/* App shell — ChatGPT / Claude layout */

.app-layout {
  flex: 1;
  display: flex;
  min-height: 0;
  width: 100%;
  height: 100%;
  overflow: hidden;
}

/* ── Sidebar ── */
.app-sidebar {
  width: var(--sidebar-w);
  flex-shrink: 0;
  background: var(--sidebar);
  border-right: 1px solid var(--border);
  display: flex;
  flex-direction: column;
  min-height: 0;
  transition: width var(--transition-base), transform var(--transition-base);
  z-index: 20;
  overflow: hidden;
}

.app-sidebar.collapsed {
  width: var(--sidebar-rail-w);
}

.app-sidebar.collapsed .sidebar-actions,
.app-sidebar.collapsed .sidebar-search,
.app-sidebar.collapsed .sidebar-nav,
.app-sidebar.collapsed .sidebar-history,
.app-sidebar.collapsed .sidebar-footer,
.app-sidebar.collapsed .brand-name {
  display: none;
}

.app-sidebar.collapsed .sidebar-header {
  flex-direction: column;
  align-items: center;
  gap: 10px;
  padding: 12px 8px;
}

.app-sidebar.collapsed .sidebar-collapse-btn {
  order: 2;
}

.sidebar-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 12px 12px 8px;
  flex-shrink: 0;
}

.sidebar-brand {
  display: flex;
  align-items: center;
  gap: 10px;
  min-width: 0;
  text-decoration: none;
  color: inherit;
}

.logo {
  width: 32px;
  height: 32px;
  border-radius: 8px;
  object-fit: contain;
  flex-shrink: 0;
  display: block;
}

.brand-logo {
  height: 32px;
  width: auto;
  max-width: 200px;
  object-fit: contain;
  display: block;
}

.brand-name {
  font-size: 0.95rem;
  font-weight: 600;
  letter-spacing: -0.02em;
  white-space: nowrap;
}

.sidebar-collapse-btn {
  width: 32px;
  height: 32px;
  border: none;
  background: transparent;
  color: var(--muted);
  border-radius: var(--radius-sm);
}

.sidebar-collapse-btn:hover {
  background: var(--surface-hover);
  color: var(--text);
}

.sidebar-actions {
  padding: 0 10px 8px;
  flex-shrink: 0;
}

.nav-btn {
  display: flex;
  align-items: center;
  gap: 10px;
  width: 100%;
  padding: 10px 12px;
  border-radius: var(--radius);
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--text);
  transition: background var(--transition-fast);
  text-align: left;
}

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

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

.nav-btn-primary {
  border: 1px solid var(--border);
  background: var(--surface);
}

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

.sidebar-search {
  display: flex;
  align-items: center;
  gap: 8px;
  margin: 0 10px 8px;
  padding: 8px 12px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  flex-shrink: 0;
}

.sidebar-search svg {
  width: 16px;
  height: 16px;
  color: var(--muted);
  flex-shrink: 0;
}

.sidebar-search input {
  flex: 1;
  border: none;
  background: transparent;
  color: var(--text);
  font-size: 0.8125rem;
  outline: none;
  min-width: 0;
}

.sidebar-search input::placeholder {
  color: var(--placeholder);
}

.sidebar-nav {
  display: flex;
  flex-direction: column;
  gap: 2px;
  padding: 0 8px 8px;
  flex-shrink: 0;
}

.nav-item {
  display: flex;
  flex-direction: row;
  align-items: center;
  gap: 10px;
  width: 100%;
  padding: 9px 12px;
  border-radius: var(--radius);
  font-size: 0.8125rem;
  font-weight: 500;
  color: var(--text-secondary);
  transition: background var(--transition-fast), color var(--transition-fast);
  text-decoration: none;
  text-align: left;
  white-space: nowrap;
}

.nav-item svg {
  width: 18px;
  height: 18px;
  flex-shrink: 0;
  opacity: 0.75;
}

