#app {
    display: flex;
}

#sidebar {
    width: 200px;
    border-right: 1px solid #ccc;
    padding: 10px;
}

#main {
    flex: 1;
    padding: 10px;
}

#chat {
    border: 1px solid #ccc;
    height: 400px;
    overflow: auto;
    margin: 10px;
    padding: 10px;
}

input {
    margin: 5px;
    padding: 5px;
    width: 200px;
}

button {
    padding: 5px 10px;
}