/* === Design Tokens === */
:root {
  /* Backgrounds */
  --color-bg: #0f1117;
  --color-surface: #1a1d26;
  --color-surface-raised: #22262f;
  --color-hover: rgba(255, 255, 255, 0.05);
  --color-active: rgba(255, 255, 255, 0.08);

  /* Text */
  --color-text: #e4e6eb;
  --color-text-secondary: #b0b3b8;
  --color-text-muted: #65676b;

  /* Borders */
  --color-border: #303338;
  --color-border-light: #404249;

  /* Accent */
  --color-accent: #00d4aa;
  --color-accent-hover: #00e8bb;
  --color-accent-alpha: rgba(0, 212, 170, 0.15);

  /* Semantic */
  --color-success: #31a065;
  --color-success-bg: rgba(49, 160, 101, 0.15);
  --color-warning: #cf9d2c;
  --color-warning-bg: rgba(207, 157, 44, 0.15);
  --color-danger: #cf4a4a;
  --color-danger-hover: #e05555;
  --color-info: #4a90cf;
  --color-info-bg: rgba(74, 144, 207, 0.15);

  /* Type colors */
  --color-requirement: #00d4aa;
  --color-note: #4a90cf;
  --color-spec: #9b59b6;
  --color-general: #65676b;

  /* Priority */
  --color-priority-high: #cf4a4a;
  --color-priority-medium: #cf9d2c;
  --color-priority-low: #31a065;

  /* Shadows */
  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.3);
  --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.25);
  --shadow-lg: 0 8px 24px rgba(0, 0, 0, 0.3);

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

  /* 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;

  /* Border Radius */
  --radius-sm: 4px;
  --radius-md: 6px;
  --radius-lg: 8px;
  --radius-xl: 12px;
  --radius-full: 9999px;

  /* Transitions */
  --transition-fast: 0.1s ease;
  --transition-normal: 0.15s ease;

  /* Z-index */
  --z-sidebar: 100;
  --z-modal: 500;
  --z-toast: 600;
}

/* === Light Theme === */
[data-theme="light"] {
  --color-bg: #f5f6f8;
  --color-surface: #ffffff;
  --color-surface-raised: #f0f1f3;
  --color-hover: rgba(0, 0, 0, 0.04);
  --color-active: rgba(0, 0, 0, 0.06);
  --color-text: #1a1d26;
  --color-text-secondary: #4a4f5c;
  --color-text-muted: #8b919d;
  --color-border: #e1e3e8;
  --color-border-light: #ebedf2;
  --color-accent: #00a884;
  --color-accent-hover: #00c49a;
  --color-accent-alpha: rgba(0, 168, 132, 0.12);
  --color-success: #22863a;
  --color-warning: #b08800;
  --color-danger: #cb2431;
  --color-info: #0366d6;
}

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

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

body {
  font-family: var(--font-sans);
  font-size: 1rem;
  line-height: 1.5;
  color: var(--color-text);
  background: var(--color-bg);
  min-height: 100vh;
}

a {
  color: var(--color-accent);
  text-decoration: none;
}

a:hover {
  text-decoration: underline;
}

button {
  font: inherit;
  cursor: pointer;
  border: none;
  background: none;
}

input, textarea, select {
  font: inherit;
}

ul, ol {
  list-style: none;
}

/* === Scrollbar === */
::-webkit-scrollbar {
  width: 8px;
  height: 8px;
}

::-webkit-scrollbar-track {
  background: var(--color-surface);
}

::-webkit-scrollbar-thumb {
  background: var(--color-border);
  border-radius: var(--radius-full);
}

::-webkit-scrollbar-thumb:hover {
  background: var(--color-text-muted);
}

/* === Layout === */
#app {
  display: flex;
  flex-direction: column;
  min-height: 100vh;
}

.app-layout {
  display: flex;
  flex: 1;
  overflow: hidden;
}

/* === Header === */
.app-header {
  display: flex;
  align-items: center;
  gap: var(--space-4);
  padding: var(--space-3) var(--space-4);
  background: var(--color-surface);
  border-bottom: 1px solid var(--color-border);
  height: 56px;
}

.app-header .logo {
  font-weight: 700;
  font-size: 1.125rem;
  color: var(--color-accent);
  display: flex;
  align-items: center;
  gap: var(--space-2);
}

