/* 官网唯一主题来源：用户选定 C 方案，奶白配品牌蓝；保留明暗切换。 */
:root {
  color-scheme: light;
  --page: #f0ece3;
  --surface: #f8f5ee;
  --wash: #e6e5df;
  --wash-strong: #dae2e8;
  --ink: #203148;
  --muted: #56616e;
  --brand: #2856ac;
  --brand-hover: #21468b;
  --on-brand: #ffffff;
  --line: #d2d4cf;
  --line-strong: #a3b4c4;
  --warm: #e8ddbd;
  --warm-ink: #69501f;
  --qr-paper: #ffffff;
  --device-line: #adb9c3;
  --shadow: 0 18px 48px rgb(30 66 124 / 12%);
  --radius: 22px;
  --max: 1160px;
}
:root[data-theme="dark"] {
    --page: #101a2b;
    --surface: #17243a;
    --wash: #15243c;
    --wash-strong: #1b3152;
    --ink: #f1f5fc;
    --muted: #b7c6dc;
    --brand: #a4c5ff;
    --brand-hover: #d1e2ff;
    --on-brand: #10213f;
    --line: #344a68;
    --line-strong: #5f7fab;
    --warm: #3d3421;
    --warm-ink: #f5d88c;
    --device-line: #6884a9;
    --shadow: 0 18px 48px rgb(0 0 0 / 22%);
    color-scheme: dark;
}
*, *::before, *::after { box-sizing: border-box; }
html { scroll-behavior: smooth; scroll-padding-top: 100px; }
body { margin: 0; color: var(--ink); background: var(--page); font: 1rem/1.75 -apple-system, BlinkMacSystemFont, "PingFang SC", "Microsoft YaHei", "Segoe UI", sans-serif; -webkit-font-smoothing: antialiased; }
h1, h2, h3, p, figure { margin: 0; }
h1, h2, h3 { line-height: 1.3; text-wrap: balance; }
a { color: inherit; text-decoration: none; }
button, summary { -webkit-tap-highlight-color: transparent; cursor: pointer; }
button { font: inherit; }
img { display: block; max-width: 100%; height: auto; }
svg { display: block; flex: none; width: 22px; height: 22px; }
[hidden] { display: none !important; }
a, button, summary { touch-action: manipulation; }
a:focus-visible, button:focus-visible, summary:focus-visible { outline: 3px solid var(--brand); outline-offset: 5px; }
a:hover { text-decoration-color: currentColor; }
.wrap { width: min(var(--max), calc(100% - 64px)); margin-inline: auto; }
.wrap > *, .hero-grid > *, .screen-panel > *, .download-card > * { min-width: 0; }
.skip-link { position: fixed; z-index: 50; top: 10px; left: 10px; padding: 10px 18px; background: var(--surface); color: var(--brand); border: 2px solid var(--brand); border-radius: 10px; transform: translateY(-160%); }
.skip-link:focus { transform: none; }
.eyebrow { color: var(--brand); font-size: 0.8125rem; font-weight: 700; letter-spacing: .06em; margin-bottom: 14px; }
.muted { color: var(--muted); }
header { position: sticky; top: 0; z-index: 20; background: var(--page); border-bottom: 1px solid var(--line); }
.nav { position: relative; min-height: 78px; display: flex; align-items: center; gap: 26px; }
.logo { display: inline-flex; align-items: center; flex: none; gap: 10px; font-size: 1.438rem; font-weight: 800; line-height: 1.1; letter-spacing: -.03em; }
.logo img { width: 39px; height: 39px; border-radius: 11px; }
.logo small { display: block; font-size: 0.625rem; line-height: 1.5; color: var(--muted); letter-spacing: .07em; font-weight: 500; margin-top: 3px; }
.nav-links { display: flex; align-items: center; justify-content: center; gap: 30px; margin-left: auto; font-size: 0.875rem; color: var(--muted); }
.nav-links a { padding-block: 12px; }
.nav-links a:hover, .footer-links a:hover { color: var(--brand); }
.button { display: inline-flex; align-items: center; justify-content: center; gap: 14px; min-height: 50px; padding: 12px 23px; background: var(--brand); border: 1px solid var(--brand); color: var(--on-brand); border-radius: 13px; font-weight: 650; font-size: 0.9375rem; line-height: 1.5; transition: background .18s ease, border-color .18s ease; }
.button:hover { background: var(--brand-hover); border-color: var(--brand-hover); }
.button-small { min-height: 44px; padding: 9px 17px; font-size: 0.875rem; }
.text-link { display: inline-flex; align-items: center; gap: 12px; min-height: 44px; color: var(--brand); font-size: 0.875rem; font-weight: 600; }
.text-link:hover { text-decoration: underline; text-underline-offset: 5px; }
