:root {
  color-scheme: light;
  --canvas: #ffffff;
  --subtle: #f6f8fa;
  --border: #d8dee4;
  --border-strong: #afb8c1;
  --text: #1f2328;
  --muted: #59636e;
  --faint: #6e7781;
  --accent: #0969da;
  --accent-hover: #0860ca;
  --success: #1a7f37;
  --radius: 10px;
  font-family: -apple-system, BlinkMacSystemFont, "SF Pro Text", "PingFang SC", "Helvetica Neue", Arial, sans-serif;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body { margin: 0; overflow-x: hidden; color: var(--text); background: var(--canvas); font-size: 16px; }
a { color: inherit; text-decoration: none; }
img { display: block; max-width: 100%; }
button { font: inherit; }
.en { display: none; }
html[data-language="en"] .zh { display: none !important; }
html[data-language="en"] .en { display: inline; }
html[data-language="en"] img.en { display: block; }
p.en, h1 .en, h2.en { display: none; }
html[data-language="en"] p.en, html[data-language="en"] h2.en { display: block; }

.skip-link { position: fixed; top: -80px; left: 16px; z-index: 100; padding: 10px 14px; border-radius: 6px; color: #fff; background: var(--text); }
.skip-link:focus { top: 16px; }

.site-header { position: sticky; top: 0; z-index: 50; display: grid; grid-template-columns: 1fr auto 1fr; align-items: center; width: 100%; min-height: 64px; padding: 10px max(24px, calc((100% - 1200px) / 2)); border-bottom: 1px solid var(--border); background: rgba(255, 255, 255, .96); }
.brand { display: inline-flex; align-items: center; gap: 10px; width: max-content; font-weight: 650; letter-spacing: -.01em; }
.brand img { border-radius: 9px; }
.site-header nav { display: flex; align-items: center; gap: 30px; color: var(--muted); font-size: 14px; }
.site-header nav a:hover, .site-header nav a:focus-visible, .text-link:hover { color: var(--accent); }
.language-toggle { justify-self: end; min-width: 48px; padding: 7px 11px; border: 1px solid var(--border); border-radius: 6px; color: var(--muted); background: #fff; cursor: pointer; }
.language-toggle:hover { background: var(--subtle); }

.hero { display: grid; grid-template-columns: minmax(0, .85fr) minmax(0, 1.15fr); align-items: center; gap: 64px; width: min(1200px, calc(100% - 48px)); margin: 0 auto; padding: 96px 0 82px; }
.eyebrow { margin: 0 0 18px; color: var(--faint); font-size: 12px; font-weight: 650; letter-spacing: .13em; text-transform: uppercase; }
.status-dot { display: inline-block; width: 7px; height: 7px; margin-right: 9px; border-radius: 50%; background: var(--success); }
h1 { max-width: 610px; margin: 0; font-size: clamp(48px, 4.8vw, 70px); line-height: 1.04; letter-spacing: -.055em; }
h1 em, h2 em { color: var(--accent); font-style: normal; }
.hero-intro { max-width: 570px; margin: 27px 0 30px; color: var(--muted); font-size: 18px; line-height: 1.68; }
.hero-actions { display: flex; align-items: stretch; gap: 10px; }
.button { display: inline-flex; align-items: center; justify-content: center; gap: 12px; min-height: 48px; padding: 9px 18px; border: 1px solid var(--border); border-radius: 7px; font-size: 14px; font-weight: 600; }
.button.primary { color: #fff; border-color: var(--accent); background: var(--accent); }
.button.primary:hover { border-color: var(--accent-hover); background: var(--accent-hover); }
.button.secondary { color: var(--text); background: var(--subtle); }
.button.secondary:hover { border-color: var(--border-strong); background: #eef1f4; }
.button span:has(b) { display: grid; gap: 2px; text-align: left; }
.button b { font-size: 14px; }
.button small { font-size: 10px; font-weight: 500; opacity: .72; }
.apple-mark { font-size: 16px; }
.license-note { margin: 13px 0 0; color: var(--faint); font-size: 11px; }

