg-input: rgba(10, 10, 20, 0.6);

  --border-subtle: rgba(255, 255, 255, 0.06);
  --border-default: rgba(255, 255, 255, 0.1);
  --border-hover: rgba(255, 255, 255, 0.15);
  --border-focus: rgba(99, 102, 241, 0.5);

  --text-primary: #f1f5f9;
  --text-secondary: #94a3b8;
  --text-muted: #64748b;
  --text-accent: #a5b4fc;

  --accent-primary: #6366f1;
  --accent-primary-hover: #818cf8;
  --accent-secondary: #8b5cf6;
  --accent-glow: rgba(99, 102, 241, 0.15);
  --accent-gradient: linear-gradient(135deg, #6366f1, #8b5cf6, #a78bfa);

  --success: #22c55e;
  --success-bg: rgba(34, 197, 94, 0.1);
  --error: #ef4444;
  --error-bg: rgba(239, 68, 68, 0.1);
  --warning: #f59e0b;
  --warning-bg: rgba(245, 158, 11, 0.1);
  --info: #06b6d4;
  --info-bg: rgba(6, 182, 212, 0.1);

  /* Typography */
  --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, system-ui, sans-serif;
  --font-mono: 'JetBrains Mono', 'Fira Code', 'Cascadia Code', monospace;

  /* Spacing */
  --sidebar-width: 260px;
  --header-height: 60px;

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

  /* Shadows */
  --shadow-sm: 0 1px 3px rgba(0,0,0,0.3);
  --shadow-md: 0 4px 16px rgba(0,0,0,0.4);
  --shadow-lg: 0 8px 32px rgba(0,0,0,0.5);
  --shadow-glow: 0 0 20px rgba(99, 102, 241, 0.15);

  /* Transitions */
  --transition-fast: 150ms cubic-bezier(0.4, 0, 0.2, 1);
  --transition-base: 250ms cubic-bezier(0.4, 0, 0.2, 1);
  --transition-slow: 400ms cubic-bezier(0.4, 0, 0.2, 1);
}

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

html {
  font-size: 15px;
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-sans);
  background: var(--bg-primary);
  color: var(--text-primary);
  min-height: 100vh;
  overflow: hidden;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

/* Animated gradient background */
body::before {
  content: '';
  position: fixed;
  top: -50%;
  left: -50%;
  width: 200%;
  height: 200%;
  background: 
    radial-gradient(ellipse at 20% 50%, rgba(99, 102, 241, 0.08) 0%, transparent 50%),
    radial-gradient(ellipse at 80% 20%, rgba(139, 92, 246, 0.06) 0%, transparent 50%),
    radial-gradient(ellipse at 50% 80%, rgba(6, 182, 212, 0.04) 0%, transparent 50%);
  animation: bgShift 20s ease-in-out infinite alternate;
  z-index: 0;
  pointer-events: none;
}

@keyframes bgShift {
  0% { transform: translate(0, 0) rotate(0deg); }
  100% { transform: translate(-5%, -5%) rotate(3deg); }
}

/* --- Scrollbar --- */
::-webkit-scrollbar { width: 6px; height: 6px; }
::-webkit-scrollbar-track { background: transparent; }
::-webkit-scrollbar-thumb {
  background: rgba(255, 255, 255, 0.1);
  border-radius: 3px;
}
::-webkit-scrollbar-thumb:hover { background: rgba(255, 255, 255, 0.2); }

/* --- App Layout --- */
#app {
  display: grid;
  grid-template-columns: var(--sidebar-width) 1fr;
  grid-template-rows: var(--header-height) 1fr;
  grid-template-areas:
    "header header"
    "sidebar main";
  height: 100vh;
  position: relative;
  z-index: 1;
}

/* --- Header --- */
.header {
  grid-area: header;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 24px;
  background: var(--bg-surface);
  backdrop-filter: blur(20px) saturate(1.5);
  border-bottom: 1px solid var(--border-subtle);
  z-index: 100;
}

