.chat-shell { position: relative; flex-direction: row !important; }
.chat-panel { display: flex; flex: 1; min-width: 0; min-height: 0; flex-direction: column; }
.conversation-sidebar[hidden], .conversation-sidebar-backdrop[hidden], .chat-hd__history[hidden] { display: none !important; }
.conversation-sidebar {
  display: flex;
  flex: 0 0 288px;
  width: 288px;
  min-width: 0;
  min-height: 0;
  flex-direction: column;
  color: var(--color-text);
  background: var(--color-surface);
  border-inline-end: 1px solid var(--color-border);
}
.conversation-sidebar__head { display: flex; align-items: center; justify-content: space-between; gap: var(--space-sm); padding: var(--space-lg) var(--space-md) var(--space-sm); }
.conversation-sidebar__head h2 { margin: 0; font: 600 var(--text-lg)/1.2 var(--font-serif); }
.conversation-sidebar__close { display: none; width: 36px; height: 36px; padding: 0; color: var(--color-text-muted); background: transparent; border: 0; border-radius: 50%; font: 1.5rem/1 var(--font-sans); cursor: pointer; }
.conversation-sidebar__new { margin: var(--space-sm) var(--space-md) var(--space-md); width: calc(100% - (var(--space-md) * 2)); }
.conversation-sidebar__notice { margin: 0 var(--space-md) var(--space-sm); color: #b42318; font-size: var(--text-xs); }
.conversation-history-list { flex: 1; min-height: 0; padding: 0 var(--space-sm) var(--space-md); overflow-y: auto; }
.conversation-sidebar__empty { padding: var(--space-lg) var(--space-sm); color: var(--color-text-muted); font-size: var(--text-sm); text-align: center; }
.conversation-sidebar__foot { padding: var(--space-sm) var(--space-md) var(--space-md); color: var(--color-text-muted); border-top: 1px solid var(--color-border); font-size: var(--text-xs); }
.conversation-item { position: relative; display: flex; align-items: center; margin-bottom: 3px; border-radius: var(--radius-md); }
.conversation-item:hover { background: var(--color-surface-2); }
.conversation-item.is-active { background: color-mix(in srgb, var(--color-accent) 12%, var(--color-surface)); }
.conversation-item__open { display: grid; flex: 1; min-width: 0; gap: 3px; padding-block: 11px; padding-inline: 12px 38px; color: inherit; background: transparent; border: 0; border-radius: var(--radius-md); cursor: pointer; text-align: start; }
.conversation-item__title { overflow: hidden; font-size: var(--text-sm); font-weight: 600; text-overflow: ellipsis; white-space: nowrap; }
.conversation-item__meta { color: var(--color-text-muted); font-size: var(--text-xs); }
.conversation-item__delete { position: absolute; inset-inline-end: 7px; display: grid; width: 28px; height: 28px; padding: 0; place-items: center; color: var(--color-text-muted); background: transparent; border: 0; border-radius: 50%; cursor: pointer; font: 1.15rem/1 var(--font-sans); opacity: 0; }
.conversation-item:hover .conversation-item__delete, .conversation-item__delete:focus-visible { opacity: 1; }
.conversation-item__delete:hover { color: #b42318; background: color-mix(in srgb, #b42318 9%, transparent); }
.chat-hd__history { display: none; width: 38px; height: 38px; padding: 0; place-items: center; color: var(--color-text-muted); background: transparent; border: 1px solid var(--color-border); border-radius: 50%; cursor: pointer; font: 1.1rem/1 var(--font-sans); }
.conversation-sidebar-backdrop { display: none; }

@media (max-width: 900px) {
  .conversation-sidebar {
    position: absolute;
    z-index: 210;
    inset-block: 0;
    inset-inline-start: 0;
    width: min(86vw, 320px);
    transform: translateX(-105%);
    box-shadow: 12px 0 36px rgba(0, 0, 0, .2);
    transition: transform .2s ease;
  }
  html[dir="rtl"] .conversation-sidebar { transform: translateX(105%); box-shadow: -12px 0 36px rgba(0, 0, 0, .2); }
  .conversation-sidebar.is-open { transform: translateX(0) !important; }
  .conversation-sidebar__close { display: grid; place-items: center; }
  .conversation-sidebar-backdrop { position: absolute; z-index: 200; inset: 0; display: block; padding: 0; background: rgba(15, 18, 24, .55); border: 0; }
  .chat-hd__history { display: grid; flex: 0 0 auto; }
  .chat-hd { padding-inline: var(--space-sm) !important; gap: var(--space-sm) !important; }
  .chat-hd__new { padding-inline: 10px !important; }
}

@media (max-width: 520px) {
  .chat-hd__sub { display: none; }
  .chat-hd__new { font-size: 0; }
  .chat-hd__new::after { content: '+'; font-size: 1.15rem; }
}

@media (prefers-reduced-motion: reduce) {
  .conversation-sidebar { transition: none; }
}