/* ============================================
   Market Gap Analyzer — Design System & Styles
   ============================================ */

/* ----- CSS Custom Properties ----- */
:root {
  /* Colors - Light */
  --color-bg-primary: #ffffff;
  --color-bg-secondary: #f8f9fb;
  --color-bg-tertiary: #f0f2f5;
  --color-bg-sidebar: #fafbfc;
  --color-bg-card: #ffffff;
  --color-bg-hover: #f4f6f8;
  --color-bg-input: #f1f3f6;
  --color-bg-tooltip: #1a1d23;
  --color-bg-modal-overlay: rgba(0,0,0,0.4);

  --color-border-primary: #e5e7eb;
  --color-border-secondary: #f0f1f3;
  --color-border-focus: #6366f1;

  --color-text-primary: #111827;
  --color-text-secondary: #6b7280;
  --color-text-tertiary: #9ca3af;
  --color-text-inverse: #ffffff;
  --color-text-link: #6366f1;

  --color-accent: #6366f1;
  --color-accent-hover: #5558e6;
  --color-accent-light: #eef2ff;
  --color-accent-glow: rgba(99,102,241,0.25);

  --color-success: #10b981;
  --color-success-light: #ecfdf5;
  --color-warning: #f59e0b;
  --color-warning-light: #fffbeb;
  --color-danger: #ef4444;
  --color-danger-light: #fef2f2;
  --color-info: #3b82f6;
  --color-info-light: #eff6ff;

  --color-pink: #ec4899;
  --color-purple: #8b5cf6;
  --color-orange: #f97316;
  --color-teal: #14b8a6;
  --color-cyan: #06b6d4;

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

  --text-xs: 0.75rem;
  --text-sm: 0.8125rem;
  --text-base: 0.9375rem;
  --text-lg: 1.0625rem;
  --text-xl: 1.25rem;
  --text-2xl: 1.5rem;
  --text-3xl: 1.875rem;

  --leading-tight: 1.25;
  --leading-normal: 1.5;
  --leading-relaxed: 1.625;

  --font-weight-normal: 400;
  --font-weight-medium: 500;
  --font-weight-semibold: 600;
  --font-weight-bold: 700;

  /* Spacing */
  --space-1: 0.25rem;
  --space-2: 0.5rem;
  --space-3: 0.75rem;
  --space-4: 1rem;
  --space-5: 1.25rem;
  --space-6: 1.5rem;
  --space-8: 2rem;
  --space-10: 2.5rem;
  --space-12: 3rem;
  --space-16: 4rem;

  /* Sizing */
  --sidebar-width: 260px;
  --sidebar-collapsed: 64px;
  --header-height: 64px;
  --card-radius: 12px;
  --card-radius-sm: 8px;
  --card-radius-lg: 16px;
  --input-radius: 10px;

  /* Shadows */
  --shadow-xs: 0 1px 2px rgba(0,0,0,0.04);
  --shadow-sm: 0 1px 3px rgba(0,0,0,0.06), 0 1px 2px rgba(0,0,0,0.04);
  --shadow-md: 0 4px 6px -1px rgba(0,0,0,0.07), 0 2px 4px -2px rgba(0,0,0,0.05);
  --shadow-lg: 0 10px 15px -3px rgba(0,0,0,0.08), 0 4px 6px -4px rgba(0,0,0,0.04);
  --shadow-xl: 0 20px 25px -5px rgba(0,0,0,0.1), 0 8px 10px -6px rgba(0,0,0,0.04);
  --shadow-card: 0 1px 3px rgba(0,0,0,0.06), 0 4px 12px rgba(0,0,0,0.04);

  /* Transitions */
  --transition-fast: 150ms cubic-bezier(0.4,0,0.2,1);
  --transition-base: 200ms cubic-bezier(0.4,0,0.2,1);
  --transition-slow: 300ms cubic-bezier(0.4,0,0.2,1);
  --transition-spring: 400ms cubic-bezier(0.34,1.56,0.64,1);