.product-preview { margin: 0; overflow: hidden; border: 1px solid var(--border); border-radius: var(--radius); background: #fff; box-shadow: 0 1px 2px rgba(31, 35, 40, .04), 0 8px 24px rgba(140, 149, 159, .12); }
.app-screenshot img { width: 100%; height: auto; aspect-ratio: 2048 / 881; object-fit: cover; }
.app-screenshot figcaption, .analysis-figure figcaption { padding: 10px 13px; color: var(--faint); background: #fff; font-size: 10px; line-height: 1.4; }

.proof-strip { display: grid; grid-template-columns: repeat(4, 1fr); width: min(1200px, calc(100% - 48px)); margin: 0 auto 116px; border: 1px solid var(--border); border-radius: var(--radius); background: var(--subtle); }
.proof-strip > span { display: grid; grid-template-columns: auto 1fr; align-items: baseline; justify-content: center; gap: 8px; padding: 21px 14px; border-right: 1px solid var(--border); }
.proof-strip > span:last-child { border: 0; }
.proof-strip b { font-size: 21px; }
.proof-strip small { color: var(--faint); font-size: 11px; }

.section { width: min(1200px, calc(100% - 48px)); margin: 0 auto; padding-bottom: 120px; }
.section-heading { max-width: 760px; margin-bottom: 42px; }
.section-heading .eyebrow { margin-bottom: 14px; }
.section h2, .privacy-section h2, .download-section h2 { margin: 0; font-size: clamp(36px, 4vw, 54px); line-height: 1.1; letter-spacing: -.045em; }
.feature-grid { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 16px; }
.feature-card { display: flex; flex-direction: column; min-height: 360px; overflow: hidden; border: 1px solid var(--border); border-radius: var(--radius); background: #fff; }
.feature-wide { grid-column: 1 / -1; display: grid; grid-template-columns: .8fr 1.2fr; min-height: 400px; }
.feature-copy { padding: 32px; }
.feature-index { display: block; margin-bottom: 54px; color: var(--faint); font-size: 12px; font-weight: 650; }
.feature-copy h3 { max-width: 460px; margin: 0 0 12px; font-size: clamp(24px, 2.2vw, 32px); letter-spacing: -.025em; }
.feature-copy p { max-width: 520px; margin: 0; color: var(--muted); font-size: 15px; line-height: 1.72; }
.feature-visual { min-height: 320px; }
.image-visual { display: flex; align-items: center; padding: 30px; background: var(--subtle); }
.analysis-figure { width: 100%; max-width: 760px; margin: auto; overflow: hidden; border: 1px solid var(--border); border-radius: 8px; background: #111318; }
.analysis-figure img { width: 100%; height: auto; aspect-ratio: 1050 / 732; object-fit: cover; }
.vector-analysis { background: #fff; }
.vector-analysis img { aspect-ratio: 960 / 360; object-fit: contain; }
.feature-card:not(.feature-wide) .feature-index { margin-bottom: 32px; }
.scan-profile-visual { display: grid; align-content: center; gap: 0; padding: 32px; background: var(--subtle); }
.profile-tabs { display: flex; flex-wrap: wrap; gap: 7px; margin-bottom: 18px; }
.profile-tabs > span { padding: 7px 11px; border: 1px solid var(--border); border-radius: 999px; color: var(--muted); background: #fff; font-size: 11px; font-weight: 600; }
.profile-tabs > .active { color: #fff; border-color: var(--accent); background: var(--accent); }
.profile-setting { display: grid; grid-template-columns: 120px minmax(0, 1fr); gap: 16px; padding: 14px 2px; border-bottom: 1px solid var(--border); color: var(--faint); font-size: 12px; }
.profile-setting b { overflow: hidden; color: var(--text); font-size: 12px; font-weight: 600; text-overflow: ellipsis; white-space: nowrap; }
.profile-summary { display: grid; grid-template-columns: repeat(3, 1fr); margin-top: 20px; border: 1px solid var(--border); border-radius: 7px; background: #fff; }
.profile-summary > span { display: grid; gap: 4px; padding: 14px; border-right: 1px solid var(--border); }
.profile-summary > span:last-child { border-right: 0; }
.profile-summary small { color: var(--faint); font-size: 10px; }
.profile-summary b { font-size: 18px; }
.map-visual { display: grid; grid-template-columns: minmax(0, 1fr) auto; align-items: center; gap: 20px; min-height: 104px; margin: auto 32px 32px; padding: 20px; border-top: 1px solid var(--border); color: var(--muted); }
.map-label { font-size: 11px; font-weight: 650; letter-spacing: .11em; text-transform: uppercase; }
.map-visual b { color: var(--text); font-size: 25px; }
.map-visual .route, .map-visual .pin { display: none; }
.album-visual { display: grid; margin: auto 32px 32px; border-top: 1px solid var(--border); }
.album-visual > span { display: grid; grid-template-columns: 10px 1fr auto; align-items: center; gap: 11px; min-height: 47px; border-bottom: 1px solid var(--border); }
.album-visual i { width: 8px; height: 8px; border-radius: 2px; background: var(--accent); }
.album-visual b { font-size: 13px; }
.album-visual small { color: var(--faint); font-size: 11px; }
.report-card { min-height: 330px; }
.report-card .feature-index { margin-bottom: 42px; }
.format-list { display: grid; grid-template-columns: repeat(4, 1fr); align-self: center; gap: 8px; padding: 32px; }
.format-list span { display: grid; gap: 30px; padding: 17px; border: 1px solid var(--border); border-radius: 7px; font-size: 17px; font-weight: 650; }
.format-list small { color: var(--faint); font-size: 10px; font-weight: 500; }