.mobile-menu { display: none; margin-left: auto; }
.hero { padding: 52px 0 42px; }
.hero-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 32px; align-items: center; }
.hero-copy { padding-bottom: 12px; }
.hero .eyebrow { display: inline-flex; align-items: center; gap: 8px; padding: 5px 12px; border-radius: 8px; background: var(--wash); border: 1px solid var(--line); margin-bottom: 22px; font-size: 0.75rem; letter-spacing: .035em; }
.hero h1 { font-size: clamp(2.5rem, 4.2vw, 3.625rem); line-height: 1.25; letter-spacing: -.045em; font-weight: 800; }
.hero h1 span { color: var(--brand); }
.hero-intro { color: var(--muted); max-width: 450px; font-size: 1.062rem; line-height: 1.95; margin-top: 22px; }
.hero-actions { display: flex; align-items: center; flex-wrap: wrap; gap: 22px; margin-top: 28px; }
.hero .availability { color: var(--muted); font-size: 0.75rem; margin-top: 14px; }
.hero-points { list-style: none; display: flex; gap: 21px; flex-wrap: wrap; padding: 22px 0 0; margin: 25px 0 0; border-top: 1px solid var(--line); color: var(--muted); font-size: 0.8125rem; }
.hero-points li { display: flex; align-items: center; gap: 6px; }
.hero-points svg { width: 17px; height: 17px; color: var(--brand); }
.hero-product { position: relative; width: 100%; min-height: 535px; border-radius: 34px; background: var(--wash); border: 1px solid var(--line); display: flex; align-items: center; justify-content: center; gap: 12px; padding: 32px 20px 38px; isolation: isolate; }
.hero-product::before { content: ""; position: absolute; z-index: -1; width: 280px; height: 280px; border-radius: 50%; background: var(--wash-strong); top: 48px; right: 26px; }
.device { position: relative; flex: none; background: var(--qr-paper); border: 1px solid var(--device-line); border-radius: 25px; padding: 6px; box-shadow: var(--shadow); }
.device img { border-radius: 19px; }
.device figcaption { position: absolute; color: var(--ink); background: var(--surface); border: 1px solid var(--line); border-radius: 9px; padding: 5px 11px; font-size: .75rem; line-height: 1.6; max-width: calc(100% + 20px); white-space: normal; text-align: center; }
.device-main { width: 56%; max-width: 239px; align-self: flex-start; margin-top: 4px; z-index: 2; }
.device-main figcaption { bottom: -16px; left: 16px; }
.device-secondary { width: 44%; max-width: 185px; margin-left: -8%; margin-top: 100px; }
.device-secondary figcaption { top: -16px; right: 8px; }
.image-note { position: absolute; bottom: 13px; left: 16px; right: 16px; text-align: center; color: var(--muted); font-size: .75rem; }
.learning-strip { padding: 20px 0 30px; }
.learning-strip .wrap { display: flex; align-items: center; justify-content: space-between; gap: 24px; padding: 22px 28px; border: 1px solid var(--line); border-radius: 16px; }
.learning-strip p { font-size: 0.875rem; font-weight: 650; }
.learning-loop { display: flex; align-items: center; flex-wrap: wrap; gap: 14px; color: var(--muted); font-size: 0.8125rem; }
.learning-loop b { color: var(--brand); font-weight: 650; }
.learning-loop span[aria-hidden] { color: var(--line-strong); }
section { padding-block: 64px; }
.section-heading { margin-bottom: 30px; }
h2 { font-size: clamp(1.6875rem, 3vw, 2.375rem); font-weight: 750; letter-spacing: -.035em; }
.section-heading > p:last-child:not(.eyebrow) { margin-top: 13px; color: var(--muted); font-size: 0.9375rem; }
.section-heading.centered { text-align: center; }
.product-section { background: var(--wash); border-block: 1px solid var(--line); }
.product-section .section-heading { text-align: center; }
.screen-controls { display: flex; width: fit-content; max-width: 100%; gap: 6px; padding: 5px; border: 1px solid var(--line); border-radius: 14px; background: var(--surface); margin: 0 auto 32px; }
.screen-controls button { background: transparent; color: var(--muted); border: 1px solid transparent; border-radius: 9px; padding: 9px 19px; min-height: 44px; font-size: 0.875rem; line-height: 1.5; }
