:root {
  --navy-950: #041021;
  --navy-900: #07152d;
  --navy-800: #0b2246;
  --blue-700: #1456c0;
  --blue-600: #1f6feb;
  --blue-500: #2f83f7;
  --cyan-400: #4fd1e3;
  --orange-500: #f28a2e;
  --orange-600: #dc741d;
  --ink-900: #10223d;
  --ink-700: #41536c;
  --ink-500: #6b7b90;
  --line: #dce5ef;
  --surface: #ffffff;
  --surface-soft: #f3f7fb;
  --shadow-sm: 0 10px 28px rgba(13, 41, 80, 0.08);
  --shadow-lg: 0 24px 70px rgba(2, 15, 35, 0.25);
  --radius: 8px;
  --container: 1200px;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; scroll-padding-top: 84px; }
body {
  margin: 0;
  color: var(--ink-900);
  background: var(--surface);
  font-family: "PingFang SC", "Microsoft YaHei", "Noto Sans CJK SC", Arial, sans-serif;
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}
body.menu-open { overflow: hidden; }
img { display: block; max-width: 100%; }
a { color: inherit; text-decoration: none; }
button, a { -webkit-tap-highlight-color: transparent; }
button { font: inherit; }
.container { width: min(calc(100% - 40px), var(--container)); margin-inline: auto; }
.section { padding: 92px 0; }
.section-tint { background: var(--surface-soft); }
.section-dark { color: #fff; background: var(--navy-900); }
.skip-link { position: fixed; top: -60px; left: 16px; z-index: 1000; padding: 10px 14px; background: #fff; border-radius: 6px; }
.skip-link:focus { top: 12px; }

.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  border-bottom: 1px solid rgba(159, 181, 215, 0.18);
  background: rgba(4, 16, 33, 0.94);
  backdrop-filter: blur(12px);
}
.nav-shell { min-height: 72px; display: flex; align-items: center; justify-content: space-between; gap: 24px; }
.brand { display: inline-flex; align-items: center; gap: 11px; color: #fff; font-size: 17px; font-weight: 800; white-space: nowrap; }
.brand img { width: 42px; height: 42px; border-radius: 50%; object-fit: cover; border: 1px solid rgba(94, 192, 255, 0.55); }
.main-nav { display: flex; align-items: center; gap: 25px; color: #cdd8e7; font-size: 14px; }
.main-nav > a:not(.button) { transition: color 160ms ease; }
.main-nav > a:not(.button):hover, .main-nav > a:not(.button):focus-visible { color: #fff; }
.menu-toggle { display: none; width: 44px; height: 44px; border: 1px solid rgba(255,255,255,.2); border-radius: 6px; background: transparent; padding: 10px; }
.menu-toggle span { display: block; height: 2px; margin: 5px 0; background: #fff; transition: transform 160ms ease, opacity 160ms ease; }

.button {
  display: inline-flex;
  min-height: 46px;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 10px 20px;
  border: 1px solid transparent;
  border-radius: 7px;
  font-size: 15px;
  font-weight: 700;
  line-height: 1.25;
  cursor: pointer;
  transition: transform 160ms ease, box-shadow 160ms ease, background-color 160ms ease, border-color 160ms ease;
}
.button:hover { transform: translateY(-2px); }
.button:focus-visible, .menu-toggle:focus-visible, .back-to-top:focus-visible { outline: 3px solid rgba(79, 209, 227, .45); outline-offset: 3px; }
.button-small { min-height: 38px; padding: 8px 15px; color: #fff; background: var(--blue-600); }
.button-accent { color: #fff; background: var(--orange-500); box-shadow: 0 10px 24px rgba(242, 138, 46, .24); }
.button-accent:hover { background: var(--orange-600); box-shadow: 0 14px 30px rgba(242, 138, 46, .3); }
.button-primary { color: #fff; border-color: var(--blue-600); background: var(--blue-600); box-shadow: 0 10px 24px rgba(31, 111, 235, .22); }
.button-primary:hover { border-color: var(--blue-700); background: var(--blue-700); box-shadow: 0 14px 30px rgba(31, 111, 235, .28); }
.button-ghost { color: #fff; border-color: rgba(255,255,255,.36); background: transparent; }
.button-ghost:hover { border-color: rgba(255,255,255,.7); background: rgba(255,255,255,.07); }
.button-light { color: var(--navy-900); background: #fff; }

