:root{--bg:#0f1720;--card:#111827;--accent:#7c3aed;--text:#e6eef8}
*{box-sizing:border-box}
html,body{height:100%;margin:0;font-family:Inter,system-ui,Segoe UI,Roboto,"Helvetica Neue",Arial;background:var(--bg);color:var(--text)}
main{max-width:720px;margin:36px auto;padding:20px}
h1{margin:0 0 8px;font-size:20px}
.card{background:var(--card);padding:16px;border-radius:8px;box-shadow:0 6px 18px rgba(0,0,0,.6)}
button{background:var(--accent);color:white;border:0;padding:8px 12px;border-radius:6px;margin-right:8px;cursor:pointer}
#output{margin-top:12px;color:#dbeafe;white-space:pre-wrap}
footer{margin-top:14px;color:#9aa4b2;font-size:12px}