:root {
  --bg-primary: #0f172a;
  --bg-secondary: #1e293b;
  --bg-tertiary: #334155;
  --text-main: #f8fafc;
  --text-muted: #94a3b8;
  --accent: #10b981;
  --accent-hover: #059669;
  --border-color: #334155;
  --user-bubble: #2563eb;
  --assistant-bubble: #1e293b;
  --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
  --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1);
  --radius-lg: 16px;
  --radius-md: 10px;
  --radius-sm: 6px;
}

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

body {
  font-family: 'Inter', system-ui, -apple-system, sans-serif;
  background-color: var(--bg-primary);
  color: var(--text-main);
  height: 100vh;
  display: flex;
  justify-content: center;
  align-items: center;
  overflow: hidden;
}

.app-container {
  width: 100%;
  max-width: 1000px;
  height: 96vh;
  background-color: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  display: flex;
  flex-direction: column;
  box-shadow: 0 20px 25px -5px rgb(0 0 0 / 0.3);
  overflow: hidden;
}

/* Header */
.chat-header {
  padding: 16px 24px;
  background-color: var(--bg-primary);
  border-bottom: 1px solid var(--border-color);
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 12px;
}

.brand {
  display: flex;
  align-items: center;
  gap: 12px;
}

.brand-logo {
  background: linear-gradient(135deg, #10b981, #047857);
  color: white;
  font-weight: 800;
  font-size: 1.1rem;
  padding: 8px 12px;
  border-radius: var(--radius-sm);
  letter-spacing: 1px;
}

.brand-info h1 {
  font-size: 1.15rem;
  font-weight: 700;
  color: var(--text-main);
}

.brand-info .subtitle {
  font-size: 0.8rem;
  color: var(--text-muted);
}

.header-controls {
  display: flex;
  align-items: center;
  gap: 16px;
}

.status-badge {
  display: flex;
  align-items: center;
  gap: 8px;
  background-color: rgba(16, 185, 129, 0.1);
  border: 1px solid rgba(16, 185, 129, 0.3);
  padding: 6px 12px;
  border-radius: 9999px;
  font-size: 0.8rem;
  color: var(--accent);
  font-weight: 500;
}

.status-dot {
  width: 8px;
  height: 8px;
  background-color: var(--accent);
  border-radius: 50%;
  box-shadow: 0 0 8px var(--accent);
  animation: pulse 2s infinite;
}

@keyframes pulse {
  0% { transform: scale(0.95); opacity: 0.8; }
  50% { transform: scale(1.15); opacity: 1; }
  100% { transform: scale(0.95); opacity: 0.8; }
}

.model-select-wrapper {
  display: flex;
  align-items: center;
  gap: 6px;
  font-size: 0.8rem;
  color: var(--text-muted);
}

.model-select-wrapper select {
  background-color: var(--bg-tertiary);
  border: 1px solid var(--border-color);
  color: var(--text-main);
  padding: 5px 10px;
  border-radius: var(--radius-sm);
  font-size: 0.8rem;
  outline: none;
  cursor: pointer;
}

/* Quick test bar */
.quick-test-bar {
  padding: 10px 24px;
  background-color: rgba(15, 23, 42, 0.6);
  border-bottom: 1px solid var(--border-color);
  display: flex;
  align-items: center;
  gap: 8px;
  overflow-x: auto;
  white-space: nowrap;
}

.quick-title {
  font-size: 0.75rem;
  color: var(--text-muted);
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.test-btn {
  background-color: var(--bg-tertiary);
  border: 1px solid var(--border-color);
  color: var(--text-main);
  padding: 6px 12px;
  border-radius: 9999px;
  font-size: 0.78rem;
  cursor: pointer;
  transition: all 0.15s ease;
}

.test-btn:hover {
  background-color: #475569;
  border-color: #64748b;
  transform: translateY(-1px);
}

/* Chat area */
.chat-main {
  flex: 1;
  padding: 24px;
  overflow-y: auto;
  display: flex;
  flex-direction: column;
  gap: 20px;
}

