/* ═══════════════════════════════════════════════════
   Zmind — 笔记与思维导图系统
   Design System & Global Styles
   ═══════════════════════════════════════════════════ */

:root {
  /* Primary palette */
  --primary: #6366f1;
  --primary-hover: #4f46e5;
  --primary-light: #eef2ff;
  --primary-dark: #4338ca;

  /* Sidebar */
  --sidebar-bg: #0f172a;
  --sidebar-bg-hover: #1e293b;
  --sidebar-text: #cbd5e1;
  --sidebar-text-muted: #64748b;
  --sidebar-active-bg: rgba(99, 102, 241, 0.15);
  --sidebar-active-text: #a5b4fc;
  --sidebar-border: #1e293b;

  /* Content area */
  --bg: #ffffff;
  --bg-secondary: #f8fafc;
  --bg-tertiary: #f1f5f9;
  --text: #1e293b;
  --text-secondary: #64748b;
  --text-muted: #94a3b8;
  --border: #e2e8f0;
  --border-light: #f1f5f9;

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

  /* Shadows */
  --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
  --shadow: 0 1px 3px 0 rgb(0 0 0 / 0.1), 0 1px 2px -1px rgb(0 0 0 / 0.1);
  --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
  --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1), 0 4px 6px -4px rgb(0 0 0 / 0.1);

  /* Radius */
  --radius-sm: 6px;
  --radius: 8px;
  --radius-lg: 12px;
  --radius-xl: 16px;

  /* Transitions */
  --transition: 150ms cubic-bezier(0.4, 0, 0.2, 1);
  --transition-slow: 300ms cubic-bezier(0.4, 0, 0.2, 1);

  /* Layout */
  --sidebar-width: 280px;
  --header-height: 56px;

  /* Typography */
  --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', 'PingFang SC', 'Microsoft YaHei', sans-serif;
  --font-mono: 'JetBrains Mono', 'Fira Code', 'Cascadia Code', 'Consolas', monospace;
}

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

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

body {
  font-family: var(--font-sans);
  color: var(--text);
  background: var(--bg);
  line-height: 1.6;
  min-height: 100vh;
}

a {
  color: var(--primary);
  text-decoration: none;
  transition: color var(--transition);
}
a:hover { color: var(--primary-hover); }

/* ──────────────────────────────────────────────
   App Layout (index.html)
   ────────────────────────────────────────────── */
.app-layout {
  display: flex;
  min-height: 100vh;
}

/* Sidebar */
.sidebar {
  width: var(--sidebar-width);
  min-width: var(--sidebar-width);
  background: var(--sidebar-bg);
  color: var(--sidebar-text);
  display: flex;
  flex-direction: column;
  position: fixed;
  top: 0;
  left: 0;
  bottom: 0;
  z-index: 100;
  overflow-y: auto;
  overflow-x: hidden;
  transition: transform var(--transition-slow);
}

/* Sidebar collapsed state */
.app-layout.sidebar-collapsed .sidebar {
  transform: translateX(calc(var(--sidebar-width) * -1));
}

.app-layout.sidebar-collapsed .main-content {
  margin-left: 0;
}

.app-layout.sidebar-collapsed .sidebar-expand-btn {
  display: flex;
}

.sidebar-header {
  padding: 20px 16px 16px 20px;
  border-bottom: 1px solid var(--sidebar-border);
  display: flex;
  align-items: center;
  gap: 10px;
  flex-shrink: 0;
}

.sidebar-collapse-btn {
  width: 28px;
  height: 28px;
  margin-left: auto;
  background: transparent;
  border: 1px solid var(--sidebar-border);
  border-radius: var(--radius-sm);
  cursor: pointer;
  font-size: 12px;
  color: var(--sidebar-text-muted);
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all var(--transition);
  flex-shrink: 0;
}

.sidebar-collapse-btn:hover {
  background: var(--sidebar-bg-hover);
  color: #fff;
  border-color: var(--sidebar-text-muted);
}

.sidebar-logo {
  width: 36px;
  height: 36px;
  background: var(--primary);
  border-radius: var(--radius);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 20px;
  flex-shrink: 0;
}

