* { box-sizing: border-box; }
body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  background: #0f1115;
  color: #e8e8ea;
  height: 100vh;
  display: flex;
  flex-direction: column;
}
.center-screen {
  flex: 1;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-direction: column;
  gap: 16px;
  padding: 24px;
  text-align: center;
}
input {
  background: #1b1e26;
  border: 1px solid #333;
  color: #e8e8ea;
  padding: 10px 14px;
  border-radius: 8px;
  font-size: 16px;
  width: 240px;
}
button {
  background: #4f7cff;
  color: white;
  border: none;
  padding: 10px 20px;
  border-radius: 8px;
  font-size: 15px;
  cursor: pointer;
}
button:hover { background: #3d63d9; }
.hint { color: #999; font-size: 14px; max-width: 320px; }
.error { color: #ff6b6b; font-size: 14px; }
img.qr {
  width: 280px;
  height: 280px;
  background: white;
  padding: 12px;
  border-radius: 12px;
}
.app-layout {
  display: none;
  flex: 1;
  overflow: hidden;
}
.app-layout.visible { display: flex; }
.chat-list {
  width: 300px;
  border-right: 1px solid #262a33;
  overflow-y: auto;
  flex-shrink: 0;
}
.chat-item {
  padding: 12px 16px;
  border-bottom: 1px solid #1c1f26;
  cursor: pointer;
}
.chat-item:hover, .chat-item.active { background: #1b1e26; }
.chat-title { font-weight: 600; font-size: 14px; }
.chat-preview { font-size: 13px; color: #999; margin-top: 2px; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.message-pane {
  flex: 1;
  display: flex;
  flex-direction: column;
  overflow: hidden;
}
.message-list {
  flex: 1;
  overflow-y: auto;
  padding: 16px;
  display: flex;
  flex-direction: column;
  gap: 8px;
}
.msg {
  max-width: 60%;
  padding: 8px 12px;
  border-radius: 10px;
  background: #1b1e26;
  align-self: flex-start;
  font-size: 14px;
}
.msg.mine { align-self: flex-end; background: #2a3a6b; }
.msg-time { font-size: 11px; color: #777; margin-top: 4px; }
.placeholder { margin: auto; color: #666; }
#top-status {
  padding: 8px 16px;
  font-size: 12px;
  color: #888;
  border-bottom: 1px solid #262a33;
}