:root {
  --primary: #6A22FF;
  --primary-dark: #3D1A8F;
  --primary-light: #F0EDFF;
  --text: #1a1a2e;
  --text-muted: #6b6b80;
  --border: #e2e2ea;
  --bg: #f8f8fc;
  --card-bg: #ffffff;
  --danger: #E53935;
  --success: #43A047;
  --warning: #F9A825;
}

* { box-sizing: border-box; margin: 0; padding: 0; }

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Arial, sans-serif;
  color: var(--text);
  background: var(--bg);
  min-height: 100vh;
}

.screen { min-height: 100vh; }
.hidden { display: none !important; }

/* Login */
.login-card {
  max-width: 400px;
  margin: 120px auto;
  background: var(--card-bg);
  padding: 40px;
  border-radius: 16px;
  box-shadow: 0 2px 20px rgba(0,0,0,0.06);
}
.login-card h1 { margin-bottom: 24px; color: var(--primary); }
.login-card input {
  width: 100%;
  padding: 12px 16px;
  border: 1px solid var(--border);
  border-radius: 8px;
  font-size: 15px;
  margin-bottom: 12px;
}
.login-card button {
  width: 100%;
  padding: 12px;
  background: var(--primary);
  color: #fff;
  border: none;
  border-radius: 8px;
  font-size: 15px;
  font-weight: 600;
  cursor: pointer;
}
.login-card button:hover { background: var(--primary-dark); }
.error { color: var(--danger); font-size: 13px; margin-bottom: 8px; min-height: 18px; }

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

.sidebar {
  width: 240px;
  background: var(--card-bg);
  border-right: 1px solid var(--border);
  padding: 20px 0;
  display: flex;
  flex-direction: column;
  position: fixed;
  top: 0;
  left: 0;
  bottom: 0;
  overflow-y: auto;
  transition: width 0.2s ease;
}
.sidebar-top {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 12px 12px 20px;
  border-bottom: 1px solid var(--border);
  margin-bottom: 8px;
}
.sidebar-brand {
  font-size: 18px;
  font-weight: 700;
  color: var(--primary);
}
.sidebar-toggle {
  background: none;
  border: none;
  font-size: 18px;
  cursor: pointer;
  color: var(--text-muted);
  padding: 4px 6px;
  border-radius: 6px;
  line-height: 1;
}
.sidebar-toggle:hover { background: var(--primary-light); color: var(--primary); }

/* Collapsed sidebar */
.sidebar.collapsed {
  width: 48px;
  overflow: hidden;
}
.sidebar.collapsed .sidebar-top {
  padding: 0;
  justify-content: center;
  border-bottom: 1px solid var(--border);
}
.sidebar.collapsed .sidebar-brand { display: none; }
.sidebar.collapsed .sidebar-toggle { padding: 12px 0; }
.sidebar.collapsed .nav-item { font-size: 0; padding: 10px 0; text-align: center; }
.sidebar.collapsed .nav-item::before {
  font-size: 16px;
  display: block;
}
.sidebar.collapsed + .content { margin-left: 48px; }
.nav-item {
  display: block;
  padding: 10px 20px;
  color: var(--text-muted);
  text-decoration: none;
  font-size: 14px;
  font-weight: 500;
  border-left: 3px solid transparent;
}
.nav-item:hover { background: var(--primary-light); color: var(--text); }
.nav-item.active { color: var(--primary); border-left-color: var(--primary); background: var(--primary-light); }
.nav-logout { margin-top: auto; color: var(--danger); }

.content {
  flex: 1;
  margin-left: 240px;
  padding: 32px;
  transition: margin-left 0.2s ease;
}

