:root{--bg:#0f1724;--card:#0b1220;--accent:#06b6d4;--text:#e6eef6}
*{box-sizing:border-box}
html,body{height:100%}
body{margin:0;font-family:Segoe UI,Roboto,Helvetica,Arial,sans-serif;background:linear-gradient(180deg,var(--bg),#071126);color:var(--text);display:flex;align-items:center;justify-content:center;padding:2rem}
.container{max-width:820px;width:100%}
h1{margin:0 0 .25rem;font-size:2rem}
.lead{margin:0 0 1rem;color:#cfeaf3}
.card{background:rgba(255,255,255,0.03);padding:1rem;border-radius:8px;margin:1rem 0}
.btn{display:inline-block;margin-top:.5rem;padding:.5rem 0.9rem;background:var(--accent);color:#042028;text-decoration:none;border-radius:6px;font-weight:600}
button.btn{border:none;cursor:pointer}
.footer{margin-top:1.5rem;text-align:center;color:#98cfd6;font-size:.9rem}

@media (min-width:600px){h1{font-size:2.4rem}}