:root {
  --teal-950: #0d302d;
  --teal-900: #123f3b;
  --teal-800: #18554f;
  --teal-700: #1f6f68;
  --teal-600: #27837a;
  --teal-200: #b7ded5;
  --teal-100: #dff3ee;
  --teal-050: #f0f9f6;
  --cream: #f8f6ef;
  --paper: #fffefa;
  --ink: #172522;
  --muted: #52645f;
  --line: #cddbd7;
  --warm: #fff2d8;
  --warm-line: #d99b32;
  --danger: #8a382f;
  --danger-bg: #fff1ee;
  --focus: #ffbf47;
  --shadow: 0 18px 50px rgba(18, 63, 59, 0.11);
  --radius-lg: 28px;
  --radius-md: 18px;
  --radius-sm: 12px;
  --content: 1120px;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  color: var(--ink);
  background: var(--cream);
  font-family: -apple-system, BlinkMacSystemFont, "SF Pro Text", "PingFang SC", "Microsoft YaHei", sans-serif;
  font-size: 17px;
  line-height: 1.75;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

a {
  color: var(--teal-800);
  text-decoration-thickness: 1.5px;
  text-underline-offset: 0.2em;
}

a:hover {
  color: var(--teal-950);
}

a:focus-visible,
button:focus-visible,
[tabindex]:focus-visible {
  outline: 4px solid var(--focus);
  outline-offset: 4px;
  border-radius: 6px;
}

.skip-link {
  position: fixed;
  z-index: 1000;
  top: 12px;
  left: 12px;
  padding: 10px 16px;
  color: var(--teal-950);
  background: var(--focus);
  border-radius: 8px;
  font-weight: 800;
  transform: translateY(-160%);
  transition: transform 160ms ease;
}

.skip-link:focus {
  transform: translateY(0);
}

.shell {
  width: min(calc(100% - 40px), var(--content));
  margin-inline: auto;
}

.site-header {
  position: sticky;
  z-index: 100;
  top: 0;
  color: #fff;
  background: rgba(13, 48, 45, 0.96);
  border-bottom: 1px solid rgba(255, 255, 255, 0.16);
  backdrop-filter: blur(14px);
}

.header-inner {
  min-height: 76px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
}

.brand {
  min-height: 44px;
  display: inline-flex;
  align-items: center;
  gap: 11px;
  color: #fff;
  text-decoration: none;
  font-size: 19px;
  font-weight: 800;
  letter-spacing: 0.02em;
}

.brand-mark {
  width: 40px;
  height: 40px;
  display: grid;
  place-items: center;
  color: var(--teal-950);
  background: var(--teal-100);
  border-radius: 12px;
  font-size: 22px;
}

.brand-app-icon {
  width: 40px;
  height: 40px;
  flex: 0 0 40px;
  object-fit: cover;
  border-radius: 12px;
  box-shadow: 0 5px 15px rgba(0, 0, 0, 0.2);
}

.brand small {
  display: block;
  color: var(--teal-200);
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.08em;
}

.site-nav {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  justify-content: flex-end;
  gap: 4px;
}

.site-nav a {
  min-height: 44px;
  display: inline-flex;
  align-items: center;
  padding: 8px 13px;
  color: #e5f2ef;
  border-radius: 10px;
  text-decoration: none;
  font-size: 15px;
  font-weight: 650;
}

.site-nav a:hover,
.site-nav a[aria-current="page"] {
  color: #fff;
  background: rgba(255, 255, 255, 0.12);
}

main:focus {
  outline: none;
}

.hero {
  position: relative;
  overflow: hidden;
  padding: 78px 0 66px;
  color: #fff;
  background:
    radial-gradient(circle at 88% 18%, rgba(183, 222, 213, 0.24), transparent 30%),
    linear-gradient(135deg, var(--teal-950) 0%, var(--teal-700) 100%);
}

.hero::after {
  content: "";
  position: absolute;
  right: -120px;
  bottom: -190px;
  width: 520px;
  height: 520px;
  border: 80px solid rgba(255, 255, 255, 0.06);
  border-radius: 50%;
}

