:root {
  --ink: #15151a;
  --muted: #696973;
  --paper: #f4f3f8;
  --card: rgba(255, 255, 255, .82);
  --line: rgba(26, 26, 31, .09);
  --green: #2cc85b;
  --green-dark: #159943;
  --amber: #f5ab19;
  --red: #f54444;
  --blue: #1689ef;
  --shadow: 0 28px 80px rgba(39, 34, 57, .12);
  --radius: 30px;
  --max: 1180px;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; overflow-x: hidden; }
body {
  margin: 0;
  color: var(--ink);
  background:
    radial-gradient(circle at 75% 5%, rgba(111, 205, 255, .14), transparent 25rem),
    radial-gradient(circle at 12% 22%, rgba(209, 177, 255, .16), transparent 30rem),
    var(--paper);
  font-family: -apple-system, BlinkMacSystemFont, "SF Pro Display", "PingFang SC", "Helvetica Neue", Arial, sans-serif;
  -webkit-font-smoothing: antialiased;
  overflow-x: clip;
}

a { color: inherit; text-decoration: none; }
button { font: inherit; }
img { display: block; max-width: 100%; }
.section-shell { width: min(var(--max), calc(100% - 48px)); margin-inline: auto; }
.i18n-en { display: none; }
body[data-lang="en"] .i18n-zh { display: none; }
body[data-lang="en"] .i18n-en { display: block; }

.site-header {
  position: sticky;
  top: 12px;
  z-index: 20;
  width: min(var(--max), calc(100% - 32px));
  height: 68px;
  margin: 12px auto 0;
  padding: 0 14px 0 12px;
  display: flex;
  align-items: center;
  gap: 28px;
  background: rgba(249, 249, 252, .76);
  border: 1px solid rgba(255, 255, 255, .85);
  border-radius: 22px;
  box-shadow: 0 12px 36px rgba(36, 31, 52, .08);
  backdrop-filter: blur(22px) saturate(150%);
  -webkit-backdrop-filter: blur(22px) saturate(150%);
}

.brand { display: inline-flex; align-items: center; gap: 10px; font-weight: 750; font-size: 19px; }
.brand img, .footer-brand img { border-radius: 11px; box-shadow: 0 6px 16px rgba(31, 31, 38, .16); }
.nav-links { display: flex; align-items: center; gap: 28px; margin-left: auto; }
.nav-links a { color: #5f5f68; font-size: 14px; font-weight: 600; transition: color .2s ease; }
.nav-links a:hover { color: var(--ink); }
.language-button {
  min-width: 48px;
  height: 38px;
  border: 1px solid var(--line);
  border-radius: 13px;
  background: white;
  color: var(--ink);
  cursor: pointer;
  font-weight: 700;
}

.hero { min-height: 760px; padding: 84px 0 72px; display: grid; grid-template-columns: 1.02fr .98fr; align-items: center; gap: 78px; }
.eyebrow, .section-kicker { color: var(--green-dark); font-weight: 760; font-size: 14px; letter-spacing: .08em; }
.eyebrow { display: inline-flex; align-items: center; gap: 10px; padding: 9px 13px; background: rgba(44, 200, 91, .1); border-radius: 999px; }
.live-dot { width: 8px; height: 8px; border-radius: 50%; background: var(--green); box-shadow: 0 0 0 5px rgba(44, 200, 91, .14); }
.hero h1 { margin: 28px 0 22px; font-size: clamp(54px, 6.3vw, 82px); line-height: .98; letter-spacing: -.065em; font-weight: 820; }
.hero h1 span { background: linear-gradient(110deg, #139b45, #2cc85b 52%, #1689ef); color: transparent; background-clip: text; -webkit-background-clip: text; }
.hero-summary { max-width: 620px; margin: 0; color: var(--muted); font-size: 19px; line-height: 1.75; }
.hero-actions { margin-top: 32px; display: flex; flex-wrap: wrap; align-items: center; gap: 24px; }
.store-button { display: inline-flex; align-items: center; gap: 11px; min-width: 186px; padding: 11px 20px; border-radius: 16px; color: white; background: #151519; box-shadow: 0 12px 30px rgba(21, 21, 25, .22); }
.store-button svg { width: 29px; height: 29px; fill: currentColor; }
.store-button span { display: flex; flex-direction: column; }
.store-button small { font-size: 10px; line-height: 1.15; opacity: .74; }
.store-button strong { font-size: 21px; line-height: 1.05; letter-spacing: -.02em; }
.store-button.compact { transform: scale(.92); transform-origin: center; }
.text-button { display: inline-flex; align-items: center; gap: 10px; color: #4c4c54; font-size: 15px; font-weight: 700; }
.text-button span:last-child { display: grid; place-items: center; width: 32px; height: 32px; border: 1px solid var(--line); border-radius: 50%; background: white; }
.trust-row { display: flex; flex-wrap: wrap; gap: 18px; margin-top: 30px; color: #696971; font-size: 13px; }
.trust-row > span { display: inline-flex; align-items: center; gap: 6px; }
.trust-row svg { width: 17px; height: 17px; fill: var(--green-dark); }

