:root {
  --bg: #f6f4ef; --card: #ffffff; --ink: #1d1b16; --muted: #6b665c; --line: #e2ddd2; --accent: #8a5a00; --bad: #a3271b;
  color-scheme: light dark;
}
@media (prefers-color-scheme: dark) {
  :root { --bg: #15140f; --card: #1f1d17; --ink: #efe9dc; --muted: #a59d8c; --line: #343026; --accent: #e0a940; --bad: #ff8a7a; }
}
* { box-sizing: border-box; }
body { margin: 0; background: var(--bg); color: var(--ink); font: 16px/1.5 system-ui, -apple-system, "Segoe UI", sans-serif; }
main { max-width: 460px; margin: 6vh auto; padding: 28px 24px; background: var(--card); border: 1px solid var(--line); border-radius: 14px; }
header { font-weight: 600; letter-spacing: .02em; color: var(--accent); margin-bottom: 18px; }
.mark { margin-right: 4px; }
h1 { font-size: 1.45rem; margin: 0 0 8px; }
h2 { font-size: 1.05rem; margin: 22px 0 8px; }
.lead { color: var(--muted); margin: 0 0 20px; }
.small { color: var(--muted); font-size: .85rem; }
button { font: inherit; padding: 10px 16px; border-radius: 10px; border: 1px solid var(--line); background: transparent; color: var(--ink); cursor: pointer; margin: 4px 6px 4px 0; }
button.primary { width: 100%; background: var(--accent); border-color: var(--accent); color: #fff; font-weight: 600; padding: 12px; }
button:disabled { opacity: .5; cursor: default; }
details { margin: 16px 0; }
summary { cursor: pointer; color: var(--muted); }
label { display: block; margin: 12px 0 4px; font-size: .9rem; }
input { font: inherit; width: 100%; padding: 10px; border-radius: 10px; border: 1px solid var(--line); background: transparent; color: var(--ink); margin-bottom: 8px; }
#msg { min-height: 1.5em; }
#msg.bad { color: var(--bad); }
ul.keys { list-style: none; padding: 0; margin: 0 0 12px; }
ul.keys li { display: flex; gap: 10px; align-items: center; justify-content: space-between; border-top: 1px solid var(--line); padding: 8px 0; flex-wrap: wrap; }
footer { margin-top: 28px; padding-top: 14px; border-top: 1px solid var(--line); color: var(--muted); font-size: .8rem; }
@media (max-width: 500px) { main { margin: 0; border-radius: 0; border-left: 0; border-right: 0; min-height: 100vh; padding: 24px 16px; } }