*{
    margin:0;
    padding:0;
    box-sizing:border-box;
}

body{
    font-family:Arial, Helvetica, sans-serif;
    background:linear-gradient(135deg,#4facfe,#00f2fe);
    display:flex;
    justify-content:center;
    align-items:center;
    height:100vh;
}

.container{
    width:500px;
    height:700px;
    background:#fff;
    border-radius:20px;
    overflow:hidden;
    box-shadow:0 15px 35px rgba(0,0,0,0.25);
    display:flex;
    flex-direction:column;
}

h2{
    background:linear-gradient(90deg,#007bff,#00c6ff);
    color:white;
    text-align:center;
    padding:18px;
    font-size:24px;
    letter-spacing:1px;
}

#chat-box{
    flex:1;
    padding:20px;
    overflow-y:auto;
    background:#f5f7fb;
}

#chat-box::-webkit-scrollbar{
    width:6px;
}

#chat-box::-webkit-scrollbar-thumb{
    background:#999;
    border-radius:10px;
}

.user{
    background:#007bff;
    color:white;
    padding:12px 16px;
    border-radius:20px 20px 0px 20px;
    margin:12px 0;
    width:fit-content;
    max-width:75%;
    margin-left:auto;
    word-wrap:break-word;
    box-shadow:0 3px 8px rgba(0,0,0,.2);
}

.bot{
    background:#e9ecef;
    color:#333;
    padding:12px 16px;
    border-radius:20px 20px 20px 0px;
    margin:12px 0;
    width:fit-content;
    max-width:75%;
    word-wrap:break-word;
    box-shadow:0 3px 8px rgba(0,0,0,.15);
}

.input-area{
    display:flex;
    padding:15px;
    background:white;
    border-top:1px solid #ddd;
}

#user-input{
    flex:1;
    padding:14px;
    border:2px solid #ddd;
    border-radius:30px;
    outline:none;
    font-size:16px;
    transition:.3s;
}

#user-input:focus{
    border-color:#007bff;
}

button{
    margin-left:10px;
    padding:0 25px;
    border:none;
    border-radius:30px;
    background:linear-gradient(90deg,#007bff,#00c6ff);
    color:white;
    font-size:16px;
    cursor:pointer;
    transition:.3s;
}

button:hover{
    transform:scale(1.05);
    box-shadow:0 5px 15px rgba(0,123,255,.4);
}

button:active{
    transform:scale(.95);
}