:root {
  --mist: #f5f8f9;
  --paper: #ffffff;
  --lake: #63bde8;
  --lake-deep: #1689c5;
  --indigo: #263b79;
  --indigo-dark: #172650;
  --coral: #ff755f;
  --mint: #75cfb4;
  --ink: #1b2946;
  --muted: #65738c;
  --line: #dce7ec;
  --soft-blue: #eaf7fc;
  --soft-mint: #ebf8f3;
  --soft-coral: #fff0ec;
  --display: "Microsoft YaHei UI", "PingFang SC", "Noto Sans CJK SC", sans-serif;
  --body: "Segoe UI", "Microsoft YaHei", sans-serif;
  --radius: 28px;
  --shadow: 0 24px 70px rgba(36, 69, 103, .12);
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  color: var(--ink);
  background: var(--paper);
  font-family: var(--body);
  font-size: 16px;
  line-height: 1.72;
  -webkit-font-smoothing: antialiased;
}
body.menu-open { overflow: hidden; }
img { max-width: 100%; }
a { color: inherit; text-decoration: none; }
button, input { font: inherit; }
h1, h2, h3, p, figure, blockquote { margin-top: 0; }
h1, h2, h3 { font-family: var(--display); letter-spacing: -.035em; }
.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}
.skip-link {
  position: fixed;
  left: 18px;
  top: -60px;
  z-index: 1000;
  padding: 10px 16px;
  border-radius: 10px;
  color: #fff;
  background: var(--indigo);
  transition: top .2s ease;
}
.skip-link:focus { top: 14px; }
:focus-visible {
  outline: 3px solid rgba(255, 117, 95, .72);
  outline-offset: 4px;
  border-radius: 6px;
}
.section-shell {
  width: min(1180px, calc(100% - 48px));
  margin-inline: auto;
}
.site-header {
  position: fixed;
  z-index: 100;
  top: 14px;
  left: 50%;
  transform: translateX(-50%);
  display: flex;
  align-items: center;
  justify-content: space-between;
  width: min(1240px, calc(100% - 32px));
  min-height: 68px;
  padding: 10px 12px 10px 20px;
  border: 1px solid rgba(213, 227, 234, .82);
  border-radius: 18px;
  background: rgba(255, 255, 255, .88);
  box-shadow: 0 10px 38px rgba(40, 74, 109, .08);
  backdrop-filter: blur(18px);
}
.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-family: var(--display);
  font-weight: 800;
  letter-spacing: -.02em;
}
.brand-mark {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 34px;
  height: 34px;
  border-radius: 11px 11px 14px 9px;
  color: #fff;
  background: var(--coral);
  font-size: 18px;
  transform: rotate(-3deg);
}
.main-nav { display: flex; align-items: center; gap: 6px; }
.main-nav a {
  padding: 9px 14px;
  border-radius: 11px;
  color: #4f5e76;
  font-size: 14px;
  font-weight: 650;
}
.main-nav a:hover, .main-nav a.active { color: var(--indigo); background: var(--mist); }
.main-nav .nav-download {
  min-width: 100px;
  color: #fff;
  text-align: center;
  background: var(--indigo);
  white-space: nowrap;
  word-break: keep-all;
  writing-mode: horizontal-tb;
}
.main-nav .nav-download:hover { color: #fff; background: var(--lake-deep); }
.menu-toggle {
  display: none;
  width: 44px;
  height: 44px;
  padding: 11px;
  border: 0;
  border-radius: 12px;
  background: var(--mist);
}
.menu-toggle > span:not(.sr-only) { display: block; width: 100%; height: 2px; margin: 5px 0; background: var(--ink); transition: .2s ease; }