  /* Z-index layers */
  --z-sidebar: 100;
  --z-header: 90;
  --z-overlay: 200;
  --z-modal: 300;
  --z-toast: 400;
}

/* ----- Dark Mode ----- */
[data-theme="dark"] {
  --color-bg-primary: #0f1117;
  --color-bg-secondary: #161820;
  --color-bg-tertiary: #1c1f28;
  --color-bg-sidebar: #13151c;
  --color-bg-card: #1a1d27;
  --color-bg-hover: #212430;
  --color-bg-input: #1e2130;
  --color-bg-tooltip: #e5e7eb;
  --color-bg-modal-overlay: rgba(0,0,0,0.6);

  --color-border-primary: #2a2d3a;
  --color-border-secondary: #222530;
  --color-border-focus: #818cf8;

  --color-text-primary: #e9eaec;
  --color-text-secondary: #9ca3af;
  --color-text-tertiary: #6b7280;
  --color-text-inverse: #111827;
  --color-text-link: #818cf8;

  --color-accent: #818cf8;
  --color-accent-hover: #6366f1;
  --color-accent-light: #1e2040;
  --color-accent-glow: rgba(129,140,248,0.2);

  --color-success: #34d399;
  --color-success-light: #0f2f24;
  --color-warning: #fbbf24;
  --color-warning-light: #2f250c;
  --color-danger: #f87171;
  --color-danger-light: #2f1515;
  --color-info: #60a5fa;
  --color-info-light: #0f2035;

  --shadow-xs: 0 1px 2px rgba(0,0,0,0.2);
  --shadow-sm: 0 1px 3px rgba(0,0,0,0.3), 0 1px 2px rgba(0,0,0,0.2);
  --shadow-md: 0 4px 6px -1px rgba(0,0,0,0.4), 0 2px 4px -2px rgba(0,0,0,0.3);
  --shadow-lg: 0 10px 15px -3px rgba(0,0,0,0.5), 0 4px 6px -4px rgba(0,0,0,0.3);
  --shadow-xl: 0 20px 25px -5px rgba(0,0,0,0.6), 0 8px 10px -6px rgba(0,0,0,0.3);
  --shadow-card: 0 1px 3px rgba(0,0,0,0.4), 0 4px 12px rgba(0,0,0,0.2);
}

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

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

body {
  font-family: var(--font-sans);
  font-size: var(--text-base);
  line-height: var(--leading-normal);
  color: var(--color-text-primary);
  background: var(--color-bg-primary);
  overflow: hidden;
  height: 100vh;
  transition: background var(--transition-base), color var(--transition-base);
}

a { color: var(--color-text-link); text-decoration: none; }
a:hover { text-decoration: underline; }
button { cursor: pointer; font-family: inherit; }
input, textarea, select { font-family: inherit; }

/* Scrollbar */
::-webkit-scrollbar { width: 6px; height: 6px; }
::-webkit-scrollbar-track { background: transparent; }
::-webkit-scrollbar-thumb { background: var(--color-border-primary); border-radius: 3px; }
::-webkit-scrollbar-thumb:hover { background: var(--color-text-tertiary); }

/* ============================================
   Layout
   ============================================ */
.app-container {
  display: flex;
  height: 100vh;
  overflow: hidden;
}

/* ----- Sidebar ----- */
.sidebar {
  width: var(--sidebar-width);
  min-width: var(--sidebar-width);
  height: 100vh;
  background: var(--color-bg-sidebar);
  border-right: 1px solid var(--color-border-primary);
  display: flex;
  flex-direction: column;
  transition: width var(--transition-base), min-width var(--transition-base), transform var(--transition-base);
  z-index: var(--z-sidebar);
  overflow: hidden;
}

.sidebar.collapsed {
  width: var(--sidebar-collapsed);
  min-width: var(--sidebar-collapsed);
}