.nav-item:hover {
  background: var(--surface-hover);
  color: var(--text);
}

.sidebar-history {
  flex: 1;
  overflow-y: auto;
  overflow-x: hidden;
  padding: 4px 8px;
  min-height: 0;
  scrollbar-width: thin;
  scrollbar-color: var(--border-strong) transparent;
}

.sidebar-history::-webkit-scrollbar { width: 4px; }
.sidebar-history::-webkit-scrollbar-thumb {
  background: var(--border-strong);
  border-radius: var(--radius-full);
}

.history-group-label {
  font-size: 0.6875rem;
  font-weight: 600;
  color: var(--muted);
  padding: 12px 12px 6px;
  letter-spacing: 0.02em;
}

.sidebar-footer {
  padding: 8px;
  border-top: 1px solid var(--border);
  flex-shrink: 0;
  display: flex;
  flex-direction: column;
  gap: 2px;
}

.sidebar-user {
  display: block;
  padding: 8px 12px 4px;
  font-size: 0.8rem;
  color: var(--muted);
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
  text-decoration: none;
}

.sidebar-user:hover {
  color: var(--text);
}

/* Backdrops */
.sidebar-backdrop {
  display: none;
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.4);
  backdrop-filter: blur(2px);
  z-index: 25;
  opacity: 0;
  transition: opacity var(--transition-base);
  pointer-events: none;
}

.panel-backdrop {
  display: none;
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.4);
  backdrop-filter: blur(2px);
  z-index: 35;
  opacity: 0;
  transition: opacity var(--transition-base);
  pointer-events: none;
}

.sidebar-backdrop.visible {
  display: block;
  opacity: 1;
  pointer-events: auto;
}

.panel-backdrop.visible {
  display: block;
  opacity: 1;
  pointer-events: auto;
}

/* ── Main area ── */
.app-main {
  flex: 1;
  display: flex;
  flex-direction: column;
  min-width: 0;
  min-height: 0;
  height: 100%;
  background: var(--bg);
  position: relative;
  overflow: hidden;
}

.app-main.is-empty {
  justify-content: center;
  align-items: center;
  gap: 20px;
  padding: 24px 16px 32px;
}

.app-main.is-empty .chat-viewport {
  flex: 0 0 auto;
  width: 100%;
  max-width: var(--composer-max);
  overflow: visible;
}

.app-main.is-empty .messages-panel {
  display: none;
}

.app-main.is-empty .scroll-fab {
  display: none;
}

.app-main.is-empty .main-topbar {
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  background: transparent;
  border-bottom: none;
}

.app-main.is-empty .status-badge {
  display: none;
}

.app-main.is-empty .composer-area {
  flex: 0 0 auto;
  width: 100%;
  max-width: var(--composer-max);
  padding: 0;
  margin: 0;
}

.app-main.is-empty .welcome-chips {
  margin-bottom: 4px;
}

.main-topbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: var(--topbar-h);
  padding: 0 16px;
  flex-shrink: 0;
  border-bottom: 1px solid var(--border);
  background: var(--bg);
  z-index: 10;
}

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

.sidebar-toggle {
  display: grid;
  place-items: center;
}

.model-badge {
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 6px 12px;
  border-radius: var(--radius);
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--text);
  cursor: default;
}

.model-badge-version {
  font-size: 0.65rem;
  font-weight: 500;
  color: var(--muted);
  padding: 2px 6px;
  background: var(--accent-soft);
  border-radius: var(--radius-full);
}

.ticker-chip {
  display: none;
  align-items: center;
  gap: 6px;
  padding: 5px 12px;
  background: var(--accent-soft);
  border: 1px solid var(--border);
  border-radius: var(--radius-full);
  font-size: 0.75rem;
  font-weight: 500;
  color: var(--text-secondary);
}

.ticker-chip.visible { display: inline-flex; }

.ticker-chip .symbol {
  font-family: var(--font-mono);
  font-weight: 700;
  color: var(--text);
}