.screen-controls button[aria-pressed="true"] { color: var(--on-brand); background: var(--brand); border-color: var(--brand); }
.screen-controls button:hover:not([aria-pressed="true"]) { background: var(--wash); border-color: var(--line); }
.screen-panel { display: grid; grid-template-columns: 1fr 1fr; gap: 64px; align-items: center; padding: 28px 64px; background: var(--surface); border: 1px solid var(--line); border-radius: 25px; }
.screen-panel + .screen-panel { margin-top: 24px; }
.gallery-enhanced .screen-panel + .screen-panel { margin-top: 0; }
.screen-copy h3 { font-size: clamp(1.625rem, 3vw, 2.25rem); margin-bottom: 16px; letter-spacing: -.035em; }
.screen-copy > p:not(.eyebrow) { color: var(--muted); font-size: 0.9375rem; }
.plain-list { padding: 0; list-style: none; margin: 20px 0 16px; }
.plain-list li { display: flex; gap: 11px; align-items: baseline; padding: 7px 0; color: var(--ink); font-size: 0.875rem; }
.plain-list li::before { content: "✓"; color: var(--brand); font-weight: 700; flex: none; }
.screen-copy .context-note { font-size: 0.75rem !important; margin-top: 15px; }
.screen-image { width: min(100%, 230px); justify-self: center; }
.screen-image img { border: 1px solid var(--device-line); border-radius: 16px; }
.screen-image figcaption { color: var(--muted); font-size: .75rem; text-align: center; margin-top: 10px; line-height: 1.7; }
.steps { display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; list-style: none; margin: 0; padding: 0; counter-reset: steps; }
.steps li { padding: 24px; background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius); }
.steps span { display: inline-flex; align-items: center; justify-content: center; width: 38px; height: 38px; color: var(--brand); background: var(--wash); border-radius: 11px; font-size: 0.875rem; font-weight: 700; }
.steps h3 { margin: 18px 0 11px; font-size: 1.188rem; }
.steps p { color: var(--muted); font-size: 0.875rem; }
.family-section { padding-top: 8px; }
.family-layout { display: grid; grid-template-columns: 1fr 1fr; gap: 60px; padding: 36px 40px; background: var(--wash); border: 1px solid var(--line); border-radius: 26px; align-items: center; }
.family-intro > p:not(.eyebrow) { color: var(--muted); font-size: 0.9375rem; margin: 18px 0; }
.family-roles { display: grid; gap: 14px; }
.family-roles article { padding: 22px 24px; background: var(--surface); border: 1px solid var(--line); border-radius: 16px; }
.family-roles .eyebrow { font-size: 0.6875rem; margin-bottom: 8px; }
.family-roles h3 { font-size: 1.25rem; margin-bottom: 10px; }
.family-roles p:last-child { color: var(--muted); font-size: 0.875rem; }
.family-tag { display: inline-flex; padding: 4px 11px; margin-bottom: 15px; color: var(--warm-ink); background: var(--warm); border-radius: 7px; font-size: 0.75rem; font-weight: 650; }
.faq-section { border-top: 1px solid var(--line); }
.faq-layout { display: grid; grid-template-columns: 1fr 1.65fr; gap: 70px; }
.faq-layout .muted { margin-top: 20px; font-size: 0.875rem; }
.faq-layout a:not(.text-link) { color: var(--brand); text-decoration: underline; text-underline-offset: 4px; }
.faq-list { border-top: 1px solid var(--line); }
.faq-list details { border-bottom: 1px solid var(--line); }
.faq-list summary { display: flex; align-items: center; justify-content: space-between; gap: 16px; padding: 18px 0; min-height: 58px; font-size: 0.9375rem; font-weight: 650; list-style: none; }
.faq-list summary::-webkit-details-marker { display: none; }
.faq-list summary::after { content: "+"; color: var(--brand); font-size: 1.438rem; font-weight: 400; flex: none; }
.faq-list details[open] summary::after { content: "−"; }
.faq-list details p { color: var(--muted); font-size: 0.875rem; padding: 0 22px 20px 0; }
.download-section { background: var(--wash); border-block: 1px solid var(--line); }
.download-section .section-heading { text-align: center; }
.download-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 22px; }
