body{margin:0;font-family:Arial;background:#f4f7ff}
.app{display:flex;height:100vh}
.sidebar{width:250px;background:#0d6efd;color:#fff;padding:20px;display:flex;flex-direction:column}
.sidebar button{margin:5px 0;padding:10px;border:none;cursor:pointer}
main{flex:1;padding:20px}
.view{display:none;height:100%}
.view.active{display:flex;flex-direction:column}
#messages{flex:1;overflow:auto}
.user{background:#0d6efd;color:white;padding:10px;margin:8px;border-radius:6px}
.ai{background:white;padding:10px;margin:8px;border-radius:6px}
.input{display:flex;gap:10px}
textarea{flex:1;padding:10px}
.center{display:flex;justify-content:center;align-items:center;height:100vh}
.login-box{background:white;padding:30px;border-radius:8px}