:root{
  --bg:#0f1724;
  --card:#0b1220;
  --accent:#6ee7b7;
  --muted:#9aa4b2;
  --glass: rgba(255,255,255,0.04);
}
*{box-sizing:border-box}
html,body{height:100%}
body{
  margin:0;
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial;
  background: linear-gradient(180deg,#071022 0%, var(--bg) 100%);
  color:#e6eef6;
  display:flex;
  align-items:center;
  justify-content:center;
}
.container{
  width:680px;
  max-width:94%;
  padding:36px;
  border-radius:12px;
  background: linear-gradient(180deg, rgba(255,255,255,0.02), rgba(255,255,255,0.01));
  box-shadow: 0 8px 30px rgba(2,6,23,0.6);
  backdrop-filter: blur(6px);
}
h1{
  margin:0 0 18px 0;
  text-align:center;
  font-weight:600;
  letter-spacing:0.2px;
}
.controls{
  display:flex;
  gap:12px;
  align-items:center;
  justify-content:center;
  margin-bottom:18px;
}
input#usernameInput{
  min-width:160px;
  padding:10px 12px;
  border-radius:8px;
  border:1px solid rgba(255,255,255,0.04);
  background:var(--card);
  color:var(--muted);
  font-size:15px;
}
select{
  min-width:320px;
  padding:10px 12px;
  border-radius:8px;
  border:1px solid rgba(255,255,255,0.04);
  background:var(--card);
  color:var(--muted);
  font-size:15px;
}
button.primary{
  padding:10px 16px;
  border-radius:8px;
  border:0;
  background:linear-gradient(90deg,var(--accent),#3ddab4);
  color:#072022;
  font-weight:600;
  cursor:pointer;
}
.message{
  margin-top:6px;
  padding:12px 14px;
  border-radius:8px;
  background:var(--glass);
  color:#dff5ea;
  text-align:center;
  transition:all .2s ease;
}
.hidden{display:none}