:root { color-scheme: light dark; }
* { box-sizing: border-box; }
body { margin: 0; min-height: 100vh; display: grid; place-items: center;
  font: 16px/1.5 system-ui, sans-serif; background: #0b1020; color: #e8ecf4; }
.card { max-width: 640px; padding: 2rem; margin: 1rem; border-radius: 16px;
  background: #131a30; box-shadow: 0 10px 40px rgba(0,0,0,.4); }
h1 { margin: 0 0 .25rem; font-size: 1.6rem; }
.tag { margin: 0 0 1rem; color: #8ea0c0; font-size: .85rem; }
.prompt { white-space: pre-wrap; background: #0b1020; padding: 1rem;
  border-radius: 10px; border: 1px solid #243154; }
.hint { color: #8ea0c0; font-size: .9rem; }