.hero { position: relative; overflow: hidden; padding: 94px 0 100px; }
.hero::before {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  opacity: .25;
  background-image: linear-gradient(rgba(92, 153, 230, .16) 1px, transparent 1px), linear-gradient(90deg, rgba(92, 153, 230, .16) 1px, transparent 1px);
  background-size: 42px 42px;
  mask-image: linear-gradient(to right, #000, transparent 82%);
}
.hero-grid { position: relative; display: grid; grid-template-columns: minmax(0, 1.25fr) minmax(340px, .75fr); align-items: center; gap: 70px; }
.eyebrow { margin: 0 0 14px; color: var(--blue-600); font-size: 13px; font-weight: 800; letter-spacing: .08em; text-transform: uppercase; }
.section-dark .eyebrow, .final-cta .eyebrow { color: #77c8f3; }
.hero h1 { margin: 0; font-size: clamp(44px, 6vw, 72px); line-height: 1.08; font-weight: 850; letter-spacing: 0; }
.hero-lead { max-width: 760px; margin: 24px 0 18px; color: #eef6ff; font-size: clamp(21px, 2.5vw, 30px); line-height: 1.55; font-weight: 650; }
.hero-proof { max-width: 720px; margin: 0; color: #aebdd1; font-size: 16px; }
.hero-actions { display: flex; flex-wrap: wrap; gap: 12px; margin-top: 32px; }
.trust-strip { display: flex; flex-wrap: wrap; gap: 18px; margin: 28px 0 0; padding: 0; list-style: none; color: #c3d0e1; font-size: 13px; }
.trust-strip li::before { content: "✓"; margin-right: 7px; color: var(--cyan-400); font-weight: 800; }
.sop-preview { position: relative; padding: 26px; overflow: hidden; border: 1px solid rgba(109, 187, 255, .32); border-radius: var(--radius); background: #0c2347; box-shadow: var(--shadow-lg); }
.sop-preview::after { content: "AI"; position: absolute; right: -8px; bottom: -62px; color: rgba(255,255,255,.035); font-size: 180px; font-weight: 900; line-height: 1; }
.preview-topline { display: flex; align-items: center; justify-content: space-between; color: #8fa6c6; font-size: 12px; }
.preview-badge { color: #8de1eb; }
.preview-logo { width: 64px; height: 64px; margin-top: 6px; border-radius: 50%; object-fit: cover; }
.preview-kicker { margin: 14px 0 3px; color: #91a6c1; font-size: 13px; }
.sop-preview h2 { margin: 0; font-size: 26px; line-height: 1.35; }
.sop-preview > p:last-of-type { color: #b7c5d8; }
.preview-list { position: relative; z-index: 1; display: flex; flex-wrap: wrap; gap: 8px; margin-top: 24px; }
.preview-list span { padding: 6px 9px; border: 1px solid rgba(93, 173, 255, .27); border-radius: 4px; color: #d9e8fa; background: rgba(17, 67, 124, .35); font-size: 12px; }

