:root {
  --red: #ff1c1c;
  --red-dark: #d90e0e;
  --ink: #151311;
  --paper: #fffaf2;
  --paper-deep: #f3eadc;
  --muted: #6f6860;
  --line: rgba(21, 19, 17, .14);
  --white: #fff;
  --max: 1180px;
  --shadow: 0 24px 70px rgba(48, 23, 11, .11);
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  overflow-x: hidden;
  color: var(--ink);
  background:
    radial-gradient(circle at 10% 8%, rgba(255, 28, 28, .08), transparent 30%),
    var(--paper);
  font-family: "PingFang SC", "Microsoft YaHei", system-ui, -apple-system, sans-serif;
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
}

a { color: inherit; text-decoration: none; }
img { display: block; max-width: 100%; }
summary { font: inherit; }
:focus-visible { outline: 3px solid var(--red); outline-offset: 4px; }
.shell { width: min(calc(100% - 40px), var(--max)); margin-inline: auto; }

.skip-link {
  position: fixed;
  z-index: 100;
  top: -80px;
  left: 18px;
  padding: 10px 18px;
  border-radius: 999px;
  color: #fff;
  background: var(--ink);
}
.skip-link:focus { top: 12px; }

.topbar {
  position: sticky;
  z-index: 50;
  top: 0;
  border-bottom: 1px solid var(--line);
  background: rgba(255, 250, 242, .9);
  backdrop-filter: blur(18px);
}
.nav {
  min-height: 72px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
}
.brand { display: flex; align-items: center; gap: 12px; font-weight: 950; letter-spacing: -.04em; }
.brand img { width: 42px; height: 42px; border-radius: 13px; box-shadow: 0 8px 22px rgba(255, 28, 28, .23); }
.brand-name { font-size: 1.18rem; }
.nav-links { display: flex; align-items: center; gap: 28px; color: var(--muted); font-weight: 700; font-size: .94rem; }
.nav-links a { position: relative; }
.nav-links a:hover, .nav-links a[aria-current="page"] { color: var(--red); }
.nav-links a[aria-current="page"]::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: -10px;
  height: 3px;
  border-radius: 99px;
  background: var(--red);
}
.nav-cta, .download-cta {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 46px;
  padding: 0 22px;
  border-radius: 999px;
  color: #fff;
  background: var(--red);
  font-weight: 900;
  box-shadow: 0 12px 26px rgba(255, 28, 28, .23);
  transition: transform .2s ease, background .2s ease;
}
.nav-cta:hover, .download-cta:hover { transform: translateY(-2px); background: var(--red-dark); }
.menu { display: none; position: relative; }
.menu summary { list-style: none; cursor: pointer; font-size: 1.55rem; line-height: 1; }
.menu summary::-webkit-details-marker { display: none; }
.menu-panel {
  position: absolute;
  top: 44px;
  right: 0;
  min-width: 200px;
  padding: 8px;
  border: 1px solid var(--line);
  border-radius: 18px;
  background: var(--paper);
  box-shadow: var(--shadow);
}
.menu-panel a { display: block; padding: 11px 13px; border-radius: 12px; font-weight: 750; }
.menu-panel a:hover, .menu-panel a[aria-current="page"] { color: var(--red); background: rgba(255, 28, 28, .06); }