.app-header .search-box {
  flex: 1;
  max-width: 400px;
  position: relative;
}

.app-header .search-box input {
  width: 100%;
  padding: var(--space-2) var(--space-4);
  padding-left: 36px;
  background: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  color: var(--color-text);
}

.app-header .search-box input:focus {
  outline: none;
  border-color: var(--color-accent);
}

.app-header .search-box .icon {
  position: absolute;
  left: 10px;
  top: 50%;
  transform: translateY(-50%);
  color: var(--color-text-muted);
}

.header-actions {
  display: flex;
  gap: var(--space-2);
  margin-left: auto;
}

/* === Sidebar === */
.sidebar {
  width: 260px;
  background: var(--color-surface);
  border-right: 1px solid var(--color-border);
  display: flex;
  flex-direction: column;
  overflow: hidden;
  flex-shrink: 0;
}

.sidebar-section {
  padding: var(--space-4);
  border-bottom: 1px solid var(--color-border);
}

.sidebar-section h3 {
  font-size: 0.75rem;
  font-weight: 600;
  color: var(--color-text-muted);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-bottom: var(--space-3);
}

.sidebar-scroll {
  flex: 1;
  overflow-y: auto;
  padding: var(--space-4);
}

.library-tree {
  display: flex;
  flex-direction: column;
  gap: var(--space-1);
}

.tree-item {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  padding: var(--space-2) var(--space-3);
  border-radius: var(--radius-md);
  cursor: pointer;
  color: var(--color-text-secondary);
  transition: var(--transition-fast);
}

.tree-item:hover {
  background: var(--color-hover);
  color: var(--color-text);
}

.tree-item.active {
  background: var(--color-accent-alpha);
  color: var(--color-accent);
}

.tree-item .icon {
  flex-shrink: 0;
  width: 16px;
  height: 16px;
}

.tree-item .label {
  flex: 1;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.tree-children {
  padding-left: var(--space-4);
}

.tree-toggle {
  width: 16px;
  height: 16px;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
  transition: transform var(--transition-fast);
}

.tree-toggle.expanded {
  transform: rotate(90deg);
}

.tag-list {
  display: flex;
  flex-direction: column;
  gap: var(--space-1);
}

.tag-item {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: var(--space-2) var(--space-3);
  border-radius: var(--radius-md);
  cursor: pointer;
  color: var(--color-text-secondary);
  transition: var(--transition-fast);
}

.tag-item:hover {
  background: var(--color-hover);
  color: var(--color-text);
}

.tag-item.active {
  background: var(--color-accent-alpha);
  color: var(--color-accent);
}

.tag-count {
  font-size: 0.75rem;
  color: var(--color-text-muted);
}

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

.content-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: var(--space-4) var(--space-6);
  border-bottom: 1px solid var(--color-border);
  background: var(--color-surface);
}

.content-header h1 {
  font-size: 1.25rem;
  font-weight: 600;
}

.content-body {
  flex: 1;
  overflow-y: auto;
  padding: var(--space-6);
}

/* === Document Cards === */
.doc-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
  gap: var(--space-4);
}

.doc-card {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: var(--space-4);
  cursor: pointer;
  transition: var(--transition-fast);
}

.doc-card:hover {
  border-color: var(--color-accent);
  box-shadow: var(--shadow-md);
}

.doc-card-header {
  display: flex;
  align-items: flex-start;
  gap: var(--space-3);
  margin-bottom: var(--space-3);
}

.doc-id {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--color-text-muted);
  background: var(--color-bg);
  padding: 2px 6px;
  border-radius: var(--radius-sm);
}

.doc-title {
  font-size: 1rem;
  font-weight: 600;
  color: var(--color-text);
  flex: 1;
  line-height: 1.4;
}

.doc-tags {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-2);
  margin-bottom: var(--space-3);
}

.tag-pill {
  font-size: 0.75rem;
  padding: 2px 8px;
  background: var(--color-accent-alpha);
  color: var(--color-accent);
  border-radius: var(--radius-full);
}

.doc-meta {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  font-size: 0.75rem;
  color: var(--color-text-muted);
}

.doc-meta-item {
  display: flex;
  align-items: center;
  gap: var(--space-1);
}

.status-badge {
  padding: 2px 8px;
  border-radius: var(--radius-full);
  font-size: 0.75rem;
  font-weight: 500;
}

.status-badge.draft {
  background: var(--color-warning-bg);
  color: var(--color-warning);
}