.sidebar-title {
  font-size: 18px;
  font-weight: 700;
  color: #fff;
  letter-spacing: -0.3px;
}

.sidebar-subtitle {
  font-size: 11px;
  color: var(--sidebar-text-muted);
  margin-top: -2px;
}

.sidebar-nav {
  flex: 1;
  padding: 12px;
  overflow-y: auto;
}

.sidebar-section {
  margin-bottom: 8px;
}

.sidebar-section-header {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 8px 12px;
  font-size: 12px;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.5px;
  color: var(--sidebar-text-muted);
  cursor: pointer;
  border-radius: var(--radius-sm);
  transition: background var(--transition);
  user-select: none;
}

.sidebar-section-header:hover {
  background: var(--sidebar-bg-hover);
}

.sidebar-section-header .icon {
  font-size: 14px;
  transition: transform var(--transition);
}

.sidebar-section-header.collapsed .icon {
  transform: rotate(-90deg);
}

.sidebar-section-items {
  overflow: hidden;
  transition: max-height var(--transition-slow);
}

.sidebar-section-items.collapsed {
  max-height: 0 !important;
}

.sidebar-item {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 9px 12px 9px 28px;
  font-size: 14px;
  color: var(--sidebar-text);
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: all var(--transition);
  position: relative;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.sidebar-item:hover {
  background: var(--sidebar-bg-hover);
  color: #fff;
}

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

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

.sidebar-item-icon {
  font-size: 15px;
  flex-shrink: 0;
  opacity: 0.7;
}

.sidebar-item.active .sidebar-item-icon {
  opacity: 1;
}

.sidebar-footer {
  padding: 12px;
  border-top: 1px solid var(--sidebar-border);
  flex-shrink: 0;
}

.sidebar-footer-btn {
  display: flex;
  align-items: center;
  gap: 8px;
  width: 100%;
  padding: 9px 12px;
  font-size: 13px;
  color: var(--sidebar-text-muted);
  background: transparent;
  border: 1px solid var(--sidebar-border);
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: all var(--transition);
  font-family: var(--font-sans);
}

.sidebar-footer-btn:hover {
  background: var(--sidebar-bg-hover);
  color: #fff;
  border-color: var(--sidebar-text-muted);
}

/* Main Content Area */
.main-content {
  flex: 1;
  margin-left: var(--sidebar-width);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

.content-header {
  padding: 16px 32px;
  border-bottom: 1px solid var(--border);
  background: var(--bg);
  position: sticky;
  top: 0;
  z-index: 50;
  display: flex;
  align-items: center;
  gap: 12px;
}

/* Sidebar toggle button in content header */
.sidebar-toggle-btn {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 34px;
  height: 34px;
  background: transparent;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  cursor: pointer;
  font-size: 16px;
  color: var(--text-secondary);
  transition: all var(--transition);
  flex-shrink: 0;
}

.sidebar-toggle-btn:hover {
  background: var(--bg-tertiary);
  color: var(--text);
  border-color: var(--text-muted);
}

/* Mindmap toolbar in header */
.content-header-tools {
  display: flex;
  align-items: center;
  gap: 4px;
  flex-shrink: 0;
}

.content-header-tools button {
  padding: 5px 9px;
  font-size: 14px;
  border: 1px solid var(--border);
  background: var(--bg);
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: all var(--transition);
  font-family: var(--font-sans);
  color: var(--text-secondary);
  line-height: 1;
}

.content-header-tools button:hover {
  background: var(--bg-tertiary);
  color: var(--text);
  border-color: var(--text-muted);
}

/* Floating expand button when sidebar is hidden */
.sidebar-expand-btn {
  display: none;
  position: fixed;
  left: 0;
  top: 50%;
  transform: translateY(-50%);
  z-index: 200;
  width: 28px;
  height: 60px;
  background: var(--sidebar-bg);
  color: var(--sidebar-text);
  border: 1px solid var(--sidebar-border);
  border-left: none;
  border-radius: 0 8px 8px 0;
  cursor: pointer;
  font-size: 14px;
  align-items: center;
  justify-content: center;
  transition: all var(--transition);
  opacity: 0.6;
}

