:root {
  --ink: #162429;
  --ink-soft: #41575d;
  --paper: #f6fbf9;
  --white: #ffffff;
  --cyan: #2dbac0;
  --cyan-dark: #16848a;
  --leaf: #7ccb5c;
  --coral: #ff5b67;
  --line: #d7e6e2;
  --shadow: 0 16px 40px rgba(22, 36, 41, 0.12);
  --page: min(1160px, calc(100% - 40px));
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  color: var(--ink);
  background: var(--paper);
  font-family: "Microsoft YaHei", "PingFang SC", Arial, sans-serif;
  font-size: 16px;
  line-height: 1.75;
  letter-spacing: 0;
}

body.menu-open {
  overflow: hidden;
}

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

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

button,
.button {
  font: inherit;
}

.skip-link {
  position: fixed;
  top: 8px;
  left: 8px;
  z-index: 200;
  padding: 8px 12px;
  color: var(--white);
  background: var(--ink);
  transform: translateY(-150%);
}

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

.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  border-bottom: 1px solid rgba(215, 230, 226, 0.85);
  background: rgba(246, 251, 249, 0.96);
  backdrop-filter: blur(14px);
}

.nav-shell {
  width: var(--page);
  min-height: 70px;
  margin: 0 auto;
  display: flex;
  align-items: center;
  gap: 28px;
}

.brand {
  display: inline-flex;
  align-items: center;
  flex: 0 0 auto;
  gap: 10px;
  font-size: 20px;
  font-weight: 800;
}

.brand img {
  width: 42px;
  height: 42px;
  border-radius: 8px;
}

.site-nav {
  margin-left: auto;
  display: flex;
  align-items: center;
  gap: 8px;
}

.site-nav a {
  min-height: 42px;
  padding: 8px 14px;
  display: inline-flex;
  align-items: center;
  border-bottom: 2px solid transparent;
  color: var(--ink-soft);
  font-weight: 700;
}

.site-nav a:hover,
.site-nav a:focus-visible,
.site-nav a[aria-current="page"] {
  color: var(--ink);
  border-color: var(--coral);
}

.button {
  min-height: 46px;
  padding: 10px 22px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  border: 2px solid var(--ink);
  border-radius: 6px;
  color: var(--white);
  background: var(--ink);
  font-weight: 800;
  cursor: pointer;
  box-shadow: 5px 5px 0 var(--cyan);
  transition: transform 160ms ease, box-shadow 160ms ease, background 160ms ease;
}

.button:hover,
.button:focus-visible {
  background: var(--cyan-dark);
  transform: translate(-2px, -2px);
  box-shadow: 7px 7px 0 var(--coral);
}

.button-light {
  color: var(--ink);
  background: var(--white);
  box-shadow: 5px 5px 0 var(--leaf);
}

.button-small {
  min-height: 40px;
  padding: 7px 16px;
}

.menu-toggle {
  width: 44px;
  height: 44px;
  margin-left: auto;
  display: none;
  border: 1px solid var(--line);
  border-radius: 6px;
  color: var(--ink);
  background: var(--white);
  font-size: 24px;
  cursor: pointer;
}

.hero {
  position: relative;
  min-height: 690px;
  overflow: hidden;
  color: var(--white);
  background-color: var(--ink);
  isolation: isolate;
}

.hero::before {
  content: "";
  position: absolute;
  inset: 0;
  z-index: -3;
  background-image: url("../images/preview-player.jpg");
  background-repeat: no-repeat;
  background-position: center;
  background-size: cover;
  filter: grayscale(1) contrast(1.15);
  opacity: 0.24;
}

.hero::after {
  content: "";
  position: absolute;
  inset: 0;
  z-index: -2;
  background: linear-gradient(90deg, rgba(22, 36, 41, 0.98) 0%, rgba(22, 36, 41, 0.88) 50%, rgba(22, 36, 41, 0.48) 100%);
}

.hero-inner {
  width: var(--page);
  min-height: 690px;
  margin: 0 auto;
  display: flex;
  align-items: center;
}

