.chat-page .app-shell { height: 100dvh; min-height: 0; }
.chat-page .workspace-main { display: flex; flex-direction: column; min-height: 0; }
.chat-page .topbar { flex: 0 0 auto; }
.chat-main { flex: 1 1 auto; width: 100%; max-width: 1500px; min-height: 0; margin: 0 auto; padding: 22px clamp(20px,3vw,48px) 28px; }
.chat-layout { display: grid; grid-template-columns: 286px minmax(0,1fr); height: 100%; overflow: hidden; border: 1px solid var(--border); background: #fff; }
.rooms-panel { min-width: 0; overflow-y: auto; border-right: 1px solid var(--border); background: #fff; }
.rooms-heading { padding: 20px 17px 9px; }
.rooms-panel h2 { margin: 2px 0 0; font-size: 17px; letter-spacing: -.03em; }
.room-list { display: grid; gap: 4px; padding: 0 8px 14px; }
.room-loading { padding: 12px; color: var(--muted); }
.room-button { display: flex; align-items: center; gap: 10px; width: 100%; min-height: 55px; padding: 10px 12px; text-align: left; border: 0; border-left: 3px solid transparent; background: transparent; font-weight: 650; }
.room-button:hover, .room-button.active { background: var(--hover); }
.room-button.active { border-left-color: var(--red); color: var(--fg); }
.room-name { overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.room-unread { margin-left: auto; min-width: 19px; height: 19px; padding: 1px 5px; border-radius: 99px; background: var(--red); color: #fff; text-align: center; font-size: 11px; }
.mention-alert { margin-left: auto; color: var(--red); font-weight: 800; }
.mention-alert + .room-unread { margin-left: 0; }
.conversation { display: flex; flex-direction: column; min-width: 0; min-height: 0; }
.conversation-head { padding: 17px 22px; border-bottom: 1px solid var(--border); }
.conversation-head h2 { margin: 0; font-size: 17px; }
.conversation-head p { margin: 4px 0 0; color: var(--muted); font-size: 12px; }
.message-list { flex: 1 1 auto; overflow-y: auto; display: flex; flex-direction: column; gap: 13px; padding: 22px; background: #fafafa; }
.message-empty { margin: auto; color: var(--muted); }
.message-date { display: flex; align-items: center; gap: 12px; flex: 0 0 auto; width: 100%; margin: 10px 0; color: var(--muted); font-size: 12px; }
.message-date::before, .message-date::after { content: ''; height: 1px; flex: 1; background: var(--border); }
.message { align-self: flex-start; max-width: min(78%, 640px); }
.message.own { align-self: flex-end; }
.message-meta { display: flex; gap: 7px; margin: 0 3px 5px; color: var(--muted); font-size: 11px; }
.message.own .message-meta { justify-content: flex-end; }
.message-body { padding: 10px 13px; border: 1px solid var(--border); background: #fff; white-space: pre-wrap; overflow-wrap: anywhere; line-height: 1.55; }
.message.own .message-body { border-color: var(--fg); background: var(--fg); color: #fff; }
.message.mentioned .message-body { border-left: 3px solid var(--red); }
.mention { padding: 1px 2px; color: var(--red); font-weight: 750; }
.message.own .mention { color: #fff; text-decoration: underline; }
.mention-suggestions { display: flex; gap: 6px; flex-wrap: wrap; padding: 8px 18px; border-top: 1px solid var(--border); }
.mention-suggestions[hidden] { display: none; }
.mention-suggestions button { min-height: 30px; padding: 4px 8px; font-size: 12px; }
.message-form { padding: 14px 18px 13px; border-top: 1px solid var(--border); }
.message-form label { display: block; margin-bottom: 6px; font-size: 12px; font-weight: 700; }
.composer { display: flex; align-items: flex-end; gap: 8px; }
.composer textarea { flex: 1; min-width: 0; max-height: 150px; resize: vertical; padding: 10px; border: 1px solid var(--border); border-radius: 4px; font: inherit; line-height: 1.5; }
.composer button { align-self: stretch; min-width: 72px; }
.composer button.primary { border-color: var(--dark); background: var(--dark); color: #fff; }
.message-form p { margin: 6px 0 0; color: var(--muted); font-size: 11px; }
@media (max-width: 720px) {
  .chat-page .app-shell { display: flex; flex-direction: column; }
  .chat-page .sidebar { flex: 0 0 auto; }
  .chat-page .workspace-main { flex: 1 1 auto; }
  .chat-main { padding: 10px; }
  .chat-layout { grid-template-columns: 1fr; grid-template-rows: auto minmax(0,1fr); }
  .rooms-panel { overflow-x: auto; overflow-y: hidden; overscroll-behavior-x: contain; border-right: 0; border-bottom: 1px solid var(--border); scrollbar-width: thin; }
  .rooms-heading { display: none; }
  .room-list { display: flex; width: max-content; min-width: 100%; padding: 7px; }
  .room-button { width: auto; min-height: 44px; padding: 5px 10px; }
  .message-list { padding: 13px; }
  .message { max-width: 90%; }
  .message-form { padding: 9px; }
}
@media (max-height: 600px) {
  .chat-page .topbar { min-height: 72px; padding-block: 10px; }
  .chat-page .topbar p { display: none; }
  .chat-main { padding-block: 8px; }
  .conversation-head { padding-block: 9px; }
  .message-form { padding-block: 8px; }
  .message-form p { display: none; }
  .composer textarea { min-height: 44px; max-height: 70px; }
}
@media (max-width: 720px) and (max-height: 600px) {
  .chat-page .topbar { display: none; }
  .chat-page .sidebar { gap: 0; padding-block: 6px; }
  .chat-main { padding: 6px; }
  .conversation-head { padding: 7px 11px; }
  .conversation-head p { margin-top: 0; font-size: 11px; }
  .message-form label { position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px; overflow: hidden; clip: rect(0,0,0,0); white-space: nowrap; border: 0; }
  .composer textarea { height: 44px; resize: none; }
}