body{

    margin:0;
    background:#eceff1;
    font-family:Arial;
}

.container{

    width:900px;
    margin:30px auto;

    background:white;

    border-radius:10px;

    overflow:hidden;

    box-shadow:0 0 20px rgba(0,0,0,.2);
}

.header{

    background:#1976d2;
    color:white;
    padding:15px;
    font-size:22px;
}

.chat-window{

    height:550px;
    overflow-y:auto;
    padding:20px;
    background:#fafafa;
}

.user{

    text-align:right;
    margin-bottom:15px;
}

.bot{

    text-align:left;
    margin-bottom:15px;
}

.message{

    display:inline-block;

    padding:12px;

    border-radius:10px;

    max-width:75%;
}

.user .message{

    background:#1976d2;
    color:white;
}

.bot .message{

    background:#e0e0e0;
}

.input-area{

    display:flex;

    padding:15px;

    gap:10px;
}

textarea{

    flex:1;

    resize:none;

    height:70px;

    padding:10px;

    font-size:16px;
}

button{

    width:120px;

    background:#1976d2;

    color:white;

    border:none;

    cursor:pointer;

    border-radius:6px;

    font-size:16px;
}

button:hover{

    background:#1565c0;
}