.status-badge.approved {
  background: var(--color-info-bg);
  color: var(--color-info);
}

.status-badge.implemented {
  background: var(--color-success-bg);
  color: var(--color-success);
}

.priority-indicator {
  font-size: 0.875rem;
}

/* === Document Viewer === */
.doc-viewer {
  display: flex;
  gap: var(--space-6);
  max-width: 1200px;
}

.doc-content {
  flex: 1;
  min-width: 0;
}

.doc-sidebar {
  width: 280px;
  flex-shrink: 0;
}

.doc-viewer-header {
  display: flex;
  align-items: center;
  gap: var(--space-4);
  margin-bottom: var(--space-6);
}

.back-btn {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  padding: var(--space-2) var(--space-3);
  border-radius: var(--radius-md);
  color: var(--color-text-secondary);
  transition: var(--transition-fast);
}

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

.doc-actions {
  display: flex;
  gap: var(--space-2);
  margin-left: auto;
}

.doc-actions button {
  padding: var(--space-2) var(--space-3);
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  gap: var(--space-2);
  color: var(--color-text-secondary);
  transition: var(--transition-fast);
}

.doc-actions button:hover {
  background: var(--color-hover);
  color: var(--color-text);
}

.doc-actions button.danger:hover {
  background: var(--color-danger-hover);
  color: white;
}

.prose {
  color: var(--color-text);
  line-height: 1.7;
}

.prose h1 { font-size: 2rem; font-weight: 700; margin: 1.5em 0 0.5em; }
.prose h2 { font-size: 1.5rem; font-weight: 600; margin: 1.5em 0 0.5em; }
.prose h3 { font-size: 1.25rem; font-weight: 600; margin: 1.25em 0 0.5em; }
.prose h4 { font-size: 1rem; font-weight: 600; margin: 1em 0 0.5em; }

.prose p { margin-bottom: 1em; }

.prose ul, .prose ol {
  margin-bottom: 1em;
  padding-left: 1.5em;
}

.prose ul { list-style-type: disc; }
.prose ol { list-style-type: decimal; }

.prose li { margin-bottom: 0.25em; }

.prose code {
  font-family: var(--font-mono);
  font-size: 0.875em;
  background: var(--color-surface);
  padding: 0.125em 0.375em;
  border-radius: var(--radius-sm);
  color: var(--color-accent);
}

.prose pre {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: 1rem;
  overflow-x: auto;
  margin-bottom: 1em;
}

.prose pre code {
  background: transparent;
  padding: 0;
  color: var(--color-text);
}

.prose blockquote {
  border-left: 4px solid var(--color-accent);
  padding-left: 1rem;
  margin: 1em 0;
  color: var(--color-text-secondary);
}

.prose table {
  width: 100%;
  border-collapse: collapse;
  margin-bottom: 1em;
}

.prose th, .prose td {
  padding: 0.5rem 0.75rem;
  border: 1px solid var(--color-border);
  text-align: left;
}

.prose th {
  background: var(--color-surface);
  font-weight: 600;
}

.prose input[type="checkbox"] {
  margin-right: 0.5em;
  accent-color: var(--color-accent);
}

.prose hr {
  border: none;
  border-top: 1px solid var(--color-border);
  margin: 2em 0;
}

/* === Metadata Panel === */
.meta-section {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  margin-bottom: var(--space-4);
}

.meta-header {
  padding: var(--space-3) var(--space-4);
  border-bottom: 1px solid var(--color-border);
  font-size: 0.75rem;
  font-weight: 600;
  color: var(--color-text-muted);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.meta-body {
  padding: var(--space-4);
}

.meta-row {
  display: flex;
  justify-content: space-between;
  margin-bottom: var(--space-3);
}

.meta-row:last-child {
  margin-bottom: 0;
}

.meta-label {
  font-size: 0.875rem;
  color: var(--color-text-muted);
}

.meta-value {
  font-size: 0.875rem;
  color: var(--color-text);
}

.doc-tags .tag-pill {
  cursor: pointer;
}

.doc-tags .tag-pill:hover {
  opacity: 0.8;
}

/* === Document Editor === */
.editor-container {
  max-width: 900px;
  margin: 0 auto;
}

.editor-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: var(--space-4) var(--space-6);
  border-bottom: 1px solid var(--color-border);
  background: var(--color-surface);
}