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

.header-logo-icon {
  width: 32px;
  height: 32px;
  background: var(--accent-gradient);
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  font-size: 14px;
  color: white;
  box-shadow: var(--shadow-glow);
}

.header-logo h1 {
  font-size: 1.2rem;
  font-weight: 700;
  background: var(--accent-gradient);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  letter-spacing: -0.02em;
}

.header-logo span {
  font-size: 0.75rem;
  color: var(--text-muted);
  font-weight: 400;
  margin-left: 4px;
}

.header-search {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 8px 14px;
  background: var(--bg-input);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: all var(--transition-fast);
  min-width: 240px;
}

.header-search:hover {
  border-color: var(--border-hover);
  background: var(--bg-surface-hover);
}

.header-search svg {
  width: 16px;
  height: 16px;
  color: var(--text-muted);
  flex-shrink: 0;
}

.header-search span {
  color: var(--text-muted);
  font-size: 0.85rem;
  flex: 1;
}

.header-search kbd {
  font-family: var(--font-sans);
  font-size: 0.7rem;
  padding: 2px 6px;
  background: rgba(255,255,255,0.06);
  border: 1px solid var(--border-subtle);
  border-radius: 4px;
  color: var(--text-muted);
}

.header-meta {
  display: flex;
  align-items: center;
  gap: 6px;
  color: var(--text-muted);
  font-size: 0.78rem;
}

.header-meta .dot {
  width: 6px;
  height: 6px;
  background: var(--success);
  border-radius: 50%;
  animation: pulse 2s ease-in-out infinite;
}

@keyframes pulse {
  0%, 100% { opacity: 1; }
  50% { opacity: 0.4; }
}

/* --- Sidebar --- */
.sidebar {
  grid-area: sidebar;
  background: var(--bg-surface);
  backdrop-filter: blur(20px);
  border-right: 1px solid var(--border-subtle);
  overflow-y: auto;
  padding: 16px 0;
}

.sidebar-category {
  padding: 0 12px;
  margin-bottom: 8px;
}

.sidebar-category-label {
  font-size: 0.68rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--text-muted);
  padding: 8px 12px 6px;
}

.sidebar-item {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 9px 12px;
  margin: 1px 0;
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: all var(--transition-fast);
  color: var(--text-secondary);
  font-size: 0.88rem;
  font-weight: 400;
  position: relative;
  user-select: none;
}

.sidebar-item:hover {
  background: var(--bg-surface-hover);
  color: var(--text-primary);
}

.sidebar-item.active {
  background: var(--accent-glow);
  color: var(--text-accent);
  font-weight: 500;
}

.sidebar-item.active::before {
  content: '';
  position: absolute;
  left: 0;
  top: 50%;
  transform: translateY(-50%);
  width: 3px;
  height: 20px;
  background: var(--accent-gradient);
  border-radius: 0 3px 3px 0;
}

.sidebar-item-icon {
  width: 28px;
  height: 28px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: var(--radius-sm);
  background: rgba(255, 255, 255, 0.04);
  font-size: 0.82rem;
  flex-shrink: 0;
  transition: all var(--transition-fast);
}

.sidebar-item:hover .sidebar-item-icon,
.sidebar-item.active .sidebar-item-icon {
  background: rgba(99, 102, 241, 0.12);
}

/* --- Main Content --- */
.main {
  grid-area: main;
  overflow-y: auto;
  padding: 28px 32px;
}

.tool-container {
  max-width: 960px;
  margin: 0 auto;
  animation: fadeIn 0.3s ease;
}

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

.tool-header {
  margin-bottom: 24px;
}

.tool-header h2 {
  font-size: 1.5rem;
  font-weight: 700;
  letter-spacing: -0.02em;
  margin-bottom: 6px;
}

.tool-header p {
  color: var(--text-secondary);
  font-size: 0.9rem;
  line-height: 1.5;
}

/* --- Tool Panels --- */
.tool-panel {
  background: var(--bg-elevated);
  backdrop-filter: blur(16px);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg);
  padding: 20px;
  margin-bottom: 16px;
  transition: border-color var(--transition-fast);
}

