.top-header {
  height: 82px;
  display: grid;
  grid-template-columns: 270px minmax(320px, 560px) 1fr;
  align-items: center;
  gap: 28px;
  padding: 0 36px;
  background: rgba(255,255,255,0.88);
  border-bottom: 1px solid var(--border);
  backdrop-filter: blur(18px);
  position: sticky;
  top: 0;
  z-index: 30;
}

.main-layout {
  display: grid;
  grid-template-columns: 290px 280px minmax(430px, 1fr) 340px;
  gap: 18px;
  padding: 22px 28px 28px;
  max-width: 1720px;
  margin: 0 auto;
}

.left-sidebar, .right-sidebar {
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.conversation-panel, .chat-panel {
  height: calc(100vh - 132px);
  min-height: 700px;
  background: var(--bg-card);
  border: 1px solid var(--border);
  box-shadow: var(--shadow-card);
  border-radius: var(--radius-xl);
  overflow: hidden;
}

.conversation-panel {
  padding: 20px;
  display: flex;
  flex-direction: column;
}

.chat-panel { display: flex; flex-direction: column; }