.editor-header h2 {
  font-size: 1rem;
  font-weight: 600;
}

.editor-form {
  padding: var(--space-6);
}

.form-row {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: var(--space-4);
  margin-bottom: var(--space-4);
}

.form-group {
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
}

.form-group label {
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--color-text-secondary);
}

.form-group input,
.form-group select,
.form-group textarea {
  padding: var(--space-3);
  background: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  color: var(--color-text);
}

.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus {
  outline: none;
  border-color: var(--color-accent);
}

.form-group textarea {
  min-height: 300px;
  resize: vertical;
  font-family: var(--font-mono);
  line-height: 1.6;
}

.form-group.full-width {
  grid-column: 1 / -1;
}

.editor-toolbar {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  padding: var(--space-3);
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-bottom: none;
  border-radius: var(--radius-lg) var(--radius-lg) 0 0;
}

.toolbar-btn {
  width: 32px;
  height: 32px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: var(--radius-sm);
  color: var(--color-text-secondary);
  transition: var(--transition-fast);
}

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

.toolbar-separator {
  width: 1px;
  height: 20px;
  background: var(--color-border);
  margin: 0 var(--space-2);
}

.toolbar-tabs {
  margin-left: auto;
  display: flex;
  gap: var(--space-1);
}

.tab-btn {
  padding: var(--space-2) var(--space-3);
  border-radius: var(--radius-sm);
  font-size: 0.875rem;
  color: var(--color-text-secondary);
  transition: var(--transition-fast);
}

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

.tab-btn.active {
  background: var(--color-accent-alpha);
  color: var(--color-accent);
}

.editor-content {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0;
  border: 1px solid var(--color-border);
  border-radius: 0 0 var(--radius-lg) var(--radius-lg);
  overflow: hidden;
}

.editor-content.full {
  grid-template-columns: 1fr;
}

.editor-pane {
  padding: var(--space-4);
  background: var(--color-bg);
}

.editor-pane:first-child {
  border-right: 1px solid var(--color-border);
}

.preview-pane {
  background: var(--color-surface);
  overflow-y: auto;
}

.preview-toggle {
  margin-left: auto;
}

/* === Buttons === */
.btn {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  padding: var(--space-2) var(--space-4);
  border-radius: var(--radius-md);
  font-weight: 500;
  font-size: 0.875rem;
  transition: var(--transition-fast);
}

.btn-primary {
  background: var(--color-accent);
  color: #000;
}

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

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

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

.btn-danger {
  background: var(--color-danger);
  color: white;
}

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

.btn-icon-only {
  width: 36px;
  height: 36px;
  padding: 0;
  display: flex;
  align-items: center;
  justify-content: center;
}

/* === Modal === */
.modal-backdrop {
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.6);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: var(--z-modal);
  animation: fadeIn 0.15s ease;
}

.modal {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-xl);
  box-shadow: var(--shadow-lg);
  min-width: 400px;
  max-width: 90vw;
  animation: scaleIn 0.15s ease;
}

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

.modal-header h3 {
  font-size: 1rem;
  font-weight: 600;
  flex: 1;
}

.modal-body {
  padding: var(--space-4);
}

.modal-footer {
  display: flex;
  justify-content: flex-end;
  gap: var(--space-3);
  padding: var(--space-4);
  border-top: 1px solid var(--color-border);
}

.modal-close {
  background: none;
  border: none;
  color: var(--color-text-muted);
  cursor: pointer;
  padding: var(--space-1);
  border-radius: var(--radius-sm);
  font-size: 1rem;
}

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

.form-control {
  width: 100%;
  padding: var(--space-3);
  background: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  color: var(--color-text);
  font-size: 0.875rem;
}

.form-control:focus {
  outline: none;
  border-color: var(--color-accent);
}

.form-control option {
  background: var(--color-surface);
  color: var(--color-text);
}

/* === Login Screen === */
.login-screen {
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--color-bg);
}

.login-card {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-xl);
  padding: var(--space-8);
  width: 100%;
  max-width: 400px;
  box-shadow: var(--shadow-lg);
}

.login-card h1 {
  font-size: 1.5rem;
  font-weight: 700;
  margin-bottom: var(--space-2);
  color: var(--color-accent);
  text-align: center;
}

.login-card p {
  color: var(--color-text-secondary);
  text-align: center;
  margin-bottom: var(--space-6);
  font-size: 0.875rem;
}

.login-form {
  display: flex;
  flex-direction: column;
  gap: var(--space-4);
}