.sidebar-header {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  padding: var(--space-5) var(--space-4);
  height: var(--header-height);
  border-bottom: 1px solid var(--color-border-secondary);
}

.sidebar-logo {
  width: 32px;
  height: 32px;
  background: linear-gradient(135deg, var(--color-accent), var(--color-purple));
  border-radius: 8px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1rem;
  flex-shrink: 0;
}

.sidebar-brand {
  font-size: var(--text-base);
  font-weight: var(--font-weight-bold);
  color: var(--color-text-primary);
  white-space: nowrap;
  overflow: hidden;
}

.sidebar-nav {
  flex: 1;
  overflow-y: auto;
  padding: var(--space-3);
  display: flex;
  flex-direction: column;
  gap: var(--space-1);
}

.nav-section-label {
  font-size: var(--text-xs);
  font-weight: var(--font-weight-semibold);
  color: var(--color-text-tertiary);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  padding: var(--space-3) var(--space-3) var(--space-2);
  white-space: nowrap;
  overflow: hidden;
}

.nav-item {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  padding: var(--space-2) var(--space-3);
  border-radius: var(--card-radius-sm);
  color: var(--color-text-secondary);
  font-size: var(--text-sm);
  font-weight: var(--font-weight-medium);
  border: none;
  background: transparent;
  width: 100%;
  text-align: left;
  transition: all var(--transition-fast);
  white-space: nowrap;
  overflow: hidden;
  cursor: pointer;
}

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

.nav-item.active {
  background: var(--color-accent-light);
  color: var(--color-accent);
  font-weight: var(--font-weight-semibold);
}

.nav-item .nav-icon {
  width: 20px;
  height: 20px;
  flex-shrink: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.1rem;
}

.nav-badge {
  margin-left: auto;
  background: var(--color-accent);
  color: var(--color-text-inverse);
  font-size: 0.625rem;
  font-weight: var(--font-weight-semibold);
  padding: 1px 6px;
  border-radius: 999px;
}

.sidebar-footer {
  padding: var(--space-3);
  border-top: 1px solid var(--color-border-secondary);
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
}

/* ----- Main Content ----- */
.main-content {
  flex: 1;
  display: flex;
  flex-direction: column;
  overflow: hidden;
  min-width: 0;
}

/* ----- Header ----- */
.header {
  height: var(--header-height);
  display: flex;
  align-items: center;
  gap: var(--space-4);
  padding: 0 var(--space-6);
  border-bottom: 1px solid var(--color-border-primary);
  background: var(--color-bg-primary);
  z-index: var(--z-header);
  flex-shrink: 0;
}

.header-toggle {
  width: 36px;
  height: 36px;
  border-radius: var(--card-radius-sm);
  border: 1px solid var(--color-border-primary);
  background: var(--color-bg-secondary);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--color-text-secondary);
  transition: all var(--transition-fast);
  flex-shrink: 0;
}

.header-toggle:hover {
  background: var(--color-bg-hover);
  color: var(--color-text-primary);
}

/* ----- Search Bar ----- */
.search-container {
  flex: 1;
  max-width: 740px;
  display: flex;
  align-items: center;
  gap: var(--space-3);
  position: relative;
}

.input-type-wrapper {
  position: relative;
  flex-shrink: 0;
}

.search-wrapper {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  background: var(--color-bg-input);
  border: 1px solid var(--color-border-primary);
  border-radius: var(--input-radius);
  padding: var(--space-2) var(--space-4);
  transition: all var(--transition-fast);
}

.search-wrapper:focus-within {
  border-color: var(--color-border-focus);
  box-shadow: 0 0 0 3px var(--color-accent-glow);
  background: var(--color-bg-primary);
}

.search-icon {
  color: var(--color-text-tertiary);
  flex-shrink: 0;
  font-size: 1rem;
}

.search-input {
  flex: 1;
  border: none;
  background: transparent;
  font-size: var(--text-sm);
  color: var(--color-text-primary);
  outline: none;
  min-width: 0;
}

