:root {
  --navy: #1b2d5c; --red: #c8103c; --gold: #c9a227; --ink: #1d2433; --muted: #5b6475;
  --bg: #f4f5f8; --card: #ffffff; --line: #dfe3ea; --ok: #1f7a4d; --bad: #b3261e;
}
* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body { margin: 0; background: var(--bg); color: var(--ink); font: 16px/1.55 system-ui, -apple-system, "Segoe UI", Roboto, Arial, sans-serif; }
.card { max-width: 560px; margin: 24px auto; padding: 24px 20px; background: var(--card); border: 1px solid var(--line); border-radius: 14px; }
.card.text { max-width: 760px; }
.brand { margin: 0 0 4px; color: var(--red); font-weight: 700; letter-spacing: .04em; text-transform: uppercase; font-size: 13px; }
h1 { margin: 0 0 12px; color: var(--navy); font-size: 24px; line-height: 1.25; }
h2 { color: var(--navy); font-size: 18px; margin: 18px 0 8px; }
.book span { display: block; color: var(--muted); font-size: 14px; }
.book strong { font-size: 20px; color: var(--navy); }
.steps { padding-inline-start: 22px; }
.steps li { margin: 14px 0; }
.btn { display: inline-block; margin-top: 8px; padding: 12px 16px; border: 1px solid var(--navy); border-radius: 10px; background: #fff;
  color: var(--navy); font: inherit; font-weight: 600; text-decoration: none; cursor: pointer; }
.btn.primary { background: var(--navy); color: #fff; }
.btn:disabled { opacity: .5; cursor: wait; }
.link { background: none; border: 0; padding: 0; color: var(--navy); text-decoration: underline; font: inherit; cursor: pointer; }
input { width: 100%; max-width: 260px; margin-top: 8px; padding: 12px; border: 1px solid var(--line); border-radius: 10px;
  font: 600 20px/1 ui-monospace, Menlo, Consolas, monospace; letter-spacing: .2em; }
input::placeholder { font: 400 16px/1 system-ui, -apple-system, "Segoe UI", Roboto, Arial, sans-serif; letter-spacing: normal; }
.status { display: block; margin-top: 8px; font-size: 15px; color: var(--ok); }
.status.bad { color: var(--bad); }
.warn { padding: 14px; border-radius: 10px; background: #fff7e0; border: 1px solid #f0d58a; }
.warn h2 { margin-top: 0; }
.small { color: var(--muted); font-size: 14px; }
a { color: var(--navy); }
@media (max-width: 600px) { .card { margin: 0; border-radius: 0; border-width: 0 0 1px; min-height: 100vh; } }