:root {
  --ink: #171717;
  --muted: #66635f;
  --paper: #f6f5f2;
  --surface: #ffffff;
  --line: #dedbd5;
  --accent: #b42318;
  --accent-dark: #861d14;
  --error: #9f1c14;
}

* { box-sizing: border-box; }
body {
  margin: 0;
  min-width: 320px;
  color: var(--ink);
  background: var(--paper);
  font-family: -apple-system, BlinkMacSystemFont, "PingFang SC", "Microsoft YaHei", sans-serif;
  -webkit-font-smoothing: antialiased;
}
a { color: inherit; }
.site-header, main, footer { width: min(1040px, calc(100% - 40px)); margin-inline: auto; }
.site-header {
  min-height: 82px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  border-bottom: 1px solid var(--line);
}
.brand { display: flex; align-items: center; gap: 12px; text-decoration: none; }
.brand-mark {
  width: 42px;
  height: 42px;
  display: grid;
  place-items: center;
  color: #fff;
  background: var(--accent);
  border-radius: 10px;
  font-size: 22px;
  font-weight: 850;
}
.brand > span:last-child { display: grid; gap: 2px; }
.brand b { font-size: 19px; letter-spacing: .02em; }
.brand small, .official-label { color: var(--muted); font-size: 11px; }
.official-label { padding: 7px 10px; border: 1px solid var(--line); border-radius: 999px; }

.hero {
  min-height: 570px;
  padding: 86px 0 92px;
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(340px, 420px);
  align-items: center;
  gap: clamp(54px, 9vw, 120px);
}
.eyebrow, .section-label { margin: 0 0 20px; color: var(--accent); font-size: 12px; font-weight: 800; letter-spacing: .16em; }
h1, h2 { font-family: "Songti SC", "Noto Serif CJK SC", serif; }
h1 { margin: 0; font-size: clamp(48px, 6.2vw, 76px); line-height: 1.08; letter-spacing: -.035em; }
h1 span { color: var(--accent); }
.lead { max-width: 560px; margin: 27px 0 0; color: var(--muted); font-size: 16px; line-height: 1.9; }

.download-panel { padding: 30px; border: 1px solid var(--line); background: var(--surface); }
.download-panel h2 { margin: 0 0 10px; font-size: 27px; }
.download-panel .hint { margin: 0 0 24px; color: var(--muted); font-size: 13px; line-height: 1.7; }
.agent-form { display: grid; gap: 12px; }
.agent-form label { font-size: 12px; font-weight: 750; }
.agent-form input {
  width: 100%;
  height: 50px;
  padding: 0 14px;
  border: 1px solid #bbb7b0;
  border-radius: 8px;
  color: var(--ink);
  background: #fff;
  font: 650 15px/1 ui-monospace, "SFMono-Regular", monospace;
  text-transform: uppercase;
}
.primary-button {
  min-height: 50px;
  padding: 0 18px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border: 0;
  border-radius: 8px;
  color: #fff;
  background: var(--accent);
  font-size: 15px;
  font-weight: 800;
  text-decoration: none;
  cursor: pointer;
}
.primary-button:hover { background: var(--accent-dark); }
.error-message { margin: 0 0 16px; padding: 10px 12px; border-left: 3px solid var(--error); color: var(--error); background: #fff3f1; font-size: 12px; line-height: 1.6; }
.success-line { margin: 0 0 18px; color: #25603b; font-size: 12px; font-weight: 750; }
.release-meta { margin: 26px 0 0; padding-top: 20px; display: grid; gap: 11px; border-top: 1px solid var(--line); }
.release-meta div { display: flex; justify-content: space-between; gap: 16px; }
.release-meta dt { color: var(--muted); font-size: 12px; }
.release-meta dd { margin: 0; font-size: 12px; font-weight: 750; }

.steps { padding: 72px 0; display: grid; grid-template-columns: .7fr 1.3fr; gap: 70px; border-top: 1px solid var(--line); }
.steps h2 { margin: 0; font-size: clamp(32px, 4vw, 48px); }
.steps ol { margin: 0; padding: 0; list-style: none; border-top: 1px solid var(--line); }
.steps li { padding: 21px 0; display: grid; grid-template-columns: 48px 1fr; gap: 18px; border-bottom: 1px solid var(--line); }
.steps li > span { color: var(--accent); font-size: 11px; font-weight: 850; }
.steps b { font-size: 15px; }
.steps p { margin: 6px 0 0; color: var(--muted); font-size: 12px; line-height: 1.7; }
.integrity { max-width: 760px; margin: 10px auto 0; border-top: 1px solid var(--line); border-bottom: 1px solid var(--line); }
.integrity summary { padding: 17px 2px; color: var(--muted); font-size: 12px; cursor: pointer; }
.integrity div { padding: 0 0 15px; display: grid; grid-template-columns: 70px 1fr; gap: 12px; }
.integrity span { color: var(--muted); font-size: 10px; font-weight: 800; }
.integrity code { overflow-wrap: anywhere; font: 600 11px/1.6 ui-monospace, "SFMono-Regular", monospace; }
.notice { margin: 18px auto 72px; max-width: 760px; color: #77736c; font-size: 11px; line-height: 1.7; text-align: center; }
footer { min-height: 88px; display: flex; align-items: center; justify-content: space-between; border-top: 1px solid var(--line); color: var(--muted); font-size: 11px; }
input:focus-visible, button:focus-visible, a:focus-visible, summary:focus-visible { outline: 3px solid #d9a29d; outline-offset: 3px; }

@media (max-width: 780px) {
  .site-header, main, footer { width: min(620px, calc(100% - 28px)); }
  .hero { min-height: 0; padding: 58px 0 68px; grid-template-columns: 1fr; gap: 44px; }
  .steps { grid-template-columns: 1fr; gap: 34px; }
}

@media (max-width: 480px) {
  .site-header { min-height: 70px; }
  .brand-mark { width: 38px; height: 38px; }
  .brand small { display: none; }
  h1 { font-size: 48px; }
  .lead { font-size: 14px; }
  .download-panel { padding: 22px 18px; }
  footer { align-items: flex-start; flex-direction: column; justify-content: center; gap: 7px; }
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { scroll-behavior: auto !important; }
}