body {
  display: flex;
}

.sidebar {
  width: var(--sidebar-width);
  height: 100vh;
  background-color: var(--bg-sidebar);
  border-right: 1px solid var(--border);
  display: flex;
  flex-direction: column;
  flex-shrink: 0;
  transition: transform var(--transition-normal), background-color var(--transition-normal);
  z-index: 100;
}

.main {
  flex: 1;
  height: 100vh;
  display: flex;
  flex-direction: column;
  min-width: 0;
  position: relative;
}

.header {
  height: var(--header-height);
  border-bottom: 1px solid var(--border);
  display: flex;
  align-items: center;
  padding: 0 16px;
  gap: 12px;
  flex-shrink: 0;
  background-color: var(--bg-primary);
  transition: background-color var(--transition-normal);
}

.header-spacer {
  flex: 1;
}

.chat-area {
  flex: 1;
  overflow-y: auto;
  display: flex;
  flex-direction: column;
  scroll-behavior: smooth;
}

.input-area {
  padding: 0 16px 16px;
  flex-shrink: 0;
  background-color: var(--bg-primary);
  transition: background-color var(--transition-normal);
}

.sidebar-overlay {
  display: none;
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.5);
  z-index: 99;
}