.section-heading { max-width: 780px; margin: 0 auto 44px; text-align: center; }
.section-heading h2, .about-copy h2, .free-copy h2, .final-cta h2 { margin: 0; font-size: clamp(30px, 4vw, 42px); line-height: 1.28; letter-spacing: 0; }
.section-heading > p:last-child { color: var(--ink-500); }
.heading-light > p:last-child { color: #9eafc6; }
.card-grid { display: grid; gap: 18px; }
.pain-grid, .solution-grid { grid-template-columns: repeat(4, 1fr); }
.info-card, .solution-card { border: 1px solid var(--line); border-radius: var(--radius); background: #fff; box-shadow: var(--shadow-sm); }
.info-card { min-height: 188px; padding: 27px; }
.card-number { color: var(--blue-600); font-size: 13px; font-weight: 800; }
.info-card p { margin: 28px 0 0; font-size: 18px; line-height: 1.65; font-weight: 650; }
.section-summary { max-width: 820px; margin: 36px auto 0; padding: 20px; border-left: 4px solid var(--blue-600); color: var(--ink-700); background: var(--surface-soft); text-align: center; font-size: 18px; font-weight: 650; }
.solution-card { padding: 30px 26px; }
.solution-icon { display: inline-flex; width: 42px; height: 42px; align-items: center; justify-content: center; border-radius: 6px; color: #fff; background: var(--blue-700); font-size: 12px; font-weight: 800; }
.solution-card h3 { margin: 18px 0 8px; font-size: 21px; }
.solution-card p { margin: 0; color: var(--ink-700); font-size: 15px; }

.free-section { background: #fff; }
.free-grid { display: grid; grid-template-columns: minmax(0, 1fr) minmax(420px, .85fr); align-items: center; gap: 76px; }
.free-copy h2 { margin-bottom: 15px; }
.free-copy h3 { margin: 0; color: var(--blue-700); font-size: 20px; }
.check-list { display: grid; grid-template-columns: 1fr 1fr; gap: 12px 20px; margin: 28px 0; padding: 0; list-style: none; }
.check-list li { color: var(--ink-700); }
.check-list li::before { content: "✓"; display: inline-flex; width: 22px; height: 22px; margin-right: 8px; align-items: center; justify-content: center; border-radius: 50%; color: var(--blue-700); background: #e6f0ff; font-size: 12px; font-weight: 900; }
.fine-print { margin: 14px 0 0; color: var(--ink-500); font-size: 13px; }
.qr-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 18px; }
.qr-card { margin: 0; padding: 20px; border: 1px solid var(--line); border-radius: var(--radius); background: var(--surface-soft); text-align: center; }
.qr-media { position: relative; width: min(100%, 196px); aspect-ratio: 1; margin: auto; overflow: hidden; border: 1px dashed #a9b6c8; border-radius: 6px; background: #e6ebf1; }
.qr-media img { position: relative; z-index: 2; width: 100%; height: 100%; object-fit: contain; background: #fff; }
.qr-media img.is-missing { display: none; }
.qr-placeholder { position: absolute; inset: 0; display: flex; align-items: center; justify-content: center; padding: 15px; color: #6c7889; font-size: 13px; }
.qr-card figcaption { display: grid; gap: 2px; margin-top: 13px; }
.qr-card figcaption span { color: var(--ink-500); font-size: 12px; }

.products-section { background: var(--navy-950); }
.product-grid { display: grid; grid-template-columns: repeat(4, minmax(0, 1fr)); gap: 16px; align-items: stretch; }
.product-card { display: flex; min-width: 0; flex-direction: column; padding: 25px 22px; border: 1px solid #253d61; border-radius: var(--radius); background: #0a1c37; }
.product-card.product-featured { border-color: #3484e9; box-shadow: 0 0 0 1px rgba(52,132,233,.18), 0 18px 45px rgba(0,0,0,.22); }
.product-level { align-self: flex-start; padding: 4px 8px; border-radius: 4px; color: #9dd7ff; background: #112c52; font-size: 11px; font-weight: 800; }
.product-card h3 { min-height: 76px; margin: 18px 0 12px; color: #fff; font-size: 18px; line-height: 1.45; }
.price { margin: 0 0 20px; color: #d6e4f6; }
.price strong { margin-right: 3px; color: #fff; font-size: 38px; line-height: 1; }
.price small { display: block; margin-top: 8px; color: #8fa0b7; font-size: 11px; }
.product-card dl { display: grid; grid-template-columns: 42px 1fr; gap: 8px 8px; margin: 0 0 24px; color: #aebdd0; font-size: 13px; }
.product-card dt { color: #6db7ee; font-weight: 800; }
.product-card dd { margin: 0; }
.product-button { width: 100%; margin-top: auto; color: #fff; border-color: #31598b; background: #173c6d; }
.product-button:hover { background: #1e5192; }
.delivery-note { max-width: 920px; margin: 28px auto 0; padding: 16px 18px; border-left: 3px solid #3484e9; color: #aebdd0; background: #0a1c37; font-size: 13px; text-align: center; }

