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

:root {
  --bg: #0f1117;
  --surface: #1a1d27;
  --surface-hover: #22263a;
  --border: #2a2e3f;
  --text: #e4e6ef;
  --text-dim: #8b8fa3;
  --primary: #6366f1;
  --primary-hover: #818cf8;
  --accent: #22d3ee;
  --success: #34d399;
  --warning: #fbbf24;
  --danger: #f87171;
  --radius: 12px;
  --user-bg: #4338ca;
  --ai-bg: #1e2235;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
  min-height: 100vh;
}

#app {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

/* Header */
header {
  background: linear-gradient(135deg, #1e1b4b 0%, #312e81 50%, #1e1b4b 100%);
  padding: 1.2rem 1.5rem;
  border-bottom: 1px solid var(--border);
  flex-shrink: 0;
}

.header-inner {
  max-width: 900px;
  margin: 0 auto;
  text-align: center;
}

header h1 {
  font-size: 1.5rem;
  font-weight: 700;
  margin-bottom: 0.2rem;
  background: linear-gradient(to right, #c7d2fe, #a5b4fc, #818cf8);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.subtitle {
  color: var(--text-dim);
  font-size: 0.85rem;
  margin-bottom: 0.75rem;
}

.header-actions {
  display: flex;
  gap: 0.5rem;
  justify-content: center;
}

/* Buttons */
.btn-secondary {
  background: rgba(99, 102, 241, 0.15);
  color: var(--primary-hover);
  border: 1px solid rgba(99, 102, 241, 0.3);
  padding: 0.35rem 0.9rem;
  border-radius: 8px;
  cursor: pointer;
  font-size: 0.8rem;
  transition: all 0.2s;
}

.btn-secondary:hover {
  background: rgba(99, 102, 241, 0.25);
  border-color: var(--primary);
}

.btn-ghost {
  background: transparent;
  color: var(--text-dim);
  border: 1px solid var(--border);
  padding: 0.35rem 0.9rem;
  border-radius: 8px;
  cursor: pointer;
  font-size: 0.8rem;
  transition: all 0.2s;
}

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

/* Main / Chat Container */
main {
  flex: 1;
  max-width: 900px;
  margin: 0 auto;
  width: 100%;
  display: flex;
  flex-direction: column;
  overflow: hidden;
}

.chat-container {
  flex: 1;
  display: flex;
  flex-direction: column;
  min-height: 0;
}

/* Messages Area */
.messages {
  flex: 1;
  overflow-y: auto;
  padding: 1.5rem;
  scroll-behavior: smooth;
}

/* Message Bubbles */
.message {
  margin-bottom: 1.5rem;
  animation: fadeInUp 0.3s ease;
}

@keyframes fadeInUp {
  from { opacity: 0; transform: translateY(8px); }
  to { opacity: 1; transform: translateY(0); }
}

.message-user {
  display: flex;
  justify-content: flex-end;
}

.message-user .message-bubble {
  background: var(--user-bg);
  color: #e0e7ff;
  border-radius: 18px 18px 4px 18px;
  padding: 0.75rem 1.1rem;
  max-width: 75%;
  font-size: 0.95rem;
  line-height: 1.5;
  word-wrap: break-word;
}

.message-ai {
  display: flex;
  gap: 0.75rem;
  align-items: flex-start;
}

.ai-avatar {
  width: 32px;
  height: 32px;
  border-radius: 8px;
  background: var(--primary);
  flex-shrink: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  margin-top: 2px;
}

.ai-avatar svg {
  width: 20px;
  height: 20px;
}

.message-ai .message-bubble {
  background: var(--ai-bg);
  border: 1px solid var(--border);
  border-radius: 4px 18px 18px 18px;
  padding: 1rem 1.2rem;
  max-width: 85%;
  min-width: 60px;
  font-size: 0.95rem;
  line-height: 1.7;
}

/* Markdown Content inside AI bubbles */
.message-bubble .md-content h1,
.message-bubble .md-content h2,
.message-bubble .md-content h3,
.message-bubble .md-content h4 {
  color: var(--text);
  margin-top: 1rem;
  margin-bottom: 0.4rem;
}

