:root {
  --ink: #10131a;
  --muted: #637087;
  --line: #dfe5ef;
  --surface: #ffffff;
  --canvas: #f4f7fc;
  --blue: #245dff;
  --blue-deep: #143fc4;
  --cyan: #12b9d6;
  --green: #14a66f;
  --max-width: 1180px;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  background: var(--canvas);
  color: var(--ink);
  font-family: "PingFang SC", "Noto Sans CJK SC", "Microsoft YaHei", sans-serif;
  letter-spacing: 0;
}

body.menu-open {
  overflow: hidden;
}

a {
  color: inherit;
  text-decoration: none;
}

button {
  font: inherit;
}

img {
  display: block;
  max-width: 100%;
}

svg {
  width: 20px;
  height: 20px;
  stroke-width: 1.8;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 40;
  height: 72px;
  display: flex;
  align-items: center;
  gap: 40px;
  padding: 0 max(24px, calc((100vw - var(--max-width)) / 2));
  border-bottom: 1px solid rgba(223, 229, 239, 0.86);
  background: rgba(244, 247, 252, 0.92);
  backdrop-filter: blur(18px);
}

.brand,
.footer-brand {
  display: flex;
  align-items: center;
  gap: 12px;
}

.brand img,
.footer-brand img {
  width: 38px;
  height: 38px;
  object-fit: cover;
  border-radius: 8px;
}

.brand span,
.footer-brand strong {
  font-size: 18px;
  font-weight: 700;
}

.desktop-nav {
  display: flex;
  align-items: center;
  gap: 32px;
  margin-left: auto;
}

.desktop-nav a,
.footer-links a {
  color: #394459;
  font-size: 14px;
}

.desktop-nav a:hover,
.footer-links a:hover {
  color: var(--blue);
}

.header-action,
.primary-action,
.text-action {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 9px;
  font-weight: 650;
}

.header-action {
  min-height: 42px;
  padding: 0 17px;
  border: 1px solid #cfd7e5;
  border-radius: 6px;
  background: var(--surface);
  font-size: 14px;
}

.menu-button {
  display: none;
  width: 42px;
  height: 42px;
  align-items: center;
  justify-content: center;
  border: 1px solid var(--line);
  border-radius: 6px;
  background: var(--surface);
  color: var(--ink);
}

.mobile-nav {
  display: none;
}

.hero {
  position: relative;
  height: min(780px, calc(100svh - 108px));
  min-height: 620px;
  overflow: hidden;
  border-bottom: 1px solid var(--line);
  background: #edf3ff;
}

.hero::before {
  content: "";
  position: absolute;
  inset: 0 50% 0 0;
  background: #f7f9fd;
}

.hero-copy {
  position: relative;
  z-index: 2;
  width: min(50%, 590px);
  margin-left: max(24px, calc((100vw - var(--max-width)) / 2));
  padding-top: clamp(86px, 12vh, 132px);
}

.eyebrow {
  margin: 0 0 18px;
  color: var(--blue);
  font-size: 14px;
  font-weight: 700;
}

.hero h1 {
  margin: 0;
  font-size: clamp(68px, 7vw, 108px);
  line-height: 1;
  font-weight: 750;
}

.hero-lead {
  max-width: 520px;
  margin: 28px 0 0;
  font-size: clamp(28px, 3vw, 44px);
  line-height: 1.32;
  font-weight: 650;
}

.hero-description {
  max-width: 520px;
  margin: 22px 0 0;
  color: var(--muted);
  font-size: 17px;
  line-height: 1.8;
}

.hero-actions {
  display: flex;
  align-items: center;
  gap: 24px;
  margin-top: 34px;
}

.primary-action {
  min-height: 50px;
  padding: 0 22px;
  border: 1px solid var(--blue);
  border-radius: 6px;
  background: var(--blue);
  color: #ffffff;
  font-size: 15px;
}

.primary-action:hover {
  border-color: var(--blue-deep);
  background: var(--blue-deep);
}

.beta-status {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  color: #526078;
  font-size: 14px;
}

.beta-status span {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--green);
  box-shadow: 0 0 0 5px rgba(20, 166, 111, 0.12);
}

.hero-device {
  position: absolute;
  z-index: 1;
  top: 74px;
  left: calc(50% + 120px);
  width: min(390px, 30vw);
  padding: 10px;
  border-radius: 54px;
  background: #111722;
  box-shadow: 0 32px 80px rgba(25, 61, 128, 0.24);
  transform: rotate(2deg);
}

.hero-device img,
.phone-frame img {
  width: 100%;
  border-radius: 45px;
}

.service-index {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  max-width: var(--max-width);
  margin: 0 auto;
  border-right: 1px solid var(--line);
  border-left: 1px solid var(--line);
  background: var(--surface);
}