.icon-btn {
  display: grid;
  place-items: center;
  width: 36px;
  height: 36px;
  border-radius: var(--radius-sm);
  border: none;
  background: transparent;
  color: var(--text-secondary);
  transition: background var(--transition-fast), color var(--transition-fast);
}

.icon-btn:hover {
  background: var(--surface-hover);
  color: var(--text);
}

.icon-btn svg {
  width: 18px;
  height: 18px;
}

.status-badge {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 4px 10px;
  border-radius: var(--radius-full);
  font-size: 0.7rem;
  font-weight: 500;
  color: var(--muted);
  white-space: nowrap;
}

.status-badge::before {
  content: "";
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--success);
}

.status-badge.thinking { color: var(--text-secondary); }
.status-badge.thinking::before {
  background: var(--muted);
  animation: pulse 1.5s ease-in-out infinite;
}

.status-badge.error { color: var(--error); }
.status-badge.error::before {
  background: var(--error);
  animation: none;
}

/* ── Chat viewport ── */
.chat-viewport {
  flex: 1;
  display: flex;
  flex-direction: column;
  min-height: 0;
  position: relative;
  overflow: hidden;
}

.empty-state {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  text-align: center;
  width: 100%;
  pointer-events: none;
  z-index: 1;
  transition: opacity var(--transition-base);
}

.empty-state.hidden {
  display: none;
}

.empty-greeting {
  font-family: var(--font-serif);
  font-size: clamp(1.5rem, 4vw, 2rem);
  font-weight: 400;
  color: var(--text);
  text-align: center;
  letter-spacing: -0.02em;
  line-height: 1.3;
  max-width: 28rem;
}

.messages-panel {
  flex: 1;
  overflow-y: auto;
  scroll-behavior: smooth;
  scrollbar-width: thin;
  scrollbar-color: var(--border-strong) transparent;
}

.messages-panel::-webkit-scrollbar { width: 6px; }
.messages-panel::-webkit-scrollbar-thumb {
  background: var(--border-strong);
  border-radius: var(--radius-full);
}

.messages-inner {
  max-width: var(--message-max);
  margin: 0 auto;
  padding: 24px 24px 32px;
  display: flex;
  flex-direction: column;
  gap: 24px;
}

/* ── Composer ── */
.composer-area {
  flex-shrink: 0;
  width: 100%;
  padding: 0 16px 16px;
  background: var(--bg);
  position: relative;
  z-index: 5;
  margin-top: auto;
}

.composer-area.scrolled {
  box-shadow: 0 -4px 16px rgba(0, 0, 0, 0.04);
}

.welcome-chips {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  justify-content: center;
  max-width: var(--composer-max);
  margin: 0 auto 12px;
  transition: opacity var(--transition-base);
}

.welcome-chips.hidden {
  opacity: 0;
  height: 0;
  margin: 0;
  overflow: hidden;
  pointer-events: none;
}

.char-count {
  font-size: 0.65rem;
  color: var(--muted);
  text-align: right;
  max-width: var(--composer-max);
  margin: 0 auto 4px;
  opacity: 0;
  transition: opacity var(--transition-fast);
}

.char-count.visible { opacity: 1; }
.char-count.warn { color: var(--warning); }

.omnibar {
  display: flex;
  align-items: flex-end;
  gap: 4px;
  width: 100%;
  max-width: var(--composer-max);
  margin: 0 auto;
  padding: 12px 14px 12px 10px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-xl);
  box-shadow: var(--shadow-omnibar);
  transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
  min-height: 56px;
}

.omnibar:focus-within {
  border-color: var(--border-strong);
  box-shadow: var(--shadow-omnibar), 0 0 0 2px var(--accent-glow);
}

.omnibar-attach-wrap {
  position: relative;
  flex-shrink: 0;
}

.omnibar-btn {
  display: grid;
  place-items: center;
  width: 36px;
  height: 36px;
  border-radius: var(--radius-full);
  color: var(--muted);
  transition: background var(--transition-fast), color var(--transition-fast);
}