.message-bubble .md-content h2 { font-size: 1.15rem; }
.message-bubble .md-content h3 { font-size: 1.05rem; }
.message-bubble .md-content h4 { font-size: 0.95rem; }

.message-bubble .md-content h2:first-child,
.message-bubble .md-content h3:first-child {
  margin-top: 0;
}

.message-bubble .md-content p {
  margin-bottom: 0.6rem;
  color: var(--text);
}

.message-bubble .md-content p:last-child {
  margin-bottom: 0;
}

.message-bubble .md-content ul,
.message-bubble .md-content ol {
  padding-left: 1.5rem;
  margin-bottom: 0.6rem;
}

.message-bubble .md-content li {
  margin-bottom: 0.3rem;
}

.message-bubble .md-content strong {
  color: #c7d2fe;
}

.message-bubble .md-content code {
  background: rgba(99, 102, 241, 0.15);
  color: var(--accent);
  padding: 0.15rem 0.4rem;
  border-radius: 4px;
  font-size: 0.88em;
  font-family: 'SF Mono', Monaco, 'Cascadia Code', monospace;
}

.message-bubble .md-content pre {
  background: #0d0f16;
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 0.8rem 1rem;
  overflow-x: auto;
  margin: 0.6rem 0;
}

.message-bubble .md-content pre code {
  background: none;
  padding: 0;
  color: var(--text);
}

.message-bubble .md-content blockquote {
  border-left: 3px solid var(--primary);
  padding-left: 0.8rem;
  margin: 0.6rem 0;
  color: var(--text-dim);
}

.message-bubble .md-content a {
  color: var(--primary-hover);
  text-decoration: none;
}

.message-bubble .md-content a:hover {
  text-decoration: underline;
}

.message-bubble .md-content hr {
  border: none;
  border-top: 1px solid var(--border);
  margin: 0.8rem 0;
}

/* Source Articles */
.source-articles {
  margin-top: 0.75rem;
  padding-top: 0.75rem;
  border-top: 1px solid var(--border);
}

.source-articles-label {
  font-size: 0.75rem;
  color: var(--text-dim);
  margin-bottom: 0.4rem;
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.source-link {
  display: block;
  color: var(--primary-hover);
  text-decoration: none;
  font-size: 0.82rem;
  padding: 0.2rem 0;
  transition: color 0.2s;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.source-link:hover {
  color: var(--accent);
  text-decoration: underline;
}

/* Typing Indicator */
.typing-indicator {
  display: inline-flex;
  gap: 4px;
  padding: 4px 0;
}

.typing-indicator span {
  width: 7px;
  height: 7px;
  background: var(--text-dim);
  border-radius: 50%;
  animation: bounce 1.4s ease-in-out infinite;
}

.typing-indicator span:nth-child(2) { animation-delay: 0.2s; }
.typing-indicator span:nth-child(3) { animation-delay: 0.4s; }

@keyframes bounce {
  0%, 60%, 100% { transform: translateY(0); }
  30% { transform: translateY(-6px); }
}

/* Error message */
.message-error .message-bubble {
  background: rgba(248, 113, 113, 0.1);
  border-color: rgba(248, 113, 113, 0.3);
  color: var(--danger);
}

/* Input Area */
.input-area {
  padding: 0.75rem 1.5rem 1rem;
  flex-shrink: 0;
}

.input-box {
  display: flex;
  align-items: flex-end;
  gap: 0.5rem;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 0.5rem;
  transition: border-color 0.2s;
}

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

.input-box textarea {
  flex: 1;
  background: none;
  border: none;
  color: var(--text);
  font-size: 0.95rem;
  padding: 0.5rem 0.5rem;
  outline: none;
  resize: none;
  max-height: 120px;
  line-height: 1.5;
  font-family: inherit;
}

.input-box textarea::placeholder {
  color: var(--text-dim);
}

#btn-send {
  background: var(--primary);
  color: white;
  border: none;
  width: 38px;
  height: 38px;
  border-radius: 8px;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: background 0.2s;
  flex-shrink: 0;
}

#btn-send:hover {
  background: var(--primary-hover);
}

#btn-send:disabled {
  opacity: 0.5;
  cursor: not-allowed;
}

#btn-send svg {
  width: 18px;
  height: 18px;
}

.input-hint {
  text-align: center;
  font-size: 0.72rem;
  color: var(--text-dim);
  margin-top: 0.4rem;
  opacity: 0.7;
}