.hero-grid {
  position: relative;
  z-index: 1;
  display: grid;
  grid-template-columns: minmax(0, 1.25fr) minmax(280px, 0.75fr);
  align-items: center;
  gap: 58px;
}

.eyebrow {
  margin: 0 0 14px;
  color: var(--teal-200);
  font-size: 15px;
  font-weight: 800;
  letter-spacing: 0.12em;
}

.hero h1,
.page-hero h1 {
  margin: 0;
  color: #fff;
  font-size: clamp(48px, 8vw, 82px);
  line-height: 1.05;
  letter-spacing: -0.05em;
}

.hero-lead {
  max-width: 700px;
  margin: 22px 0 0;
  color: #eff9f6;
  font-size: clamp(22px, 3.3vw, 32px);
  line-height: 1.45;
  font-weight: 720;
}

.hero-copy {
  max-width: 680px;
  margin: 18px 0 0;
  color: #d5e9e4;
  font-size: 18px;
}

.badge-row {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 28px;
}

.badge {
  min-height: 40px;
  display: inline-flex;
  align-items: center;
  padding: 7px 13px;
  color: var(--teal-950);
  background: var(--teal-100);
  border: 1px solid rgba(255, 255, 255, 0.4);
  border-radius: 999px;
  font-size: 14px;
  font-weight: 800;
}

.hero-art {
  min-height: 320px;
  display: grid;
  place-items: center;
}

.sound-orbit {
  position: relative;
  width: min(310px, 72vw);
  aspect-ratio: 1;
  display: grid;
  place-items: center;
  border: 1px solid rgba(255, 255, 255, 0.18);
  border-radius: 50%;
  box-shadow: inset 0 0 0 34px rgba(255, 255, 255, 0.035), inset 0 0 0 78px rgba(255, 255, 255, 0.025);
}

.sound-orbit::before,
.sound-orbit::after {
  content: "";
  position: absolute;
  width: 70%;
  height: 70%;
  border: 2px solid rgba(223, 243, 238, 0.45);
  border-left-color: transparent;
  border-radius: 50%;
  transform: rotate(-18deg);
}

.sound-orbit::after {
  width: 45%;
  height: 45%;
  border-width: 3px;
}

.hero-app-icon {
  position: relative;
  z-index: 2;
  width: min(174px, 48vw);
  height: auto;
  aspect-ratio: 1;
  object-fit: cover;
  border-radius: 25%;
  box-shadow: 0 22px 45px rgba(0, 0, 0, 0.2);
}

.section {
  padding: 76px 0;
}

.section.alt {
  background: var(--paper);
  border-block: 1px solid var(--line);
}

.section-heading {
  max-width: 760px;
  margin-bottom: 34px;
}

.kicker {
  display: block;
  margin-bottom: 9px;
  color: var(--teal-700);
  font-size: 14px;
  font-weight: 850;
  letter-spacing: 0.12em;
}

h2,
h3 {
  color: var(--teal-950);
  line-height: 1.3;
}

h2 {
  margin: 0;
  font-size: clamp(31px, 4.8vw, 46px);
  letter-spacing: -0.035em;
}

h3 {
  margin: 0 0 10px;
  font-size: 22px;
}

p {
  margin: 0 0 1em;
}

.lede {
  margin-top: 13px;
  color: var(--muted);
  font-size: 19px;
}

.steps,
.feature-grid,
.facts-grid {
  display: grid;
  gap: 20px;
}

.steps {
  grid-template-columns: repeat(3, 1fr);
}

.step,
.feature,
.fact-card,
.faq-item {
  background: var(--paper);
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
  box-shadow: 0 8px 26px rgba(18, 63, 59, 0.055);
}

.step {
  padding: 27px;
}

.step-number {
  width: 48px;
  height: 48px;
  display: grid;
  place-items: center;
  margin-bottom: 19px;
  color: #fff;
  background: var(--teal-700);
  border-radius: 15px;
  font-size: 20px;
  font-weight: 850;
}

