:root {
  color-scheme: light;
  --ink: #171717;
  --paper: #ffffff;
  --soft: #f4f5f2;
  --muted: #656861;
  --line: #d8dad4;
  --green: #176b43;
  --yellow: #ffc62f;
  --red: #e7493e;
  --max: 1160px;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: -apple-system, BlinkMacSystemFont, "PingFang SC", "Microsoft YaHei", "Noto Sans CJK SC", Arial, sans-serif;
  line-height: 1.65;
  text-rendering: optimizeLegibility;
}

img { max-width: 100%; }
a { color: inherit; }

.skip-link {
  position: fixed;
  left: 16px;
  top: -80px;
  z-index: 100;
  padding: 10px 14px;
  background: var(--ink);
  color: #fff;
}

.skip-link:focus { top: 12px; }

.site-header {
  position: sticky;
  top: 0;
  z-index: 20;
  border-bottom: 1px solid rgba(216, 218, 212, .85);
  background: rgba(255, 255, 255, .94);
  -webkit-backdrop-filter: blur(14px);
  backdrop-filter: blur(14px);
}

.nav {
  width: min(100%, var(--max));
  min-height: 68px;
  margin: 0 auto;
  padding: 10px 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 28px;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  flex: 0 0 auto;
  text-decoration: none;
  font-size: 18px;
  font-weight: 800;
}

.brand img {
  width: 38px;
  height: 38px;
  border-radius: 8px;
}

.brand small {
  color: var(--muted);
  font-size: 12px;
  font-weight: 600;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 24px;
  color: #4d504a;
  font-size: 14px;
  white-space: nowrap;
}

.nav-links a { text-decoration: none; }
.nav-links a:hover { color: var(--green); }

.hero {
  position: relative;
  min-height: min(720px, calc(100vh - 68px));
  display: flex;
  align-items: center;
  overflow: hidden;
  background-image: url("./assets/ios-join-1.1-51.png");
  background-position: 76% 20%;
  background-size: cover;
  background-color: #40423e;
  background-blend-mode: multiply;
}

.hero-overlay {
  position: absolute;
  inset: 0;
  background: rgba(13, 14, 13, .46);
}

.hero-copy {
  position: relative;
  width: min(100%, var(--max));
  margin: 0 auto;
  padding: 72px 24px 80px;
  color: #fff;
}

.eyebrow,
.section-kicker {
  margin: 0 0 12px;
  font-size: 13px;
  font-weight: 800;
  letter-spacing: 0;
  text-transform: uppercase;
}

.eyebrow { color: #f8d66a; }

h1, h2, h3, p { overflow-wrap: break-word; }

h1 {
  margin: 0;
  max-width: 720px;
  font-size: 82px;
  line-height: 1.02;
  letter-spacing: 0;
}

.hero-tagline {
  margin: 18px 0 0;
  max-width: 680px;
  font-size: 27px;
  font-weight: 760;
}

.lead {
  margin: 20px 0 0;
  max-width: 670px;
  color: rgba(255,255,255,.9);
  font-size: 18px;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 30px;
}

.button {
  display: inline-flex;
  min-height: 46px;
  align-items: center;
  justify-content: center;
  padding: 10px 18px;
  border: 1px solid #fff;
  border-radius: 6px;
  text-decoration: none;
  font-weight: 800;
}

.button-light { background: #fff; color: var(--ink); }
.button-outline { background: transparent; color: #fff; }

.hero-note {
  max-width: 720px;
  margin: 28px 0 0;
  color: rgba(255,255,255,.76);
  font-size: 13px;
}

.notice-band {
  border-bottom: 1px solid #e3c868;
  background: #fff4c7;
}

.notice-inner {
  min-height: 68px;
  display: flex;
  align-items: center;
  gap: 20px;
  padding-top: 14px;
  padding-bottom: 14px;
}

.notice-inner strong { flex: 0 0 auto; }
.notice-inner span { color: #62582f; }

.section { border-top: 1px solid var(--line); }
.section[id] { scroll-margin-top: 88px; }
.section-soft { background: var(--soft); }

.section-inner {
  width: min(100%, var(--max));
  margin: 0 auto;
  padding: 72px 24px;
}

.section-heading { max-width: 780px; margin-bottom: 34px; }
.section-kicker { color: var(--green); }

.section-heading h2 {
  margin: 0;
  font-size: 40px;
  line-height: 1.18;
}

.section-heading > p:last-child {
  margin: 16px 0 0;
  color: var(--muted);
  font-size: 17px;
}

.feature-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  border-top: 1px solid var(--line);
  border-left: 1px solid var(--line);
}

.feature {
  min-width: 0;
  min-height: 230px;
  padding: 24px;
  border-right: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
  background: #fff;
}

.feature-index {
  color: var(--green);
  font-size: 13px;
  font-weight: 800;
}

.feature h3,
.step h3,
.download-item h3,
.screen-copy h3 {
  margin: 12px 0 7px;
  font-size: 21px;
  line-height: 1.25;
}

.feature p,
.step p,
.download-item p,
.screen-copy p {
  margin: 0;
  color: var(--muted);
}

.steps {
  margin: 0;
  padding: 0;
  list-style: none;
  border-top: 1px solid var(--line);
}

.step {
  display: grid;
  grid-template-columns: 52px minmax(0, 1fr);
  gap: 22px;
  padding: 26px 0;
  border-bottom: 1px solid var(--line);
}

