:root{
  --bg1:#0f172a;
  --bg2:#0b1220;
  --accent:#7c3aed;
  --card:#0b1220cc;
  --text:#e6eef8;
}
*{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(135deg,var(--bg1),var(--bg2));
  color:var(--text);
  -webkit-font-smoothing:antialiased;
  -moz-osx-font-smoothing:grayscale;
}
.center{
  min-height:100vh;
  display:flex;
  align-items:center;
  justify-content:center;
  padding:2rem;
}
.card{
  width:100%;
  max-width:760px;
  background:linear-gradient(180deg, rgba(255,255,255,0.02), rgba(255,255,255,0.01));
  border:1px solid rgba(255,255,255,0.04);
  padding:2.25rem;
  border-radius:14px;
  text-align:center;
  box-shadow:0 8px 30px rgba(2,6,23,0.6);
}
.logo{
  font-weight:700;
  letter-spacing:0.6px;
  display:inline-block;
  padding:6px 10px;
  background:linear-gradient(90deg,var(--accent),#06b6d4);
  color:white;
  border-radius:8px;
  margin-bottom:1rem;
}
h1{margin:0 0 .4rem;font-size:1.6rem}
.lead{margin:.25rem 0 1.25rem;color:rgba(230,238,248,0.85)}
.small{margin-top:1rem;color:rgba(230,238,248,0.6);font-size:.85rem}
.note{font-size:.9rem;color:rgba(230,238,248,0.65);margin-top:.6rem}
.preview-hint{margin-top:1rem;color:rgba(230,238,248,0.6);font-size:.9rem}
code{background:rgba(255,255,255,0.02);padding:2px 6px;border-radius:4px}

@media (max-width:520px){
  .card{padding:1.25rem}
  h1{font-size:1.25rem}
}