/* ── Reset & Base ───────────────────────────────────────────────────── */

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

:root {
  --bg: #ffffff;
  --bg-secondary: #f9fafb;
  --sidebar-bg: #f7f7f8;
  --sidebar-hover: #e5e5e7;
  --surface: #ffffff;
  --primary: #1f2937;
  --primary-hover: #374151;
  --text: #1f2937;
  --text-secondary: #6b7280;
  --text-muted: #9ca3af;
  --border: #e5e7eb;
  --user-msg: rgb(244, 244, 244);
  --user-text: #1f2937;
  --assistant-msg: #ffffff;
  --assistant-text: #1f2937;
  --danger: #ef4444;
  --success: #22c55e;
  --radius: 12px;
  --radius-sm: 8px;
  --shadow: 0 1px 3px rgba(0,0,0,0.08);
  --shadow-lg: 0 4px 16px rgba(0,0,0,0.12);
  --sidebar-width: 220px;
  --sidebar-collapsed: 0px;
  --topbar-height: 56px;
  --max-width: 760px;
}

html, body {
  height: 100%;
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  font-size: 16px;
  line-height: 1.5;
  color: var(--text);
  background: var(--bg);
  -webkit-font-smoothing: antialiased;
}

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

input, textarea {
  font: inherit;
  outline: none;
}

/* ── App Layout ────────────────────────────────────────────────────── */

.app-layout {
  display: flex;
  height: 100vh;
}

/* ── Sidebar (collapsed by default) ────────────────────────────────── */

.sidebar {
  width: var(--sidebar-collapsed);
  overflow: hidden;
  background: var(--sidebar-bg);
  border-right: 1px solid var(--border);
  display: flex;
  flex-direction: column;
  transition: width 0.2s ease;
  flex-shrink: 0;
}

.sidebar.open {
  width: var(--sidebar-width);
}

.sidebar-inner {
  width: var(--sidebar-width);
  height: 100%;
  display: flex;
  flex-direction: column;
}

.sidebar-top {
  padding: 8px;
  border-bottom: 1px solid var(--border);
}

.sidebar-nav {
  flex: 1;
  padding: 8px;
  overflow-y: auto;
}

.sidebar-footer {
  padding: 8px;
  border-top: 1px solid var(--border);
}

.sidebar-btn {
  display: flex;
  align-items: center;
  gap: 12px;
  width: 100%;
  padding: 10px 12px;
  border-radius: var(--radius-sm);
  font-size: 0.88rem;
  color: var(--text);
  transition: background 0.15s;
}

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

.sidebar-btn svg {
  width: 18px;
  height: 18px;
  flex-shrink: 0;
}

.sidebar-btn .label {
  white-space: nowrap;
}

.new-chat-btn {
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  justify-content: space-between;
  color: var(--text);
}

.new-chat-btn:hover {
  background: var(--sidebar-hover);
}

/* ── Main area ─────────────────────────────────────────────────────── */

.main-area {
  flex: 1;
  display: flex;
  flex-direction: column;
  min-width: 0;
  height: 100vh;
  overflow: hidden;
}

/* ── Top bar ───────────────────────────────────────────────────────── */

.topbar {
  display: flex;
  align-items: center;
  height: var(--topbar-height);
  padding: 0 16px;
  border-bottom: 1px solid var(--border);
  background: var(--bg);
  position: sticky;
  top: 0;
  z-index: 10;
  flex-shrink: 0;
}

.topbar-left {
  display: flex;
  align-items: center;
  gap: 8px;
}

.hamburger-btn {
  padding: 8px;
  border-radius: var(--radius-sm);
  transition: background 0.15s;
}

.hamburger-btn:hover {
  background: var(--bg-secondary);
}

.hamburger-btn svg {
  width: 20px;
  height: 20px;
}

.topbar-center {
  position: absolute;
  left: 50%;
  transform: translateX(-50%);
  display: flex;
  align-items: center;
}

.tenant-trigger {
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 6px 14px;
  border-radius: 20px;
  font-size: 0.88rem;
  font-weight: 500;
  color: var(--text);
  transition: background 0.15s;
  position: relative;
}

.tenant-trigger:hover {
  background: var(--bg-secondary);
}

.tenant-trigger .arrow {
  font-size: 0.65rem;
  color: var(--text-muted);
  transition: transform 0.2s;
}

.tenant-trigger .arrow.open {
  transform: rotate(180deg);
}

.tenant-dropdown {
  display: none;
  position: absolute;
  top: 100%;
  left: 50%;
  transform: translateX(-50%);
  margin-top: 8px;
  min-width: 180px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow-lg);
  z-index: 100;
  overflow: hidden;
}

.tenant-dropdown.open {
  display: block;
}

.tenant-option {
  padding: 10px 14px;
  font-size: 0.88rem;
  cursor: pointer;
  transition: background 0.15s;
}

.tenant-option:hover {
  background: var(--bg-secondary);
}

.tenant-option.active {
  color: var(--primary);
  font-weight: 600;
}

/* ── Login Screen ──────────────────────────────────────────────────── */

#login-screen {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  height: 100vh;
  padding: 24px;
  gap: 24px;
}

#login-screen h1 {
  font-size: 1.5rem;
  font-weight: 600;
  color: var(--text);
}

#login-screen .subtitle {
  color: var(--text-secondary);
  text-align: center;
  font-size: 0.9rem;
}

#login-screen form {
  width: 100%;
  max-width: 360px;
  display: flex;
  flex-direction: column;
  gap: 12px;
}

#login-screen input {
  width: 100%;
  padding: 14px 16px;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  font-size: 1rem;
  background: var(--surface);
  color: var(--text);
  transition: border-color 0.2s;
}