.download-card { display: grid; grid-template-columns: minmax(0, 1fr) 132px; align-items: center; gap: 24px; padding: 30px; border: 1px solid var(--line); border-radius: var(--radius); background: var(--surface); }
.download-card .eyebrow { font-size: 0.75rem; margin-bottom: 10px; }
.download-card h3 { font-size: 1.375rem; margin-bottom: 12px; }
.download-card p { color: var(--muted); font-size: 0.875rem; }
.download-card .button { margin-top: 20px; font-size: 0.875rem; padding: 11px 16px; }
.download-card .download-hint { margin-top: 14px; font-size: 0.75rem; line-height: 1.8; }
.download-card figure img { width: 132px; height: 132px; object-fit: contain; background: var(--qr-paper); padding: 3px; border-radius: 7px; }
.download-card figcaption { color: var(--muted); font-size: .75rem; text-align: center; margin-top: 9px; }
.download-card .miniapp-name { color: var(--ink); font-weight: 650; padding: 10px 13px; margin-top: 22px; border: 1px solid var(--line); border-radius: 10px; background: var(--wash); }
.about-section { padding-block: 44px; }
.about-layout { display: grid; grid-template-columns: 1fr 1.8fr; gap: 64px; }
.about-layout h2 { font-size: 1.625rem; }
.about-copy h3 { font-size: 1rem; margin-bottom: 9px; }
.about-copy h3:not(:first-child) { margin-top: 20px; }
.about-copy p, .about-copy address { font-size: 0.8125rem; color: var(--muted); line-height: 1.95; }
.about-copy a { color: var(--brand); text-decoration: underline; text-underline-offset: 4px; }
.about-copy address { font-style: normal; margin-top: 20px; padding-top: 18px; border-top: 1px solid var(--line); }
footer { background: var(--wash); border-top: 1px solid var(--line); padding: 34px 0 20px; }
.footer-main { display: grid; grid-template-columns: 1fr .9fr 1.25fr; gap: 38px; font-size: 0.8125rem; }
.footer-main > div > p { color: var(--muted); margin-top: 12px; }
.footer-main .logo { font-size: 1.25rem; }
.footer-main .text-link { margin-top: 7px; font-size: 0.75rem; }
.footer-links { display: grid; align-content: start; gap: 12px; color: var(--muted); }
.footer-contact { display: flex; align-items: flex-start; justify-content: space-between; gap: 16px; }
.footer-contact > div > p { margin-top: 10px; color: var(--muted); line-height: 2; }
.footer-contact figure img { width: 94px; height: 94px; background: var(--qr-paper); border-radius: 7px; }
.footer-contact figcaption { margin-top: 6px; font-size: .75rem; text-align: center; color: var(--muted); }
.footer-bottom { display: flex; flex-wrap: wrap; justify-content: space-between; gap: 10px; border-top: 1px solid var(--line); margin-top: 28px; padding-top: 17px; font-size: .75rem; color: var(--muted); }
@media (max-width: 1050px) {
  .wrap { width: calc(100% - 48px); }
  .nav { gap: 18px; }
  .nav-links { gap: 20px; }
  .hero-grid { gap: 22px; grid-template-columns: 1.05fr 1fr; }
  .hero-product { min-height: 480px; padding-inline: 14px; }
  .device-secondary { margin-top: 100px; }
  .hero h1 { font-size: 2.875rem; }
  .hero-intro { font-size: 1rem; }
  .hero-points { gap: 13px; font-size: 0.75rem; }
  .screen-panel { padding-inline: 36px; gap: 35px; }
  .download-card { padding: 24px; gap: 15px; grid-template-columns: minmax(0, 1fr) 110px; }
  .download-card figure img { width: 110px; height: 110px; }
  .download-card h3 { font-size: 1.188rem; }
  .family-layout { gap: 32px; padding: 30px; }
}
@media (max-width: 760px) {
  html { scroll-padding-top: 90px; }
  .wrap { width: calc(100% - 36px); }
  .nav { min-height: 68px; gap: 12px; flex-wrap: wrap; }
  .nav-links { display: none; }
  .logo { font-size: 1.25rem; }
  .logo img { width: 34px; height: 34px; }
  .button-small { font-size: 0.75rem; padding-inline: 12px; }
  .mobile-menu { display: block; position: static; }
  .mobile-menu summary { display: flex; align-items: center; min-height: 44px; padding: 8px; color: var(--muted); font-size: 0.8125rem; list-style: none; }
  .mobile-menu summary::-webkit-details-marker { display: none; }