.hero {
  position: relative;
  display: grid;
  grid-template-columns: minmax(0, .88fr) minmax(480px, 1.12fr);
  align-items: center;
  min-height: 790px;
  padding: 142px max(5vw, calc((100vw - 1180px) / 2)) 84px;
  overflow: hidden;
  background:
    radial-gradient(circle at 13% 25%, rgba(99, 189, 232, .15), transparent 25%),
    radial-gradient(circle at 93% 74%, rgba(117, 207, 180, .16), transparent 25%),
    linear-gradient(180deg, #fbfdfd 0%, #f4f9fb 100%);
}
.hero::before {
  content: "";
  position: absolute;
  width: 50vw;
  height: 50vw;
  right: -24vw;
  top: -30vw;
  border: 1px solid rgba(99, 189, 232, .25);
  border-radius: 50%;
}
.hero-copy { position: relative; z-index: 4; max-width: 620px; padding-right: 22px; }
.eyebrow {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-bottom: 22px;
  color: var(--lake-deep);
  font-size: 13px;
  font-weight: 750;
  letter-spacing: .12em;
}
.eyebrow > span { width: 34px; height: 2px; background: var(--coral); }
.hero h1, .download-hero h1, .help-hero h1 {
  margin-bottom: 25px;
  font-size: clamp(48px, 5.1vw, 78px);
  line-height: 1.08;
  font-weight: 760;
}
h1 em {
  position: relative;
  color: var(--lake-deep);
  font-style: normal;
}
h1 em::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: -5px;
  height: 8px;
  border-radius: 50%;
  background: rgba(255, 117, 95, .25);
}
.hero-intro { max-width: 570px; margin-bottom: 30px; color: var(--muted); font-size: 18px; }
.hero-actions { display: flex; flex-wrap: wrap; gap: 12px; }
.button, .download-link {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  flex-direction: row;
  min-width: 138px;
  min-height: 48px;
  padding: 12px 21px;
  border: 1px solid transparent;
  border-radius: 13px;
  font-weight: 700;
  white-space: nowrap;
  word-break: keep-all;
  writing-mode: horizontal-tb;
  transition: transform .2s ease, background .2s ease, border-color .2s ease;
}
.button:hover, .download-link:hover { transform: translateY(-2px); }
.button-primary { color: #fff; background: var(--indigo); box-shadow: 0 12px 28px rgba(38, 59, 121, .2); }
.button-primary:hover { background: var(--lake-deep); }
.button-quiet { color: var(--indigo); background: rgba(255,255,255,.65); border-color: var(--line); }
.button-quiet span { margin-left: 10px; }
.hero-notes { display: flex; gap: 25px; margin: 26px 0 0; padding: 0; color: #738198; font-size: 13px; list-style: none; }
.hero-notes li { position: relative; padding-left: 15px; }
.hero-notes li::before { content: ""; position: absolute; left: 0; top: 10px; width: 5px; height: 5px; border-radius: 50%; background: var(--mint); }
.hero-media {
  position: relative;
  z-index: 2;
  align-self: center;
  min-width: 0;
}
.hero-media::before {
  content: "";
  position: absolute;
  z-index: -1;
  inset: 10% -8% 4% 4%;
  border-radius: 46% 54% 54% 46% / 62% 46% 54% 38%;
  background: linear-gradient(140deg, rgba(255,255,255,.92), rgba(230,246,252,.9));
  box-shadow: var(--shadow);
}
.river-path { position: absolute; z-index: 1; inset: -4% -10% -3% -18%; pointer-events: none; }
.river-path svg { width: 100%; height: 100%; overflow: visible; }
.river-base, .river-pulse { fill: none; stroke-linecap: round; }
.river-base { stroke: rgba(99, 189, 232, .23); stroke-width: 18; }
.river-pulse { stroke: rgba(38, 59, 121, .72); stroke-width: 3; stroke-dasharray: 7 20; animation: river 8s linear infinite; }
.doc-chip {
  position: absolute;
  z-index: 5;
  width: 116px;
  padding: 13px 13px 12px 36px;
  border: 1px solid rgba(211, 226, 233, .94);
  border-radius: 12px 18px 12px 16px;
  background: rgba(255,255,255,.94);
  box-shadow: 0 13px 28px rgba(48, 77, 105, .13);
  font-size: 11px;
  line-height: 1.2;
  animation: float-doc 5.6s ease-in-out infinite;
}
.doc-chip i { position: absolute; left: 12px; top: 13px; width: 14px; height: 18px; border-radius: 3px; }
.doc-chip i::after { content: ""; position: absolute; right: 2px; top: 4px; width: 7px; height: 2px; background: rgba(255,255,255,.8); box-shadow: 0 4px rgba(255,255,255,.8); }
.doc-red { background: var(--coral); }
.doc-blue { background: var(--lake); }
.doc-green { background: var(--mint); }
.doc-chip span { display: block; margin-bottom: 7px; font-weight: 750; }
.doc-chip b { display: block; height: 3px; margin-top: 4px; border-radius: 9px; background: #e5edf1; }
.doc-chip b:last-child { width: 66%; }
.doc-chip-a { left: -8%; bottom: 9%; }
.doc-chip-b { left: 17%; top: 4%; animation-delay: -1.8s; }
.doc-chip-c { right: -4%; top: 17%; animation-delay: -3.4s; }
.member-dot {
  position: absolute;
  z-index: 4;
  display: grid;
  place-items: center;
  width: 34px;
  height: 34px;
  border: 4px solid #fff;
  border-radius: 50%;
  color: #fff;
  font-size: 11px;
  font-weight: 800;
  box-shadow: 0 8px 18px rgba(38,59,121,.18);
}
.member-a { left: 9%; bottom: 3%; background: var(--coral); }
.member-b { left: 37%; top: 0; background: var(--indigo); }
.member-c { right: 4%; top: 8%; background: #36a98a; }
.hero-main-image { position: relative; z-index: 3; }
@keyframes river { to { stroke-dashoffset: -216; } }
@keyframes float-doc { 0%,100% { transform: translateY(0) rotate(-1deg); } 50% { transform: translateY(-12px) rotate(1deg); } }

.flow-strip {
  display: grid;
  grid-template-columns: .85fr 2.15fr;
  align-items: center;
  gap: 50px;
  padding: 34px max(5vw, calc((100vw - 1180px) / 2));
  color: #fff;
  background: var(--indigo);
}
.flow-strip > p { margin: 0; font-size: 14px; letter-spacing: .08em; }
.flow-strip ol { display: grid; grid-template-columns: repeat(4, 1fr); margin: 0; padding: 0; list-style: none; }
.flow-strip li { position: relative; padding: 0 20px; border-left: 1px solid rgba(255,255,255,.18); }
.flow-strip b, .flow-strip span { display: block; }
.flow-strip b { font-size: 16px; }
.flow-strip span { color: rgba(255,255,255,.62); font-size: 12px; }