.omnibar-btn:hover {
  background: var(--surface-hover);
  color: var(--text);
}

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

.omnibar textarea {
  flex: 1;
  resize: none;
  border: none;
  background: transparent;
  color: var(--text);
  font-size: 1rem;
  line-height: 1.5;
  padding: 10px 6px;
  min-height: 28px;
  max-height: 200px;
  outline: none;
  width: 100%;
}

.omnibar textarea::placeholder {
  color: var(--placeholder);
}

.omnibar-send,
.omnibar-stop {
  display: grid;
  place-items: center;
  width: 36px;
  height: 36px;
  border-radius: var(--radius-full);
  flex-shrink: 0;
  transition: background var(--transition-fast), opacity var(--transition-fast), transform var(--transition-fast);
}

.omnibar-send {
  background: var(--accent);
  color: var(--bg);
}

.omnibar-send:not(:disabled):hover {
  background: var(--accent-hover);
  transform: scale(1.05);
}

.omnibar-send:disabled {
  opacity: 0.35;
  cursor: not-allowed;
}

.omnibar-send svg {
  width: 18px;
  height: 18px;
}

.omnibar-stop {
  background: var(--error);
  color: #fff;
}

.omnibar-stop svg {
  width: 14px;
  height: 14px;
}

.attach-menu {
  display: none;
  position: absolute;
  bottom: calc(100% + 8px);
  left: 0;
  min-width: 220px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow-lg);
  padding: 6px;
  z-index: 50;
}

.attach-menu.open {
  display: block;
  animation: fadeInUp 0.15s ease both;
}

.attach-menu-item {
  display: flex;
  align-items: center;
  gap: 10px;
  width: 100%;
  padding: 10px 12px;
  border-radius: var(--radius-sm);
  font-size: 0.8125rem;
  font-weight: 500;
  color: var(--text);
  text-align: left;
  transition: background var(--transition-fast);
}

.attach-menu-item svg {
  width: 16px;
  height: 16px;
  color: var(--muted);
}

.attach-menu-item:hover {
  background: var(--surface-hover);
}

.disclaimer {
  font-size: 0.6875rem;
  color: var(--muted);
  text-align: center;
  max-width: var(--composer-max);
  margin: 10px auto 0;
  line-height: 1.5;
}

.disclaimer a {
  color: var(--muted);
  text-decoration: underline;
  text-underline-offset: 2px;
}

.disclaimer a:hover {
  color: var(--text-secondary);
}

/* Auth banner */
.auth-banner {
  display: none;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  padding: 10px 20px;
  background: var(--warning-soft);
  border-bottom: 1px solid rgba(217, 119, 6, 0.2);
  color: var(--warning);
  font-size: 0.8125rem;
  flex-shrink: 0;
}

.auth-banner.visible { display: flex; }

.auth-banner button {
  padding: 6px 14px;
  border-radius: var(--radius-full);
  background: var(--warning);
  color: #fff;
  font-weight: 600;
  font-size: 0.75rem;
}

/* Responsive */
@media (max-width: 768px) {
  .app-sidebar {
    position: fixed;
    top: 0;
    left: 0;
    bottom: 0;
    width: min(var(--sidebar-w), 88vw);
    transform: translateX(-100%);
    box-shadow: var(--shadow-lg);
  }

  .app-sidebar.open {
    transform: translateX(0);
  }

  .app-sidebar.collapsed {
    width: min(var(--sidebar-w), 88vw);
    transform: translateX(-100%);
  }

  .app-sidebar.open,
  .app-sidebar.collapsed.open {
    transform: translateX(0);
  }

  .sidebar-collapse-btn { display: none; }
  .status-badge { display: none; }

  .messages-inner { padding: 16px 16px 24px; }
  .composer-area { padding: 0 12px 12px; }
  .empty-greeting { font-size: 1.375rem; }
}

@media (min-width: 769px) {
  .sidebar-backdrop { display: none !important; }
}