.search-input::placeholder {
  color: var(--color-text-tertiary);
}

.search-shortcut {
  font-size: var(--text-xs);
  color: var(--color-text-tertiary);
  background: var(--color-bg-secondary);
  padding: 2px 6px;
  border-radius: 4px;
  border: 1px solid var(--color-border-primary);
  font-family: var(--font-mono);
  flex-shrink: 0;
}

/* Input type selector */
.input-type-selector {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  padding: var(--space-2) var(--space-3);
  background: var(--color-bg-secondary);
  border: 1px solid var(--color-border-primary);
  border-radius: var(--input-radius);
  font-size: var(--text-sm);
  color: var(--color-text-secondary);
  cursor: pointer;
  transition: all var(--transition-fast);
  white-space: nowrap;
}

.input-type-selector:hover {
  background: var(--color-bg-hover);
}

/* Header actions */
.header-actions {
  display: flex;
  align-items: center;
  gap: var(--space-2);
}

.header-btn {
  width: 36px;
  height: 36px;
  border-radius: var(--card-radius-sm);
  border: 1px solid var(--color-border-primary);
  background: var(--color-bg-secondary);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--color-text-secondary);
  transition: all var(--transition-fast);
  position: relative;
}

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

.header-btn .pulse {
  position: absolute;
  top: 6px;
  right: 6px;
  width: 7px;
  height: 7px;
  background: var(--color-danger);
  border-radius: 50%;
  border: 1.5px solid var(--color-bg-primary);
}

/* ----- Dashboard ----- */
.dashboard {
  flex: 1;
  overflow-y: auto;
  overflow-x: hidden;
  padding: var(--space-6);
  display: flex;
  flex-direction: column;
  gap: var(--space-6);
}

/* Section Header */
.section-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: var(--space-4);
}

.section-title {
  font-size: var(--text-lg);
  font-weight: var(--font-weight-semibold);
  color: var(--color-text-primary);
  display: flex;
  align-items: center;
  gap: var(--space-2);
}

.section-title .icon {
  font-size: 1.1rem;
}

.section-actions {
  display: flex;
  align-items: center;
  gap: var(--space-2);
}

.section-count {
  font-size: var(--text-sm);
  color: var(--color-text-tertiary);
  background: var(--color-bg-secondary);
  padding: 2px 8px;
  border-radius: 999px;
  border: 1px solid var(--color-border-primary);
}

/* ============================================
   Cards
   ============================================ */

/* Card Grid */
.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
  gap: var(--space-4);
}

.card-grid.compact {
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: var(--space-3);
}

/* Individual Card */
.card {
  background: var(--color-bg-card);
  border: 1px solid var(--color-border-primary);
  border-radius: var(--card-radius);
  padding: var(--space-5);
  transition: all var(--transition-base);
  cursor: pointer;
  position: relative;
  overflow: hidden;
  display: flex;
  flex-direction: column;
  gap: var(--space-4);
}

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

.card:active {
  transform: translateY(0);
}

.card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: linear-gradient(90deg, var(--color-accent), var(--color-purple));
  opacity: 0;
  transition: opacity var(--transition-base);
}

.card:hover::before {
  opacity: 1;
}

/* Card header */
.card-header {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: var(--space-3);
}

.card-icon {
  width: 40px;
  height: 40px;
  border-radius: var(--card-radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.2rem;
  flex-shrink: 0;
}

.card-icon.gap { background: var(--color-warning-light); }
.card-icon.tool { background: var(--color-accent-light); }
.card-icon.insight { background: var(--color-info-light); }
.card-icon.money { background: var(--color-success-light); }
.card-icon.weakness { background: var(--color-danger-light); }
.card-icon.app { background: linear-gradient(135deg, var(--color-accent-light), #fdf2f8); }

.card-tags {
  display: flex;
  gap: var(--space-1);
  flex-wrap: wrap;
  justify-content: flex-end;
}

