body{
  margin:0;
  font-family:Inter,system-ui;
  background:linear-gradient(135deg,#0f2027,#203a43,#2c5364);
  min-height:100vh;
  display:flex;
  justify-content:center;
  align-items:center;
  color:#fff;
}
.bg{position:fixed;inset:0}
.card{
  background:rgba(0,0,0,.6);
  backdrop-filter:blur(20px);
  padding:30px;
  border-radius:20px;
  width:380px;
  box-shadow:0 20px 60px rgba(0,0,0,.6);
}
h1,h2,h3{text-align:center}
input,button{
  width:100%;
  padding:12px;
  margin:8px 0;
  border-radius:12px;
  border:none;
}
input{background:#111;color:#fff}
button{cursor:pointer;font-weight:700}
button.main{
  background:linear-gradient(135deg,#00c6ff,#7f00ff);
  color:#000;
  margin-top:15px;
}
button:not(.main){background:#222;color:#aaa}