.step-number {
  width: 46px;
  height: 46px;
  display: grid;
  place-items: center;
  border: 1px solid var(--ink);
  border-radius: 50%;
  background: #fff;
  font-weight: 850;
}

.step h3 { margin-top: 0; }
.step p { max-width: 820px; }

.screens-layout {
  display: grid;
  grid-template-columns: minmax(280px, 430px) minmax(0, 1fr);
  gap: 58px;
  align-items: start;
}

.screen-main { margin: 0; }

.screen-main img {
  width: 100%;
  max-height: 720px;
  object-fit: cover;
  object-position: top;
  display: block;
  border: 1px solid var(--line);
  border-radius: 8px;
}

.screen-main figcaption {
  padding-top: 10px;
  color: var(--muted);
  font-size: 13px;
}

.screen-copy { border-top: 1px solid var(--line); }

.screen-copy article {
  padding: 22px 0;
  border-bottom: 1px solid var(--line);
}

.screen-copy article > span {
  color: var(--green);
  font-size: 13px;
  font-weight: 800;
}

.section-dark { background: #171717; color: #fff; }
.section-dark .section-kicker { color: #f8d66a; }
.section-dark .section-heading > p:last-child { color: #bcbfb8; }

.download-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 12px;
}

.download-item {
  min-width: 0;
  min-height: 240px;
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  padding: 22px;
  border: 1px solid #3f423d;
  border-radius: 8px;
  background: #222320;
}

.platform-mark {
  min-width: 54px;
  height: 34px;
  display: inline-grid;
  place-items: center;
  padding: 0 9px;
  border: 1px solid #656961;
  border-radius: 5px;
  color: #fff;
  font-size: 12px;
  font-weight: 850;
}

.download-item h3 { margin-top: 20px; }
.download-item p { color: #bcbfb8; }

.status-pill {
  margin-top: auto;
  padding: 5px 9px;
  border: 1px solid #746c48;
  border-radius: 999px;
  color: #f8d66a;
  font-size: 12px;
  font-weight: 800;
  text-decoration: none;
}

.status-pill.status-open {
  border-color: #8fc5a4;
  background: #eaf6ee;
  color: #176738;
}

.download-note { margin: 22px 0 0; color: #9fa29b; font-size: 13px; }

.faq-layout {
  display: grid;
  grid-template-columns: minmax(220px, .75fr) minmax(0, 1.25fr);
  gap: 54px;
}

.faq-list { border-top: 1px solid var(--line); }

.faq-list details { border-bottom: 1px solid var(--line); }

.faq-list summary {
  padding: 22px 36px 22px 0;
  cursor: pointer;
  font-weight: 800;
  list-style-position: outside;
}

.faq-list details p { margin: -4px 0 22px; color: var(--muted); }

.legal-layout { max-width: 860px; }
.legal-layout h1 { font-size: 42px; line-height: 1.15; }
.legal-layout h2 { margin-top: 34px; font-size: 24px; }
.legal-layout p, .legal-layout li { color: #3f434a; }

.footer {
  border-top: 1px solid var(--line);
  background: var(--soft);
  color: var(--muted);
  font-size: 13px;
}

.footer-inner {
  width: min(100%, var(--max));
  margin: 0 auto;
  padding: 34px 24px;
  display: grid;
  grid-template-columns: 1fr auto;
  align-items: center;
  gap: 20px;
}

.footer-brand { display: flex; align-items: center; gap: 10px; }
.footer-brand img { width: 40px; height: 40px; border-radius: 8px; }
.footer-brand strong, .footer-brand span { display: block; }
.footer-brand strong { color: var(--ink); font-size: 16px; }

.footer-links { display: flex; flex-wrap: wrap; gap: 16px; justify-content: flex-end; }
.footer-links a { text-decoration: none; }
.footer-inner > p { grid-column: 1 / -1; margin: 0; }

@media (max-width: 900px) {
  .section[id] { scroll-margin-top: 112px; }
  .nav { align-items: flex-start; flex-direction: column; gap: 8px; padding-bottom: 12px; }
  .nav-links { width: 100%; overflow-x: auto; padding-bottom: 3px; }
  .hero { min-height: 660px; background-position: 62% 12%; }
  .feature-grid, .download-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .screens-layout, .faq-layout { grid-template-columns: 1fr; gap: 30px; }
  .screen-main { max-width: 430px; }
}

@media (max-width: 620px) {
  .nav, .section-inner, .hero-copy, .footer-inner { padding-left: 18px; padding-right: 18px; }
  .brand small { display: none; }
  .nav-links { gap: 18px; }
  .hero { min-height: 610px; background-position: 54% top; }
  .hero-overlay { background: rgba(13, 14, 13, .58); }
  .hero-copy { padding-top: 54px; padding-bottom: 58px; }
  h1 { font-size: 54px; }
  .hero-tagline { font-size: 22px; }
  .lead { font-size: 16px; }
  .hero-actions { align-items: stretch; flex-direction: column; }
  .button { width: 100%; }
  .notice-inner { align-items: flex-start; flex-direction: column; gap: 2px; }
  .section-inner { padding-top: 54px; padding-bottom: 54px; }
  .section-heading h2 { font-size: 31px; }
  .feature-grid, .download-grid { grid-template-columns: 1fr; }
  .feature { min-height: 0; }
  .step { grid-template-columns: 42px minmax(0, 1fr); gap: 14px; }
  .step-number { width: 38px; height: 38px; }
  .download-item { min-height: 210px; }
  .footer-inner { grid-template-columns: 1fr; }
  .footer-links { justify-content: flex-start; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
}