.tool-panel:hover {
  border-color: var(--border-default);
}

.tool-panel-label {
  font-size: 0.78rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--text-muted);
  margin-bottom: 10px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.tool-columns {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
}

.tool-row {
  display: flex;
  gap: 12px;
  align-items: center;
  flex-wrap: wrap;
}

/* --- Form Controls --- */
textarea,
input[type="text"],
input[type="number"] {
  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-mono);
  font-size: 0.85rem;
  line-height: 1.6;
  resize: vertical;
  transition: all var(--transition-fast);
  outline: none;
}

textarea:focus,
input[type="text"]:focus,
input[type="number"]:focus {
  border-color: var(--border-focus);
  box-shadow: 0 0 0 3px var(--accent-glow);
}

textarea::placeholder,
input::placeholder {
  color: var(--text-muted);
}

textarea {
  min-height: 160px;
}

textarea.tall {
  min-height: 260px;
}

select {
  padding: 8px 12px;
  background: var(--bg-input);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-sm);
  color: var(--text-primary);
  font-family: var(--font-sans);
  font-size: 0.85rem;
  outline: none;
  cursor: pointer;
  transition: all var(--transition-fast);
  appearance: none;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' viewBox='0 0 24 24' fill='none' stroke='%2364748b' stroke-width='2'%3E%3Cpath d='M6 9l6 6 6-6'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 10px center;
  padding-right: 30px;
}

select:focus {
  border-color: var(--border-focus);
  box-shadow: 0 0 0 3px var(--accent-glow);
}

label {
  font-size: 0.82rem;
  color: var(--text-secondary);
  font-weight: 500;
}

/* --- Buttons --- */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 9px 16px;
  border-radius: var(--radius-sm);
  font-family: var(--font-sans);
  font-size: 0.85rem;
  font-weight: 500;
  border: none;
  cursor: pointer;
  transition: all var(--transition-fast);
  white-space: nowrap;
  user-select: none;
}

.btn-primary {
  background: var(--accent-gradient);
  color: white;
  box-shadow: var(--shadow-sm), 0 0 12px rgba(99, 102, 241, 0.2);
}

.btn-primary:hover {
  transform: translateY(-1px);
  box-shadow: var(--shadow-md), 0 0 20px rgba(99, 102, 241, 0.3);
}

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

.btn-secondary {
  background: rgba(255, 255, 255, 0.06);
  color: var(--text-secondary);
  border: 1px solid var(--border-subtle);
}

.btn-secondary:hover {
  background: rgba(255, 255, 255, 0.1);
  color: var(--text-primary);
  border-color: var(--border-default);
}

.btn-sm {
  padding: 6px 10px;
  font-size: 0.78rem;
}

.btn-icon {
  padding: 8px;
  border-radius: var(--radius-sm);
  background: rgba(255, 255, 255, 0.04);
  border: 1px solid var(--border-subtle);
  color: var(--text-muted);
  cursor: pointer;
  transition: all var(--transition-fast);
  display: inline-flex;
  align-items: center;
  justify-content: center;
}

.btn-icon:hover {
  background: rgba(255, 255, 255, 0.08);
  color: var(--text-primary);
  border-color: var(--border-default);
}

.btn-group {
  display: flex;
  gap: 6px;
  flex-wrap: wrap;
}

/* --- Chip/Tag Buttons --- */
.chip {
  padding: 6px 14px;
  border-radius: 50px;
  font-size: 0.8rem;
  font-weight: 500;
  background: rgba(255, 255, 255, 0.04);
  border: 1px solid var(--border-subtle);
  color: var(--text-secondary);
  cursor: pointer;
  transition: all var(--transition-fast);
}

.chip:hover,
.chip.active {
  background: var(--accent-glow);
  border-color: rgba(99, 102, 241, 0.3);
  color: var(--text-accent);
}

/* --- Toggle --- */
.toggle-group {
  display: flex;
  background: var(--bg-input);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-sm);
  overflow: hidden;
}