.hero-visual { position: relative; display: grid; place-items: center; min-height: 650px; }
.phone-frame { position: relative; width: 340px; height: 694px; padding: 10px; overflow: hidden; border: 2px solid rgba(25, 25, 29, .85); border-radius: 55px; background: #101014; box-shadow: 0 38px 95px rgba(31, 27, 45, .28), 0 0 0 7px rgba(255, 255, 255, .7); transform: rotate(2deg); }
.phone-frame img { width: 100%; height: 100%; object-fit: cover; border-radius: 44px; }
.phone-speaker { position: absolute; z-index: 2; top: 19px; left: 50%; width: 92px; height: 25px; transform: translateX(-50%); border-radius: 99px; background: #050506; }
.tone { position: absolute; border-radius: 50%; filter: blur(1px); }
.tone-one { width: 450px; height: 450px; background: radial-gradient(circle at 32% 32%, rgba(71, 223, 121, .48), rgba(32, 150, 255, .17) 55%, transparent 70%); }
.tone-two { width: 300px; height: 300px; right: -20px; bottom: 10px; background: radial-gradient(circle, rgba(246, 187, 58, .28), transparent 68%); }
.floating-note { position: absolute; z-index: 3; min-width: 102px; padding: 14px 17px; border: 1px solid rgba(255, 255, 255, .92); border-radius: 19px; background: rgba(255, 255, 255, .84); box-shadow: 0 16px 40px rgba(31, 27, 45, .16); backdrop-filter: blur(18px); font-size: 24px; font-weight: 820; }
.floating-note small { display: block; color: var(--muted); font-size: 11px; margin-top: 2px; font-weight: 650; }
.note-a { top: 115px; right: -6px; }
.note-e { left: -16px; bottom: 105px; }
.note-e small { color: var(--green-dark); }

.proof-strip { max-width: 1260px; margin: 0 auto; display: grid; grid-template-columns: repeat(4, 1fr); border-block: 1px solid var(--line); }
.proof-strip div { min-height: 116px; display: flex; flex-direction: column; align-items: center; justify-content: center; gap: 5px; border-right: 1px solid var(--line); }
.proof-strip div:last-child { border-right: 0; }
.proof-strip strong { font-size: 24px; letter-spacing: -.03em; }
.proof-strip span { color: var(--muted); font-size: 13px; }