.browsing-showcase { padding-top: 10px; }
.browsing-list { display: grid; gap: 18px; }
.browsing-item { display: grid; grid-template-columns: .42fr 1.58fr; align-items: center; min-height: 460px; overflow: hidden; border: 1px solid var(--border); border-radius: var(--radius); background: var(--subtle); }
.browsing-item-reverse { grid-template-columns: 1.58fr .42fr; }
.browsing-item-reverse .browsing-copy { order: 2; }
.browsing-copy { padding: 34px; }
.browsing-copy .feature-index { margin-bottom: 72px; }
.browsing-copy h3 { margin: 0 0 12px; font-size: clamp(25px, 2.4vw, 34px); letter-spacing: -.03em; }
.browsing-copy p { margin: 0; color: var(--muted); font-size: 14px; line-height: 1.72; }
.browsing-figure { margin: 0; padding: 18px; }
.browsing-figure img { width: 100%; height: auto; border: 1px solid var(--border); border-radius: 9px; background: #fff; box-shadow: 0 12px 32px rgba(31, 35, 40, .12); }

.privacy-section { display: grid; grid-template-columns: .7fr 1.3fr; align-items: center; gap: 72px; width: min(1200px, calc(100% - 48px)); margin: 0 auto 120px; padding: 64px; border: 1px solid var(--border); border-radius: var(--radius); background: var(--subtle); }
.privacy-orbit { display: grid; place-items: center; min-height: 270px; border-right: 1px solid var(--border); }
.privacy-orbit img { width: 92px; height: 92px; border-radius: 19px; }
.privacy-orbit > span, .privacy-orbit > i { display: none; }
.privacy-copy h2 { font-size: clamp(36px, 3.7vw, 52px); }
.privacy-copy > p:not(.eyebrow) { max-width: 670px; margin: 24px 0; color: var(--muted); line-height: 1.76; }
.privacy-points { display: flex; flex-wrap: wrap; gap: 8px 20px; margin-bottom: 22px; }
.privacy-points > span { display: flex; align-items: center; gap: 7px; color: var(--muted); font-size: 12px; }
.privacy-points b { color: var(--success); }
.text-link { color: var(--accent); font-size: 13px; font-weight: 600; }

