:root {
  --bg-primary: #0a0a0f;
  --bg-secondary: #12121a;
  --bg-surface: #1a1a25;
  --bg-surface-hover: #22222f;
  --bg-overlay: rgba(10, 10, 15, 0.85);
  --border: #2a2a3a;
  --border-focus: #10b981;

  --text-primary: #e8e8ef;
  --text-secondary: #8888a0;
  --text-muted: #55556a;

  --accent: #10b981;
  --accent-hover: #059669;
  --accent-dim: rgba(16, 185, 129, 0.15);
  --accent-glow: rgba(16, 185, 129, 0.25);

  --danger: #ef4444;
  --danger-dim: rgba(239, 68, 68, 0.15);
  --warning: #f59e0b;
  --info: #3b82f6;

  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 16px;

  --font-mono: "JetBrains Mono", "Fira Code", monospace;
  --font-sans: system-ui, -apple-system, sans-serif;

  --transition: 150ms ease;
}

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

html, body {
  height: 100%;
  font-family: var(--font-sans);
  font-size: 14px;
  background: var(--bg-primary);
  color: var(--text-primary);
  -webkit-font-smoothing: antialiased;
}

body {
  display: flex;
  flex-direction: column;
}

/* Header */
.header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 12px 20px;
  background: var(--bg-secondary);
  border-bottom: 1px solid var(--border);
  flex-shrink: 0;
}

.header h1 {
  font-size: 18px;
  font-weight: 600;
  color: var(--accent);
  letter-spacing: -0.02em;
}

.header nav {
  display: flex;
  gap: 4px;
}

.header nav button {
  padding: 6px 14px;
  border: none;
  background: transparent;
  color: var(--text-secondary);
  border-radius: var(--radius-sm);
  cursor: pointer;
  font-size: 13px;
  font-weight: 500;
  transition: all var(--transition);
}

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

.header nav button.active {
  background: var(--accent-dim);
  color: var(--accent);
}

/* Main content */
.main {
  flex: 1;
  overflow: hidden;
  position: relative;
}

.view {
  display: none;
  height: 100%;
  overflow-y: auto;
  padding: 20px;
}

.view.active {
  display: block;
}

/* Upload zone */
.upload-zone {
  border: 2px dashed var(--border);
  border-radius: var(--radius-lg);
  padding: 60px 40px;
  text-align: center;
  transition: all var(--transition);
  cursor: pointer;
}

.upload-zone:hover,
.upload-zone.dragover {
  border-color: var(--accent);
  background: var(--accent-dim);
}

.upload-zone h2 {
  font-size: 18px;
  font-weight: 500;
  margin-bottom: 8px;
}

.upload-zone p {
  color: var(--text-secondary);
  font-size: 13px;
}

.upload-zone input[type="file"] {
  display: none;
}

/* Upload queue */
.upload-queue {
  margin-top: 20px;
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.upload-item {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 12px 16px;
  background: var(--bg-surface);
  border-radius: var(--radius-md);
  border: 1px solid var(--border);
}

.upload-item .name {
  flex: 1;
  font-size: 13px;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.upload-item .size {
  color: var(--text-muted);
  font-size: 12px;
  font-family: var(--font-mono);
}

.upload-item .status {
  font-size: 12px;
  font-weight: 500;
  padding: 2px 8px;
  border-radius: var(--radius-sm);
}

.upload-item .status.pending { background: var(--accent-dim); color: var(--accent); }
.upload-item .status.done { background: var(--accent-dim); color: var(--accent); }
.upload-item .status.error { background: var(--danger-dim); color: var(--danger); }

/* Progress bar */
.progress-bar {
  flex: 1;
  height: 6px;
  background: var(--bg-primary);
  border-radius: 3px;
  overflow: hidden;
}

.progress-bar .fill {
  height: 100%;
  background: var(--accent);
  border-radius: 3px;
  transition: width 300ms ease;
  width: 0%;
}

/* Library */
.doc-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 12px;
}

.doc-card {
  padding: 16px;
  background: var(--bg-surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  transition: all var(--transition);
  cursor: pointer;
}

.doc-card:hover {
  border-color: var(--accent);
  background: var(--bg-surface-hover);
}

.doc-card .title {
  font-size: 14px;
  font-weight: 500;
  margin-bottom: 6px;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.doc-card .meta {
  display: flex;
  gap: 12px;
  font-size: 12px;
  color: var(--text-secondary);
}

.doc-card .meta .tag {
  padding: 1px 6px;
  background: var(--accent-dim);
  color: var(--accent);
  border-radius: var(--radius-sm);
  font-size: 11px;
}

.doc-card .summary {
  margin-top: 8px;
  font-size: 12px;
  color: var(--text-secondary);
  line-height: 1.5;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.doc-card .actions {
  margin-top: 10px;
  display: flex;
  justify-content: flex-end;
}

.doc-card .actions button {
  padding: 4px 8px;
  border: none;
  background: transparent;
  color: var(--text-muted);
  cursor: pointer;
  font-size: 12px;
  border-radius: var(--radius-sm);
  transition: all var(--transition);
}