.sub-hero {
  min-height: 520px;
  display: grid;
  grid-template-columns: 1.15fr .85fr;
  gap: 68px;
  align-items: center;
  padding-block: 82px;
}
.breadcrumb { margin: 0 0 26px; color: var(--muted); font-size: .88rem; font-weight: 700; }
.breadcrumb a:hover { color: var(--red); }
.breadcrumb span { margin: 0 9px; color: rgba(21, 19, 17, .35); }
.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 9px;
  margin: 0 0 18px;
  color: var(--red-dark);
  font-size: .82rem;
  font-weight: 850;
  letter-spacing: .14em;
  text-transform: uppercase;
}
.eyebrow::before { content: ""; width: 28px; height: 3px; background: var(--red); border-radius: 99px; }
.sub-hero h1 {
  margin: 0;
  font-size: clamp(3.2rem, 6.8vw, 6.2rem);
  line-height: .98;
  letter-spacing: -.065em;
  font-weight: 1000;
}
.sub-hero h1 span { display: block; color: var(--red); }
.sub-hero > * { min-width: 0; }
.hero-copy { max-width: 680px; margin: 28px 0 0; color: var(--muted); font-size: 1.08rem; }
.hero-mark {
  min-height: 340px;
  position: relative;
  display: grid;
  place-items: center;
}
.mark-card {
  width: min(330px, 86%);
  aspect-ratio: 1;
  display: grid;
  place-items: center;
  border: 1px solid var(--line);
  border-radius: 42px;
  background: rgba(255,255,255,.62);
  box-shadow: var(--shadow);
  transform: rotate(4deg);
}
.mark-card strong { color: var(--red); font-size: clamp(6rem, 11vw, 10rem); line-height: 1; letter-spacing: -.08em; }
.mark-card small { position: absolute; bottom: 28px; color: var(--muted); font-weight: 850; letter-spacing: .12em; }
.mark-dot { position: absolute; width: 68px; height: 68px; border-radius: 50%; background: var(--red); right: 5%; top: 10%; box-shadow: 0 12px 26px rgba(255,28,28,.22); }
.mark-ring { position: absolute; width: 88px; height: 88px; border: 14px solid var(--ink); border-radius: 50%; left: 3%; bottom: 8%; }

.section { padding-block: 92px; border-top: 1px solid var(--line); }
.section-head { display: grid; grid-template-columns: .7fr 1.3fr; gap: 60px; align-items: start; margin-bottom: 40px; }
.section-head h2 { margin: 0; font-size: clamp(2.15rem, 4vw, 4rem); line-height: 1.08; letter-spacing: -.055em; }
.section-head p { margin: 8px 0 0; color: var(--muted); }
.grid-3 { display: grid; grid-template-columns: repeat(3, 1fr); gap: 18px; }
.info-card {
  min-height: 330px;
  padding: 34px;
  border: 1px solid var(--line);
  border-radius: 26px;
  background: rgba(255,255,255,.5);
  box-shadow: 0 18px 45px rgba(48,23,11,.05);
}
.info-card.dark { color: #fff; background: var(--ink); }
.info-card.accent { background: var(--red); color: #fff; }
.card-no { display: block; margin-bottom: 70px; color: var(--red); font-size: .78rem; font-weight: 900; letter-spacing: .14em; }
.dark .card-no, .accent .card-no { color: rgba(255,255,255,.7); }
.info-card h3 { margin: 0 0 14px; font-size: 1.7rem; line-height: 1.2; letter-spacing: -.035em; }
.info-card p { margin: 0; color: var(--muted); }
.dark p, .accent p { color: rgba(255,255,255,.72); }

.statement {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 55px;
  align-items: center;
  padding: 48px;
  border-radius: 28px;
  background: var(--paper-deep);
}
.statement h2 { margin: 0; font-size: clamp(2rem, 4vw, 3.6rem); line-height: 1.08; letter-spacing: -.055em; }
.statement p { margin: 0; color: var(--muted); }

.timeline { border-top: 1px solid var(--line); }
.timeline-item {
  display: grid;
  grid-template-columns: 100px .8fr 1.2fr;
  gap: 35px;
  padding: 38px 0;
  border-bottom: 1px solid var(--line);
  align-items: start;
}
.timeline-item > strong { color: var(--red); font-size: 1rem; letter-spacing: .1em; }
.timeline-item h3 { margin: 0; font-size: 1.8rem; line-height: 1.2; }
.timeline-item p { margin: 0; color: var(--muted); }