.sidebar-expand-btn:hover {
  opacity: 1;
  width: 32px;
  color: #fff;
}

.content-header-title {
  font-size: 22px;
  font-weight: 700;
  color: var(--text);
  letter-spacing: -0.3px;
  flex: 1;
}

.content-header-badge {
  font-size: 12px;
  padding: 4px 10px;
  border-radius: 20px;
  font-weight: 500;
}

.badge-note {
  background: var(--info-light);
  color: var(--info);
}

.badge-mindmap {
  background: var(--primary-light);
  color: var(--primary);
}

.content-body {
  flex: 1;
  padding: 32px;
  max-width: 860px;
  width: 100%;
  display: flex;
  flex-direction: column;
}

.content-body.has-mindmap {
  max-width: none;
  padding: 0;
}

/* Empty state */
.empty-state {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  min-height: 60vh;
  text-align: center;
  color: var(--text-secondary);
}

.empty-state-icon {
  font-size: 64px;
  margin-bottom: 16px;
  opacity: 0.6;
}

.empty-state-title {
  font-size: 20px;
  font-weight: 600;
  color: var(--text);
  margin-bottom: 8px;
}

.empty-state-desc {
  font-size: 14px;
  max-width: 360px;
  line-height: 1.7;
}

/* ──────────────────────────────────────────────
   Markdown Content Styles
   ────────────────────────────────────────────── */
.markdown-body {
  line-height: 1.85;
  color: var(--text);
  font-size: 15px;
}

.markdown-body h1 {
  font-size: 28px;
  font-weight: 800;
  margin: 0 0 16px;
  padding-bottom: 12px;
  border-bottom: 2px solid var(--border);
  letter-spacing: -0.5px;
  color: #0f172a;
}

.markdown-body h2 {
  font-size: 22px;
  font-weight: 700;
  margin: 32px 0 12px;
  letter-spacing: -0.3px;
  color: #1e293b;
}

.markdown-body h3 {
  font-size: 18px;
  font-weight: 600;
  margin: 24px 0 10px;
  color: #334155;
}

.markdown-body h4, .markdown-body h5, .markdown-body h6 {
  font-size: 16px;
  font-weight: 600;
  margin: 20px 0 8px;
  color: #475569;
}

.markdown-body p {
  margin: 0 0 14px;
}

.markdown-body ul, .markdown-body ol {
  margin: 0 0 14px;
  padding-left: 24px;
}

.markdown-body li {
  margin: 4px 0;
}

.markdown-body li > ul, .markdown-body li > ol {
  margin-bottom: 0;
}

.markdown-body blockquote {
  margin: 16px 0;
  padding: 12px 18px;
  border-left: 4px solid var(--primary);
  background: var(--primary-light);
  border-radius: 0 var(--radius) var(--radius) 0;
  color: var(--primary-dark);
}

.markdown-body blockquote p {
  margin: 0;
}

.markdown-body code {
  font-family: var(--font-mono);
  font-size: 0.875em;
  background: var(--bg-tertiary);
  padding: 2px 6px;
  border-radius: 4px;
  color: #e11d48;
}

.markdown-body pre {
  margin: 16px 0;
  padding: 18px 20px;
  background: #1e293b;
  border-radius: var(--radius);
  overflow-x: auto;
}

.markdown-body pre code {
  background: transparent;
  color: #e2e8f0;
  padding: 0;
  font-size: 13.5px;
  line-height: 1.7;
}

.markdown-body table {
  width: 100%;
  margin: 16px 0;
  border-collapse: collapse;
  font-size: 14px;
}

.markdown-body th {
  background: var(--bg-tertiary);
  font-weight: 600;
  text-align: left;
  padding: 10px 14px;
  border: 1px solid var(--border);
}

.markdown-body td {
  padding: 9px 14px;
  border: 1px solid var(--border);
}

.markdown-body tr:hover td {
  background: var(--bg-secondary);
}

.markdown-body hr {
  margin: 24px 0;
  border: none;
  border-top: 1px solid var(--border);
}