.service-index div {
  display: flex;
  align-items: center;
  gap: 16px;
  min-height: 92px;
  padding: 0 28px;
  border-right: 1px solid var(--line);
}

.service-index div:last-child {
  border-right: 0;
}

.service-index strong {
  color: var(--blue);
  font-size: 13px;
}

.service-index span {
  font-size: 16px;
  font-weight: 650;
}

.section {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 120px 0;
}

.section-heading {
  max-width: 660px;
  margin-bottom: 54px;
}

.section-heading h2,
.product-copy h2,
.support-band h2 {
  margin: 0;
  font-size: clamp(34px, 4vw, 54px);
  line-height: 1.18;
}

.section-heading > p:last-child,
.product-copy > p:last-of-type {
  margin: 22px 0 0;
  color: var(--muted);
  font-size: 17px;
  line-height: 1.8;
}

.service-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  border-top: 1px solid var(--line);
  border-left: 1px solid var(--line);
}

.service-item {
  position: relative;
  min-height: 220px;
  display: grid;
  grid-template-columns: 54px 1fr;
  gap: 22px;
  padding: 38px;
  border-right: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
  background: rgba(255, 255, 255, 0.54);
}

.service-item > svg {
  width: 48px;
  height: 48px;
  padding: 11px;
  border: 1px solid #cbd8fa;
  border-radius: 8px;
  color: var(--blue);
  background: #edf3ff;
}

.service-item h3 {
  margin: 2px 0 10px;
  font-size: 24px;
}

.service-item p {
  max-width: 360px;
  margin: 0;
  color: var(--muted);
  line-height: 1.75;
}

.service-item > span {
  position: absolute;
  right: 30px;
  bottom: 25px;
  color: #a3afc2;
  font-size: 13px;
}

.product-section {
  overflow: hidden;
  background: #101725;
  color: #ffffff;
}

.product-inner {
  min-height: 800px;
  display: grid;
  grid-template-columns: 1fr 1fr;
  align-items: center;
  gap: 80px;
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 100px 0;
}

.product-copy .eyebrow {
  color: #80aaff;
}

.product-copy > p:last-of-type {
  max-width: 500px;
  color: #aeb8c8;
}

.product-tabs {
  display: flex;
  flex-direction: column;
  gap: 8px;
  margin-top: 42px;
}

.product-tab {
  min-height: 58px;
  display: flex;
  align-items: center;
  gap: 14px;
  padding: 0 18px;
  border: 1px solid #303b4e;
  border-radius: 6px;
  background: transparent;
  color: #cbd3df;
  text-align: left;
  cursor: pointer;
}

.product-tab.active,
.product-tab:hover {
  border-color: #4878ff;
  background: #1b2c52;
  color: #ffffff;
}

.product-stage {
  height: 660px;
  display: flex;
  align-items: flex-start;
  justify-content: center;
  overflow: hidden;
}

.phone-frame {
  width: 350px;
  padding: 9px;
  border-radius: 49px;
  background: #090d14;
  box-shadow: 0 36px 90px rgba(0, 0, 0, 0.46);
}

.phone-frame img {
  transition: opacity 180ms ease, transform 220ms ease;
}

.phone-frame img.changing {
  opacity: 0;
  transform: translateY(12px);
}

.privacy {
  display: grid;
  grid-template-columns: 0.9fr 1.1fr;
  column-gap: 100px;
}

.privacy-heading {
  margin: 0;
}

.privacy-list {
  border-top: 1px solid var(--line);
}

.privacy-list > div {
  display: grid;
  grid-template-columns: 44px 150px 1fr;
  align-items: center;
  gap: 18px;
  min-height: 116px;
  border-bottom: 1px solid var(--line);
}

.privacy-list svg {
  color: var(--blue);
}

.privacy-list h3,
.privacy-list p {
  margin: 0;
}

.privacy-list h3 {
  font-size: 19px;
}

.privacy-list p {
  color: var(--muted);
  line-height: 1.6;
}

.text-action {
  grid-column: 2;
  justify-self: start;
  margin-top: 30px;
  color: var(--blue);
  font-size: 15px;
}

.faq {
  border-top: 1px solid var(--line);
}

.faq-list {
  border-top: 1px solid var(--line);
}

.faq-list details {
  border-bottom: 1px solid var(--line);
}

.faq-list summary {
  min-height: 82px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  font-size: 19px;
  font-weight: 650;
  cursor: pointer;
  list-style: none;
}

.faq-list summary::-webkit-details-marker {
  display: none;
}

.faq-list details[open] summary svg {
  transform: rotate(45deg);
}

.faq-list p {
  max-width: 760px;
  margin: -4px 0 30px;
  color: var(--muted);
  line-height: 1.8;
}