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

/* Search bar */
.search-bar {
  margin-bottom: 16px;
}

.search-bar input {
  width: 100%;
  padding: 10px 16px;
  background: var(--bg-surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  color: var(--text-primary);
  font-size: 14px;
  outline: none;
  transition: border-color var(--transition);
}

.search-bar input:focus {
  border-color: var(--accent);
}

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

/* Empty state */
.empty-state {
  text-align: center;
  padding: 60px 20px;
  color: var(--text-secondary);
}

.empty-state h3 {
  font-size: 16px;
  font-weight: 500;
  margin-bottom: 6px;
  color: var(--text-primary);
}

/* Login */
.login-screen {
  display: flex;
  align-items: center;
  justify-content: center;
  height: 100%;
  padding: 20px;
}

.login-box {
  background: var(--bg-surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 32px;
  width: 100%;
  max-width: 360px;
}

.login-box h2 {
  font-size: 20px;
  font-weight: 600;
  margin-bottom: 20px;
  color: var(--accent);
}

.login-box input {
  width: 100%;
  padding: 10px 14px;
  background: var(--bg-primary);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  color: var(--text-primary);
  font-size: 14px;
  outline: none;
  margin-bottom: 12px;
}

.login-box input:focus {
  border-color: var(--accent);
}

.login-box button {
  width: 100%;
  padding: 10px;
  background: var(--accent);
  color: #fff;
  border: none;
  border-radius: var(--radius-md);
  font-size: 14px;
  font-weight: 500;
  cursor: pointer;
  transition: background var(--transition);
}

.login-box button:hover {
  background: var(--accent-hover);
}

/* Utility */
.badge {
  display: inline-block;
  padding: 2px 8px;
  border-radius: var(--radius-sm);
  font-size: 11px;
  font-weight: 500;
}

.badge.pending { background: #f59e0b20; color: var(--warning); }
.badge.processing { background: var(--accent-dim); color: var(--accent); }
.badge.ready { background: #10b98120; color: var(--accent); }
.badge.failed { background: var(--danger-dim); color: var(--danger); }

/* Chat */
.chat-container {
  display: flex;
  flex-direction: column;
  height: 100%;
}

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

.chat-header select {
  flex: 1;
  padding: 6px 10px;
  background: var(--bg-surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  color: var(--text-primary);
  font-size: 13px;
  outline: none;
}

.model-toggle button {
  padding: 4px 10px;
  border: 1px solid var(--border);
  background: var(--accent-dim);
  color: var(--accent);
  border-radius: var(--radius-sm);
  cursor: pointer;
  font-size: 12px;
  font-weight: 600;
  text-transform: uppercase;
  transition: all var(--transition);
}

.model-toggle button:hover {
  background: var(--accent);
  color: #fff;
}

.chat-messages {
  flex: 1;
  overflow-y: auto;
  padding: 16px;
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.msg {
  max-width: 85%;
  padding: 10px 14px;
  border-radius: var(--radius-md);
  font-size: 14px;
  line-height: 1.6;
  word-wrap: break-word;
  white-space: pre-wrap;
}

.msg.user {
  align-self: flex-end;
  background: var(--accent-dim);
  color: var(--text-primary);
  border: 1px solid var(--accent);
}

.msg.assistant {
  align-self: flex-start;
  background: var(--bg-surface);
  border: 1px solid var(--border);
}

.msg.assistant .sources {
  margin-top: 8px;
  padding-top: 8px;
  border-top: 1px solid var(--border);
  font-size: 11px;
  color: var(--text-secondary);
}

.msg.assistant .sources .src {
  display: inline-block;
  padding: 1px 6px;
  margin: 2px 2px;
  background: var(--accent-dim);
  color: var(--accent);
  border-radius: var(--radius-sm);
  cursor: default;
}

.msg.streaming::after {
  content: '';
  display: inline-block;
  width: 6px;
  height: 14px;
  background: var(--accent);
  margin-left: 2px;
  animation: blink 0.8s infinite;
  vertical-align: text-bottom;
}

@keyframes blink {
  0%, 50% { opacity: 1; }
  51%, 100% { opacity: 0; }
}

.chat-input-area {
  display: flex;
  gap: 8px;
  padding: 12px 16px;
  border-top: 1px solid var(--border);
  background: var(--bg-secondary);
  flex-shrink: 0;
}

.chat-input-area textarea {
  flex: 1;
  padding: 10px 14px;
  background: var(--bg-surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  color: var(--text-primary);
  font-size: 14px;
  font-family: var(--font-sans);
  resize: none;
  outline: none;
  max-height: 120px;
  line-height: 1.4;
}

.chat-input-area textarea:focus {
  border-color: var(--accent);
}

.chat-input-area button {
  padding: 10px 20px;
  background: var(--accent);
  color: #fff;
  border: none;
  border-radius: var(--radius-md);
  font-size: 14px;
  font-weight: 500;
  cursor: pointer;
  transition: background var(--transition);
  align-self: flex-end;
}

.chat-input-area button:hover {
  background: var(--accent-hover);
}

.chat-input-area button:disabled {
  opacity: 0.5;
  cursor: not-allowed;
}

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