.hero-copy {
  position: relative;
  z-index: 3;
  width: min(620px, 58%);
  padding: 74px 0 90px;
}

.eyebrow {
  margin: 0 0 16px;
  color: var(--leaf);
  font-weight: 800;
}

.hero h1 {
  margin: 0 0 22px;
  max-width: 560px;
  font-size: clamp(44px, 6vw, 70px);
  line-height: 1.06;
  letter-spacing: 0;
  word-break: break-all;
}

.hero-lead {
  max-width: 580px;
  margin: 0 0 30px;
  color: #d9e9e5;
  font-size: 19px;
  line-height: 1.8;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
}

.hero-note {
  margin: 20px 0 0;
  color: #b7d1cb;
  font-size: 14px;
}

.hero-phone {
  position: absolute;
  right: max(5vw, calc((100vw - 1160px) / 2));
  bottom: -62px;
  z-index: 2;
  width: min(300px, 28vw);
  max-width: 400px;
  border: 8px solid #0d1619;
  border-radius: 28px;
  box-shadow: 24px 30px 0 rgba(45, 186, 192, 0.4), var(--shadow);
  transform: rotate(3deg);
}

.fact-strip {
  position: relative;
  z-index: 4;
  width: var(--page);
  margin: -38px auto 0;
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  border: 2px solid var(--ink);
  background: var(--white);
  box-shadow: 8px 8px 0 var(--leaf);
}

.fact {
  min-height: 92px;
  padding: 16px 22px;
  display: flex;
  flex-direction: column;
  justify-content: center;
  border-right: 1px solid var(--line);
}

.fact:last-child {
  border-right: 0;
}

.fact strong {
  font-size: 20px;
  line-height: 1.35;
}

.fact span {
  color: var(--ink-soft);
  font-size: 13px;
}

.section {
  padding: 94px 0;
}

.section-tight {
  padding: 68px 0;
}

.section-dark {
  color: var(--white);
  background: var(--ink);
}

.section-cyan {
  background: #dff5f3;
}

.section-white {
  background: var(--white);
}

.container {
  width: var(--page);
  margin: 0 auto;
}

.section-heading {
  margin: 0 0 42px;
  display: flex;
  align-items: flex-end;
  justify-content: space-between;
  gap: 24px;
}

.section-heading h2,
.content-title h1 {
  margin: 0;
  max-width: 780px;
  font-size: clamp(32px, 5vw, 54px);
  line-height: 1.16;
  letter-spacing: 0;
}

.section-heading .index {
  color: var(--coral);
  font-size: 14px;
  font-weight: 800;
}

.section-heading .aside {
  max-width: 360px;
  margin: 0;
  color: var(--ink-soft);
}

.section-dark .section-heading .aside {
  color: #b7d1cb;
}

.feature-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 18px;
}

.feature-item {
  min-height: 240px;
  padding: 28px;
  border: 1px solid var(--line);
  border-top: 5px solid var(--cyan);
  border-radius: 6px;
  background: var(--white);
}

.feature-item:nth-child(2) {
  border-top-color: var(--leaf);
}

.feature-item:nth-child(3) {
  border-top-color: var(--coral);
}

.feature-item:nth-child(4) {
  border-top-color: var(--ink);
}

.feature-number {
  display: block;
  margin-bottom: 30px;
  color: var(--cyan-dark);
  font-family: Consolas, monospace;
  font-size: 14px;
  font-weight: 700;
}

.feature-item h3 {
  margin: 0 0 10px;
  font-size: 21px;
}

.feature-item p {
  margin: 0;
  color: var(--ink-soft);
}

.screenshot-track {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 24px;
}

.shot {
  margin: 0;
}

.shot img {
  width: 100%;
  max-width: 300px;
  margin: 0 auto;
  border: 6px solid #0d1619;
  border-radius: 24px;
  box-shadow: 14px 16px 0 rgba(45, 186, 192, 0.3);
}