.step p,
.feature p,
.fact-card p,
.faq-item p {
  color: var(--muted);
}

.feature-grid {
  grid-template-columns: repeat(2, 1fr);
}

.feature {
  display: grid;
  grid-template-columns: 50px 1fr;
  gap: 18px;
  padding: 26px;
}

.feature-icon {
  width: 50px;
  height: 50px;
  display: grid;
  place-items: center;
  color: var(--teal-950);
  background: var(--teal-100);
  border-radius: 15px;
  font-size: 25px;
}

.feature p {
  margin: 0;
}

.privacy-band {
  padding: 42px;
  color: #fff;
  background: linear-gradient(135deg, var(--teal-950), var(--teal-800));
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow);
}

.privacy-band h2 {
  color: #fff;
}

.privacy-band .lede {
  color: #d4eae5;
}

.privacy-points {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 12px;
  margin-top: 26px;
}

.privacy-point {
  min-height: 92px;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 15px;
  text-align: center;
  background: rgba(255, 255, 255, 0.09);
  border: 1px solid rgba(255, 255, 255, 0.14);
  border-radius: var(--radius-sm);
  font-weight: 750;
}

.notice-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 20px;
}

.notice {
  padding: 26px 27px;
  background: var(--warm);
  border: 1px solid #f0d3a0;
  border-left: 5px solid var(--warm-line);
  border-radius: var(--radius-sm);
}

.notice.danger {
  background: var(--danger-bg);
  border-color: #edc5bf;
  border-left-color: var(--danger);
}

.notice p:last-child,
.legal-copy p:last-child,
.faq-item p:last-child {
  margin-bottom: 0;
}

.cta {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 32px;
  padding: 38px 42px;
  background: var(--teal-100);
  border: 1px solid var(--teal-200);
  border-radius: var(--radius-lg);
}

.cta h2 {
  font-size: clamp(27px, 4vw, 38px);
}

.button {
  min-height: 52px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 12px 22px;
  color: #fff;
  background: var(--teal-800);
  border: 2px solid var(--teal-800);
  border-radius: 13px;
  text-decoration: none;
  font-weight: 800;
  white-space: nowrap;
}

.button:hover {
  color: #fff;
  background: var(--teal-950);
  border-color: var(--teal-950);
}

.page-hero {
  padding: 62px 0 54px;
  color: #fff;
  background: linear-gradient(135deg, var(--teal-950), var(--teal-700));
}

.page-hero h1 {
  font-size: clamp(38px, 6vw, 64px);
}

.page-hero p {
  max-width: 780px;
  margin: 16px 0 0;
  color: #d9ebe7;
  font-size: 18px;
}

.document-layout {
  display: grid;
  grid-template-columns: 230px minmax(0, 1fr);
  gap: 54px;
  align-items: start;
}

.document-nav {
  position: sticky;
  top: 104px;
  padding: 20px;
  background: var(--paper);
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
}

.document-nav strong {
  display: block;
  margin-bottom: 9px;
  color: var(--teal-950);
}

.document-nav a {
  min-height: 44px;
  display: flex;
  align-items: center;
  padding: 6px 8px;
  border-radius: 8px;
  text-decoration: none;
  font-size: 15px;
}

.legal-copy {
  max-width: 800px;
}

.legal-copy section {
  padding-top: 7px;
  margin-bottom: 46px;
  scroll-margin-top: 110px;
}

.legal-copy h2 {
  margin-bottom: 16px;
  font-size: clamp(27px, 4vw, 36px);
}

.legal-copy h3 {
  margin-top: 25px;
}

.legal-copy ul,
.check-list {
  padding-left: 1.2em;
}

.legal-copy li,
.check-list li {
  margin-bottom: 8px;
}

.meta-line {
  display: flex;
  flex-wrap: wrap;
  gap: 10px 24px;
  margin-top: 22px;
  color: #e2f0ed;
  font-size: 15px;
}