.scene-grid { display: grid; grid-template-columns: 1.25fr .75fr; gap: 18px; }
.scene-card {
  min-height: 310px;
  padding: 36px;
  border: 1px solid var(--line);
  border-radius: 26px;
  background: rgba(255,255,255,.55);
  display: flex;
  flex-direction: column;
  justify-content: space-between;
}
.scene-card.wide { grid-row: span 2; min-height: 638px; background: var(--red); color: #fff; }
.scene-card.dark { color: #fff; background: var(--ink); }
.scene-card h3 { margin: 0 0 12px; font-size: clamp(1.8rem, 3vw, 3.2rem); line-height: 1.08; letter-spacing: -.05em; }
.scene-card p { margin: 0; color: var(--muted); }
.scene-card.wide p, .scene-card.dark p { color: rgba(255,255,255,.72); }
.scene-word { align-self: flex-end; font-size: clamp(4rem, 9vw, 8rem); font-weight: 1000; line-height: .9; opacity: .2; }

.faq-list { max-width: 920px; margin: 0 auto; }
.faq-list details { border-top: 1px solid var(--line); }
.faq-list details:last-child { border-bottom: 1px solid var(--line); }
.faq-list summary {
  position: relative;
  cursor: pointer;
  list-style: none;
  padding: 26px 55px 26px 0;
  font-size: 1.16rem;
  font-weight: 900;
}
.faq-list summary::-webkit-details-marker { display: none; }
.faq-list summary::after { content: "+"; position: absolute; right: 8px; top: 19px; color: var(--red); font-size: 1.8rem; }
.faq-list details[open] summary::after { content: "−"; }
.faq-list details p { max-width: 760px; margin: -4px 0 28px; color: var(--muted); }

.download-band {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 32px;
  margin-bottom: 92px;
  padding: 42px 46px;
  border-radius: 28px;
  color: #fff;
  background: var(--ink);
}
.download-band h2 { margin: 0 0 8px; font-size: clamp(1.8rem, 3vw, 2.8rem); line-height: 1.1; }
.download-band p { margin: 0; color: rgba(255,255,255,.65); }
.download-cta { flex: 0 0 auto; }

footer { border-top: 1px solid var(--line); padding: 34px 0 22px; background: rgba(255,255,255,.4); }
.footer-row { display: flex; align-items: center; justify-content: space-between; gap: 30px; }
.footer-brand { font-weight: 950; }
.footer-row small { color: var(--muted); }
.footer-links { display: flex; flex-wrap: wrap; justify-content: center; gap: 10px 17px; max-width: 680px; color: var(--muted); font-size: .77rem; }
.footer-links a:hover { color: var(--red); }
.footer-meta { display: flex; justify-content: flex-end; margin-top: 18px; padding-top: 16px; border-top: 1px solid var(--line); color: var(--muted); font-size: .78rem; }
.footer-meta a:hover { color: var(--red); }

@media (max-width: 860px) {
  .nav-links, .nav-cta { display: none; }
  .menu { display: block; }
  .sub-hero { grid-template-columns: 1fr; gap: 30px; padding-block: 58px; }
  .hero-mark { min-height: 270px; }
  .mark-card { width: 250px; }
  .section-head { grid-template-columns: 1fr; gap: 12px; }
  .grid-3 { grid-template-columns: 1fr; }
  .info-card { min-height: 260px; }
  .card-no { margin-bottom: 45px; }
  .scene-grid { grid-template-columns: 1fr; }
  .scene-card.wide { grid-row: auto; min-height: 430px; }
  .timeline-item { grid-template-columns: 60px 1fr; }
  .timeline-item p { grid-column: 2; }
  .statement { grid-template-columns: 1fr; gap: 20px; padding: 34px; }
  .download-band { align-items: flex-start; flex-direction: column; }
  .footer-row { align-items: flex-start; flex-direction: column; }
  .footer-links { justify-content: flex-start; }
  .footer-meta { justify-content: flex-start; }
}

@media (max-width: 520px) {
  .shell { width: min(calc(100% - 28px), var(--max)); }
  .sub-hero { padding-block: 42px; }
  .sub-hero h1 { font-size: 3.35rem; }
  .hero-copy { font-size: 1rem; }
  .hero-mark { min-height: 230px; }
  .mark-card { width: 210px; border-radius: 30px; }
  .mark-card small { bottom: 18px; }
  .section { padding-block: 65px; }
  .info-card, .scene-card { padding: 27px; }
  .download-band { padding: 30px 26px; margin-bottom: 65px; }
  .download-cta { width: 100%; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { transition-duration: .01ms !important; }
}