#chat {  
  border: 1px solid #ccc; 
  height: 400px; 
  overflow-y: scroll; 
  padding: 10px; 
  margin-bottom: 10px; 
  background: #f9f9f9; 
}
.msg { 
  margin-bottom: 15px; 
  padding: 8px 12px; 
  border-radius: 8px; 
  max-width: 80%; 
}
.user { 
  background: #DCF8C6; 
  margin-left: auto; 
  text-align: right; 
}
.ai { 
  background: #FFFFFF; 
  border: 1px solid #eee; 
  margin-right: auto; 
}
input, button { 
  padding: 10px; 
  font-size: 16px; 
}
#input { 
  width: 100%; 
  margin-right: 10px; 
}