.markdown-body img {
  max-width: 100%;
  border-radius: var(--radius);
}

.markdown-body strong {
  font-weight: 600;
  color: #0f172a;
}

.markdown-body a {
  color: var(--primary);
  text-decoration: underline;
  text-underline-offset: 2px;
}

/* ──────────────────────────────────────────────
   Mind Map Container
   ────────────────────────────────────────────── */
#mindmapArea {
  flex: 1;
  display: flex;
  flex-direction: column;
  min-height: 0;
}

.mindmap-container {
  flex: 1;
  width: 100%;
  min-height: 0;
  border: none;
  border-top: 1px solid var(--border);
  background: var(--bg);
  overflow: hidden;
  position: relative;
}

.mindmap-container svg {
  display: block;
  width: 100%;
  height: 100%;
}

.mindmap-toolbar {
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 8px 14px;
  background: var(--bg-secondary);
  border-bottom: 1px solid var(--border);
  flex-shrink: 0;
}

.mindmap-toolbar button {
  padding: 5px 10px;
  font-size: 12px;
  border: 1px solid var(--border);
  background: #fff;
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: all var(--transition);
  font-family: var(--font-sans);
  color: var(--text-secondary);
}

.mindmap-toolbar button:hover {
  background: var(--bg-tertiary);
  border-color: var(--text-muted);
}

/* Upload progress indicator */
.upload-toast {
  position: fixed;
  bottom: 24px;
  right: 24px;
  background: #1e293b;
  color: #fff;
  padding: 10px 18px;
  border-radius: var(--radius);
  font-size: 13px;
  z-index: 10000;
  box-shadow: var(--shadow-lg);
  display: flex;
  align-items: center;
  gap: 8px;
}

.upload-toast .spinner {
  width: 16px;
  height: 16px;
  border: 2px solid rgba(255,255,255,0.3);
  border-top-color: #fff;
  border-radius: 50%;
  animation: spin 0.6s linear infinite;
}

@keyframes spin {
  to { transform: rotate(360deg); }
}

/* ──────────────────────────────────────────────
   Login Page
   ────────────────────────────────────────────── */
.login-page {
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  padding: 20px;
}

.login-card {
  width: 100%;
  max-width: 400px;
  background: #fff;
  border-radius: var(--radius-xl);
  padding: 40px;
  box-shadow: var(--shadow-lg);
}

.login-card-header {
  text-align: center;
  margin-bottom: 32px;
}

.login-card-logo {
  width: 56px;
  height: 56px;
  background: var(--primary);
  border-radius: var(--radius-lg);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 28px;
  margin: 0 auto 16px;
}

.login-card-title {
  font-size: 24px;
  font-weight: 700;
  color: #0f172a;
  letter-spacing: -0.3px;
}

.login-card-desc {
  font-size: 14px;
  color: var(--text-secondary);
  margin-top: 4px;
}

.form-group {
  margin-bottom: 18px;
}

.form-label {
  display: block;
  font-size: 14px;
  font-weight: 500;
  color: var(--text);
  margin-bottom: 6px;
}

.form-input {
  width: 100%;
  padding: 10px 14px;
  font-size: 14px;
  border: 1.5px solid var(--border);
  border-radius: var(--radius);
  font-family: var(--font-sans);
  transition: all var(--transition);
  color: var(--text);
  background: var(--bg);
  outline: none;
}

.form-input:focus {
  border-color: var(--primary);
  box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.1);
}

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

.form-error {
  background: var(--danger-light);
  color: var(--danger);
  font-size: 13px;
  padding: 10px 14px;
  border-radius: var(--radius-sm);
  margin-bottom: 16px;
  display: none;
}

.form-error.show {
  display: block;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 10px 20px;
  font-size: 14px;
  font-weight: 500;
  border: none;
  border-radius: var(--radius);
  cursor: pointer;
  transition: all var(--transition);
  font-family: var(--font-sans);
  line-height: 1.4;
}