.message {
  display: flex;
  gap: 12px;
  max-width: 85%;
  animation: fadeIn 0.2s ease forwards;
}

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(6px); }
  to { opacity: 1; transform: translateY(0); }
}

.user-message {
  align-self: flex-end;
  flex-direction: row-reverse;
}

.assistant-message {
  align-self: flex-start;
}

.message-avatar {
  width: 36px;
  height: 36px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.75rem;
  font-weight: 700;
  flex-shrink: 0;
}

.assistant-message .message-avatar {
  background-color: var(--accent);
  color: white;
}

.user-message .message-avatar {
  background-color: var(--user-bubble);
  color: white;
}

.message-content {
  background-color: var(--assistant-bubble);
  border: 1px solid var(--border-color);
  padding: 14px 18px;
  border-radius: var(--radius-md);
  font-size: 0.92rem;
  line-height: 1.6;
}

.user-message .message-content {
  background-color: var(--user-bubble);
  border-color: transparent;
  color: white;
}

.message-content p {
  margin-bottom: 8px;
}

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

.message-content strong {
  color: #38bdf8;
}

.user-message .message-content strong {
  color: white;
}

.help-hint {
  margin-top: 8px;
  padding: 8px 12px;
  background-color: rgba(255, 255, 255, 0.05);
  border-left: 3px solid var(--accent);
  border-radius: 4px;
  font-size: 0.83rem;
  color: var(--text-muted);
}

/* Sources accordion */
.sources-container {
  margin-top: 12px;
  border-top: 1px dashed var(--border-color);
  padding-top: 8px;
}

.sources-toggle {
  font-size: 0.75rem;
  color: var(--text-muted);
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  gap: 4px;
  background: none;
  border: none;
  padding: 4px 0;
}

.sources-toggle:hover {
  color: #38bdf8;
}

.sources-list {
  margin-top: 8px;
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.source-item {
  background-color: rgba(15, 23, 42, 0.5);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  padding: 8px 12px;
  font-size: 0.78rem;
  color: #cbd5e1;
}

.source-header {
  display: flex;
  justify-content: space-between;
  margin-bottom: 4px;
  font-weight: 600;
  color: var(--accent);
}

/* Typing indicator */
.typing-indicator {
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 10px 24px;
  background-color: rgba(15, 23, 42, 0.4);
  border-top: 1px solid var(--border-color);
  font-size: 0.82rem;
  color: var(--text-muted);
}

.dot {
  width: 6px;
  height: 6px;
  background-color: var(--accent);
  border-radius: 50%;
  animation: bounce 1.4s infinite ease-in-out both;
}

.dot:nth-child(1) { animation-delay: -0.32s; }
.dot:nth-child(2) { animation-delay: -0.16s; }

@keyframes bounce {
  0%, 80%, 100% { transform: scale(0); }
  40% { transform: scale(1); }
}

/* Footer / Input */
.chat-footer {
  padding: 16px 24px;
  background-color: var(--bg-primary);
  border-top: 1px solid var(--border-color);
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.input-form {
  display: flex;
  gap: 12px;
  align-items: flex-end;
}

.input-form textarea {
  flex: 1;
  background-color: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 12px 16px;
  color: var(--text-main);
  font-family: inherit;
  font-size: 0.92rem;
  resize: none;
  min-height: 44px;
  max-height: 120px;
  outline: none;
  transition: border-color 0.15s ease;
}

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

.send-btn {
  background-color: var(--accent);
  color: white;
  border: none;
  border-radius: var(--radius-md);
  width: 44px;
  height: 44px;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: background-color 0.15s ease, transform 0.1s ease;
  flex-shrink: 0;
}

.send-btn:hover {
  background-color: var(--accent-hover);
  transform: scale(1.03);
}

.send-btn:disabled {
  background-color: var(--bg-tertiary);
  cursor: not-allowed;
  opacity: 0.5;
  transform: none;
}

.footer-meta {
  display: flex;
  justify-content: center;
  font-size: 0.72rem;
  color: var(--text-muted);
}