.facts-grid {
  grid-template-columns: repeat(3, 1fr);
  margin-bottom: 42px;
}

.fact-card {
  padding: 23px;
}

.fact-label {
  display: block;
  margin-bottom: 7px;
  color: var(--teal-700);
  font-size: 13px;
  font-weight: 850;
  letter-spacing: 0.09em;
}

.faq-list {
  display: grid;
  gap: 16px;
}

.faq-item {
  padding: 26px 28px;
  scroll-margin-top: 110px;
}

.site-footer {
  padding: 52px 0 28px;
  color: #d8e8e4;
  background: var(--teal-950);
}

.footer-grid {
  display: grid;
  grid-template-columns: minmax(250px, 1.4fr) repeat(2, minmax(160px, 0.6fr));
  gap: 42px;
}

.site-footer h2,
.site-footer h3 {
  color: #fff;
  font-size: 18px;
}

.site-footer p {
  color: #bcd1cc;
}

.site-footer a {
  min-height: 44px;
  display: flex;
  align-items: center;
  color: #d8e8e4;
}

.copyright {
  margin-top: 36px;
  padding-top: 22px;
  color: #9db8b2;
  border-top: 1px solid rgba(255, 255, 255, 0.13);
  font-size: 14px;
}

.copyright a {
  min-height: 44px;
  display: inline-flex;
  color: #b9d0cb;
}

@media (max-width: 900px) {
  .hero-grid {
    grid-template-columns: 1fr;
    gap: 28px;
  }

  .hero-art {
    min-height: 230px;
  }

  .sound-orbit {
    width: 230px;
  }

  .steps,
  .facts-grid {
    grid-template-columns: 1fr;
  }

  .privacy-points {
    grid-template-columns: repeat(2, 1fr);
  }

  .document-layout {
    grid-template-columns: 1fr;
    gap: 28px;
  }

  .document-nav {
    position: static;
  }
}

@media (max-width: 760px) {
  body {
    font-size: 16px;
  }

  .shell {
    width: min(calc(100% - 28px), var(--content));
  }

  .header-inner {
    min-height: auto;
    padding: 12px 0 10px;
    align-items: flex-start;
    flex-direction: column;
    gap: 7px;
  }

  .brand small {
    display: none;
  }

  .site-nav {
    width: 100%;
    flex-wrap: nowrap;
    justify-content: flex-start;
    overflow-x: auto;
    padding-bottom: 3px;
    scrollbar-width: thin;
  }

  .site-nav a {
    flex: 0 0 auto;
    padding-inline: 10px;
  }

  .hero {
    padding: 54px 0 48px;
  }

  .hero h1 {
    font-size: clamp(48px, 18vw, 72px);
  }

  .section {
    padding: 56px 0;
  }

  .feature-grid,
  .notice-grid {
    grid-template-columns: 1fr;
  }

  .privacy-band,
  .cta {
    padding: 28px 24px;
  }

  .cta {
    align-items: flex-start;
    flex-direction: column;
  }

  .footer-grid {
    grid-template-columns: 1fr;
    gap: 24px;
  }
}

@media (max-width: 480px) {
  .hero-art {
    min-height: 190px;
  }

  .sound-orbit {
    width: 185px;
  }

  .hero-app-icon {
    width: 112px;
  }

  .privacy-points {
    grid-template-columns: 1fr;
  }

  .feature {
    grid-template-columns: 1fr;
  }

  .page-hero {
    padding: 42px 0 38px;
  }
}

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    scroll-behavior: auto !important;
    transition-duration: 0.01ms !important;
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
  }
}

@media print {
  .site-header,
  .document-nav,
  .site-footer,
  .skip-link {
    display: none;
  }

  body {
    color: #000;
    background: #fff;
    font-size: 12pt;
  }

  .section {
    padding: 24px 0;
  }

  .document-layout {
    display: block;
  }
}

/* mobile nav scrollbar hidden */
@media (max-width:760px){.site-nav{scrollbar-width:none}.site-nav::-webkit-scrollbar{display:none}}