:root{
  --bg:#0b1320; --card:#111a2a; --text:#e8eef7; --muted:#a8b3c7; --accent:#2b8a3e; --accent-2:#1f6a2f;
}
*{box-sizing:border-box}
html,body{margin:0;padding:0;background:var(--bg);color:var(--text);font:16px/1.5 system-ui, -apple-system, Segoe UI, Roboto, Arial, sans-serif}
a{color:#89b7ff;text-decoration:none} a:hover{text-decoration:underline}
.container{max-width:840px;margin:24px auto;padding:0 16px}
h1,h2{line-height:1.2;margin:0 0 12px 0}
.card{
  background:var(--card); padding:16px; border-radius:14px; margin:16px 0;
  box-shadow:0 10px 30px rgba(0,0,0,.25);
}
button{
  background:var(--accent); color:#fff; border:0; padding:10px 14px; border-radius:10px; cursor:pointer;
}
button:hover{background:var(--accent-2)}
.result{background:#0a0f1a; padding:12px; border-radius:8px; color:#cde1ff; min-height:2em}
.muted{color:var(--muted)}
code{background:#0a0f1a; padding:2px 6px; border-radius:6px}