.chat-page { height: 100dvh; min-height: 0; overflow: hidden; }
.chat-page [hidden] { display: none !important; }
.chat-shell { display: grid; grid-template-columns: var(--sidebar) minmax(0, 1fr); height: 100%; }
.chat-sidebar { background: var(--gray-100); border-right: 1px solid var(--gray-200); padding: var(--space-5); display: flex; flex-direction: column; gap: var(--space-5); min-height: 0; }
.chat-brand { display: flex; justify-content: space-between; align-items: center; font-weight: 700; font-size: 1.125rem; }
.chat-page a { color: var(--primary-700); text-decoration: none; }
.chat-page a:hover { text-decoration: underline; }
.chat-list-heading { font-size: .75rem; color: var(--gray-500); font-weight: 600; }
.chat-list { display: flex; flex-direction: column; gap: var(--space-1); overflow-y: auto; flex: 1; }
.chat-list button { text-align: left; width: 100%; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; border-radius: var(--radius-lg); padding: var(--space-3); border: 0; background: transparent; }
.chat-list button:hover { background: var(--gray-200); }
.chat-list button[aria-current="page"] { background: var(--primary-100); color: var(--primary-800); }
.chat-sidebar-footer { display: flex; flex-wrap: wrap; gap: var(--space-3); align-items: center; font-size: .875rem; }
.chat-main { display: flex; flex-direction: column; min-width: 0; min-height: 0; }
.chat-toolbar { display: flex; align-items: center; gap: var(--space-2); padding: var(--space-3) var(--space-6); border-bottom: 1px solid var(--gray-200); }
.chat-toolbar h1 { font-size: 1rem; font-weight: 600; flex: 1; min-width: 0; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.chat-toolbar .btn { white-space: nowrap; }
#toggle-sidebar, #close-sidebar { display: none; }
.chat-feedback { font-size: .875rem; color: var(--gray-600); padding: var(--space-2) var(--space-6); }
.chat-feedback:empty { display: none; }
.chat-feedback[data-error="true"] { color: var(--red-700); }
.chat-inline { display: flex; align-items: center; flex-wrap: wrap; gap: var(--space-3); padding: var(--space-3) var(--space-6); }
.chat-inline input { flex: 1; min-width: 80px; }
.chat-messages { flex: 1; min-height: 0; overflow-y: auto; padding: var(--space-6) max(var(--space-6), calc((100% - 780px) / 2)); scroll-behavior: smooth; }
.chat-empty { display: grid; place-content: center; min-height: 60%; color: var(--gray-500); }
.chat-empty h2 { font-size: 1.5rem; font-weight: 500; }
.chat-message { margin-bottom: var(--space-8); overflow-wrap: anywhere; }
.chat-message[data-role="user"] { background: var(--gray-100); padding: var(--space-4); border-radius: var(--radius-xl); margin-left: var(--space-8); }
.chat-message-label { font-size: .75rem; color: var(--gray-500); margin-bottom: var(--space-2); display: flex; align-items: center; gap: var(--space-2); }
.chat-message-content { line-height: 1.75; }
.chat-message-content p + p, .chat-message-content pre, .chat-message-content ul, .chat-message-content ol { margin-top: var(--space-3); }
.chat-message-content h1, .chat-message-content h2, .chat-message-content h3 { font-size: 1.125rem; margin-top: var(--space-4); }
.chat-message-content pre { background: var(--gray-100); border: 1px solid var(--gray-200); border-radius: var(--radius-lg); padding: var(--space-4); overflow-x: auto; font-family: var(--mono); font-size: .875rem; white-space: pre; }
.chat-message-content code { font-family: var(--mono); }
.chat-message-content blockquote { margin: var(--space-3) 0; padding: var(--space-3); background: var(--gray-100); border: 1px solid var(--gray-200); }
.chat-message-content.is-streaming { white-space: pre-wrap; }
.chat-message-actions { display: flex; gap: var(--space-2); margin-top: var(--space-2); }
.chat-message-actions .btn { font-size: .75rem; padding: var(--space-1) var(--space-2); }
.chat-message-error { font-size: .875rem; color: var(--red-700); margin-top: var(--space-2); }
.chat-message img { max-height: 240px; object-fit: contain; border-radius: var(--radius-lg); }
.chat-composer { width: min(100%, 828px); margin: 0 auto; padding: var(--space-3) var(--space-6) max(var(--space-4), env(safe-area-inset-bottom)); }
.chat-selectors { display: flex; align-items: center; flex-wrap: wrap; gap: var(--space-2); margin-bottom: var(--space-2); font-size: .75rem; color: var(--gray-600); }
.chat-page select, .chat-page input:not([type="file"]) { border: 1px solid var(--gray-200); background: var(--gray-50); border-radius: var(--radius-lg); padding: var(--space-2); max-width: 100%; }
.chat-selectors select { max-width: 220px; min-width: 0; }
.chat-composer textarea { resize: vertical; display: block; width: 100%; max-height: 180px; min-height: 70px; border: 1px solid var(--gray-300); border-radius: var(--radius-xl); padding: var(--space-3); background: var(--gray-50); font-size: 1rem; }
.chat-compose-actions { display: flex; align-items: center; gap: var(--space-2); margin-top: var(--space-2); }
.chat-hint { flex: 1; font-size: .75rem; color: var(--gray-500); }
.chat-upload { position: relative; overflow: hidden; }
.chat-upload:has(input:disabled) { opacity: .5; }
.chat-upload input { position: absolute; inset: 0; opacity: 0; width: 100%; cursor: pointer; }
.chat-attachments { display: flex; gap: var(--space-2); flex-wrap: wrap; padding-bottom: var(--space-2); }
.chat-attachments img { width: 60px; height: 60px; object-fit: cover; }
.chat-attachment { display: flex; align-items: center; gap: var(--space-1); }
.chat-page .btn-primary { background: var(--primary-600); box-shadow: none; }
.chat-page .btn-primary:hover { background: var(--primary-700); }
@media (max-width: 720px) {
  .chat-shell { grid-template-columns: minmax(0, 1fr); }
  .chat-sidebar { display: none; }
  .chat-sidebar.is-open { display: flex; position: fixed; inset: 0 auto 0 0; width: min(88vw, 320px); z-index: 20; box-shadow: var(--shadow-card); padding-top: max(var(--space-5), env(safe-area-inset-top)); }
  #toggle-sidebar, #close-sidebar { display: inline-flex; }
  .chat-toolbar { padding: max(var(--space-2), env(safe-area-inset-top)) var(--space-2) var(--space-2); gap: 0; }
  .chat-toolbar .btn { padding: var(--space-2); min-height: 44px; }
  .chat-messages { padding: var(--space-4); }
  .chat-composer { padding: var(--space-2) var(--space-3) max(var(--space-2), env(safe-area-inset-bottom)); }
  .chat-selectors { gap: var(--space-1); }
  .chat-selectors select { max-width: 135px; }
  .chat-feedback { padding: var(--space-2) var(--space-4); }
  .chat-compose-actions .btn { min-height: 44px; padding: var(--space-2); }
}
@media (prefers-reduced-motion: reduce) { .chat-page * { scroll-behavior: auto; transition: none; } }