.tag {
  font-size: var(--text-xs);
  font-weight: var(--font-weight-medium);
  padding: 2px 8px;
  border-radius: 999px;
  background: var(--color-bg-secondary);
  color: var(--color-text-secondary);
  border: 1px solid var(--color-border-primary);
  white-space: nowrap;
}

.tag.opportunity { background: var(--color-success-light); color: var(--color-success); border-color: transparent; }
.tag.gap { background: var(--color-warning-light); color: var(--color-warning); border-color: transparent; }
.tag.weakness { background: var(--color-danger-light); color: var(--color-danger); border-color: transparent; }
.tag.insight { background: var(--color-info-light); color: var(--color-info); border-color: transparent; }

/* Card body */
.card-title {
  font-size: var(--text-base);
  font-weight: var(--font-weight-semibold);
  color: var(--color-text-primary);
  line-height: var(--leading-tight);
}

.card-pitch {
  font-size: var(--text-sm);
  color: var(--color-text-secondary);
  line-height: var(--leading-relaxed);
}

/* Card meta */
.card-meta {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  flex-wrap: wrap;
}

.meta-item {
  display: flex;
  align-items: center;
  gap: var(--space-1);
  font-size: var(--text-xs);
  color: var(--color-text-tertiary);
}

.meta-dot {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--color-text-tertiary);
}

.meta-dot.easy { background: var(--color-success); }
.meta-dot.medium { background: var(--color-warning); }
.meta-dot.hard { background: var(--color-danger); }

/* Card footer */
.card-footer {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  padding-top: var(--space-2);
  border-top: 1px solid var(--color-border-secondary);
}

.card-footer .btn {
  font-size: var(--text-xs);
  padding: var(--space-1) var(--space-3);
  border-radius: 6px;
  font-weight: var(--font-weight-medium);
  border: 1px solid var(--color-border-primary);
  background: var(--color-bg-secondary);
  color: var(--color-text-secondary);
  transition: all var(--transition-fast);
  white-space: nowrap;
}

.card-footer .btn:hover {
  background: var(--color-accent);
  color: var(--color-text-inverse);
  border-color: var(--color-accent);
}

.card-footer .btn.primary {
  background: var(--color-accent);
  color: var(--color-text-inverse);
  border-color: var(--color-accent);
}

.card-footer .btn.primary:hover {
  background: var(--color-accent-hover);
}

/* ============================================
   Detail Modal
   ============================================ */
.modal-overlay {
  position: fixed;
  inset: 0;
  background: var(--color-bg-modal-overlay);
  z-index: var(--z-overlay);
  display: flex;
  align-items: center;
  justify-content: center;
  opacity: 0;
  pointer-events: none;
  transition: opacity var(--transition-base);
  backdrop-filter: blur(4px);
}

.modal-overlay.visible {
  opacity: 1;
  pointer-events: all;
}

.modal {
  background: var(--color-bg-card);
  border: 1px solid var(--color-border-primary);
  border-radius: var(--card-radius-lg);
  width: 90%;
  max-width: 640px;
  max-height: 85vh;
  overflow-y: auto;
  padding: var(--space-8);
  box-shadow: var(--shadow-xl);
  transform: translateY(16px) scale(0.97);
  transition: transform var(--transition-spring);
}

.modal-overlay.visible .modal {
  transform: translateY(0) scale(1);
}

.modal-header {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  margin-bottom: var(--space-6);
}

.modal-title {
  font-size: var(--text-xl);
  font-weight: var(--font-weight-bold);
  color: var(--color-text-primary);
}

.modal-close {
  width: 32px;
  height: 32px;
  border-radius: var(--card-radius-sm);
  border: 1px solid var(--color-border-primary);
  background: var(--color-bg-secondary);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--color-text-secondary);
  transition: all var(--transition-fast);
}