.toggle-btn {
  padding: 7px 16px;
  font-family: var(--font-sans);
  font-size: 0.82rem;
  font-weight: 500;
  background: transparent;
  border: none;
  color: var(--text-muted);
  cursor: pointer;
  transition: all var(--transition-fast);
}

.toggle-btn.active {
  background: var(--accent-glow);
  color: var(--text-accent);
}

.toggle-btn:hover:not(.active) {
  color: var(--text-secondary);
  background: rgba(255, 255, 255, 0.03);
}

/* --- Output Displays --- */
.output-display {
  background: var(--bg-input);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  padding: 14px;
  font-family: var(--font-mono);
  font-size: 0.85rem;
  line-height: 1.6;
  color: var(--text-primary);
  min-height: 80px;
  white-space: pre-wrap;
  word-break: break-all;
  overflow-x: auto;
  position: relative;
}

.output-display.success { border-color: rgba(34, 197, 94, 0.3); }
.output-display.error { border-color: rgba(239, 68, 68, 0.3); color: var(--error); }

/* --- Result Cards --- */
.result-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
  gap: 12px;
}

.result-card {
  background: var(--bg-input);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  padding: 14px;
  transition: all var(--transition-fast);
  cursor: pointer;
}

.result-card:hover {
  border-color: var(--border-hover);
  transform: translateY(-1px);
}

.result-card-label {
  font-size: 0.72rem;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--text-muted);
  margin-bottom: 4px;
}

.result-card-value {
  font-family: var(--font-mono);
  font-size: 0.9rem;
  font-weight: 500;
  word-break: break-all;
}

/* --- Color Swatch --- */
.color-swatch {
  width: 100%;
  height: 80px;
  border-radius: var(--radius-md);
  border: 1px solid var(--border-subtle);
  transition: all var(--transition-base);
}

.color-row {
  display: flex;
  gap: 12px;
  align-items: flex-start;
}

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

.color-input-group label {
  display: block;
  margin-bottom: 6px;
}

/* --- Diff --- */
.diff-container {
  font-family: var(--font-mono);
  font-size: 0.82rem;
  line-height: 1.7;
  background: var(--bg-input);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  padding: 14px;
  overflow-x: auto;
  min-height: 100px;
}

.diff-line { padding: 1px 0; }
.diff-add { color: var(--success); background: var(--success-bg); padding: 1px 4px; border-radius: 2px; }
.diff-remove { color: var(--error); background: var(--error-bg); padding: 1px 4px; border-radius: 2px; }
.diff-unchanged { color: var(--text-muted); }

/* --- Stats Bar --- */
.stats-bar {
  display: flex;
  gap: 20px;
  padding: 12px 16px;
  background: var(--bg-input);
  border-radius: var(--radius-md);
  border: 1px solid var(--border-subtle);
  flex-wrap: wrap;
}

.stat-item {
  display: flex;
  flex-direction: column;
  gap: 2px;
}

.stat-label {
  font-size: 0.7rem;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--text-muted);
}

.stat-value {
  font-family: var(--font-mono);
  font-size: 1rem;
  font-weight: 600;
  color: var(--text-accent);
}

/* --- Regex Match Highlight --- */
.regex-output mark {
  background: rgba(99, 102, 241, 0.3);
  color: var(--text-primary);
  padding: 1px 3px;
  border-radius: 2px;
  border-bottom: 2px solid var(--accent-primary);
}

