#sidebar {
  width: var(--sidebar-width);
  background-color: #f0f2f5;
  border-right: 1px solid #e0e0e0;
  display: flex;
  flex-direction: column;
  z-index: 10;
  transition: transform 0.3s ease;
}

#sidebar-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 15px 20px;
  background-color: #f0f2f5;
  border-bottom: 1px solid #e0e0e0;
}

#sidebar-header h2 {
  font-size: 1.2rem;
  font-weight: 500;
}

#menu-toggle, #new-chat {
  background: none;
  border: none;
  font-size: 1.5rem;
  width: 40px;
  height: 40px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: background-color 0.2s;
}

#menu-toggle:hover, #new-chat:hover {
  background-color: #e0e0e0;
}

#chat-list {
  flex: 1;
  overflow-y: auto;
  padding: 10px 0;
}

.chat-item {
  display: flex;
  align-items: center;
  padding: 12px 20px;
  cursor: pointer;
  transition: background-color 0.2s;
}

.chat-item:hover {
  background-color: #f5f5f5;
}

.chat-item.active {
  background-color: #e6e9ef;
}

.avatar-placeholder {
  width: 50px;
  height: 50px;
  border-radius: 50%;
  background-color: #d8d8d8;
  margin-right: 15px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.2rem;
  color: #777;
}

.chat-info {
  flex: 1;
  min-width: 0;
}

.chat-name {
  font-weight: 500;
  margin-bottom: 4px;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.last-message {
  font-size: 0.85rem;
  color: #777;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}