:root {
  color-scheme: light;
  --bg: #f3f5f8;
  --surface: #ffffff;
  --surface-blue: #eaf1ff;
  --ink: #202c3e;
  --muted: #637189;
  --line: #dfe6f0;
  --accent: #2465da;
  --accent-strong: #1855c0;
  --navy: #1a2230;
  --navy-muted: #aebcd0;
  --sans: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", "Noto Sans SC", "Microsoft YaHei", sans-serif;
  --mono: ui-monospace, SFMono-Regular, Consolas, "Liberation Mono", monospace;
  --radius-lg: 24px;
  --radius-md: 16px;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font-family: var(--sans);
  -webkit-font-smoothing: antialiased;
}
a { color: inherit; }
a:focus-visible { outline: 3px solid #8db2ff; outline-offset: 4px; }
.wrap { width: min(1120px, calc(100% - 56px)); margin-inline: auto; }

.topbar {
  min-height: 82px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  border-bottom: 1px solid var(--line);
}
.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  color: var(--ink);
  text-decoration: none;
  font-size: 19px;
  font-weight: 780;
  letter-spacing: -.03em;
}
.brand-mark {
  width: 32px;
  height: 32px;
  display: grid;
  place-items: center;
  padding: 4px;
  overflow: hidden;
  border: 1px solid #d4deed;
  border-radius: 9px;
  background: #e4e9f1;
}
.brand-mark img { display: block; width: 100%; height: 100%; object-fit: contain; }
.topnav { display: flex; gap: 27px; }
.topnav a {
  color: var(--muted);
  font-size: 13px;
  text-decoration: none;
}
.topnav a:hover { color: var(--accent); }

.hero {
  display: grid;
  grid-template-columns: minmax(0, .9fr) minmax(420px, 1.1fr);
  align-items: center;
  gap: 72px;
  min-height: 650px;
  padding-top: 62px;
  padding-bottom: 72px;
}
.eyebrow {
  display: flex;
  align-items: center;
  gap: 9px;
  margin: 0 0 19px;
  color: var(--accent-strong);
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: .08em;
}
.status-dot { width: 7px; height: 7px; display: inline-block; border-radius: 50%; background: var(--accent); }
.hero h1,
.section-heading h2,
.buy-intro h2,
.fit-copy h2 {
  margin: 0;
  font-weight: 760;
  letter-spacing: -.065em;
  line-height: 1.14;
}
.hero h1 { font-size: clamp(47px, 6vw, 76px); }
.hero h1 span { color: var(--accent); }
.lede {
  max-width: 460px;
  margin: 25px 0 29px;
  color: var(--muted);
  font-size: 16px;
  line-height: 1.9;
}
.hero-actions { display: flex; align-items: center; gap: 24px; }
.button {
  min-height: 51px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 15px;
  padding: 0 21px;
  border: 1px solid transparent;
  border-radius: 12px;
  font-size: 14px;
  font-weight: 740;
  text-decoration: none;
  transition: transform .18s ease, background-color .18s ease, border-color .18s ease;
}
.button:hover { transform: translateY(-2px); }
.button-primary { background: var(--accent); color: #fff; box-shadow: 0 8px 19px #2465da2e; }
.button-primary:hover { background: var(--accent-strong); }
.button strong { font-size: 16px; }
.button span { font-size: 17px; font-weight: 400; }
.text-link { color: var(--muted); font-size: 13px; font-weight: 650; text-decoration: none; }
.text-link:hover { color: var(--accent); }
.text-link span { margin-left: 6px; color: var(--accent); }
.hero-meta {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-top: 18px;
  color: #8290a6;
  font-family: var(--mono);
  font-size: 10px;
}
.hero-meta i { width: 3px; height: 3px; border-radius: 50%; background: #aab7c9; }