.section-heading { max-width: 740px; margin-bottom: 56px; }
.section-kicker { margin-bottom: 12px; color: var(--lake-deep); font-size: 13px; font-weight: 750; letter-spacing: .12em; }
.section-heading h2, .platform-copy h2, .download-heading h2 {
  margin-bottom: 18px;
  font-size: clamp(36px, 4vw, 57px);
  line-height: 1.12;
}
.section-heading > p:last-child, .platform-copy > p:last-child { max-width: 620px; color: var(--muted); }
.feature-section { padding-top: 140px; padding-bottom: 140px; }
.feature-orbit { display: grid; grid-template-columns: .78fr 1.22fr; align-items: center; gap: 70px; }
.feature-visual { position: relative; margin: 0; }
.feature-visual img { position: relative; z-index: 2; display: block; width: 100%; height: auto; border-radius: 32px 70px 32px 70px; box-shadow: var(--shadow); }
.image-wash { position: absolute; inset: -25px 35px 24px -30px; border-radius: 42% 58% 48% 52%; }
.wash-blue { background: var(--soft-blue); }
.feature-list { display: grid; grid-template-columns: repeat(2, 1fr); gap: 2px 40px; }
.feature-list article { display: grid; grid-template-columns: 48px 1fr; gap: 17px; padding: 23px 0; border-bottom: 1px solid var(--line); }
.feature-symbol { display: grid; place-items: center; width: 46px; height: 46px; border-radius: 15px 15px 20px 11px; font-weight: 800; }
.symbol-text, .symbol-pdf { color: #d94c3f; background: var(--soft-coral); }
.symbol-sheet, .symbol-cloud { color: #258f73; background: var(--soft-mint); }
.symbol-slide, .symbol-ai { color: var(--lake-deep); background: var(--soft-blue); }
.feature-list h3 { margin: 0 0 7px; font-size: 18px; }
.feature-list p { margin: 0; color: var(--muted); font-size: 14px; line-height: 1.65; }

.platform-section {
  display: grid;
  grid-template-columns: .7fr 1.3fr;
  gap: 70px;
  padding: 115px max(5vw, calc((100vw - 1180px) / 2));
  background: var(--mist);
}
.platform-copy { align-self: start; position: sticky; top: 120px; }
.platform-downloads { display: grid; grid-template-columns: repeat(2, 1fr); border: 1px solid var(--line); border-radius: 28px; overflow: hidden; background: #fff; }
.platform-downloads article { display: grid; grid-template-columns: 48px 1fr; gap: 16px; padding: 30px; }
.platform-downloads article:nth-child(odd) { border-right: 1px solid var(--line); }
.platform-downloads article:nth-child(-n+2) { border-bottom: 1px solid var(--line); }
.platform-glyph, .os-mark { display: grid; place-items: center; width: 44px; height: 44px; border-radius: 14px; color: var(--indigo); background: var(--soft-blue); font-weight: 800; }
.platform-downloads h3 { margin: 0; }
.platform-downloads p { margin: 3px 0 0; color: var(--muted); font-size: 13px; }
.platform-downloads .download-link { grid-column: 1 / -1; min-width: 160px; min-height: 42px; margin-top: 8px; color: var(--indigo); border-color: var(--line); background: var(--mist); font-size: 13px; }

.scene-section { padding-top: 145px; padding-bottom: 145px; }
.scene-heading { margin-left: 33%; }
.scene-path { position: relative; }
.scene-path::before { content: ""; position: absolute; left: 27px; top: 52px; bottom: 52px; width: 2px; background: linear-gradient(var(--coral), var(--lake), var(--mint)); }
.scene { display: grid; grid-template-columns: 56px 1fr; gap: 35px; max-width: 660px; margin-bottom: 36px; }
.scene:nth-child(2) { margin-left: 16%; }
.scene:nth-child(3) { margin-left: 32%; }
.scene > span { position: relative; z-index: 1; display: grid; place-items: center; width: 56px; height: 56px; border-radius: 50%; color: #fff; background: var(--coral); font-size: 12px; font-weight: 800; box-shadow: 0 0 0 10px #fff; }
.scene:nth-child(2) > span { background: var(--lake); }
.scene:nth-child(3) > span { background: var(--mint); }
.scene > div { padding: 5px 0 30px; border-bottom: 1px solid var(--line); }
.scene h3 { margin-bottom: 8px; font-size: 26px; }
.scene p { margin-bottom: 14px; color: var(--muted); }
.scene ul { display: flex; gap: 10px; margin: 0; padding: 0; list-style: none; }
.scene li { padding: 5px 11px; border-radius: 999px; color: var(--indigo); background: var(--soft-blue); font-size: 12px; }
.scene-image { width: 44%; margin: -210px 0 0 auto; }
.scene-image img { display: block; border-radius: 38px 16px 70px 22px; box-shadow: var(--shadow); }