/* Welcome Screen */
.welcome-screen {
  text-align: center;
  padding: 3rem 0 1rem;
}

.welcome-avatar {
  margin-bottom: 1rem;
}

.welcome-avatar svg {
  width: 64px;
  height: 64px;
}

.welcome-screen h2 {
  color: var(--text);
  font-size: 1.4rem;
  margin-bottom: 0.4rem;
}

.welcome-desc {
  color: var(--text-dim);
  font-size: 0.9rem;
  margin-bottom: 2rem;
}

.suggestion-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
  gap: 0.6rem;
  text-align: left;
}

.suggestion-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 0.8rem 1rem;
  cursor: pointer;
  transition: all 0.2s;
  display: flex;
  align-items: center;
  gap: 0.6rem;
  font-size: 0.88rem;
  color: var(--text);
  text-align: left;
  font-family: inherit;
}

.suggestion-card:hover {
  border-color: var(--primary);
  background: var(--surface-hover);
  transform: translateY(-1px);
}

.suggestion-icon {
  font-size: 1.3rem;
  flex-shrink: 0;
}

/* Stats Panel */
.stats-panel {
  position: fixed;
  top: 0;
  right: 0;
  bottom: 0;
  width: 380px;
  background: var(--surface);
  border-left: 1px solid var(--border);
  z-index: 100;
  box-shadow: -4px 0 20px rgba(0, 0, 0, 0.5);
  animation: slideIn 0.3s ease;
  overflow-y: auto;
}

@keyframes slideIn {
  from { transform: translateX(100%); }
  to { transform: translateX(0); }
}

.stats-content {
  padding: 1.5rem;
}

.stats-content h3 {
  font-size: 1.2rem;
  margin-bottom: 1rem;
}

.close-btn {
  float: right;
  background: none;
  border: none;
  color: var(--text-dim);
  font-size: 1.5rem;
  cursor: pointer;
}

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

.stat-item {
  background: var(--bg);
  border-radius: 8px;
  padding: 1rem;
  margin-bottom: 0.75rem;
}

.stat-item .label {
  color: var(--text-dim);
  font-size: 0.8rem;
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.stat-item .value {
  font-size: 1.3rem;
  font-weight: 700;
  color: var(--primary-hover);
}

/* Update Banner */
.update-banner {
  background: rgba(99, 102, 241, 0.1);
  border: 1px solid rgba(99, 102, 241, 0.3);
  border-radius: var(--radius);
  padding: 0.75rem 1rem;
  margin: 0.75rem 1.5rem 0;
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-shrink: 0;
}

.update-banner p {
  color: var(--primary-hover);
  font-size: 0.85rem;
}

.update-banner button {
  background: none;
  border: none;
  color: var(--text-dim);
  cursor: pointer;
  font-size: 0.8rem;
}

/* Footer */
footer {
  text-align: center;
  padding: 1rem;
  color: var(--text-dim);
  font-size: 0.75rem;
  border-top: 1px solid var(--border);
  flex-shrink: 0;
}

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

footer a:hover {
  text-decoration: underline;
}

/* Utility */
.hidden {
  display: none !important;
}

/* Scrollbar */
.messages::-webkit-scrollbar {
  width: 6px;
}

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

.messages::-webkit-scrollbar-thumb {
  background: var(--border);
  border-radius: 3px;
}

.messages::-webkit-scrollbar-thumb:hover {
  background: var(--text-dim);
}

/* Responsive */
@media (max-width: 600px) {
  header { padding: 1rem; }
  header h1 { font-size: 1.2rem; }
  .subtitle { font-size: 0.8rem; }
  .messages { padding: 1rem; }
  .input-area { padding: 0.5rem 1rem 0.75rem; }
  .suggestion-grid { grid-template-columns: 1fr 1fr; }
  .stats-panel { width: 100%; }
  .message-user .message-bubble { max-width: 85%; }
  .message-ai .message-bubble { max-width: 95%; }
  .welcome-screen { padding: 1.5rem 0 0.5rem; }
}