body {
  margin:0;
  font-family:Arial,sans-serif;
  background:#0f172a;
  color:#e5e7eb;
}
#loginView,#appView{height:100vh;display:flex}
#loginView{justify-content:center;align-items:center}
.login-box{
  background:#020617;
  padding:30px;
  border-radius:16px;
  width:340px;
}
input,button{
  width:100%;
  margin-top:10px;
  padding:12px;
  border-radius:8px;
  border:none;
}
button{background:#2563eb;color:#fff;font-weight:600;cursor:pointer}
.sidebar{width:300px;background:#020617;padding:10px}
.friend-item{
  display:flex;
  justify-content:space-between;
  border-bottom:1px solid #1e293b;
  padding:10px;
}
.main{flex:1;display:flex;flex-direction:column}
.call-panel{padding:10px;border-top:1px solid #1e293b}
video{width:220px;border-radius:10px;background:#000}