.support-band {
  min-height: 310px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 48px;
  padding: 70px max(24px, calc((100vw - var(--max-width)) / 2));
  background: var(--blue);
  color: #ffffff;
}

.support-band .eyebrow {
  color: #cbd8ff;
}

.support-band h2 {
  max-width: 760px;
}

.primary-action.light {
  flex: 0 0 auto;
  border-color: #ffffff;
  background: #ffffff;
  color: var(--blue-deep);
}

footer {
  max-width: var(--max-width);
  display: grid;
  grid-template-columns: 1fr auto;
  align-items: center;
  gap: 36px;
  margin: 0 auto;
  padding: 54px 0;
}

.footer-brand div {
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.footer-brand span,
footer > p {
  color: var(--muted);
  font-size: 12px;
}

.footer-links {
  display: flex;
  gap: 24px;
}

footer > p {
  grid-column: 1 / -1;
  margin: 0;
  padding-top: 24px;
  border-top: 1px solid var(--line);
}

@media (max-width: 900px) {
  .site-header {
    height: 64px;
    padding: 0 20px;
  }

  .desktop-nav,
  .header-action {
    display: none;
  }

  .menu-button {
    display: flex;
    margin-left: auto;
  }

  .mobile-nav {
    position: fixed;
    z-index: 35;
    inset: 64px 0 auto;
    display: flex;
    flex-direction: column;
    padding: 18px 20px 24px;
    border-bottom: 1px solid var(--line);
    background: #ffffff;
    transform: translateY(-130%);
    transition: transform 180ms ease;
  }

  .mobile-nav.open {
    transform: translateY(0);
  }

  .mobile-nav a {
    padding: 15px 0;
    border-bottom: 1px solid var(--line);
  }

  .hero {
    height: calc(100svh - 92px);
    min-height: 650px;
  }

  .hero::before {
    inset: 0;
  }

  .hero-copy {
    width: auto;
    margin: 0 20px;
    padding-top: 52px;
  }

  .hero h1 {
    font-size: 64px;
  }

  .hero-lead {
    max-width: 360px;
    font-size: 30px;
  }

  .hero-description {
    max-width: 330px;
    font-size: 15px;
  }

  .hero-device {
    top: auto;
    right: -74px;
    bottom: -310px;
    left: auto;
    width: 310px;
    transform: rotate(5deg);
  }

  .service-index {
    grid-template-columns: repeat(2, 1fr);
    margin: 0 20px;
  }

  .service-index div {
    min-height: 72px;
    padding: 0 16px;
    border-bottom: 1px solid var(--line);
  }

  .section,
  .product-inner,
  footer {
    padding-right: 20px;
    padding-left: 20px;
  }

  .section {
    padding-top: 84px;
    padding-bottom: 84px;
  }

  .service-grid,
  .product-inner,
  .privacy {
    grid-template-columns: 1fr;
  }

  .product-inner {
    gap: 54px;
  }

  .product-stage {
    height: 590px;
  }

  .phone-frame {
    width: 310px;
  }

  .privacy {
    row-gap: 48px;
  }

  .text-action {
    grid-column: 1;
  }

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

@media (max-width: 560px) {
  .hero {
    height: calc(100svh - 84px);
    min-height: 620px;
  }

  .hero h1 {
    font-size: 54px;
  }

  .hero-lead {
    max-width: 330px;
    font-size: 27px;
  }

  .hero-description {
    max-width: 310px;
    margin-top: 16px;
    line-height: 1.65;
  }

  .hero-actions {
    align-items: flex-start;
    flex-direction: column;
    gap: 17px;
    margin-top: 24px;
  }

  .hero-device {
    right: -86px;
    bottom: -330px;
    width: 285px;
  }

  .section-heading h2,
  .product-copy h2,
  .support-band h2 {
    font-size: 36px;
  }

  .service-item {
    min-height: 190px;
    grid-template-columns: 42px 1fr;
    gap: 16px;
    padding: 28px 22px;
  }

  .service-item > svg {
    width: 40px;
    height: 40px;
    padding: 9px;
  }

  .service-item h3 {
    font-size: 21px;
  }

  .privacy-list > div {
    grid-template-columns: 34px 1fr;
    align-items: start;
    gap: 8px 14px;
    padding: 24px 0;
  }

  .privacy-list p {
    grid-column: 2;
  }

  .support-band {
    min-height: 360px;
    padding-top: 64px;
    padding-bottom: 64px;
  }

  footer {
    grid-template-columns: 1fr;
  }

  .footer-links {
    flex-wrap: wrap;
  }
}

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

  *,
  *::before,
  *::after {
    transition-duration: 0.01ms !important;
  }
}