body{
    margin:0;
    font-family:Arial,Helvetica,sans-serif;
    background:#f3f4f6;
}

h1{
    margin:0;
    padding:15px;
    background:#2563eb;
    color:white;
    text-align:center;
}

#messages{
    padding:15px;
    padding-bottom:90px;
}

.message{
    background:white;
    margin-bottom:10px;
    padding:10px;
    border-radius:10px;
    box-shadow:0 1px 4px rgba(0,0,0,.15);
}

.user{
    font-size:12px;
    color:#666;
    margin-bottom:5px;
}

#bottom{
    position:fixed;
    bottom:0;
    left:0;
    right:0;
    display:flex;
    padding:10px;
    background:white;
    border-top:1px solid #ddd;
}

#message{
    flex:1;
    padding:10px;
    font-size:16px;
}

button{
    margin-left:10px;
    padding:10px 20px;
    font-size:16px;
    cursor:pointer;
}