.section h2 { margin-bottom: 20px; font-size: 22px; }

/* Toolbar */
.toolbar {
  display: flex;
  gap: 12px;
  margin-bottom: 20px;
  align-items: center;
}
.toolbar input, .toolbar select {
  padding: 8px 14px;
  border: 1px solid var(--border);
  border-radius: 8px;
  font-size: 14px;
}
.btn-primary {
  padding: 8px 20px;
  background: var(--primary);
  color: #fff;
  border: none;
  border-radius: 8px;
  font-size: 14px;
  font-weight: 600;
  cursor: pointer;
}
.btn-primary:hover { background: var(--primary-dark); }
.btn-secondary {
  padding: 8px 20px;
  background: var(--card-bg);
  color: var(--text);
  border: 1px solid var(--border);
  border-radius: 8px;
  font-size: 14px;
  cursor: pointer;
}
.btn-danger { background: var(--danger); color: #fff; border: none; padding: 6px 14px; border-radius: 6px; cursor: pointer; font-size: 13px; }

/* Stats grid */
.stats-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(200px, 1fr)); gap: 16px; }
.stat-card {
  background: var(--card-bg);
  padding: 20px;
  border-radius: 12px;
  border: 1px solid var(--border);
}
.stat-card .stat-value { font-size: 28px; font-weight: 700; color: var(--primary); }
.stat-card .stat-label { font-size: 13px; color: var(--text-muted); margin-top: 4px; }

/* Data table */
.data-table { width: 100%; border-collapse: collapse; background: var(--card-bg); border-radius: 12px; overflow: hidden; border: 1px solid var(--border); }
.data-table th { text-align: left; padding: 12px 16px; font-size: 12px; text-transform: uppercase; color: var(--text-muted); background: var(--bg); border-bottom: 1px solid var(--border); }
.data-table td { padding: 12px 16px; font-size: 14px; border-bottom: 1px solid var(--border); }
.data-table tr:last-child td { border-bottom: none; }
.data-table tr:hover td { background: var(--primary-light); }

/* Card list */
.card-list { display: flex; flex-direction: column; gap: 12px; }
.card-item {
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 16px 20px;
  display: flex;
  justify-content: space-between;
  align-items: center;
}
.card-item-info h3 { font-size: 16px; margin-bottom: 4px; }
.card-item-info p { font-size: 13px; color: var(--text-muted); }
.card-item-actions { display: flex; gap: 8px; }

/* KB folder layout */
.kb-layout { display: flex; gap: 20px; }
.kb-sidebar { width: 220px; flex-shrink: 0; }
.kb-docs { flex: 1; min-width: 0; }
.kb-folder-item {
  padding: 8px 12px;
  font-size: 14px;
  cursor: pointer;
  border-radius: 8px;
  margin-bottom: 2px;
  color: var(--text-muted);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}
.kb-folder-item:hover { background: var(--primary-light); color: var(--text); }
.kb-folder-active { background: var(--primary-light); color: var(--primary); font-weight: 600; }
.kb-folder-child { padding-left: 28px; font-size: 13px; }
.kb-folder-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
}
.kb-folder-actions { display: flex; gap: 4px; opacity: 0; transition: opacity 0.15s; }
.kb-folder-item:hover .kb-folder-actions { opacity: 1; }
.kb-folder-action-btn {
  background: none; border: none; cursor: pointer; font-size: 13px;
  color: var(--text-muted); padding: 0 4px; line-height: 1;
}
.kb-folder-action-btn:hover { color: var(--danger); }

@media (max-width: 768px) {
  .kb-layout { flex-direction: column; }
  .kb-sidebar { width: 100%; display: flex; gap: 8px; flex-wrap: wrap; }
  .kb-folder-child { padding-left: 12px; }
}

/* Upload progress bar */
.upload-progress {
  margin-top: 16px;
}
.upload-progress-bar-track {
  width: 100%;
  height: 8px;
  background: var(--border);
  border-radius: 4px;
  overflow: hidden;
}
.upload-progress-bar-fill {
  height: 100%;
  background: var(--primary);
  border-radius: 4px;
  width: 0%;
  transition: width 0.3s ease;
}
.upload-progress-label {
  display: flex;
  justify-content: space-between;
  font-size: 12px;
  color: var(--text-muted);
  margin-top: 6px;
}