.voices-section {
  display: grid;
  grid-template-columns: .75fr 1.25fr;
  gap: 90px;
  padding: 120px max(5vw, calc((100vw - 1180px) / 2));
  background: #edf7f7;
}
.voices-intro h2 { margin-bottom: 36px; font-size: clamp(34px, 3.8vw, 54px); line-height: 1.16; }
.voices-intro img { display: block; width: 82%; border-radius: 18px 56px 18px 56px; }
.voices { display: flex; flex-direction: column; justify-content: center; }
.voices blockquote { margin: 0; padding: 28px 0; border-bottom: 1px solid #cfe1e2; }
.voices blockquote:first-child { border-top: 1px solid #cfe1e2; }
.voices blockquote > p { margin-bottom: 20px; font-size: 18px; line-height: 1.7; }
.voices footer { display: flex; align-items: center; gap: 13px; }
.avatar { display: grid; place-items: center; width: 40px; height: 40px; border-radius: 50%; color: #fff; font-weight: 750; }
.avatar-coral { background: var(--coral); }.avatar-blue { background: var(--lake-deep); }.avatar-green { background: #379f83; }
.voices strong, .voices small { display: block; }
.voices small { color: var(--muted); font-size: 12px; }

.pricing-section { padding-top: 140px; padding-bottom: 150px; }
.pricing-grid { display: grid; grid-template-columns: repeat(3, 1fr); align-items: center; gap: 18px; }
.price-panel { min-height: 425px; padding: 40px 34px; border: 1px solid var(--line); border-radius: 28px 28px 50px 28px; background: #fff; }
.price-panel.featured { position: relative; min-height: 480px; padding-top: 64px; color: #fff; border-color: var(--indigo); background: var(--indigo); box-shadow: 0 26px 54px rgba(38,59,121,.2); }
.featured-ribbon { position: absolute; top: 0; left: 30px; padding: 7px 15px; border-radius: 0 0 12px 12px; color: var(--indigo); background: var(--mint); font-size: 12px; font-weight: 800; }
.price-label { color: var(--lake-deep); font-size: 13px; font-weight: 800; letter-spacing: .1em; }
.featured .price-label { color: var(--mint); }
.price-panel h3 { margin-bottom: 8px; font-size: 27px; }
.price-note { min-height: 52px; color: var(--muted); font-size: 14px; }
.featured .price-note { color: rgba(255,255,255,.65); }
.price-panel ul { min-height: 142px; margin: 20px 0 25px; padding: 21px 0 0; border-top: 1px solid var(--line); list-style: none; }
.featured ul { border-color: rgba(255,255,255,.18); }
.price-panel li { position: relative; margin-bottom: 11px; padding-left: 21px; }
.price-panel li::before { content: "✓"; position: absolute; left: 0; color: var(--mint); font-weight: 900; }
.button-outline { width: 100%; color: var(--indigo); border-color: var(--line); }
.featured .button-primary { width: 100%; color: var(--indigo); background: var(--mint); }

.faq-section { display: grid; grid-template-columns: .75fr 1.25fr; gap: 90px; padding-bottom: 150px; }
.faq-title h2 { margin-bottom: 25px; font-size: clamp(35px, 4vw, 56px); line-height: 1.15; }
.faq-title a { color: var(--lake-deep); font-weight: 700; }
.faq-title a span { margin-left: 8px; }
.faq-list details { border-bottom: 1px solid var(--line); }
.faq-list details:first-child { border-top: 1px solid var(--line); }
.faq-list summary { position: relative; padding: 25px 42px 25px 0; cursor: pointer; list-style: none; font-weight: 750; }
.faq-list summary::-webkit-details-marker { display: none; }
.faq-list summary span::before, .faq-list summary span::after { content: ""; position: absolute; right: 5px; top: 35px; width: 16px; height: 2px; background: var(--indigo); transition: transform .2s ease; }
.faq-list summary span::after { transform: rotate(90deg); }
.faq-list details[open] summary span::after { transform: rotate(0); }
.faq-list details > p { padding-right: 45px; color: var(--muted); }
.faq-list details > p a { color: var(--lake-deep); text-decoration: underline; }

.final-cta, .download-help-band, .help-exit {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 40px;
  padding: 72px max(5vw, calc((100vw - 1180px) / 2));
  color: #fff;
  background: var(--lake-deep);
}
.final-cta { border-radius: 90px 90px 0 0; }
.final-cta p { margin-bottom: 8px; color: rgba(255,255,255,.7); }
.final-cta h2, .download-help-band h2, .help-exit h2 { margin: 0; font-size: clamp(34px, 4vw, 54px); line-height: 1.15; }
.button-light { color: var(--indigo); background: #fff; }