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

.modal-section {
  margin-bottom: var(--space-5);
}

.modal-section-title {
  font-size: var(--text-sm);
  font-weight: var(--font-weight-semibold);
  color: var(--color-text-secondary);
  text-transform: uppercase;
  letter-spacing: 0.04em;
  margin-bottom: var(--space-2);
}

.modal-features {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-2);
}

.modal-feature {
  font-size: var(--text-sm);
  padding: var(--space-1) var(--space-3);
  background: var(--color-accent-light);
  color: var(--color-accent);
  border-radius: 6px;
  font-weight: var(--font-weight-medium);
}

.modal-stack {
  display: flex;
  gap: var(--space-2);
  flex-wrap: wrap;
}

.stack-badge {
  font-size: var(--text-xs);
  font-weight: var(--font-weight-medium);
  padding: var(--space-1) var(--space-3);
  border-radius: 6px;
  background: var(--color-bg-tertiary);
  color: var(--color-text-secondary);
  font-family: var(--font-mono);
}

/* ============================================
   Onboarding / Empty States
   ============================================ */
.empty-state {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  text-align: center;
  padding: var(--space-16) var(--space-6);
  gap: var(--space-4);
}

.empty-icon {
  font-size: 4rem;
  margin-bottom: var(--space-2);
  animation: float 3s ease-in-out infinite;
}

@keyframes float {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-8px); }
}

.empty-title {
  font-size: var(--text-2xl);
  font-weight: var(--font-weight-bold);
  color: var(--color-text-primary);
}

.empty-text {
  font-size: var(--text-base);
  color: var(--color-text-secondary);
  max-width: 480px;
  line-height: var(--leading-relaxed);
}

.empty-examples {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-2);
  justify-content: center;
  margin-top: var(--space-4);
}

.example-chip {
  font-size: var(--text-sm);
  padding: var(--space-2) var(--space-4);
  background: var(--color-bg-secondary);
  border: 1px solid var(--color-border-primary);
  border-radius: 999px;
  color: var(--color-text-secondary);
  cursor: pointer;
  transition: all var(--transition-fast);
}

.example-chip:hover {
  background: var(--color-accent-light);
  color: var(--color-accent);
  border-color: var(--color-accent);
}

/* ----- Onboarding Tips Banner ----- */
.onboarding-tips {
  background: linear-gradient(135deg, var(--color-accent-light), rgba(139,92,246,0.08));
  border: 1px solid var(--color-accent);
  border-radius: var(--card-radius);
  padding: var(--space-5) var(--space-6);
  display: flex;
  align-items: center;
  gap: var(--space-4);
  margin-bottom: var(--space-4);
}

.onboarding-tips .tip-icon {
  font-size: 2rem;
  flex-shrink: 0;
}

.onboarding-tips .tip-content {
  flex: 1;
}

.onboarding-tips .tip-title {
  font-weight: var(--font-weight-semibold);
  color: var(--color-text-primary);
  margin-bottom: var(--space-1);
}

.onboarding-tips .tip-text {
  font-size: var(--text-sm);
  color: var(--color-text-secondary);
}

.onboarding-tips .tip-close {
  width: 28px;
  height: 28px;
  border-radius: 6px;
  border: none;
  background: transparent;
  color: var(--color-text-tertiary);
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all var(--transition-fast);
}

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

/* ============================================
   Skeleton Loading
   ============================================ */
.skeleton {
  background: linear-gradient(90deg,
    var(--color-bg-tertiary) 25%,
    var(--color-bg-secondary) 50%,
    var(--color-bg-tertiary) 75%
  );
  background-size: 200% 100%;
  animation: shimmer 1.5s ease-in-out infinite;
  border-radius: var(--card-radius-sm);
}

@keyframes shimmer {
  0% { background-position: 200% 0; }
  100% { background-position: -200% 0; }
}

.skeleton-card {
  background: var(--color-bg-card);
  border: 1px solid var(--color-border-primary);
  border-radius: var(--card-radius);
  padding: var(--space-5);
  display: flex;
  flex-direction: column;
  gap: var(--space-4);
}