/* --- Markdown Preview --- */
.md-preview {
  padding: 20px;
  line-height: 1.75;
}
.md-preview h1 { font-size: 1.6rem; margin: 16px 0 8px; border-bottom: 1px solid var(--border-subtle); padding-bottom: 8px; }
.md-preview h2 { font-size: 1.3rem; margin: 14px 0 6px; }
.md-preview h3 { font-size: 1.1rem; margin: 12px 0 4px; }
.md-preview p { margin: 8px 0; }
.md-preview code {
  background: rgba(99, 102, 241, 0.15);
  padding: 2px 6px;
  border-radius: 4px;
  font-family: var(--font-mono);
  font-size: 0.88em;
}
.md-preview pre {
  background: var(--bg-input);
  padding: 14px;
  border-radius: var(--radius-md);
  overflow-x: auto;
  margin: 10px 0;
}
.md-preview pre code { background: transparent; padding: 0; }
.md-preview ul, .md-preview ol { padding-left: 24px; margin: 8px 0; }
.md-preview blockquote {
  border-left: 3px solid var(--accent-primary);
  padding-left: 14px;
  color: var(--text-secondary);
  margin: 10px 0;
}
.md-preview a { color: var(--text-accent); text-decoration: none; }
.md-preview a:hover { text-decoration: underline; }
.md-preview hr { border: none; border-top: 1px solid var(--border-subtle); margin: 16px 0; }
.md-preview table { border-collapse: collapse; width: 100%; margin: 10px 0; }
.md-preview th, .md-preview td { border: 1px solid var(--border-subtle); padding: 8px 12px; text-align: left; }
.md-preview th { background: var(--bg-surface); font-weight: 600; }

/* --- Command Palette Overlay --- */
.command-palette-overlay {
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.6);
  backdrop-filter: blur(8px);
  z-index: 1000;
  display: flex;
  align-items: flex-start;
  justify-content: center;
  padding-top: 15vh;
  opacity: 0;
  pointer-events: none;
  transition: opacity var(--transition-fast);
}

.command-palette-overlay.open {
  opacity: 1;
  pointer-events: auto;
}

.command-palette {
  width: 520px;
  max-height: 420px;
  background: var(--bg-elevated);
  border: 1px solid var(--border-default);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-lg), 0 0 60px rgba(99, 102, 241, 0.1);
  overflow: hidden;
  transform: scale(0.96) translateY(-10px);
  transition: transform var(--transition-fast);
}

.command-palette-overlay.open .command-palette {
  transform: scale(1) translateY(0);
}

.command-palette-input {
  width: 100%;
  padding: 16px 20px;
  background: transparent;
  border: none;
  border-bottom: 1px solid var(--border-subtle);
  color: var(--text-primary);
  font-family: var(--font-sans);
  font-size: 1rem;
  outline: none;
}

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

.command-palette-results {
  overflow-y: auto;
  max-height: 350px;
  padding: 8px;
}

.command-palette-item {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 10px 14px;
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: all var(--transition-fast);
  color: var(--text-secondary);
}

.command-palette-item:hover,
.command-palette-item.selected {
  background: var(--accent-glow);
  color: var(--text-primary);
}

.command-palette-item-icon {
  width: 28px;
  height: 28px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: var(--radius-sm);
  background: rgba(255, 255, 255, 0.04);
  font-size: 0.82rem;
  flex-shrink: 0;
}

.command-palette-item-name {
  flex: 1;
  font-size: 0.9rem;
}

.command-palette-item-category {
  font-size: 0.72rem;
  color: var(--text-muted);
}

/* --- Toast Notifications --- */
.toast-container {
  position: fixed;
  bottom: 24px;
  right: 24px;
  z-index: 2000;
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.toast {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 12px 18px;
  background: var(--bg-elevated);
  border: 1px solid var(--border-default);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-lg);
  font-size: 0.85rem;
  color: var(--text-primary);
  animation: toastIn 0.3s ease, toastOut 0.3s ease 2.2s forwards;
  backdrop-filter: blur(16px);
  min-width: 220px;
}

.toast-success { border-left: 3px solid var(--success); }
.toast-error { border-left: 3px solid var(--error); }
.toast-info { border-left: 3px solid var(--info); }

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

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

/* --- Checkbox --- */
.checkbox-group {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

.checkbox-label {
  display: flex;
  align-items: center;
  gap: 6px;
  cursor: pointer;
  font-size: 0.85rem;
  color: var(--text-secondary);
  user-select: none;
}

.checkbox-label input[type="checkbox"] {
  appearance: none;
  width: 16px;
  height: 16px;
  border: 1px solid var(--border-default);
  border-radius: 4px;
  background: var(--bg-input);
  cursor: pointer;
  transition: all var(--transition-fast);
  position: relative;
}