#login-screen input:focus {
  border-color: var(--primary);
}

#login-screen button[type="submit"] {
  width: 100%;
  padding: 14px;
  background: var(--primary);
  color: white;
  border-radius: var(--radius);
  font-size: 1rem;
  font-weight: 500;
  transition: background 0.2s;
}

#login-screen button[type="submit"]:hover {
  background: var(--primary-hover);
}

#login-error {
  color: var(--danger);
  font-size: 0.85rem;
  text-align: center;
}

/* ── Chat Layout ───────────────────────────────────────────────────── */

#chat-screen {
  display: flex;
  flex-direction: column;
  flex: 1;
  overflow: hidden;
  max-width: var(--max-width);
  margin: 0 auto;
  width: 100%;
}

.chat-messages {
  flex: 1;
  overflow-y: auto;
  padding: 32px 16px 16px;
  display: flex;
  flex-direction: column;
  gap: 16px;
  scroll-behavior: smooth;
}

.message {
  display: flex;
  flex-direction: column;
  gap: 4px;
  max-width: 90%;
  animation: fadeIn 0.2s ease;
}

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

.message.user {
  align-self: flex-end;
  max-width: 70%;
}

.message.assistant {
  align-self: flex-start;
  max-width: 100%;
}

.message-bubble {
  padding: 12px 16px;
  border-radius: 16px;
  font-size: 0.92rem;
  line-height: 1.6;
  white-space: pre-wrap;
  word-wrap: break-word;
}

.message.user .message-bubble {
  background: var(--user-msg);
  color: var(--user-text);
  border-bottom-right-radius: 4px;
}

.message.assistant .message-bubble {
  background: var(--assistant-msg);
  color: var(--assistant-text);
  border: 1px solid var(--border);
  border-bottom-left-radius: 4px;
  box-shadow: var(--shadow);
}

.message-sql {
  margin-top: 4px;
  font-size: 0.78rem;
  font-family: 'SF Mono', 'Fira Code', monospace;
  background: var(--bg-secondary);
  padding: 8px 12px;
  border-radius: 8px;
  color: var(--text-secondary);
  overflow-x: auto;
  white-space: pre-wrap;
  word-break: break-all;
  border: 1px solid var(--border);
}

/* Data table in messages */
.data-table-wrapper {
  margin-top: 4px;
  overflow-x: auto;
  border-radius: 8px;
  border: 1px solid var(--border);
  background: var(--surface);
}

.data-table-wrapper table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.8rem;
}

.data-table-wrapper th {
  background: var(--bg-secondary);
  padding: 8px 10px;
  text-align: left;
  font-weight: 600;
  color: var(--text-secondary);
  border-bottom: 1px solid var(--border);
  white-space: nowrap;
}

.data-table-wrapper td {
  padding: 6px 10px;
  border-bottom: 1px solid var(--border);
  white-space: nowrap;
}

.data-table-wrapper tr:last-child td {
  border-bottom: none;
}

/* Input area */
.chat-input-area {
  padding: 8px 16px 20px;
  background: var(--bg);
}

.chat-input-row {
  display: flex;
  gap: 8px;
  align-items: flex-end;
  max-width: var(--max-width);
  margin: 0 auto;
  width: 100%;
}

.chat-input-row textarea {
  flex: 1;
  padding: 12px 16px;
  border: 1px solid var(--border);
  border-radius: 20px;
  font-size: 0.92rem;
  resize: none;
  max-height: 120px;
  min-height: 44px;
  background: var(--surface);
  color: var(--text);
  transition: border-color 0.2s;
  box-shadow: var(--shadow);
  scrollbar-width: none;
}

.chat-input-row textarea::-webkit-scrollbar {
  display: none;
}

.chat-input-row textarea:focus {
  border-color: var(--primary);
}

.send-btn {
  width: 44px;
  height: 44px;
  border-radius: 50%;
  background: var(--primary);
  color: white;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.2rem;
  flex-shrink: 0;
  transition: background 0.2s, opacity 0.2s;
}

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

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

/* Typing indicator */
.typing-indicator {
  display: flex;
  gap: 4px;
  padding: 8px 12px;
  align-items: center;
}

.typing-indicator span {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--text-muted);
  animation: typing 1.4s infinite;
}

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

@keyframes typing {
  0%, 60%, 100% { opacity: 0.3; transform: translateY(0); }
  30% { opacity: 1; transform: translateY(-4px); }
}

/* Data error */
.data-error {
  font-size: 0.78rem;
  color: var(--danger);
  margin-top: 4px;
}

/* Empty state */
.empty-state {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  height: 100%;
  color: var(--text-secondary);
  text-align: center;
  padding: 32px;
  gap: 8px;
}

.empty-state h2 {
  font-size: 1.3rem;
  font-weight: 600;
  color: var(--text);
}

.empty-state p {
  font-size: 0.88rem;
}

/* Scrollbar styling */
.chat-messages::-webkit-scrollbar {
  width: 4px;
}

.chat-messages::-webkit-scrollbar-thumb {
  background: var(--border);
  border-radius: 2px;
}

/* ── Responsive ────────────────────────────────────────────────────── */

@media (min-width: 768px) {
  .chat-messages {
    padding: 40px 24px 16px;
  }

  .message {
    max-width: 75%;
  }

  .message.assistant {
    max-width: 100%;
  }
}

@media (max-width: 480px) {
  .message-bubble {
    font-size: 0.88rem;
    padding: 10px 14px;
  }

  .chat-messages {
    padding: 20px 12px 12px;
    gap: 12px;
  }
}