*{box-sizing:border-box;margin:0;padding:0}html,body{background:#faf8f4;height:100%}.chat-shell{max-width:460px;height:100vh;margin:0 auto}@media (min-width:768px){body{background:#eef1f5}.chat-shell{border:1px solid #0f1f3d0f;border-radius:16px;max-width:760px;height:calc(100vh - 80px);margin:40px auto;box-shadow:0 24px 60px #0f1f3d29}}