.checkbox-label input[type="checkbox"]:checked {
  background: var(--accent-primary);
  border-color: var(--accent-primary);
}

.checkbox-label input[type="checkbox"]:checked::after {
  content: '✓';
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  font-size: 11px;
  color: white;
  font-weight: 700;
}

/* --- Range Slider --- */
input[type="range"] {
  -webkit-appearance: none;
  width: 100%;
  height: 4px;
  background: var(--border-subtle);
  border-radius: 2px;
  outline: none;
}

input[type="range"]::-webkit-slider-thumb {
  -webkit-appearance: none;
  width: 16px;
  height: 16px;
  background: var(--accent-primary);
  border-radius: 50%;
  cursor: pointer;
  box-shadow: 0 0 8px rgba(99, 102, 241, 0.3);
}

/* --- Number Input Inline --- */
.inline-number {
  width: 70px;
  padding: 6px 8px;
  text-align: center;
}

/* --- Generated Items List --- */
.generated-list {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.generated-item {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 10px 14px;
  background: var(--bg-input);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  transition: all var(--transition-fast);
}

.generated-item:hover {
  border-color: var(--border-hover);
}

.generated-item-value {
  flex: 1;
  font-family: var(--font-mono);
  font-size: 0.88rem;
  word-break: break-all;
}

.generated-item .btn-icon {
  flex-shrink: 0;
}

/* --- Header Left --- */
.header-left {
  display: flex;
  align-items: center;
  gap: 12px;
}

/* --- Hamburger Menu --- */
.hamburger {
  display: none;
  flex-direction: column;
  gap: 4px;
  padding: 8px;
  background: transparent;
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: all var(--transition-fast);
}

.hamburger span {
  display: block;
  width: 18px;
  height: 2px;
  background: var(--text-secondary);
  border-radius: 1px;
  transition: all var(--transition-base);
}

.hamburger:hover {
  border-color: var(--border-hover);
}

.hamburger:hover span {
  background: var(--text-primary);
}

.hamburger.active span:nth-child(1) {
  transform: rotate(45deg) translate(4px, 4px);
}

.hamburger.active span:nth-child(2) {
  opacity: 0;
}

.hamburger.active span:nth-child(3) {
  transform: rotate(-45deg) translate(4px, -4px);
}

/* --- Sidebar Enhancements --- */
.sidebar-item-name {
  flex: 1;
  min-width: 0;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.sidebar-star {
  opacity: 0;
  background: transparent;
  border: none;
  color: var(--text-muted);
  cursor: pointer;
  font-size: 0.9rem;
  padding: 2px 6px;
  border-radius: 4px;
  transition: all var(--transition-fast);
  margin-left: auto;
  flex-shrink: 0;
  line-height: 1;
}

.sidebar-item:hover .sidebar-star,
.sidebar-star.starred {
  opacity: 1;
}

.sidebar-star.starred {
  color: #f59e0b;
}

.sidebar-star:hover {
  color: #f59e0b;
  transform: scale(1.2);
}

/* --- Drop Zone Overlay --- */
.drop-zone-overlay {
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.7);
  backdrop-filter: blur(12px);
  z-index: 3000;
  display: flex;
  align-items: center;
  justify-content: center;
  opacity: 0;
  pointer-events: none;
  transition: opacity var(--transition-base);
}

.drop-zone-overlay.visible {
  opacity: 1;
  pointer-events: auto;
}

.drop-zone-content {
  text-align: center;
  padding: 60px 80px;
  border: 2px dashed var(--accent-primary);
  border-radius: var(--radius-xl);
  background: var(--accent-glow);
  animation: dropPulse 1.5s ease-in-out infinite;
}

@keyframes dropPulse {
  0%, 100% { border-color: var(--accent-primary); box-shadow: 0 0 30px rgba(99, 102, 241, 0.1); }
  50% { border-color: var(--accent-primary-hover); box-shadow: 0 0 60px rgba(99, 102, 241, 0.25); }
}