.btn-primary {
  background: var(--primary);
  color: #fff;
  width: 100%;
}

.btn-primary:hover {
  background: var(--primary-hover);
  box-shadow: var(--shadow-md);
}

.btn-sm {
  padding: 6px 12px;
  font-size: 12px;
  border-radius: var(--radius-sm);
}

.btn-danger {
  background: var(--danger);
  color: #fff;
}
.btn-danger:hover { background: #dc2626; }

.btn-outline {
  background: transparent;
  border: 1.5px solid var(--border);
  color: var(--text);
}
.btn-outline:hover {
  background: var(--bg-tertiary);
  border-color: var(--text-muted);
}

.btn-ghost {
  background: transparent;
  color: var(--text-secondary);
}
.btn-ghost:hover {
  background: var(--bg-tertiary);
  color: var(--text);
}

.login-back-link {
  display: block;
  text-align: center;
  margin-top: 20px;
  font-size: 13px;
  color: var(--text-secondary);
}

.login-back-link a {
  color: var(--primary);
  font-weight: 500;
}

/* ──────────────────────────────────────────────
   Admin Page
   ────────────────────────────────────────────── */
.admin-layout {
  display: flex;
  min-height: 100vh;
}

.admin-sidebar {
  width: var(--sidebar-width);
  min-width: var(--sidebar-width);
  background: var(--sidebar-bg);
  display: flex;
  flex-direction: column;
  position: fixed;
  top: 0;
  left: 0;
  bottom: 0;
  z-index: 100;
}

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

.admin-sidebar-title {
  font-size: 16px;
  font-weight: 700;
  color: #fff;
}

.admin-sidebar-actions {
  padding: 12px;
  display: flex;
  gap: 6px;
}

.admin-btn-new {
  flex: 1;
  padding: 8px;
  font-size: 12px;
  font-weight: 500;
  background: var(--primary);
  color: #fff;
  border: none;
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: all var(--transition);
  font-family: var(--font-sans);
}

.admin-btn-new:hover {
  background: var(--primary-hover);
}

.admin-list {
  flex: 1;
  overflow-y: auto;
  padding: 8px 12px;
}

.admin-list-section {
  margin-bottom: 8px;
}

.admin-list-section-title {
  font-size: 11px;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.5px;
  color: var(--sidebar-text-muted);
  padding: 8px 8px 4px;
}

.admin-list-item {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 9px 10px;
  font-size: 13px;
  color: var(--sidebar-text);
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: all var(--transition);
}

.admin-list-item:hover {
  background: var(--sidebar-bg-hover);
}

.admin-list-item.active {
  background: var(--sidebar-active-bg);
  color: var(--sidebar-active-text);
  font-weight: 500;
}

.admin-list-item-title {
  flex: 1;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.admin-list-item-del {
  padding: 2px 6px;
  font-size: 12px;
  color: var(--sidebar-text-muted);
  background: transparent;
  border: none;
  cursor: pointer;
  border-radius: 4px;
  transition: all var(--transition);
  opacity: 0;
}

.admin-list-item:hover .admin-list-item-del {
  opacity: 1;
}

.admin-list-item-del:hover {
  color: var(--danger);
  background: var(--danger-light);
}

.admin-main {
  flex: 1;
  margin-left: var(--sidebar-width);
  display: flex;
  flex-direction: column;
  min-height: 100vh;
}

.admin-toolbar {
  padding: 12px 24px;
  border-bottom: 1px solid var(--border);
  background: var(--bg);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  position: sticky;
  top: 0;
  z-index: 50;
}

.admin-toolbar-title {
  font-size: 18px;
  font-weight: 600;
  color: var(--text);
}

.admin-toolbar-actions {
  display: flex;
  gap: 8px;
}

.admin-editor {
  flex: 1;
  display: flex;
  flex-direction: column;
  padding: 24px;
  gap: 16px;
  overflow-y: auto;
}

.admin-editor-title-input {
  font-size: 22px;
  font-weight: 700;
  padding: 10px 0;
  border: none;
  border-bottom: 2px solid var(--border);
  outline: none;
  font-family: var(--font-sans);
  color: var(--text);
  background: transparent;
  transition: border-color var(--transition);
}