.alert-preview {
  position: relative;
  margin: 0;
  padding: 18px 18px 16px;
  overflow: hidden;
  border: 1px solid #d2ddea;
  border-radius: var(--radius-lg);
  background: #e4eaf4;
  box-shadow: 0 24px 60px #202c3e18;
}
.alert-preview::before {
  content: "";
  position: absolute;
  top: -105px;
  right: -50px;
  width: 260px;
  height: 260px;
  border: 1px solid #c6d2e3;
  border-radius: 50%;
  box-shadow: 0 0 0 24px #e4eaf4, 0 0 0 25px #c6d2e3, 0 0 0 63px #e4eaf4, 0 0 0 64px #c6d2e3;
  opacity: .7;
}
.preview-bar, .alert-preview figcaption { position: relative; z-index: 1; display: flex; align-items: center; }
.preview-bar { justify-content: space-between; padding: 1px 3px 16px; color: var(--muted); font-size: 11px; }
.preview-brand { display: inline-flex; align-items: center; gap: 8px; font-weight: 740; }
.preview-brand img { width: 23px; height: 23px; padding: 3px; border-radius: 6px; background: #d5dfed; }
.preview-status { display: inline-flex; align-items: center; gap: 7px; font-family: var(--mono); font-size: 9px; letter-spacing: .07em; }
.preview-status b { width: 6px; height: 6px; border-radius: 50%; background: var(--accent); }
.alert-preview > img { position: relative; z-index: 1; display: block; width: 100%; border: 1px solid #c9d5e5; border-radius: 14px; box-shadow: 0 15px 30px #202c3e1c; }
.alert-preview figcaption { gap: 12px; margin-top: 15px; color: var(--muted); font-size: 10px; }
.caption-line { height: 1px; flex: 1; background: #b6c5d9; }

.signal-strip { background: var(--navy); color: #e6edf7; }
.signal-inner { min-height: 61px; display: flex; align-items: center; justify-content: center; flex-wrap: wrap; gap: 18px; font-size: 11px; letter-spacing: .04em; }
.signal-inner i { width: 4px; height: 4px; border-radius: 50%; background: #91b5ff; }

.features { display: grid; grid-template-columns: minmax(255px, .72fr) minmax(0, 1.28fr); gap: 78px; padding-top: 118px; padding-bottom: 125px; }
.section-heading h2, .buy-intro h2, .fit-copy h2 { font-size: clamp(34px, 4.4vw, 52px); }
.section-heading > p:last-child { max-width: 280px; margin: 22px 0 0; color: var(--muted); font-size: 14px; line-height: 1.8; }
.feature-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 14px; }
.feature-card {
  position: relative;
  min-height: 248px;
  padding: 24px 20px 20px;
  overflow: hidden;
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
  background: var(--surface);
}
.feature-card::before { content: ""; position: absolute; top: 0; left: 20px; width: 37px; height: 3px; background: var(--accent); }
.feature-icon { width: 43px; height: 43px; display: block; margin-bottom: 47px; border: 1px solid #cbd9ee; border-radius: 13px; background: var(--surface-blue); position: relative; }
.feature-icon::before, .feature-icon::after { content: ""; position: absolute; background: var(--accent); }
.icon-watch::before { width: 17px; height: 12px; top: 11px; left: 12px; border: 2px solid var(--accent); border-radius: 3px; background: transparent; }
.icon-watch::after { width: 11px; height: 2px; top: 27px; left: 15px; }
.icon-bell::before { width: 14px; height: 16px; top: 9px; left: 13px; border: 2px solid var(--accent); border-radius: 9px 9px 5px 5px; background: transparent; }
.icon-bell::after { width: 20px; height: 2px; bottom: 9px; left: 10px; }
.icon-theme::before { width: 19px; height: 19px; top: 10px; left: 10px; border: 2px solid var(--accent); border-radius: 50%; background: transparent; }
.icon-theme::after { width: 7px; height: 7px; top: 16px; left: 16px; border-radius: 50%; }
.feature-card h3 { margin: 0 0 10px; font-size: 15px; letter-spacing: -.02em; }
.feature-card p { margin: 0; color: var(--muted); font-size: 13px; line-height: 1.8; }