.skeleton-line { height: 12px; border-radius: 6px; }
.skeleton-line.short { width: 60%; }
.skeleton-line.medium { width: 80%; }
.skeleton-line.long { width: 100%; }
.skeleton-circle { width: 40px; height: 40px; border-radius: 8px; }

/* ============================================
   Toast Notifications
   ============================================ */
.toast-container {
  position: fixed;
  bottom: var(--space-6);
  right: var(--space-6);
  z-index: var(--z-toast);
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
}

.toast {
  background: var(--color-bg-card);
  border: 1px solid var(--color-border-primary);
  border-radius: var(--card-radius-sm);
  padding: var(--space-3) var(--space-4);
  box-shadow: var(--shadow-lg);
  display: flex;
  align-items: center;
  gap: var(--space-3);
  font-size: var(--text-sm);
  color: var(--color-text-primary);
  animation: slideInRight 0.3s ease-out;
  min-width: 280px;
}

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

.toast.removing {
  animation: slideOutRight 0.2s ease-in forwards;
}

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

.toast-icon { font-size: 1.1rem; flex-shrink: 0; }
.toast-close {
  margin-left: auto;
  background: none;
  border: none;
  color: var(--color-text-tertiary);
  font-size: 1rem;
  cursor: pointer;
  padding: 2px;
}

/* ============================================
   Input Type Dropdown
   ============================================ */
.dropdown {
  position: absolute;
  top: calc(100% + 4px);
  left: 0;
  background: var(--color-bg-card);
  border: 1px solid var(--color-border-primary);
  border-radius: var(--card-radius-sm);
  box-shadow: var(--shadow-lg);
  min-width: 200px;
  z-index: 50;
  overflow: hidden;
  animation: fadeInScale 0.15s ease-out;
}

@keyframes fadeInScale {
  from { opacity: 0; transform: scale(0.95); }
  to { opacity: 1; transform: scale(1); }
}

.dropdown-item {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  padding: var(--space-2) var(--space-4);
  font-size: var(--text-sm);
  color: var(--color-text-secondary);
  cursor: pointer;
  transition: background var(--transition-fast);
  border: none;
  background: none;
  width: 100%;
  text-align: left;
}

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

.dropdown-item .dropdown-icon {
  width: 24px;
  height: 24px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.9rem;
}

/* ============================================
   Buttons
   ============================================ */
.btn {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  padding: var(--space-2) var(--space-4);
  border-radius: var(--card-radius-sm);
  font-size: var(--text-sm);
  font-weight: var(--font-weight-medium);
  border: 1px solid var(--color-border-primary);
  background: var(--color-bg-secondary);
  color: var(--color-text-secondary);
  transition: all var(--transition-fast);
  cursor: pointer;
  white-space: nowrap;
}

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

.btn-primary {
  background: var(--color-accent);
  color: var(--color-text-inverse);
  border-color: var(--color-accent);
}

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

.btn-ghost {
  background: transparent;
  border-color: transparent;
}

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

.btn-sm {
  font-size: var(--text-xs);
  padding: var(--space-1) var(--space-2);
}

.btn-lg {
  font-size: var(--text-base);
  padding: var(--space-3) var(--space-6);
}

/* ============================================
   Export / Import Panel
   ============================================ */
.export-panel {
  position: fixed;
  right: var(--space-6);
  top: calc(var(--header-height) + var(--space-4));
  background: var(--color-bg-card);
  border: 1px solid var(--color-border-primary);
  border-radius: var(--card-radius);
  padding: var(--space-4);
  box-shadow: var(--shadow-lg);
  z-index: 50;
  display: none;
  flex-direction: column;
  gap: var(--space-3);
  min-width: 280px;
  animation: fadeInScale 0.15s ease-out;
}

.export-panel.visible { display: flex; }

.export-panel .panel-title {
  font-size: var(--text-sm);
  font-weight: var(--font-weight-semibold);
  color: var(--color-text-primary);
  margin-bottom: var(--space-1);
}