.admin-editor-title-input:focus {
  border-bottom-color: var(--primary);
}

.admin-editor-textarea {
  flex: 1;
  min-height: 360px;
  padding: 14px;
  font-family: var(--font-mono);
  font-size: 14px;
  line-height: 1.7;
  border: 1.5px solid var(--border);
  border-radius: var(--radius);
  resize: vertical;
  outline: none;
  color: var(--text);
  background: var(--bg);
  transition: border-color var(--transition);
  tab-size: 2;
}

.admin-editor-textarea:focus {
  border-color: var(--primary);
  box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.08);
}

.admin-preview-tabs {
  display: flex;
  gap: 0;
  border-bottom: 2px solid var(--border);
  margin-bottom: -1px;
}

.admin-preview-tab {
  padding: 8px 16px;
  font-size: 13px;
  font-weight: 500;
  color: var(--text-secondary);
  background: transparent;
  border: none;
  border-bottom: 2px solid transparent;
  cursor: pointer;
  transition: all var(--transition);
  font-family: var(--font-sans);
  margin-bottom: -2px;
}

.admin-preview-tab.active {
  color: var(--primary);
  border-bottom-color: var(--primary);
}

.admin-preview-panel {
  flex: 1;
  min-height: 360px;
  border: 1.5px solid var(--border);
  border-radius: 0 0 var(--radius) var(--radius);
  padding: 20px;
  overflow-y: auto;
  background: var(--bg);
  display: none;
}

.admin-preview-panel.active {
  display: block;
}

.admin-editor-actions {
  display: flex;
  justify-content: flex-end;
  gap: 8px;
  padding-top: 8px;
}

.admin-empty {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  flex: 1;
  color: var(--text-secondary);
  text-align: center;
}

.admin-empty-icon {
  font-size: 56px;
  margin-bottom: 12px;
  opacity: 0.5;
}

.admin-empty-title {
  font-size: 18px;
  font-weight: 600;
  color: var(--text);
}

.admin-empty-desc {
  font-size: 13px;
  margin-top: 4px;
}

.toast {
  position: fixed;
  top: 20px;
  right: 20px;
  z-index: 9999;
  padding: 12px 20px;
  border-radius: var(--radius);
  font-size: 14px;
  font-weight: 500;
  color: #fff;
  box-shadow: var(--shadow-lg);
  transform: translateX(120%);
  transition: transform var(--transition-slow);
  max-width: 360px;
}

.toast.show {
  transform: translateX(0);
}

.toast-success { background: var(--success); }
.toast-error { background: var(--danger); }
.toast-info { background: var(--info); }

/* ──────────────────────────────────────────────
   Scrollbar
   ────────────────────────────────────────────── */
::-webkit-scrollbar {
  width: 6px;
  height: 6px;
}

::-webkit-scrollbar-track {
  background: transparent;
}

::-webkit-scrollbar-thumb {
  background: #cbd5e1;
  border-radius: 3px;
}

::-webkit-scrollbar-thumb:hover {
  background: #94a3b8;
}

/* ──────────────────────────────────────────────
   Responsive
   ────────────────────────────────────────────── */
@media (max-width: 768px) {
  :root {
    --sidebar-width: 0px;
  }

  .sidebar {
    transform: translateX(-100%);
    transition: transform var(--transition-slow);
    width: 280px;
    min-width: 280px;
  }

  .sidebar.mobile-open {
    transform: translateX(0);
    --sidebar-width: 280px;
  }

  .main-content {
    margin-left: 0;
  }

  .content-body {
    padding: 20px 16px;
  }

  .admin-sidebar {
    transform: translateX(-100%);
    transition: transform var(--transition-slow);
  }

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

  .admin-main {
    margin-left: 0;
  }

  .mobile-menu-btn {
    display: flex !important;
  }
}

.mobile-menu-btn {
  display: none;
  width: 36px;
  height: 36px;
  align-items: center;
  justify-content: center;
  background: var(--bg-tertiary);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  cursor: pointer;
  font-size: 18px;
  color: var(--text);
  transition: all var(--transition);
}

