body {
  margin: 0;
  font-family: 'Segoe UI', sans-serif;
  display: flex;
  height: 100vh;
  background: #f5f6f8;
}

.sidebar {
  width: 25%;
  border-right: 1px solid #ddd;
  background: #fff;
  overflow-y: auto;
}

.user-item {
  display: flex;
  align-items: center;
  padding: 10px;
  border-bottom: 1px solid #eee;
  cursor: pointer;
}

.user-item:hover {
  background: #f0f2f5;
}

.user-item img {
  width: 45px;
  height: 45px;
  border-radius: 50%;
  margin-right: 10px;
}

.user-name {
  font-weight: bold;
  color: #333;
}

.chat {
  flex: 1;
  display: flex;
  flex-direction: column;
  background: #e5ddd5;
}

.header {
  background: #0084ff;
  color: #fff;
  padding: 12px 15px;
  font-weight: bold;
  font-size: 16px;
}

.messages {
  flex: 1;
  padding: 15px;
  overflow-y: auto;
  display: flex;
  flex-direction: column;
}

.msg {
  max-width: 70%;
  margin: 5px 0;
  padding: 10px;
  border-radius: 18px;
  font-size: 15px;
  line-height: 1.4;
}

.user {
  align-self: flex-start;
  background: #fff;
}

.bot {
  align-self: flex-end;
  background: #0084ff;
  color: #fff;
}

.inputbox {
  display: flex;
  padding: 10px;
  background: #fff;
  border-top: 1px solid #ddd;
}

.inputbox input {
  flex: 1;
  border: none;
  outline: none;
  padding: 10px;
  font-size: 15px;
  border-radius: 20px;
  background: #f0f2f5;
}

.inputbox button {
  border: none;
  background: #0084ff;
  color: white;
  padding: 10px 20px;
  border-radius: 20px;
  margin-left: 10px;
  cursor: pointer;
}