.drop-zone-icon {
  font-size: 3rem;
  margin-bottom: 16px;
}

.drop-zone-text {
  font-size: 1.3rem;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: 8px;
}

.drop-zone-hint {
  font-size: 0.85rem;
  color: var(--text-muted);
}

/* --- Auto-Detect Toast --- */
.auto-detect-toast {
  display: flex;
  align-items: center;
  gap: 12px;
  border-left: 3px solid var(--info) !important;
  animation: toastIn 0.3s ease, toastOut 0.3s ease 4.7s forwards;
}

.auto-detect-toast .auto-detect-action {
  flex-shrink: 0;
}

/* --- Shortcuts Overlay --- */
.shortcuts-overlay {
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.6);
  backdrop-filter: blur(8px);
  z-index: 1500;
  display: flex;
  align-items: center;
  justify-content: center;
  opacity: 0;
  pointer-events: none;
  transition: opacity var(--transition-fast);
}

.shortcuts-overlay.open {
  opacity: 1;
  pointer-events: auto;
}

.shortcuts-panel {
  background: var(--bg-elevated);
  border: 1px solid var(--border-default);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-lg), 0 0 60px rgba(99, 102, 241, 0.1);
  padding: 28px;
  width: 440px;
  max-width: 90vw;
  transform: scale(0.96) translateY(-10px);
  transition: transform var(--transition-fast);
}

.shortcuts-overlay.open .shortcuts-panel {
  transform: scale(1) translateY(0);
}

.shortcuts-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 24px;
  padding-bottom: 16px;
  border-bottom: 1px solid var(--border-subtle);
}

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

.shortcuts-grid {
  display: flex;
  flex-direction: column;
  gap: 14px;
}

.shortcut-item {
  display: flex;
  align-items: center;
  gap: 6px;
  font-size: 0.88rem;
  color: var(--text-secondary);
}

.shortcut-item span {
  margin-left: auto;
  color: var(--text-muted);
  font-size: 0.82rem;
}

.shortcut-item kbd {
  font-family: var(--font-sans);
  font-size: 0.72rem;
  padding: 3px 8px;
  background: rgba(255,255,255,0.06);
  border: 1px solid var(--border-subtle);
  border-radius: 4px;
  color: var(--text-secondary);
  min-width: 28px;
  text-align: center;
}

/* --- Responsive --- */
@media (max-width: 900px) {
  #app {
    grid-template-columns: 1fr;
    grid-template-areas:
      "header"
      "main";
  }
  .hamburger {
    display: flex;
  }
  .sidebar {
    position: fixed;
    top: var(--header-height);
    left: 0;
    bottom: 0;
    width: var(--sidebar-width);
    z-index: 50;
    transform: translateX(-100%);
    transition: transform var(--transition-base);
    background: var(--bg-secondary);
    backdrop-filter: blur(20px);
  }
  .sidebar.open {
    transform: translateX(0);
    box-shadow: var(--shadow-lg);
  }
  .main {
    padding: 20px 16px;
  }
  .tool-columns {
    grid-template-columns: 1fr;
  }
  .header-meta {
    display: none;
  }
  .header-search span {
    display: none;
  }
  .header-search {
    min-width: unset;
  }
}

/* --- Utility --- */
.flex { display: flex; }
.flex-col { flex-direction: column; }
.items-center { align-items: center; }
.justify-between { justify-content: space-between; }
.gap-8 { gap: 8px; }
.gap-12 { gap: 12px; }
.gap-16 { gap: 16px; }
.gap-20 { gap: 20px; }
.mt-12 { margin-top: 12px; }
.mt-16 { margin-top: 16px; }
.mb-8 { margin-bottom: 8px; }
.mb-12 { margin-bottom: 12px; }
.w-full { width: 100%; }
.text-mono { font-family: var(--font-mono); }
.text-sm { font-size: 0.82rem; }
.text-muted { color: var(--text-muted); }
.text-success { color: var(--success); }
.text-error { color: var(--error); }
.hidden { display: none !important; }