.shot figcaption {
  max-width: 300px;
  margin: 20px auto 0;
  color: #d9e9e5;
}

.shot figcaption strong {
  display: block;
  color: var(--white);
  font-size: 18px;
}

.route-list {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0 48px;
  border-top: 2px solid var(--ink);
}

.route-item {
  padding: 30px 0;
  display: grid;
  grid-template-columns: 58px 1fr;
  gap: 20px;
  border-bottom: 1px solid var(--line);
}

.route-mark {
  width: 52px;
  height: 52px;
  display: grid;
  place-items: center;
  border: 2px solid var(--ink);
  border-radius: 50%;
  color: var(--ink);
  background: var(--leaf);
  font-weight: 900;
}

.route-item h3 {
  margin: 0 0 6px;
  font-size: 20px;
}

.route-item p {
  margin: 0;
  color: var(--ink-soft);
}

.deep-links {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 24px;
}

.deep-link {
  min-height: 310px;
  padding: 38px;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  border: 2px solid var(--ink);
  border-radius: 6px;
  background: var(--white);
  box-shadow: 8px 8px 0 var(--cyan);
}

.deep-link:nth-child(2) {
  box-shadow: 8px 8px 0 var(--coral);
}

.deep-link .tag {
  color: var(--cyan-dark);
  font-size: 13px;
  font-weight: 800;
}

.deep-link h3 {
  margin: 20px 0 12px;
  font-size: 32px;
  line-height: 1.25;
}

.deep-link p {
  margin: 0;
  color: var(--ink-soft);
}

.text-link {
  margin-top: 34px;
  color: var(--ink);
  font-weight: 900;
}

.text-link:hover,
.text-link:focus-visible {
  color: var(--coral);
}

.reviews {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
}

.review {
  margin: 0;
  padding: 28px;
  border-left: 5px solid var(--coral);
  background: var(--white);
}

.review blockquote {
  margin: 0 0 20px;
  font-size: 17px;
}

.review figcaption {
  color: var(--ink-soft);
  font-size: 14px;
}

.faq-list {
  border-top: 2px solid var(--ink);
}

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

.faq-list summary {
  position: relative;
  padding: 24px 56px 24px 0;
  list-style: none;
  font-size: 19px;
  font-weight: 800;
  cursor: pointer;
}

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

.faq-list summary::after {
  content: "+";
  position: absolute;
  top: 18px;
  right: 8px;
  width: 34px;
  height: 34px;
  display: grid;
  place-items: center;
  border: 1px solid var(--ink);
  border-radius: 50%;
}

.faq-list details[open] summary::after {
  content: "−";
  background: var(--leaf);
}

.faq-answer {
  max-width: 880px;
  padding: 0 56px 24px 0;
  color: var(--ink-soft);
}

.faq-answer p {
  margin: 0 0 12px;
}

.download-band {
  padding: 72px 0;
  color: var(--white);
  background: var(--coral);
}

.download-band .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 32px;
}

.download-band h2 {
  margin: 0 0 8px;
  font-size: clamp(30px, 4vw, 48px);
  line-height: 1.2;
}

.download-band p {
  margin: 0;
  color: #fff4f5;
}

.content-hero {
  padding: 88px 0 64px;
  color: var(--white);
  background: var(--ink);
}

.content-title {
  width: var(--page);
  margin: 0 auto;
}

.content-title .eyebrow {
  margin-bottom: 12px;
}

.content-title .lead {
  max-width: 760px;
  margin: 22px 0 0;
  color: #c5dad5;
  font-size: 18px;
}

.anchor-bar {
  border-bottom: 1px solid var(--line);
  background: var(--white);
}

.anchor-bar .container {
  min-height: 62px;
  display: flex;
  align-items: center;
  gap: 8px;
  overflow-x: auto;
}

.anchor-bar a {
  flex: 0 0 auto;
  padding: 8px 14px;
  border: 1px solid var(--line);
  border-radius: 6px;
  font-weight: 700;
}

