:root { --bg: #f6f3ee; --panel: #fffdf9; --ink: #2b2620; --muted: #776d62; --line: #ddd3c6; --acc: #0072B2; --bad: #b3261e; }
@media (prefers-color-scheme: dark) {
  :root { --bg: #1b1a18; --panel: #24221f; --ink: #ece6dc; --muted: #a59a8c; --line: #3a3631; --acc: #56B4E9; --bad: #f2b8b5; }
}
* { box-sizing: border-box; }
html, body { height: 100%; }
body { margin: 0; background: var(--bg); color: var(--ink); font: 16px/1.5 system-ui, -apple-system, "Segoe UI", sans-serif;
  display: grid; place-items: center; padding: 16px; }
main { width: 100%; max-width: 420px; background: var(--panel); border: 1px solid var(--line); border-radius: 16px;
  padding: 32px 24px; text-align: center; }
.mark { width: 56px; height: 56px; color: var(--acc); }
h1 { font: 600 28px/1.2 Georgia, "Times New Roman", serif; margin: 8px 0 6px; }
.sub { color: var(--muted); margin: 0 0 24px; }
#gbtn { display: flex; justify-content: center; min-height: 44px; }
#msg { margin: 18px 0 0; font-size: 15px; }
#msg.bad { color: var(--bad); }