.buy-section { padding: 105px 0 112px; border-block: 1px solid #d7e0ec; background: #eaf0f8; }
.buy-layout { display: grid; grid-template-columns: minmax(250px, .72fr) minmax(0, 1.28fr); gap: 78px; align-items: start; }
.buy-lede { max-width: 360px; margin: 23px 0 23px; color: var(--muted); font-size: 14px; line-height: 1.9; }
.buy-note { display: flex; align-items: flex-start; gap: 10px; max-width: 350px; padding-top: 17px; border-top: 1px solid #d2ddeb; color: #4f6380; font-size: 12px; line-height: 1.7; }
.note-check { display: grid; place-items: center; width: 19px; height: 19px; flex: 0 0 19px; border-radius: 50%; background: var(--accent); color: #fff; font-size: 12px; font-weight: 800; }
.payment-options { display: grid; grid-template-columns: 1fr 1fr; gap: 15px; }
.payment-card { padding: 23px; border: 1px solid var(--line); border-radius: var(--radius-md); background: var(--surface); box-shadow: 0 12px 28px #202c3e0c; }
.payment-card-stripe { min-height: 285px; }
.payment-card-wechat { min-height: 350px; }
.payment-head { display: flex; align-items: center; gap: 12px; }
.payment-icon { width: 39px; height: 39px; display: grid; place-items: center; flex: 0 0 39px; border-radius: 12px; font-weight: 800; }
.stripe-icon { background: #eaf1ff; color: var(--accent); font-family: Georgia, serif; font-size: 22px; font-style: italic; }
.wechat-icon { background: #eaf1ff; color: #2465da; font-size: 16px; }
.payment-head h3 { margin: 0; font-size: 15px; letter-spacing: -.02em; }
.payment-head p { margin: 4px 0 0; color: var(--muted); font-size: 11px; }
.payment-price { display: flex; align-items: baseline; gap: 8px; margin: 32px 0 22px; }
.payment-price strong { font-size: 34px; letter-spacing: -.06em; }
.payment-price span { color: var(--muted); font-size: 11px; }
.payment-button { width: 100%; }
.wechat-body { display: flex; align-items: center; gap: 17px; margin-top: 19px; }
.qr-frame { width: 126px; height: 126px; flex: 0 0 126px; padding: 7px; border: 1px solid #d9e1ed; border-radius: 12px; background: #fff; }
.qr-frame img { display: block; width: 100%; height: 100%; object-fit: contain; }
.wechat-steps { display: grid; gap: 8px; margin: 0; padding: 0; list-style: none; counter-reset: wechat-step; color: var(--muted); font-size: 11px; line-height: 1.65; }
.wechat-steps li { counter-increment: wechat-step; position: relative; padding-left: 24px; }
.wechat-steps li::before { content: counter(wechat-step); position: absolute; top: 1px; left: 0; width: 17px; height: 17px; display: grid; place-items: center; border-radius: 50%; background: var(--surface-blue); color: var(--accent); font-family: var(--mono); font-size: 9px; }
.wechat-steps strong { color: var(--ink); }
.wechat-steps a { color: var(--accent); word-break: break-word; }
.wechat-foot { margin: 17px 0 0; padding-top: 13px; border-top: 1px solid var(--line); color: #8290a6; font-size: 10px; }

.how-section { display: grid; grid-template-columns: minmax(280px, .72fr) minmax(0, 1.28fr); gap: 78px; padding-top: 116px; padding-bottom: 113px; }
.compact-heading h2 { max-width: 340px; }
.steps { display: grid; grid-template-columns: repeat(3, 1fr); gap: 14px; margin: 0; padding: 0; list-style: none; }
.steps li { min-height: 174px; padding: 20px; border: 1px solid var(--line); border-radius: var(--radius-md); background: #fff; }
.steps li > span { width: 27px; height: 27px; display: grid; place-items: center; margin-bottom: 27px; border: 1px solid #aec2e1; border-radius: 50%; color: var(--accent); font-family: var(--mono); font-size: 10px; }
.steps h3 { margin: 0 0 8px; font-size: 14px; }
.steps p { margin: 0; color: var(--muted); font-size: 12px; line-height: 1.75; }