.mobile-menu-btn:hover {
  background: var(--border);
}

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

.fade-in {
  animation: fadeIn 0.3s ease;
}

@keyframes pulse {
  0%, 100% { opacity: 1; }
  50% { opacity: 0.5; }
}

.loading {
  animation: pulse 1.5s ease infinite;
  color: var(--text-muted);
}

/* ──────────────────────────────────────────────
   Folder Tree (Admin)
   ────────────────────────────────────────────── */
.folder-group {
  margin-bottom: 2px;
  border-radius: var(--radius-sm);
  transition: background var(--transition);
}

.folder-group.drag-over {
  background: rgba(99, 102, 241, 0.12);
  outline: 2px dashed var(--primary);
  outline-offset: -2px;
}

.folder-header {
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 7px 8px;
  border-radius: var(--radius-sm);
  transition: background var(--transition);
  cursor: default;
}

.folder-header:hover {
  background: var(--sidebar-bg-hover);
}

.folder-arrow {
  font-size: 12px;
  color: var(--sidebar-text-muted);
  transition: transform var(--transition);
  cursor: pointer;
  width: 16px;
  text-align: center;
  flex-shrink: 0;
}

.folder-arrow.collapsed {
  transform: rotate(-90deg);
}

.folder-icon {
  font-size: 14px;
  flex-shrink: 0;
}

.folder-name {
  flex: 1;
  font-size: 13px;
  font-weight: 500;
  color: var(--sidebar-text);
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.folder-count {
  font-size: 10px;
  color: var(--sidebar-text-muted);
  background: var(--sidebar-bg-hover);
  padding: 1px 6px;
  border-radius: 10px;
  flex-shrink: 0;
}

.folder-action {
  padding: 2px 5px;
  font-size: 11px;
  color: var(--sidebar-text-muted);
  background: transparent;
  border: none;
  cursor: pointer;
  border-radius: 3px;
  transition: all var(--transition);
  opacity: 0;
  flex-shrink: 0;
}

.folder-header:hover .folder-action {
  opacity: 1;
}

.folder-action:hover {
  color: #fff;
  background: var(--sidebar-bg-hover);
}

.folder-items {
  overflow: hidden;
  transition: max-height var(--transition-slow);
}

.folder-items.collapsed {
  max-height: 0 !important;
}

.folder-empty {
  padding: 12px;
  text-align: center;
  font-size: 11px;
  color: var(--sidebar-text-muted);
  border: 1px dashed var(--sidebar-border);
  border-radius: var(--radius-sm);
  margin: 4px 0 4px 20px;
}

.root-group > .folder-header {
  padding-left: 4px;
}

/* ──────────────────────────────────────────────
   Drag & Drop
   ────────────────────────────────────────────── */
.draggable-item {
  position: relative;
}

.drag-handle {
  cursor: grab;
  color: var(--sidebar-text-muted);
  font-size: 14px;
  letter-spacing: -2px;
  flex-shrink: 0;
  user-select: none;
  opacity: 0;
  transition: opacity var(--transition);
}

.admin-list-item:hover .drag-handle,
.visibility-toggle {
  /* visibility toggle is always shown */
}

.admin-list-item:hover .drag-handle {
  opacity: 0.7;
}

.dragging {
  opacity: 0.45;
}

.draggable-item.drag-over,
.admin-list-item.drag-over {
  outline: 2px solid var(--primary);
  outline-offset: -2px;
  background: rgba(99, 102, 241, 0.1);
}

/* ──────────────────────────────────────────────
   Visibility Toggle
   ────────────────────────────────────────────── */
.visibility-toggle {
  padding: 2px 5px;
  font-size: 13px;
  color: var(--sidebar-text-muted);
  background: transparent;
  border: none;
  cursor: pointer;
  border-radius: 4px;
  transition: all var(--transition);
  flex-shrink: 0;
  opacity: 0;
}