.feature-section, .preview-section { padding-block: 128px; }
.section-heading { max-width: 750px; margin-bottom: 48px; }
.section-kicker { margin: 0 0 14px; text-transform: uppercase; }
.section-heading h2, .privacy-panel h2, .closing-section h2 { margin: 0; font-size: clamp(38px, 4.5vw, 58px); line-height: 1.12; letter-spacing: -.045em; }
.section-heading > p:last-child { max-width: 660px; margin: 18px 0 0; color: var(--muted); font-size: 18px; line-height: 1.7; }
.feature-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 20px; }
.feature-card { position: relative; min-height: 320px; padding: 34px; overflow: hidden; border: 1px solid rgba(255, 255, 255, .9); border-radius: var(--radius); background: var(--card); box-shadow: 0 18px 55px rgba(45, 40, 61, .07); }
.feature-card h3 { margin: 30px 0 12px; font-size: 25px; letter-spacing: -.025em; }
.feature-card p { max-width: 500px; margin: 0; color: var(--muted); font-size: 16px; line-height: 1.7; }
.feature-icon { width: 70px; height: 70px; display: flex; align-items: center; justify-content: center; border-radius: 21px; background: #f1f1f5; }
.strings-icon { gap: 7px; transform: rotate(9deg); }
.strings-icon i { width: 3px; height: 43px; border-radius: 99px; background: #3d3d45; }
.strings-icon i:nth-child(2) { height: 51px; }
.strings-icon i:nth-child(3) { height: 48px; }
.waveform-icon { gap: 4px; }
.waveform-icon i { width: 4px; height: 18px; border-radius: 99px; background: var(--blue); }
.waveform-icon i:nth-child(2), .waveform-icon i:nth-child(6) { height: 30px; }
.waveform-icon i:nth-child(3), .waveform-icon i:nth-child(5) { height: 44px; }
.waveform-icon i:nth-child(4) { height: 56px; }
.lock-icon { background: rgba(44, 200, 91, .11); }
.lock-icon span { position: relative; width: 30px; height: 27px; margin-top: 10px; border-radius: 7px; background: var(--green-dark); }
.lock-icon span::before { content: ""; position: absolute; left: 6px; top: -15px; width: 14px; height: 17px; border: 4px solid var(--green-dark); border-bottom: 0; border-radius: 12px 12px 0 0; }
.privacy-card-small { background: linear-gradient(145deg, rgba(239, 255, 244, .92), rgba(255, 255, 255, .78)); }
.mini-meter { width: min(320px, 100%); display: grid; grid-template-columns: 1fr auto 1fr; gap: 10px; align-items: start; color: #8a8a91; font-size: 12px; }
.mini-meter span:last-child { text-align: right; }
.mini-meter b { color: var(--ink); }
.meter-band { position: relative; grid-column: 1 / -1; height: 54px; overflow: hidden; border-radius: 100% 100% 18px 18px; background: linear-gradient(90deg, var(--red) 0 22%, var(--amber) 22% 46%, var(--green) 46% 54%, var(--amber) 54% 78%, var(--red) 78%); clip-path: polygon(0 65%, 18% 20%, 40% 2%, 60% 2%, 82% 20%, 100% 65%, 95% 90%, 80% 51%, 59% 31%, 41% 31%, 20% 51%, 5% 90%); }
.meter-band i { position: absolute; left: 50%; top: 6px; width: 3px; height: 44px; border-radius: 9px; background: rgba(20, 20, 24, .65); }

.instrument-section { padding-block: 120px; background: #18191f; color: white; }
.light-heading .section-kicker { color: #62dd87; }
.light-heading > p:last-child { color: #aaaab2; }
.instrument-cloud { display: flex; flex-wrap: wrap; gap: 13px; }
.instrument-cloud span { padding: 13px 20px; border: 1px solid rgba(255, 255, 255, .13); border-radius: 999px; background: rgba(255, 255, 255, .06); color: #ededf1; font-size: 16px; }
.instrument-cloud span:nth-child(4n+1) { border-color: rgba(73, 211, 112, .35); background: rgba(44, 200, 91, .1); }

.preview-heading { margin-bottom: 42px; }
.screenshot-row { display: grid; grid-template-columns: repeat(4, 1fr); gap: 22px; }
.screenshot-row figure { margin: 0; }
.screenshot-row img { width: 100%; border: 8px solid #1c1c21; border-radius: 38px; background: #1c1c21; box-shadow: 0 25px 60px rgba(36, 32, 50, .16); transition: transform .35s ease, box-shadow .35s ease; }
.screenshot-row figure:nth-child(even) { transform: translateY(28px); }
.screenshot-row figure:hover img { transform: translateY(-7px); box-shadow: 0 34px 72px rgba(36, 32, 50, .22); }
.screenshot-row figcaption { padding: 16px 4px 0; text-align: center; color: var(--muted); font-size: 14px; font-weight: 650; }

.privacy-section { padding: 36px 0 120px; }
.privacy-panel { display: grid; grid-template-columns: auto 1fr auto; align-items: center; gap: 34px; padding: 44px; border-radius: 34px; background: linear-gradient(120deg, #e4faeb, #eaf4ff); border: 1px solid rgba(255, 255, 255, .9); }
.privacy-panel h2 { max-width: 700px; font-size: clamp(32px, 3.6vw, 48px); }
.privacy-panel p:not(.section-kicker) { max-width: 700px; margin: 15px 0 0; color: #5e6863; line-height: 1.7; }
.privacy-mark { width: 86px; height: 86px; display: grid; place-items: center; border-radius: 26px; background: rgba(255, 255, 255, .74); box-shadow: 0 15px 35px rgba(26, 112, 57, .1); }
.privacy-mark span { position: relative; width: 38px; height: 34px; margin-top: 12px; border-radius: 9px; background: var(--green-dark); }
.privacy-mark span::before { content: ""; position: absolute; left: 7px; top: -20px; width: 17px; height: 23px; border: 4px solid var(--green-dark); border-bottom: 0; border-radius: 15px 15px 0 0; }
.outline-button { white-space: nowrap; padding: 14px 20px; border: 1px solid rgba(21, 153, 67, .28); border-radius: 14px; background: rgba(255, 255, 255, .7); color: #147c3b; font-size: 14px; font-weight: 750; }