.weekly-card { display: grid; grid-template-columns: minmax(0, 1fr) auto; align-items: center; gap: 44px; padding: 34px 38px; border: 1px solid var(--line); border-left: 4px solid var(--blue-600); border-radius: var(--radius); background: #fff; box-shadow: var(--shadow-sm); }
.weekly-content h3 { margin: 0 0 12px; color: var(--ink-900); font-size: 24px; line-height: 1.45; }
.weekly-content > p { max-width: 760px; margin: 0; color: var(--ink-700); }
.weekly-tags { display: flex; flex-wrap: wrap; gap: 8px; margin-top: 20px; }
.weekly-tags span { padding: 5px 9px; border: 1px solid #cbdcf2; border-radius: 4px; color: var(--blue-700); background: #f4f8fd; font-size: 12px; font-weight: 700; }
.weekly-button { flex-shrink: 0; color: #fff; background: var(--blue-700); }
.weekly-button:hover { background: var(--blue-600); }

.audience-grid { display: grid; grid-template-columns: repeat(3, 1fr); border-top: 1px solid var(--line); border-left: 1px solid var(--line); }
.audience-item { min-height: 116px; display: flex; align-items: center; gap: 18px; padding: 26px; border-right: 1px solid var(--line); border-bottom: 1px solid var(--line); }
.audience-item span { color: var(--blue-600); font-size: 12px; font-weight: 800; }
.audience-item strong { font-size: 17px; }
.about-grid { display: grid; grid-template-columns: minmax(0, 1fr) minmax(420px, .8fr); align-items: center; gap: 70px; }
.about-copy p:not(.eyebrow) { color: var(--ink-700); font-size: 17px; }
.proof-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 12px; }
.proof-grid div { display: grid; min-height: 142px; align-content: center; padding: 22px; border: 1px solid var(--line); border-radius: var(--radius); background: #fff; box-shadow: var(--shadow-sm); }
.proof-grid strong { color: var(--blue-700); font-size: 25px; }
.proof-grid span { color: var(--ink-500); font-size: 13px; }

.final-cta { padding: 62px 0; color: #fff; background: var(--navy-800); }
.final-cta-inner { display: grid; grid-template-columns: 1fr auto; align-items: center; gap: 50px; }
.final-cta h2 { max-width: 760px; font-size: clamp(26px, 3vw, 36px); }
.cta-actions { display: flex; justify-content: flex-end; max-width: 260px; }
.final-cta .cta-actions .button { min-width: 210px; }

.site-footer { padding: 46px 0 22px; color: #aab9cd; background: var(--navy-950); }
.footer-grid { display: grid; grid-template-columns: 1.6fr 1fr 1fr; gap: 34px; }
.footer-grid > div { display: grid; align-content: start; gap: 7px; font-size: 13px; }
.footer-grid strong { color: #fff; font-size: 13px; }
.footer-grid p { margin: 4px 0 0; }
.footer-brand { font-size: 16px; }
.footer-brand img { width: 38px; height: 38px; }
.footer-bottom { display: flex; justify-content: space-between; gap: 20px; margin-top: 38px; padding-top: 20px; border-top: 1px solid #1c2d46; font-size: 12px; }
.back-to-top { position: fixed; right: 20px; bottom: 20px; z-index: 80; width: 42px; height: 42px; border: 0; border-radius: 6px; color: #fff; background: var(--blue-700); box-shadow: var(--shadow-sm); cursor: pointer; opacity: 0; pointer-events: none; transform: translateY(8px); transition: opacity 160ms ease, transform 160ms ease; }
.back-to-top.is-visible { opacity: 1; pointer-events: auto; transform: translateY(0); }

