body {
  font-family: Arial, sans-serif;
  background-color: #f4f4f4;
  margin: 0;
  padding: 0;
}

header, main {
  max-width: 900px;
  margin: auto;
  padding: 20px;
}

h1, h2, h3 {
  text-align: center;
}

#chatSection {
  margin-top: 20px;
}

#chatInput {
  width: 70%;
  padding: 8px;
  margin-right: 5px;
}

#sendBtn {
  padding: 8px 12px;
}