.site-footer { padding: 70px max(5vw, calc((100vw - 1180px) / 2)) 30px; color: #dce6f9; background: var(--indigo-dark); }
.site-footer .brand { color: #fff; }
.footer-brand { display: flex; align-items: center; justify-content: space-between; gap: 30px; padding-bottom: 35px; border-bottom: 1px solid rgba(255,255,255,.14); }
.footer-brand p { max-width: 440px; margin: 0; color: rgba(255,255,255,.54); }
.footer-links { display: grid; grid-template-columns: repeat(3, 1fr); gap: 50px; width: 66%; margin: 50px 0 60px auto; }
.footer-links h2 { margin-bottom: 15px; color: #fff; font-size: 15px; }
.footer-links a { display: block; margin: 8px 0; color: rgba(255,255,255,.58); font-size: 14px; }
.footer-links a:hover { color: #fff; }
.footer-bottom { display: flex; justify-content: space-between; padding-top: 24px; border-top: 1px solid rgba(255,255,255,.14); color: rgba(255,255,255,.42); font-size: 12px; }

/* 下载页：以平台选择和设备接力为独立信息架构 */
.download-hero {
  display: grid;
  grid-template-columns: .86fr 1.14fr;
  align-items: center;
  min-height: 700px;
  padding: 145px max(5vw, calc((100vw - 1180px) / 2)) 80px;
  overflow: hidden;
  background: linear-gradient(128deg, #f8fcfd 0 54%, #eaf6fa 54%);
}
.download-hero-copy { position: relative; z-index: 2; }
.download-hero-copy > p:not(.eyebrow) { max-width: 520px; margin-bottom: 28px; color: var(--muted); font-size: 18px; }
.download-hero-image { position: relative; align-self: center; margin: 0 0 0 50px; }
.download-hero-image img { position: relative; z-index: 2; display: block; width: 100%; height: auto; border-radius: 90px 30px 90px 30px; box-shadow: var(--shadow); }
.download-ring { position: absolute; inset: -22% -18% -22% -18%; border: 1px solid rgba(99,189,232,.4); border-radius: 50%; }
.download-ring::before, .download-ring::after { content: ""; position: absolute; border-radius: 50%; background: var(--coral); }
.download-ring::before { width: 16px; height: 16px; left: 15%; top: 7%; }
.download-ring::after { width: 10px; height: 10px; right: 6%; bottom: 24%; background: var(--mint); }
.download-selector { padding-top: 130px; padding-bottom: 145px; }
.download-heading { display: grid; grid-template-columns: .35fr 1.15fr .8fr; gap: 35px; align-items: end; margin-bottom: 50px; }
.download-heading > span { align-self: start; color: var(--lake-deep); font-size: 13px; font-weight: 750; letter-spacing: .1em; }
.download-heading h2 { margin: 0; }
.download-heading p { margin: 0; color: var(--muted); }
.download-matrix { display: grid; grid-template-columns: repeat(2, 1fr); gap: 18px; }
.download-card { padding: 34px; border: 1px solid var(--line); border-radius: 20px 42px 20px 42px; background: #fff; }
.download-card-top { display: flex; align-items: center; justify-content: space-between; margin-bottom: 28px; }
.download-card-top small { color: var(--muted); }
.download-card h3 { margin-bottom: 8px; font-size: 28px; }
.download-card > p { color: var(--muted); }
.download-card dl { margin: 24px 0; padding: 18px 0; border-top: 1px solid var(--line); border-bottom: 1px solid var(--line); }
.download-card dl div { display: grid; grid-template-columns: 60px 1fr; margin: 6px 0; font-size: 13px; }
.download-card dt { color: var(--muted); }
.download-card dd { margin: 0; font-weight: 650; }
.download-link.solid { width: 100%; color: #fff; background: var(--indigo); }
.mac-card { background: #f6fbfd; }.android-card { background: #f3faf7; }.ios-card { background: #fff7f4; }
.handoff-section { position: relative; display: grid; grid-template-columns: .8fr 1.2fr; gap: 100px; padding: 120px max(5vw, calc((100vw - 1180px) / 2)); overflow: hidden; background: var(--indigo); color: #fff; }
.handoff-copy { align-self: center; }
.handoff-copy h2 { margin-bottom: 22px; font-size: clamp(38px, 4vw, 57px); line-height: 1.12; }
.handoff-copy > p:last-child { color: rgba(255,255,255,.64); }
.handoff-steps { margin: 0; padding: 0; list-style: none; }
.handoff-steps li { display: grid; grid-template-columns: 56px 1fr; gap: 20px; padding: 27px 0; border-bottom: 1px solid rgba(255,255,255,.15); }
.handoff-steps li > span { display: grid; place-items: center; width: 50px; height: 50px; border-radius: 50%; color: var(--indigo); background: var(--mint); font-weight: 800; }
.handoff-steps h3 { margin: 0; }
.handoff-steps p { margin: 5px 0 0; color: rgba(255,255,255,.58); }
.handoff-track { position: absolute; left: -12%; right: -12%; top: 48%; height: 1px; background: rgba(99,189,232,.14); transform: rotate(-8deg); }
.handoff-track i { position: absolute; width: 8px; height: 8px; border-radius: 50%; background: var(--coral); }
.handoff-track i:nth-child(1) { left: 12%; }.handoff-track i:nth-child(2) { left: 48%; }.handoff-track i:nth-child(3) { right: 12%; }
.install-guide { display: grid; grid-template-columns: .85fr 1.15fr; align-items: center; gap: 90px; padding-top: 145px; padding-bottom: 145px; }
.install-guide figure { margin: 0; }
.install-guide figure img { display: block; border-radius: 22px 70px 22px 70px; box-shadow: var(--shadow); }
.install-copy > h2 { margin-bottom: 38px; font-size: clamp(36px, 4vw, 55px); line-height: 1.13; }
.guide-lines article { position: relative; padding: 24px 0 24px 84px; border-top: 1px solid var(--line); }
.guide-lines article > span { position: absolute; left: 0; top: 25px; width: 54px; color: var(--lake-deep); font-size: 13px; font-weight: 800; letter-spacing: .12em; }
.guide-lines h3 { margin-bottom: 5px; font-size: 20px; }
.guide-lines p { margin: 0; color: var(--muted); }
.download-compare { padding: 115px max(5vw, calc((100vw - 1180px) / 2)); background: var(--mist); }
.download-compare header { max-width: 720px; margin-bottom: 40px; }
.download-compare h2 { font-size: clamp(34px, 4vw, 54px); line-height: 1.15; }
.compare-table { overflow: hidden; border: 1px solid var(--line); border-radius: 24px; background: #fff; }
.compare-row { display: grid; grid-template-columns: .6fr 1.2fr 1.2fr; }
.compare-row + .compare-row { border-top: 1px solid var(--line); }
.compare-row > * { padding: 20px 24px; }
.compare-row > * + * { border-left: 1px solid var(--line); }
.compare-row strong { color: var(--indigo); }
.compare-row span { color: var(--muted); }
.compare-head { color: #fff; background: var(--indigo); font-size: 13px; font-weight: 750; }
.compare-head span { color: #fff; }
.download-help-band { background: var(--coral); }
.download-help-band h2 { font-size: clamp(30px, 3vw, 44px); }
.download-help-band p { margin: 9px 0 0; color: rgba(255,255,255,.78); }