.download-section { display: grid; grid-template-columns: 1.25fr .75fr; align-items: end; gap: 60px; width: min(1200px, calc(100% - 48px)); margin: 0 auto 80px; padding: 72px 0; border-top: 1px solid var(--border); }
.download-section p:not(.eyebrow) { color: var(--muted); }
.download-actions { display: grid; justify-items: start; gap: 13px; }
.button.large { min-height: 62px; padding: 11px 21px; }
.download-actions > small { color: var(--faint); font-size: 10px; }

footer { display: grid; grid-template-columns: 1fr 1.3fr 1fr; align-items: center; gap: 24px; width: 100%; padding: 30px max(24px, calc((100% - 1200px) / 2)); border-top: 1px solid var(--border); color: var(--faint); background: var(--subtle); font-size: 11px; }
.footer-brand { color: var(--text); }
footer p { text-align: center; }
footer div { display: flex; justify-content: flex-end; gap: 20px; }
footer a:hover { color: var(--accent); }
footer > small { grid-column: 1 / -1; padding-top: 20px; border-top: 1px solid var(--border); text-align: center; font-size: 10px; }

@media (max-width: 900px) {
  .site-header { grid-template-columns: 1fr auto; }
  .site-header nav { display: none; }
  .hero { grid-template-columns: 1fr; gap: 48px; padding-top: 72px; }
  .hero-copy { max-width: 740px; }
  .feature-wide { grid-template-columns: 1fr; }
  .image-visual { min-height: 280px; }
  .privacy-section { grid-template-columns: 1fr; gap: 36px; padding: 48px; }
  .privacy-orbit { min-height: 150px; border-right: 0; border-bottom: 1px solid var(--border); }
  .report-card { display: block; }
  .browsing-item, .browsing-item-reverse { grid-template-columns: 1fr; }
  .browsing-item-reverse .browsing-copy { order: 0; }
  .browsing-copy .feature-index { margin-bottom: 34px; }
}

@media (max-width: 640px) {
  .site-header { min-height: 58px; padding: 8px 16px; }
  .brand img { width: 36px; height: 36px; }
  .hero, .section, .privacy-section, .download-section, .proof-strip { width: calc(100% - 32px); }
  .hero { padding: 62px 0 56px; }
  h1 { font-size: clamp(40px, 12vw, 54px); }
  .hero-intro { font-size: 16px; }
  .hero-actions { flex-direction: column; }
  .button { width: 100%; }
  .proof-strip { grid-template-columns: repeat(2, 1fr); margin-bottom: 82px; }
  .proof-strip > span:nth-child(2) { border-right: 0; }
  .proof-strip > span:nth-child(-n + 2) { border-bottom: 1px solid var(--border); }
  .section { padding-bottom: 82px; }
  .section-heading { margin-bottom: 30px; }
  .feature-grid { grid-template-columns: 1fr; }
  .feature-wide { grid-column: auto; }
  .feature-card { min-height: auto; }
  .feature-copy { padding: 24px; }
  .feature-index, .feature-card:not(.feature-wide) .feature-index { margin-bottom: 26px; }
  .image-visual { min-height: 220px; padding: 20px; }
  .scan-profile-visual { padding: 24px; }
  .profile-setting { grid-template-columns: 92px minmax(0, 1fr); }
  .map-visual, .album-visual { margin: 16px 24px 24px; }
  .map-visual { grid-template-columns: 1fr; gap: 10px; }
  .format-list { grid-template-columns: repeat(2, 1fr); padding: 24px; }
  .browsing-copy { padding: 24px; }
  .browsing-figure { padding: 0 10px 10px; }
  .privacy-section { margin-bottom: 82px; padding: 32px 24px; }
  .download-section { grid-template-columns: 1fr; gap: 28px; margin-bottom: 48px; padding: 58px 0; }
  footer { grid-template-columns: 1fr; justify-items: center; text-align: center; }
  footer p { margin: 0; }
  footer div { justify-content: center; }
  footer > small { grid-column: auto; width: 100%; }
}

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