.login-form .form-group {
  gap: var(--space-2);
}

.login-form input {
  padding: var(--space-3);
  background: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  color: var(--color-text);
  font-family: var(--font-mono);
  font-size: 0.875rem;
}

.login-form input:focus {
  outline: none;
  border-color: var(--color-accent);
}

.login-error {
  color: var(--color-danger);
  font-size: 0.875rem;
  text-align: center;
  display: none;
}

.login-error.visible {
  display: block;
}

/* === Toast === */
#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-3);
}

.toast {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  padding: var(--space-3) var(--space-4);
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-lg);
  animation: slideInRight 0.2s ease;
  min-width: 250px;
}

.toast.success {
  border-left: 4px solid var(--color-success);
}

.toast.error {
  border-left: 4px solid var(--color-danger);
}

.toast.info {
  border-left: 4px solid var(--color-info);
}

.toast-message {
  flex: 1;
  font-size: 0.875rem;
}

.toast-close {
  color: var(--color-text-muted);
  padding: var(--space-1);
  border-radius: var(--radius-sm);
}

.toast-close:hover {
  background: var(--color-hover);
  color: var(--color-text);
}

/* === Empty State === */
.empty-state {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: var(--space-16);
  text-align: center;
  color: var(--color-text-muted);
}

.empty-state .icon {
  font-size: 3rem;
  margin-bottom: var(--space-4);
  opacity: 0.5;
}

.empty-state h3 {
  font-size: 1.125rem;
  font-weight: 600;
  color: var(--color-text-secondary);
  margin-bottom: var(--space-2);
}

.empty-state p {
  margin-bottom: var(--space-6);
}

/* === Loading === */
.loading {
  display: flex;
  align-items: center;
  justify-content: center;
  padding: var(--space-16);
  color: var(--color-text-muted);
}

.loading::before {
  content: '';
  width: 24px;
  height: 24px;
  border: 2px solid var(--color-border);
  border-top-color: var(--color-accent);
  border-radius: 50%;
  animation: spin 0.8s linear infinite;
  margin-right: var(--space-3);
}

/* === Breadcrumbs === */
.breadcrumbs {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  font-size: 0.875rem;
  color: var(--color-text-secondary);
  margin-bottom: var(--space-4);
}

.breadcrumb-item {
  color: var(--color-text-secondary);
  cursor: pointer;
  transition: var(--transition-fast);
}

.breadcrumb-item:hover {
  color: var(--color-accent);
}

.breadcrumb-separator {
  color: var(--color-text-muted);
}

/* === Quick Links === */
.quick-links {
  display: flex;
  flex-direction: column;
  gap: var(--space-1);
  margin-top: var(--space-4);
  padding-top: var(--space-4);
  border-top: 1px solid var(--color-border);
}

.quick-link {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  padding: var(--space-2) var(--space-3);
  border-radius: var(--radius-md);
  color: var(--color-text-secondary);
  font-size: 0.875rem;
  cursor: pointer;
  transition: var(--transition-fast);
}

.quick-link:hover {
  background: var(--color-hover);
  color: var(--color-text);
}

/* === Type Badges === */
.type-badge {
  display: inline-flex;
  align-items: center;
  padding: 2px 8px;
  border-radius: var(--radius-sm);
  font-size: 0.75rem;
  font-weight: 600;
  text-transform: uppercase;
}

.type-badge.requirement {
  background: var(--color-accent-alpha);
  color: var(--color-requirement);
}

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

.type-badge.spec {
  background: rgba(155, 89, 182, 0.15);
  color: var(--color-spec);
}

.type-badge.general {
  background: var(--color-hover);
  color: var(--color-text-muted);
}

/* === Animations === */
@keyframes fadeIn {
  from { opacity: 0; }
  to { opacity: 1; }
}

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

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

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

/* === Mobile Navigation Drawer === */
.mobile-nav-btn { display: flex; margin-right: 8px; } .mobile-nav-btnOLD {
  display: none;
  width: 44px;
  height: 44px;
  align-items: center;
  justify-content: center;
  border-radius: var(--radius-md);
  color: var(--color-text-secondary);
  font-size: 1.25rem;
  transition: var(--transition-fast);
  flex-shrink: 0;
}

.mobile-nav-btn:hover {
  background: var(--color-hover);
  color: var(--color-text);
}

.sidebar-overlay {
  display: none;
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.5);
  z-index: calc(var(--z-sidebar) - 1);
  opacity: 0;
  transition: opacity 0.2s ease;
}

