:root { color-scheme: dark; font-family: system-ui, -apple-system, sans-serif; }
body { margin: 0; min-height: 100vh; background: #04060b; color: #eaf4f1; }
main { min-height: 100vh; display: grid; place-items: center; padding: 1.25rem; box-sizing: border-box; }
.gate { width: min(28rem, 100%); padding: 1.5rem; border: 1px solid #1c2b3f;
  border-radius: 18px; background: #0a101c; box-sizing: border-box; }
.mark { color: #00e5c7; font: 700 .8rem ui-monospace, monospace; letter-spacing: .2em; }
h1 { margin: .4rem 0 1rem; font-size: 1.8rem; }
p { color: #a9bac8; line-height: 1.5; }
button { width: 100%; margin-top: .75rem; padding: .9rem 1rem; border-radius: 12px;
  border: 1px solid #00e5c7; background: #101828; color: #eaf4f1; font: inherit; }
button:disabled { opacity: .65; }
.error { color: #ff789f; }