.admin-list-item:hover .visibility-toggle {
  opacity: 1;
}

.visibility-toggle:hover {
  background: var(--sidebar-bg-hover);
}

/* ──────────────────────────────────────────────
   Modal
   ────────────────────────────────────────────── */
.modal-overlay {
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.5);
  z-index: 10000;
  display: flex;
  align-items: center;
  justify-content: center;
  backdrop-filter: blur(4px);
}

.modal-card {
  background: #fff;
  border-radius: var(--radius-lg);
  padding: 24px;
  width: 360px;
  max-width: 90vw;
  box-shadow: var(--shadow-lg);
}

.modal-card h3 {
  font-size: 18px;
  font-weight: 600;
  margin-bottom: 14px;
  color: var(--text);
}

.modal-card .form-input {
  margin-bottom: 0;
}

/* ──────────────────────────────────────────────
   Image Lightbox
   ────────────────────────────────────────────── */
.lightbox-overlay {
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.85);
  z-index: 20000;
  display: flex;
  align-items: center;
  justify-content: center;
  opacity: 0;
  visibility: hidden;
  transition: opacity 0.25s ease, visibility 0.25s ease;
}

.lightbox-overlay.show {
  opacity: 1;
  visibility: visible;
}

.lightbox-content {
  position: relative;
  max-width: 92vw;
  max-height: 92vh;
  display: flex;
  align-items: center;
  justify-content: center;
}

.lightbox-content img {
  max-width: 92vw;
  max-height: 92vh;
  object-fit: contain;
  border-radius: var(--radius);
  box-shadow: 0 20px 60px rgba(0, 0, 0, 0.5);
  background: #fff;
}

.lightbox-close {
  position: absolute;
  top: -36px;
  right: -36px;
  width: 32px;
  height: 32px;
  background: rgba(255, 255, 255, 0.15);
  color: #fff;
  border: none;
  border-radius: 50%;
  font-size: 20px;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: background 0.15s;
  line-height: 1;
}

.lightbox-close:hover {
  background: rgba(255, 255, 255, 0.3);
}

.lightbox-arrow {
  position: absolute;
  top: 50%;
  transform: translateY(-50%);
  width: 44px;
  height: 72px;
  background: rgba(255, 255, 255, 0.08);
  color: #fff;
  border: none;
  border-radius: var(--radius);
  font-size: 28px;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: background 0.15s;
  z-index: 10;
}

.lightbox-arrow:hover {
  background: rgba(255, 255, 255, 0.22);
}

.lightbox-arrow.prev {
  left: -56px;
}

.lightbox-arrow.next {
  right: -56px;
}

.lightbox-counter {
  position: absolute;
  bottom: -36px;
  left: 0;
  right: 0;
  text-align: center;
  color: rgba(255, 255, 255, 0.7);
  font-size: 13px;
  font-weight: 500;
}

/* Clickable image indicator in mindmap */
.mindmap-image-node {
  cursor: pointer;
  fill: #6366f1 !important;
  text-decoration: underline;
}

.mindmap-image-node:hover {
  fill: #4f46e5 !important;
}

/* Hint popover */
.hint-popover {
  position: fixed;
  z-index: 20001;
  background: #fff;
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 14px 18px;
  max-width: 380px;
  min-width: 160px;
  box-shadow: 0 8px 30px rgba(0, 0, 0, 0.18);
  font-size: 14px;
  line-height: 1.7;
  color: var(--text);
  display: none;
  word-break: break-word;
}

.hint-popover.show {
  display: block;
  animation: fadeIn 0.15s ease;
}

.hint-popover-close {
  position: absolute;
  top: 4px;
  right: 8px;
  background: none;
  border: none;
  font-size: 16px;
  color: var(--text-muted);
  cursor: pointer;
  padding: 2px 6px;
  border-radius: 4px;
  line-height: 1;
}

.hint-popover-close:hover {
  color: var(--text);
  background: var(--bg-tertiary);
}

/* Dotted underline for hint nodes */
.mindmap-hint-node {
  cursor: pointer;
  text-decoration: underline dotted;
  text-underline-offset: 3px;
}