body {
    font-family: Arial, sans-serif;
    width: 500px;
    margin: 50px auto;
}

.chat_box {
    border: 1px solid #ccc;
    height: 400px;
    overflow-y: scroll;
    padding: 10px;
    margin-bottom: 5px;
}

form input {
    padding: 5px;
    margin-right: 5px;
}