/* 帮助页：以任务索引、指南和问答为独立信息架构 */
.help-hero { display: grid; grid-template-columns: 1.08fr .92fr; align-items: end; gap: 90px; min-height: 610px; padding: 160px max(5vw, calc((100vw - 1180px) / 2)) 95px; background: linear-gradient(180deg, #f8fbfc, #eef7fa); }
.help-hero-text > p:last-child { max-width: 590px; color: var(--muted); font-size: 18px; }
.help-search { padding: 30px; border-radius: 24px 48px 24px 48px; background: #fff; box-shadow: var(--shadow); }
.help-search label { display: block; margin-bottom: 12px; font-size: 13px; font-weight: 800; }
.help-search > div { display: flex; }
.help-search input { min-width: 0; flex: 1; height: 52px; padding: 0 15px; border: 1px solid var(--line); border-radius: 12px 0 0 12px; color: var(--ink); }
.help-search button { padding: 0 20px; border: 0; border-radius: 0 12px 12px 0; color: #fff; background: var(--indigo); cursor: pointer; }
.help-search > p { margin: 10px 0 0; color: var(--muted); font-size: 12px; }
.help-map { padding-top: 105px; padding-bottom: 125px; }
.help-map > header { display: flex; align-items: baseline; gap: 45px; margin-bottom: 38px; }
.help-map > header span { color: var(--lake-deep); font-size: 13px; font-weight: 800; letter-spacing: .1em; }
.help-map > header h2 { font-size: clamp(34px, 4vw, 52px); }
.help-lanes { display: grid; grid-template-columns: repeat(4, 1fr); border-top: 1px solid var(--line); border-bottom: 1px solid var(--line); }
.help-lanes a { position: relative; min-height: 220px; padding: 28px 24px; border-right: 1px solid var(--line); transition: background .2s ease; }
.help-lanes a:last-child { border-right: 0; }
.help-lanes a:hover { background: var(--soft-blue); }
.lane-icon { display: grid; place-items: center; width: 45px; height: 45px; margin-bottom: 46px; border-radius: 50%; color: var(--indigo); background: var(--soft-blue); font-weight: 800; }
.help-lanes strong, .help-lanes small { display: block; }
.help-lanes strong { font-size: 18px; }
.help-lanes small { margin-top: 4px; color: var(--muted); }
.help-lanes b { position: absolute; right: 22px; bottom: 24px; color: var(--lake-deep); }
.quick-answer { display: grid; grid-template-columns: 1.1fr .9fr; align-items: center; gap: 90px; padding: 105px max(5vw, calc((100vw - 1180px) / 2)); background: var(--soft-mint); }
.quick-answer figure { margin: 0; }
.quick-answer img { display: block; border-radius: 70px 20px 70px 20px; box-shadow: var(--shadow); }
.quick-answer h2 { margin-bottom: 26px; font-size: clamp(35px, 4vw, 54px); }
.quick-answer ol { margin: 0 0 26px; padding: 0; list-style: none; counter-reset: quick; }
.quick-answer li { display: grid; grid-template-columns: .75fr 1.25fr; gap: 20px; padding: 15px 0; border-top: 1px solid rgba(37,143,115,.2); }
.quick-answer li span { font-weight: 750; }
.quick-answer li p { margin: 0; color: var(--muted); }
.guide-index { padding-top: 140px; padding-bottom: 145px; }
.guide-columns { display: grid; grid-template-columns: repeat(2, 1fr); border-top: 1px solid var(--line); border-left: 1px solid var(--line); }
.guide-columns > section { position: relative; min-height: 320px; padding: 42px; border-right: 1px solid var(--line); border-bottom: 1px solid var(--line); }
.guide-number { display: block; margin-bottom: 55px; color: var(--coral); font-weight: 900; }
.guide-columns h2 { margin-bottom: 20px; font-size: 27px; }
.guide-columns ul { margin: 0; padding: 0; list-style: none; }
.guide-columns li { border-top: 1px solid var(--line); }
.guide-columns a { display: flex; justify-content: space-between; padding: 10px 0; color: var(--muted); font-size: 14px; }
.guide-columns a:hover { color: var(--lake-deep); }
.help-faq { display: grid; grid-template-columns: .7fr 1.3fr; gap: 80px; padding: 120px max(5vw, calc((100vw - 1180px) / 2)); background: var(--mist); }
.help-faq-index { align-self: start; position: sticky; top: 120px; }
.help-faq-index > p { color: var(--lake-deep); font-size: 13px; font-weight: 800; letter-spacing: .1em; }
.help-faq-index h2 { margin-bottom: 30px; font-size: clamp(38px, 4vw, 56px); line-height: 1.14; }
.help-faq-index nav { display: flex; flex-wrap: wrap; gap: 8px; }
.help-faq-index nav a { padding: 6px 12px; border: 1px solid var(--line); border-radius: 999px; background: #fff; font-size: 12px; }
.support-info { display: grid; grid-template-columns: repeat(3, 1fr); gap: 1px; padding-top: 130px; padding-bottom: 130px; background: var(--line); }
.support-info article { padding: 38px; background: #fff; }
.support-info h2 { margin-bottom: 18px; font-size: 26px; }
.support-info article > p:not(.section-kicker) { color: var(--muted); }
.support-info a { color: var(--lake-deep); font-weight: 700; }
.help-exit { background: var(--indigo); }
.help-exit h2 { font-size: clamp(32px, 3.8vw, 50px); }
.help-exit > div:last-child { display: flex; flex-wrap: wrap; gap: 10px; }
.button-ghost-light { color: #fff; border-color: rgba(255,255,255,.36); }