.fit-section { display: grid; grid-template-columns: minmax(0, 1fr) minmax(260px, .62fr); gap: 78px; align-items: center; padding-top: 0; padding-bottom: 118px; }
.fit-copy p:last-child { max-width: 620px; margin: 21px 0 0; color: var(--muted); font-size: 14px; line-height: 1.9; }
.fit-aside { display: flex; align-items: flex-start; gap: 12px; padding: 19px; border: 1px solid #cfddf0; border-radius: var(--radius-md); background: var(--surface-blue); }
.fit-aside p { margin: 0; color: #50647f; font-size: 12px; line-height: 1.75; }
.checkmark { color: var(--accent); font-weight: 800; }

.footer { background: var(--navy); color: #e8eef8; }
.footer-inner { min-height: 118px; display: flex; align-items: center; gap: 24px; }
.footer .brand { color: #fff; font-size: 16px; }
.footer .brand-mark { width: 27px; height: 27px; padding: 3px; border-color: #52647c; background: #e4e9f1; }
.footer p, .footer a:not(.brand) { color: #b7c4d7; font-size: 11px; text-decoration: none; }
.footer a:not(.brand):hover { color: #fff; }
.footer small { margin-left: auto; color: #8999b0; font-size: 10px; }

@media (max-width: 940px) {
  .hero { grid-template-columns: 1fr; gap: 42px; }
  .hero-copy { max-width: 680px; }
  .alert-preview { max-width: 680px; }
  .features, .buy-layout, .how-section { grid-template-columns: 1fr; gap: 44px; }
  .section-heading > p:last-child { max-width: 430px; }
  .fit-section { grid-template-columns: 1fr; gap: 34px; }
  .fit-aside { max-width: 520px; }
}
@media (max-width: 680px) {
  .wrap { width: min(100% - 34px, 560px); }
  .topbar { min-height: 70px; }
  .topnav { gap: 14px; }
  .topnav a { font-size: 12px; }
  .hero { min-height: auto; padding-top: 54px; padding-bottom: 57px; }
  .hero h1 { font-size: clamp(43px, 12vw, 65px); }
  .hero-actions { align-items: flex-start; flex-direction: column; gap: 16px; }
  .hero-meta { align-items: flex-start; flex-wrap: wrap; line-height: 1.6; }
  .signal-inner { justify-content: flex-start; gap: 9px 13px; padding-top: 14px; padding-bottom: 14px; }
  .signal-inner i { margin: 0 2px; }
  .features { padding-top: 78px; padding-bottom: 80px; }
  .feature-grid, .payment-options, .steps { grid-template-columns: 1fr; }
  .feature-card { min-height: 0; }
  .feature-icon { margin-bottom: 28px; }
  .buy-section { padding: 78px 0 82px; }
  .payment-card-stripe, .payment-card-wechat { min-height: 0; }
  .wechat-body { align-items: flex-start; }
  .how-section { padding-top: 78px; padding-bottom: 79px; }
  .steps li { min-height: 0; }
  .steps li > span { margin-bottom: 17px; }
  .fit-section { padding-bottom: 82px; }
  .footer-inner { align-items: flex-start; flex-direction: column; gap: 13px; padding-top: 27px; padding-bottom: 29px; }
  .footer p { margin: 0; }
  .footer small { margin-left: 0; }
}
@media (max-width: 410px) {
  .wrap { width: calc(100% - 28px); }
  .topnav a:first-child { display: none; }
  .alert-preview { padding: 13px 12px 13px; }
  .alert-preview figcaption { gap: 8px; font-size: 9px; }
  .payment-card { padding: 19px; }
  .wechat-body { flex-direction: column; }
  .qr-frame { width: 142px; height: 142px; }
}
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .button { transition: none; }
  .button:hover { transform: none; }
}