.sidebar-overlay.active {
  opacity: 1;
}

.sidebar-close-btn {
  display: none;
  position: absolute;
  top: var(--space-3);
  right: var(--space-3);
  width: 44px;
  height: 44px;
  align-items: center;
  justify-content: center;
  border-radius: var(--radius-md);
  color: var(--color-text-secondary);
  font-size: 1.25rem;
  z-index: 1;
}

.sidebar-close-btn:hover {
  background: var(--color-hover);
  color: var(--color-text);
}

/* === Responsive === */
@media (max-width: 1024px) {
  .sidebar {
    position: fixed;
    left: 0;
    top: 0;
    bottom: 0;
    z-index: var(--z-sidebar);
    transform: translateX(-100%);
    transition: transform 0.25s ease;
    box-shadow: var(--shadow-lg);
  }

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

  .sidebar-scroll {
    padding-top: 56px;
  }

  .sidebar-close-btn {
    display: flex;
  }

  .mobile-nav-btn { display: flex; margin-right: 8px; } .mobile-nav-btnOLD {
    display: flex;
  }

  .sidebar-overlay {
    display: block;
  }

  .doc-sidebar {
    display: none;
  }

  .editor-content {
    grid-template-columns: 1fr;
  }

  .editor-pane:first-child {
    border-right: none;
  }

  .preview-pane {
    display: none;
  }

  .editor-content.show-preview .editor-pane:first-child {
    display: none;
  }

  .editor-content.show-preview .preview-pane {
    display: block;
  }
}

@media (max-width: 768px) {
  .app-header .search-box {
    display: none;
  }

  .content-body {
    padding: var(--space-3);
  }

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

  .doc-card {
    padding: var(--space-4);
    min-height: 44px;
  }

  .doc-card-actions {
    opacity: 1;
    position: static;
    margin-top: var(--space-2);
    display: flex;
    gap: var(--space-2);
  }

  .modal {
    min-width: auto;
    width: 100%;
    height: 100%;
    max-width: 100%;
    margin: 0;
    border-radius: 0;
    display: flex;
    flex-direction: column;
  }

  .modal-backdrop {
    padding: 0;
    align-items: stretch;
  }

  .modal-header {
    padding: var(--space-4);
    flex-shrink: 0;
  }

  .modal-body {
    flex: 1;
    overflow-y: auto;
    padding: var(--space-4);
  }

  .modal-footer {
    flex-shrink: 0;
    padding: var(--space-4);
    gap: var(--space-3);
  }

  .login-card {
    margin: var(--space-4);
    padding: var(--space-6);
  }

  /* === Projects Page Mobile === */
  .projects-page {
    padding: var(--space-4);
  }

  .projects-header {
    margin-bottom: var(--space-6);
  }

  .projects-header h1 {
    font-size: 1.5rem;
  }

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

  .project-card {
    padding: var(--space-4);
  }

  .project-card-header {
    flex-direction: column;
    gap: var(--space-3);
  }

  .project-icon {
    font-size: 1.5rem;
  }

  .project-name {
    font-size: 1rem;
  }

  /* === Header Mobile === */
  .app-header {
    padding: var(--space-2) var(--space-3);
    gap: var(--space-2);
  }

  .app-header .logo {
    font-size: 1rem;
    flex: 1;
    min-width: 0;
  }

  .header-actions .btn {
    padding: var(--space-2) var(--space-3);
    font-size: 0.8125rem;
  }

  /* === Content Header Mobile === */
  .content-header {
    padding: var(--space-3) var(--space-4);
    flex-wrap: wrap;
    gap: var(--space-3);
  }

  .content-header-left {
    flex-direction: column;
    gap: var(--space-1);
    align-items: flex-start;
  }

  .content-header-left h1 {
    font-size: 1.125rem;
  }

  .content-header-right {
    width: 100%;
    flex-wrap: wrap;
  }

  .search-box-inline {
    flex: 1;
    min-width: 0;
  }

  .search-box-inline input {
    width: 100%;
  }

  /* === Editor Mobile === */
  .editor-container {
    max-width: 100%;
  }

  .editor-header {
    padding: var(--space-3) var(--space-4);
  }

  .editor-form {
    padding: var(--space-4);
  }

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

  .editor-toolbar {
    overflow-x: auto;
    -webkit-overflow-scrolling: touch;
    gap: var(--space-1);
    padding: var(--space-2);
    flex-wrap: nowrap;
    justify-content: flex-start;
  }