  .mobile-menu nav { position: absolute; top: calc(100% + 8px); left: 0; right: 0; min-width: 0; display: grid; padding: 10px; border: 1px solid var(--line); border-radius: 14px; background: var(--surface); box-shadow: var(--shadow); }
  .mobile-menu nav a { padding: 12px; font-size: 0.875rem; border-radius: 7px; }
  .mobile-menu nav a:hover { background: var(--wash); }
  .hero { padding: 32px 0 26px; }
  .hero-grid { grid-template-columns: 1fr; gap: 27px; }
  .hero-copy { padding: 0; }
  .hero .eyebrow { font-size: 0.6875rem; margin-bottom: 17px; }
  .hero h1 { font-size: clamp(2.3125rem, 8vw, 3.1875rem); }
  .hero-intro { margin-top: 17px; max-width: 560px; }
  .hero-actions { margin-top: 22px; gap: 18px; }
  .hero-points { padding-top: 18px; margin-top: 22px; gap: 16px; }
  .hero-product { min-height: 470px; max-width: 540px; justify-self: center; border-radius: 24px; padding-top: 25px; }
  .device-secondary { margin-top: 85px; }
  .learning-strip { padding: 8px 0 28px; }
  .learning-strip .wrap { align-items: flex-start; flex-direction: column; gap: 10px; padding: 18px; }
  .learning-loop { gap: 10px; font-size: 0.75rem; }
  section { padding-block: 42px; }
  .section-heading { margin-bottom: 23px; }
  .section-heading .eyebrow { font-size: 0.75rem; margin-bottom: 10px; }
  .section-heading > p:last-child:not(.eyebrow) { font-size: 0.875rem; }
  .screen-controls { width: 100%; gap: 3px; padding: 4px; margin-bottom: 22px; flex-wrap: wrap; }
  .screen-controls button { flex: 1 1 43%; padding: 9px 7px; font-size: 0.8125rem; }
  .screen-panel { grid-template-columns: 1fr; gap: 24px; padding: 25px 22px; border-radius: 20px; }
  .screen-copy h3 { font-size: 1.688rem; }
  .screen-image { width: min(100%, 230px); }
  .steps { grid-template-columns: 1fr; gap: 14px; }
  .steps li { padding: 22px; }
  .steps h3 { margin-top: 12px; }
  .family-section { padding-top: 0; }
  .family-layout { grid-template-columns: 1fr; gap: 24px; padding: 25px 22px; }
  .family-roles article { padding: 20px; }
  .faq-layout, .about-layout { grid-template-columns: 1fr; gap: 25px; }
  .faq-layout .muted { margin-top: 12px; }
  .faq-list summary { font-size: 0.875rem; }
  .download-grid { grid-template-columns: 1fr; gap: 16px; }
  .download-card { grid-template-columns: minmax(0, 1fr) 120px; gap: 20px; padding: 24px; }
  .download-card figure img { width: 120px; height: 120px; }
  .download-card h3 { font-size: 1.312rem; }
  .about-section { padding-block: 34px; }
  .about-layout h2 { font-size: 1.5rem; }
  .footer-main { grid-template-columns: 1fr 1fr; gap: 28px; }
  .footer-contact { grid-column: 1 / -1; justify-content: flex-start; gap: 35px; }
}
@media (max-width: 390px) {
  .nav { gap: 7px; }
  .hero-actions { gap: 14px; }
  .hero-actions .button { padding-inline: 17px; font-size: 0.875rem; }
  .hero-actions .text-link { font-size: 0.8125rem; }
  .hero-product { min-height: 405px; padding: 23px 10px 34px; }
  .device-secondary { margin-top: 77px; }
  .hero-points { gap: 10px; font-size: .75rem; }
  .download-card { grid-template-columns: 1fr; }
  .download-card figure { justify-self: start; }
  .download-card figure img { width: 140px; height: 140px; }
  .footer-main { grid-template-columns: 1fr; }
  .footer-contact { grid-column: auto; }
}
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { animation: none !important; transition: none !important; }
}

.appearance-toggle { border: 1px solid var(--line); border-radius: 8px; background: var(--surface); color: var(--muted); padding: 5px 11px; font-size: .75rem; min-height: 36px; }

@media (max-width: 480px) { .nav .button-small span { display: none; } }

@media (max-width: 390px) { .nav .button-small { padding-inline: 10px; } .mobile-menu summary { padding-inline: 6px; } }

section[id] { scroll-margin-top: 1.25rem; }

@media (max-width: 480px) { .nav { width: calc(100% - 24px); } .nav .logo { font-size: 1rem; gap: 8px; } .nav .button-small { padding-inline: 8px; } }