@media (max-width: 1020px) {
  .hero { grid-template-columns: 1fr 1fr; padding-inline: 36px; }
  .hero h1, .download-hero h1, .help-hero h1 { font-size: clamp(43px, 6vw, 62px); }
  .feature-orbit, .install-guide { gap: 45px; }
  .scene-image { width: 38%; }
  .download-hero, .help-hero { gap: 45px; }
  .help-lanes { grid-template-columns: repeat(2, 1fr); }
  .help-lanes a:nth-child(2) { border-right: 0; }
  .help-lanes a:nth-child(-n+2) { border-bottom: 1px solid var(--line); }
}

@media (max-width: 820px) {
  .site-header { top: 8px; min-height: 60px; }
  .menu-toggle { display: block; }
  .main-nav {
    position: fixed;
    top: 68px;
    left: 0;
    right: 0;
    display: none;
    flex-direction: column;
    align-items: stretch;
    padding: 16px;
    border: 1px solid var(--line);
    border-radius: 18px;
    background: #fff;
    box-shadow: var(--shadow);
  }
  .main-nav.open { display: flex; }
  .main-nav a { text-align: center; }
  .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); }
  .hero { grid-template-columns: 1fr; min-height: 0; padding: 128px 28px 75px; }
  .hero-copy { max-width: 680px; padding-right: 0; }
  .hero-media { width: min(680px, 94%); margin-inline: auto; }
  .flow-strip { grid-template-columns: 1fr; gap: 20px; padding-inline: 28px; }
  .feature-orbit, .platform-section, .voices-section, .faq-section, .download-hero, .handoff-section, .install-guide, .help-hero, .quick-answer, .help-faq { grid-template-columns: 1fr; }
  .feature-orbit { gap: 65px; }
  .feature-visual { width: min(560px, 90%); margin-inline: auto; }
  .platform-copy, .help-faq-index { position: static; }
  .scene-heading { margin-left: 0; }
  .scene:nth-child(2), .scene:nth-child(3) { margin-left: 0; }
  .scene-image { width: 74%; margin: 45px 0 0 auto; }
  .voices-intro { display: grid; grid-template-columns: 1fr .7fr; gap: 30px; }
  .voices-intro .section-kicker { grid-column: 1 / -1; }
  .voices-intro img { width: 100%; }
  .pricing-grid { grid-template-columns: 1fr; max-width: 620px; margin-inline: auto; }
  .price-panel, .price-panel.featured { min-height: 0; }
  .footer-links { width: 100%; }
  .download-hero { padding-top: 145px; background: linear-gradient(180deg, #f8fcfd 0 50%, #eaf6fa 50%); }
  .download-hero-image { width: min(650px, 90%); margin: 35px auto 0; }
  .download-heading { grid-template-columns: 1fr; gap: 8px; }
  .handoff-section { gap: 45px; }
  .install-guide figure { width: min(560px, 90%); margin-inline: auto; }
  .help-hero { align-items: center; padding-top: 145px; }
  .quick-answer figure { width: min(580px, 94%); margin-inline: auto; }
  .support-info { grid-template-columns: 1fr; }
  .final-cta, .download-help-band, .help-exit { align-items: flex-start; flex-direction: column; }
}