/* ============================================
   Progress / Complexity Bar
   ============================================ */
.complexity-bar {
  display: flex;
  gap: 2px;
  height: 4px;
  border-radius: 2px;
  overflow: hidden;
  margin-top: var(--space-1);
}

.complexity-segment {
  flex: 1;
  background: var(--color-border-primary);
}

.complexity-segment.filled.easy { background: var(--color-success); }
.complexity-segment.filled.medium { background: var(--color-warning); }
.complexity-segment.filled.hard { background: var(--color-danger); }

/* ============================================
   Stats Row
   ============================================ */
.stats-row {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(160px, 1fr));
  gap: var(--space-4);
}

.stat-card {
  background: var(--color-bg-card);
  border: 1px solid var(--color-border-primary);
  border-radius: var(--card-radius);
  padding: var(--space-4);
  display: flex;
  flex-direction: column;
  gap: var(--space-1);
}

.stat-label {
  font-size: var(--text-xs);
  color: var(--color-text-tertiary);
  font-weight: var(--font-weight-medium);
  text-transform: uppercase;
  letter-spacing: 0.04em;
}

.stat-value {
  font-size: var(--text-2xl);
  font-weight: var(--font-weight-bold);
  color: var(--color-text-primary);
}

/* ============================================
   Responsive
   ============================================ */
@media (max-width: 1024px) {
  .sidebar {
    position: fixed;
    left: 0;
    top: 0;
    transform: translateX(-100%);
    box-shadow: var(--shadow-xl);
  }

  .sidebar.mobile-open {
    transform: translateX(0);
  }

  .sidebar.collapsed { transform: translateX(-100%); }

  .card-grid {
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  }

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

@media (max-width: 768px) {
  .header {
    padding: 0 var(--space-4);
    gap: var(--space-2);
  }

  .dashboard {
    padding: var(--space-4);
    gap: var(--space-4);
  }

  .card-grid {
    grid-template-columns: 1fr;
    gap: var(--space-3);
  }

  .card-grid.compact {
    grid-template-columns: 1fr;
  }

  .stats-row {
    grid-template-columns: 1fr 1fr;
  }

  .input-type-selector span:last-child {
    display: none;
  }

  .search-shortcut { display: none; }

  .onboarding-tips {
    flex-direction: column;
    text-align: center;
    gap: var(--space-2);
    padding: var(--space-4);
  }

  .modal {
    width: 95%;
    padding: var(--space-5);
    max-height: 90vh;
  }

  .section-header {
    flex-direction: column;
    align-items: flex-start;
    gap: var(--space-2);
  }
}

@media (max-width: 480px) {
  .stats-row {
    grid-template-columns: 1fr;
  }

  .header-actions .header-btn:nth-child(3) { display: none; }

  .toast-container {
    left: var(--space-4);
    right: var(--space-4);
    bottom: var(--space-4);
  }

  .toast {
    min-width: 0;
  }
}

/* ============================================
   Utility Classes
   ============================================ */
.text-accent { color: var(--color-accent); }
.text-success { color: var(--color-success); }
.text-warning { color: var(--color-warning); }
.text-danger { color: var(--color-danger); }
.text-muted { color: var(--color-text-tertiary); }
.fw-semibold { font-weight: var(--font-weight-semibold); }
.fw-bold { font-weight: var(--font-weight-bold); }
.truncate { overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.flex-center { display: flex; align-items: center; justify-content: center; }
.gap-2 { gap: var(--space-2); }
.gap-3 { gap: var(--space-3); }
.gap-4 { gap: var(--space-4); }
.mt-2 { margin-top: var(--space-2); }
.mt-4 { margin-top: var(--space-4); }
.mb-4 { margin-bottom: var(--space-4); }
.hidden { display: none !important; }
.sr-only { position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px; overflow: hidden; clip: rect(0,0,0,0); border: 0; }