@media (max-width: 1080px) {
  .main-nav { gap: 16px; }
  .hero-grid { gap: 40px; }
  .pain-grid, .solution-grid { grid-template-columns: 1fr 1fr; }
  .product-grid { grid-template-columns: 1fr 1fr; }
  .product-card h3 { min-height: auto; }
}

@media (max-width: 860px) {
  .container { width: min(calc(100% - 32px), var(--container)); }
  .menu-toggle { display: block; }
  .menu-toggle[aria-expanded="true"] span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
  .menu-toggle[aria-expanded="true"] span:nth-child(2) { opacity: 0; }
  .menu-toggle[aria-expanded="true"] span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }
  .main-nav { position: fixed; inset: 72px 0 auto; display: none; max-height: calc(100vh - 72px); overflow: auto; flex-direction: column; align-items: stretch; gap: 0; padding: 16px; border-top: 1px solid #263955; background: var(--navy-950); }
  .main-nav.is-open { display: flex; }
  .main-nav a { padding: 13px 8px; }
  .main-nav .button { margin-top: 8px; }
  .hero { padding: 70px 0 76px; }
  .hero-grid, .free-grid, .about-grid, .final-cta-inner { grid-template-columns: 1fr; }
  .hero-grid { gap: 42px; }
  .sop-preview { max-width: 560px; }
  .free-grid, .about-grid { gap: 48px; }
  .audience-grid { grid-template-columns: 1fr 1fr; }
  .weekly-card { grid-template-columns: 1fr; gap: 28px; }
  .weekly-button { justify-self: start; }
  .cta-actions { justify-content: flex-start; max-width: none; }
  .footer-grid { grid-template-columns: 1fr 1fr; }
}

@media (max-width: 600px) {
  .container { width: min(calc(100% - 24px), var(--container)); }
  .section { padding: 66px 0; }
  .nav-shell { min-height: 64px; }
  .brand { font-size: 15px; }
  .brand img { width: 38px; height: 38px; }
  .main-nav { inset: 64px 0 auto; max-height: calc(100vh - 64px); }
  .hero { padding: 56px 0 64px; }
  .hero h1 { font-size: 42px; }
  .hero-lead { font-size: 21px; line-height: 1.55; }
  .hero-actions, .hero-actions .button, .cta-actions, .cta-actions .button { width: 100%; }
  .trust-strip { gap: 8px 16px; }
  .sop-preview { padding: 22px; }
  .section-heading { margin-bottom: 32px; text-align: left; }
  .section-heading h2, .about-copy h2, .free-copy h2 { font-size: 29px; }
  .pain-grid, .solution-grid, .product-grid, .audience-grid, .proof-grid { grid-template-columns: 1fr; }
  .info-card { min-height: 0; }
  .check-list { grid-template-columns: 1fr; }
  .qr-grid { gap: 10px; }
  .qr-card { padding: 12px; }
  .qr-card figcaption span { min-height: 40px; }
  .product-card { padding: 24px 20px; }
  .weekly-card { padding: 24px 20px; }
  .weekly-content h3 { font-size: 21px; }
  .weekly-button { width: 100%; }
  .audience-grid { border-top: 0; }
  .audience-item { min-height: 86px; border-top: 1px solid var(--line); border-left: 1px solid var(--line); }
  .final-cta { padding: 54px 0; }
  .footer-grid { grid-template-columns: 1fr; gap: 24px; }
  .footer-bottom { flex-direction: column; gap: 5px; }
  .back-to-top { right: 12px; bottom: 12px; }
}

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