.closing-section { padding: 80px 0 110px; display: flex; flex-direction: column; align-items: center; text-align: center; }
.closing-section img { border-radius: 25px; box-shadow: 0 22px 50px rgba(38, 34, 52, .18); }
.closing-section h2 { max-width: 780px; margin-top: 30px; }
.closing-section p { margin: 16px 0 24px; color: var(--muted); font-size: 17px; }
.site-footer { min-height: 110px; display: flex; align-items: center; gap: 30px; border-top: 1px solid var(--line); color: var(--muted); font-size: 13px; }
.footer-brand { display: flex; align-items: center; gap: 10px; color: var(--ink); font-size: 16px; }
.footer-links { display: flex; gap: 24px; margin-left: auto; }
.footer-links a:hover { color: var(--ink); }

@media (max-width: 980px) {
  .hero { grid-template-columns: 1fr; padding-top: 70px; text-align: center; gap: 30px; }
  .hero-copy { display: flex; flex-direction: column; align-items: center; }
  .hero-visual { min-height: 710px; }
  .trust-row { justify-content: center; }
  .screenshot-row { grid-template-columns: repeat(2, 1fr); max-width: 700px; margin-inline: auto; gap: 42px; }
  .screenshot-row figure:nth-child(even) { transform: translateY(0); }
  .privacy-panel { grid-template-columns: auto 1fr; }
  .privacy-panel .outline-button { grid-column: 2; justify-self: start; }
}

@media (max-width: 720px) {
  .section-shell { width: min(100% - 30px, var(--max)); }
  .site-header { top: 8px; width: calc(100% - 16px); height: 60px; margin-top: 8px; border-radius: 18px; }
  .brand img { width: 38px; height: 38px; }
  .nav-links { display: none; }
  .language-button { margin-left: auto; }
  .hero { min-height: 0; padding: 64px 0 46px; }
  .hero h1 { font-size: clamp(48px, 15vw, 66px); }
  .hero-summary { font-size: 17px; line-height: 1.65; }
  .hero-visual { min-height: 615px; width: 100%; }
  .tone-one { width: 100vw; height: 100vw; }
  .phone-frame { width: 286px; height: 585px; border-radius: 46px; }
  .phone-frame img { border-radius: 36px; }
  .floating-note { min-width: 88px; padding: 11px 13px; font-size: 20px; }
  .note-a { right: -4px; top: 92px; }
  .note-e { left: -4px; bottom: 78px; }
  .proof-strip { grid-template-columns: repeat(2, 1fr); }
  .proof-strip div { min-height: 100px; }
  .proof-strip div:nth-child(2) { border-right: 0; }
  .proof-strip div:nth-child(-n+2) { border-bottom: 1px solid var(--line); }
  .feature-section, .preview-section { padding-block: 86px; }
  .section-heading { margin-bottom: 34px; }
  .section-heading h2, .closing-section h2 { font-size: 38px; }
  .section-heading > p:last-child { font-size: 16px; }
  .feature-grid { grid-template-columns: 1fr; }
  .feature-card { min-height: 292px; padding: 27px; }
  .instrument-section { padding-block: 86px; }
  .instrument-cloud { gap: 9px; }
  .instrument-cloud span { padding: 10px 14px; font-size: 14px; }
  .screenshot-row { display: flex; overflow-x: auto; margin-inline: -15px; padding: 4px 24px 32px; scroll-snap-type: x mandatory; scrollbar-width: none; }
  .screenshot-row::-webkit-scrollbar { display: none; }
  .screenshot-row figure { flex: 0 0 72vw; scroll-snap-align: center; }
  .screenshot-row img { border-width: 6px; border-radius: 31px; }
  .privacy-section { padding-bottom: 70px; }
  .privacy-panel { grid-template-columns: 1fr; gap: 22px; padding: 30px 25px; }
  .privacy-panel .outline-button { grid-column: 1; }
  .privacy-mark { width: 68px; height: 68px; border-radius: 20px; }
  .closing-section { padding: 60px 0 80px; }
  .site-footer { padding: 28px 0; flex-wrap: wrap; justify-content: center; text-align: center; }
  .footer-links { order: 3; width: 100%; margin: 0; justify-content: center; flex-wrap: wrap; gap: 16px 22px; }
}

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