  .toolbar-btn {
    width: 44px;
    height: 44px;
    flex-shrink: 0;
  }

  .toolbar-separator {
    flex-shrink: 0;
  }

  .toolbar-tabs {
    margin-left: auto;
    flex-shrink: 0;
  }

  .tab-btn {
    padding: var(--space-2) var(--space-3);
    min-height: 44px;
    display: flex;
    align-items: center;
  }

  .form-group textarea {
    min-height: 200px;
    font-size: 16px; /* Prevents zoom on iOS */
  }

  .form-group input,
  .form-group select {
    min-height: 44px;
    font-size: 16px; /* Prevents zoom on iOS */
  }

  /* === Doc Card Mobile === */
  .doc-card-header {
    flex-wrap: wrap;
  }

  .doc-title {
    font-size: 0.9375rem;
  }

  .doc-tags {
    margin-top: var(--space-2);
  }

  .doc-meta {
    flex-wrap: wrap;
    gap: var(--space-2);
  }

  /* === Touch Targets === */
  .btn {
    min-height: 44px;
    min-width: 44px;
    display: inline-flex;
    align-items: center;
    justify-content: center;
  }

  .btn-icon-only {
    width: 44px;
    height: 44px;
  }

  .tree-item {
    min-height: 44px;
    padding: var(--space-2) var(--space-3);
  }

  .tree-item .tree-action {
    width: 32px;
    height: 32px;
    opacity: 1;
  }

  .tag-item {
    min-height: 44px;
    padding: var(--space-2) var(--space-3);
  }

  .quick-link {
    min-height: 44px;
    padding: var(--space-2) var(--space-3);
  }

  .doc-card {
    cursor: pointer;
  }

  /* === Empty State Mobile === */
  .empty-state {
    padding: var(--space-8);
  }

  /* === Breadcrumbs Mobile === */
  .breadcrumb-nav {
    margin-left: 0;
    flex-wrap: wrap;
    font-size: 0.8125rem;
  }

  /* === Toast Mobile === */
  #toast-container {
    bottom: var(--space-4);
    right: var(--space-4);
    left: var(--space-4);
  }

  .toast {
    min-width: auto;
    width: 100%;
  }
}

/* Ensure minimum touch target size */
@media (max-width: 768px) {
  a, button, [role="button"] {
    min-height: 44px;
    min-width: 44px;
  }

  input, select, textarea {
    font-size: 16px; /* Prevents iOS zoom */
  }
}

/* === Projects Page === */
.projects-page {
  max-width: 1200px;
  margin: 0 auto;
  padding: var(--space-6);
}

.projects-header {
  margin-bottom: var(--space-8);
}

.projects-header h1 {
  font-size: 2rem;
  font-weight: 700;
  margin-bottom: var(--space-2);
}

.projects-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(350px, 1fr));
  gap: var(--space-4);
}

.project-card {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: var(--space-5);
  cursor: pointer;
  transition: var(--transition-fast);
}

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

.project-card-header {
  display: flex;
  gap: var(--space-4);
  margin-bottom: var(--space-4);
}

.project-icon {
  font-size: 2rem;
  flex-shrink: 0;
}

.project-info {
  flex: 1;
  min-width: 0;
}

.project-name {
  font-size: 1.125rem;
  font-weight: 600;
  margin-bottom: var(--space-2);
  color: var(--color-text);
}

.project-description {
  font-size: 0.875rem;
  color: var(--color-text-secondary);
  margin: 0;
  line-height: 1.5;
}

.project-card-meta {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-4);
  font-size: 0.8125rem;
  color: var(--color-text-muted);
}

.project-card-meta .meta-item {
  display: flex;
  align-items: center;
  gap: var(--space-1);
}

/* === Breadcrumb Nav === */
.breadcrumb-nav {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  font-size: 0.875rem;
  margin-left: var(--space-4);
}

.breadcrumb-link {
  color: var(--color-text-muted);
  cursor: pointer;
  transition: var(--transition-fast);
}

.breadcrumb-link:hover {
  color: var(--color-accent);
}

.breadcrumb-sep {
  color: var(--color-text-muted);
}

.breadcrumb-current {
  color: var(--color-text);
  font-weight: 500;
}

/* === Project Sidebar === */
.project-sidebar .sidebar-scroll {
  padding: var(--space-3);
}

