body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  background-color: #f4f4f8;
  margin: 0;
  display: flex;
  justify-content: center;
  align-items: center;
  height: 100vh;
}
#chat-container {
  width: 90%;
  max-width: 600px;
  height: 90vh;
  background-color: #fff;
  border-radius: 8px;
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
  display: flex;
  flex-direction: column;
}
#message-list {
  flex-grow: 1;
  overflow-y: auto;
  padding: 20px;
  border-bottom: 1px solid #eee;
}
.message {
  margin-bottom: 15px;
}
.message .username {
  font-weight: bold;
  color: #333;
  margin-bottom: 4px;
}
.message .text {
  background-color: #e9e9eb;
  padding: 10px 15px;
  border-radius: 18px;
  display: inline-block;
  max-width: 80%;
}
#message-form {
  display: flex;
  padding: 15px;
  gap: 10px;
}
#message-form input {
  border: 1px solid #ddd;
  border-radius: 20px;
  padding: 10px 15px;
  font-size: 16px;
}
#username-input {
  flex-basis: 120px;
}
#message-input {
  flex-grow: 1;
}
#message-form button {
  background-color: #007bff;
  color: white;
  border: none;
  padding: 0 20px;
  border-radius: 20px;
  cursor: pointer;
  font-size: 16px;
}
#message-form button:hover {
  background-color: #0056b3;
}