/* Document links */
.doc-link {
  color: var(--primary);
  text-decoration: none;
  font-weight: 500;
}
.doc-link:hover { text-decoration: underline; }

/* Document viewer */
.doc-viewer {
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: 16px;
  overflow: hidden;
}
.doc-viewer-header {
  padding: 20px 24px;
  border-bottom: 1px solid var(--border);
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 16px;
}
.doc-viewer-header h3 {
  font-size: 18px;
  margin: 0;
  word-break: break-word;
  cursor: pointer;
}
.doc-viewer-header h3:hover .rename-hint { opacity: 1; }
.rename-hint {
  font-size: 14px;
  opacity: 0.3;
  transition: opacity 0.15s;
}
/* Name cell: pencil pinned to the right edge, same position for every row */
.data-table td:has(.btn-rename) {
  position: relative;
  padding-right: 32px;
}
.btn-rename {
  position: absolute;
  right: 8px;
  top: 50%;
  transform: translateY(-50%);
  background: none;
  border: none;
  cursor: pointer;
  font-size: 13px;
  opacity: 0;
  padding: 4px;
  transition: opacity 0.15s;
}
.data-table tr:hover .btn-rename { opacity: 0.4; }
.btn-rename:hover { opacity: 1 !important; }
.doc-viewer-back {
  background: none;
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 6px 14px;
  font-size: 13px;
  cursor: pointer;
  white-space: nowrap;
  color: var(--text-muted);
}
.doc-viewer-back:hover { background: var(--bg); color: var(--text); }
.doc-viewer-meta {
  padding: 16px 24px;
  background: var(--bg);
  display: flex;
  flex-wrap: wrap;
  gap: 20px;
  border-bottom: 1px solid var(--border);
  font-size: 13px;
}
.doc-meta-item { display: flex; flex-direction: column; gap: 2px; }
.doc-meta-label { color: var(--text-muted); font-size: 11px; text-transform: uppercase; letter-spacing: 0.5px; }
.doc-meta-value { color: var(--text); font-weight: 500; }
.doc-viewer-content {
  padding: 24px;
  max-height: 65vh;
  overflow-y: auto;
  font-size: 14px;
  line-height: 1.7;
  white-space: pre-wrap;
  word-break: break-word;
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Arial, sans-serif;
  color: var(--text);
}

/* Status badges */
.badge {
  display: inline-block;
  padding: 2px 10px;
  border-radius: 12px;
  font-size: 12px;
  font-weight: 600;
}
.badge-success { background: #e8f5e9; color: var(--success); }
.badge-warning { background: #fff8e1; color: var(--warning); }
.badge-danger { background: #ffebee; color: var(--danger); }
.badge-muted { background: #f5f5f5; color: var(--text-muted); }

/* Modal */
.modal {
  position: fixed;
  top: 0; left: 0; right: 0; bottom: 0;
  background: rgba(0,0,0,0.4);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 1000;
}
.modal-content {
  background: var(--card-bg);
  border-radius: 16px;
  padding: 32px;
  width: 90%;
  max-width: 520px;
  max-height: 80vh;
  overflow-y: auto;
  position: relative;
}
.modal-close {
  position: absolute;
  top: 12px;
  right: 16px;
  background: none;
  border: none;
  font-size: 24px;
  cursor: pointer;
  color: var(--text-muted);
}
.modal-content h3 { margin-bottom: 16px; }
.modal-content label { display: block; font-size: 13px; color: var(--text-muted); margin-bottom: 4px; margin-top: 12px; }
.modal-content input, .modal-content select, .modal-content textarea {
  width: 100%;
  padding: 10px 14px;
  border: 1px solid var(--border);
  border-radius: 8px;
  font-size: 14px;
}
.modal-content textarea { min-height: 80px; resize: vertical; }
.modal-content .btn-primary { margin-top: 20px; width: 100%; padding: 12px; }

/* Responsive */
@media (max-width: 768px) {
  .sidebar { width: 200px; }
  .content { margin-left: 200px; padding: 20px; }
  .stats-grid { grid-template-columns: repeat(2, 1fr); }
}