.project-sidebar .sidebar-section {
  padding: var(--space-3);
  border-bottom: none;
}

.project-sidebar .section-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: var(--space-3);
}

.project-sidebar .section-header h3 {
  font-size: 0.75rem;
  font-weight: 600;
  color: var(--color-text-muted);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin: 0;
}

.project-sidebar .btn-icon-only {
  width: 24px;
  height: 24px;
  font-size: 1rem;
  color: var(--color-text-muted);
}

.project-sidebar .btn-icon-only:hover {
  color: var(--color-accent);
}

/* === Folder Tree === */
.folder-tree {
  display: flex;
  flex-direction: column;
  gap: 2px;
}

.tree-node {
  display: flex;
  flex-direction: column;
}

.tree-item {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  padding: var(--space-2) var(--space-3);
  border-radius: var(--radius-md);
  cursor: pointer;
  color: var(--color-text-secondary);
  transition: var(--transition-fast);
  position: relative;
}

.tree-item:hover {
  background: var(--color-hover);
  color: var(--color-text);
}

.tree-item.active {
  background: var(--color-accent-alpha);
  color: var(--color-accent);
}

.tree-item .icon {
  flex-shrink: 0;
  font-size: 0.875rem;
}

.tree-item .label {
  flex: 1;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  font-size: 0.875rem;
}

.tree-item .count {
  font-size: 0.75rem;
  color: var(--color-text-muted);
  background: var(--color-bg);
  padding: 1px 6px;
  border-radius: var(--radius-full);
}

.tree-item .tree-action {
  opacity: 0;
  width: 20px;
  height: 20px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  font-size: 0.875rem;
  color: var(--color-text-muted);
  cursor: pointer;
  transition: var(--transition-fast);
}

.tree-item:hover .tree-action {
  opacity: 1;
}

.tree-item .tree-action:hover {
  background: var(--color-accent);
  border-color: var(--color-accent);
  color: #000;
}

.tree-children {
  padding-left: var(--space-4);
  margin-left: var(--space-3);
  border-left: 1px solid var(--color-border);
}

/* === Content Header Extensions === */
.content-header-left {
  display: flex;
  align-items: baseline;
  gap: var(--space-3);
}

.content-header-left h1 {
  font-size: 1.25rem;
  font-weight: 600;
}

.doc-count {
  font-size: 0.875rem;
  color: var(--color-text-muted);
}

.content-header-right {
  display: flex;
  align-items: center;
  gap: var(--space-3);
}

.search-box-inline {
  position: relative;
  display: flex;
  align-items: center;
}

.search-box-inline input {
  padding: var(--space-2) var(--space-3);
  padding-left: 32px;
  background: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  color: var(--color-text);
  font-size: 0.875rem;
  width: 200px;
}

.search-box-inline input:focus {
  outline: none;
  border-color: var(--color-accent);
}

.search-box-inline .icon {
  position: absolute;
  left: 10px;
  color: var(--color-text-muted);
}

/* === Doc Card Actions === */
.doc-card {
  position: relative;
}

.doc-card-actions {
  position: absolute;
  top: var(--space-3);
  right: var(--space-3);
  opacity: 0;
  transition: var(--transition-fast);
}

.doc-card:hover .doc-card-actions {
  opacity: 1;
}

.doc-card-actions .btn-icon-only {
  width: 28px;
  height: 28px;
  font-size: 0.875rem;
}

/* === Mobile Menu === */
.mobile-menu {
  display: none;
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: var(--color-bg);
  z-index: 1000;
  padding: var(--space-4);
}

.mobile-menu.open {
  display: block;
}

.mobile-menu-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: var(--space-4);
  padding-bottom: var(--space-4);
  border-bottom: 1px solid var(--color-border);
}

.mobile-menu-header span {
  font-weight: 600;
  font-size: 1.125rem;
}

.mobile-menu-content {
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
}

.mobile-menu-content a {
  display: block;
  padding: var(--space-3);
  background: var(--color-bg-secondary);
  border-radius: var(--radius-md);
  color: var(--color-text);
  text-decoration: none;
  font-size: 1rem;
}

.mobile-menu-content a:active {
  background: var(--color-bg-tertiary);
}

@media (max-width: 768px) {
  .mobile-menu {
    display: none;
  }
  .mobile-menu.open {
    display: block;
  }
}