@media (max-width: 600px) {
  body { font-size: 15px; }
  .section-shell { width: min(100% - 32px, 1180px); }
  .site-header { width: calc(100% - 16px); padding-left: 14px; }
  .brand { font-size: 14px; }
  .hero { padding-inline: 20px; }
  .hero h1, .download-hero h1, .help-hero h1 { font-size: 42px; }
  .hero-intro { font-size: 16px; }
  .hero-actions { align-items: stretch; flex-direction: column; }
  .hero-actions .button { width: 100%; }
  .hero-notes { gap: 12px; }
  .doc-chip { transform: scale(.82); }
  .doc-chip-a { left: -9%; }
  .doc-chip-c { right: -9%; }
  .flow-strip ol { grid-template-columns: repeat(2, 1fr); gap: 20px 0; }
  .feature-section, .scene-section, .pricing-section, .guide-index { padding-top: 95px; padding-bottom: 95px; }
  .feature-list { grid-template-columns: 1fr; }
  .platform-section, .voices-section, .download-compare, .quick-answer, .help-faq { padding: 85px 18px; }
  .platform-downloads, .download-matrix { grid-template-columns: 1fr; }
  .platform-downloads article { border-right: 0 !important; border-bottom: 1px solid var(--line); }
  .platform-downloads article:last-child { border-bottom: 0; }
  .platform-downloads .download-link, .download-card .download-link { min-width: 180px; width: 100%; }
  .scene { grid-template-columns: 44px 1fr; gap: 18px; }
  .scene > span { width: 44px; height: 44px; }
  .scene-path::before { left: 21px; }
  .scene-image { width: 100%; }
  .voices-intro { grid-template-columns: 1fr; }
  .voices-intro .section-kicker { grid-column: auto; }
  .voices-intro img { width: 72%; }
  .faq-section { gap: 45px; }
  .final-cta, .download-help-band, .help-exit { padding: 60px 20px; border-radius: 0; }
  .footer-brand { align-items: flex-start; flex-direction: column; }
  .footer-links { grid-template-columns: 1fr 1fr; gap: 28px; }
  .footer-bottom { gap: 15px; flex-direction: column; }
  .download-hero, .help-hero { padding: 130px 20px 75px; }
  .download-selector { padding-top: 90px; padding-bottom: 95px; }
  .download-card { padding: 26px; }
  .handoff-section { padding: 85px 20px; }
  .install-guide { padding-top: 95px; padding-bottom: 95px; }
  .compare-table { overflow-x: auto; }
  .compare-row { min-width: 650px; }
  .help-search { padding: 20px; }
  .help-search > div { flex-direction: column; gap: 8px; }
  .help-search input, .help-search button { width: 100%; border-radius: 10px; }
  .help-map { padding-top: 80px; padding-bottom: 85px; }
  .help-map > header { align-items: flex-start; flex-direction: column; gap: 8px; }
  .help-lanes { grid-template-columns: 1fr; }
  .help-lanes a { min-height: 170px; border-right: 0; border-bottom: 1px solid var(--line); }
  .lane-icon { margin-bottom: 24px; }
  .quick-answer li { grid-template-columns: 1fr; gap: 3px; }
  .guide-columns { grid-template-columns: 1fr; }
  .guide-columns > section { min-height: 0; padding: 30px; }
  .guide-number { margin-bottom: 32px; }
  .support-info { width: 100%; padding-top: 0; padding-bottom: 0; }
  .help-exit > div:last-child, .help-exit .button { width: 100%; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { animation-duration: .01ms !important; animation-iteration-count: 1 !important; transition-duration: .01ms !important; }
  .doc-chip, .river-pulse { animation: none !important; }
}

/* Hero 约束最终覆盖：主图保持自然比例，动效仅属于独立文档页片与同步路径 */
.hero {
  align-items: center !important;
}
.hero .hero-media {
  align-self: center !important;
  height: auto !important;
  min-height: 0 !important;
  max-height: none !important;
  padding: 0 !important;
  margin-top: 0 !important;
  margin-bottom: 0 !important;
  overflow: visible !important;
  clip-path: none !important;
  transform: none !important;
}
.hero .hero-main-image {
  display: block !important;
  width: 100% !important;
  height: auto !important;
  min-height: 0 !important;
  max-height: none !important;
  margin: 0 !important;
  padding: 0 !important;
  object-fit: contain !important;
  object-position: center !important;
  clip-path: none !important;
  transform: none !important;
}