.anchor-bar a:hover,
.anchor-bar a:focus-visible {
  border-color: var(--coral);
  color: var(--coral);
}

.guide-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 320px;
  gap: 64px;
  align-items: start;
}

.steps {
  counter-reset: guide-step;
}

.step {
  position: relative;
  padding: 0 0 48px 78px;
  counter-increment: guide-step;
}

.step::before {
  content: counter(guide-step, decimal-leading-zero);
  position: absolute;
  top: 0;
  left: 0;
  width: 54px;
  height: 54px;
  display: grid;
  place-items: center;
  border: 2px solid var(--ink);
  border-radius: 50%;
  color: var(--ink);
  background: var(--cyan);
  font-weight: 900;
}

.step::after {
  content: "";
  position: absolute;
  top: 58px;
  bottom: 4px;
  left: 26px;
  width: 2px;
  background: var(--line);
}

.step:last-child::after {
  display: none;
}

.step h2 {
  margin: 0 0 12px;
  font-size: 28px;
}

.step p {
  margin: 0 0 12px;
  color: var(--ink-soft);
}

.step ul,
.check-list {
  margin: 14px 0 0;
  padding: 0;
  list-style: none;
}

.step li,
.check-list li {
  position: relative;
  padding: 7px 0 7px 24px;
}

.step li::before,
.check-list li::before {
  content: "";
  position: absolute;
  top: 17px;
  left: 0;
  width: 9px;
  height: 9px;
  background: var(--leaf);
  transform: rotate(45deg);
}

.side-panel {
  position: sticky;
  top: 96px;
  padding: 28px;
  border: 2px solid var(--ink);
  border-radius: 6px;
  background: var(--white);
  box-shadow: 7px 7px 0 var(--leaf);
}

.side-panel h2 {
  margin: 0 0 14px;
  font-size: 22px;
}

.side-panel p {
  margin: 0 0 18px;
  color: var(--ink-soft);
}

.side-panel .button {
  width: 100%;
}

.content-block {
  margin-bottom: 54px;
}

.content-block h2 {
  margin: 0 0 22px;
  font-size: 32px;
  line-height: 1.3;
}

.content-block h3 {
  margin: 26px 0 8px;
  font-size: 21px;
}

.content-block p {
  margin: 0 0 15px;
  color: var(--ink-soft);
}

.feature-detail-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 18px;
}

.feature-detail {
  padding: 26px;
  border: 1px solid var(--line);
  border-radius: 6px;
  background: var(--white);
}

.feature-detail h3 {
  margin-top: 0;
}

.notice {
  padding: 24px;
  border-left: 5px solid var(--coral);
  background: #fff0f2;
}

.notice strong {
  display: block;
  margin-bottom: 6px;
}

.site-footer {
  padding: 52px 0 30px;
  color: #bfd0cc;
  background: #0d171a;
}

.footer-grid {
  display: grid;
  grid-template-columns: 1.3fr 1fr 1fr;
  gap: 48px;
}

.footer-brand {
  color: var(--white);
}

.footer-title {
  margin: 0 0 14px;
  color: var(--white);
  font-weight: 800;
}

.footer-links {
  display: grid;
  gap: 8px;
}

.footer-links a:hover,
.footer-links a:focus-visible {
  color: var(--leaf);
}

.disclaimer {
  margin: 34px 0 0;
  padding-top: 24px;
  border-top: 1px solid #2b3d42;
  font-size: 13px;
}

.copyright {
  margin: 8px 0 0;
  font-size: 13px;
}

.back-top {
  position: fixed;
  right: 22px;
  bottom: 22px;
  z-index: 80;
  width: 46px;
  height: 46px;
  display: grid;
  place-items: center;
  border: 2px solid var(--ink);
  border-radius: 50%;
  color: var(--ink);
  background: var(--leaf);
  font-size: 22px;
  cursor: pointer;
  opacity: 0;
  pointer-events: none;
  transform: translateY(10px);
  transition: opacity 160ms ease, transform 160ms ease;
}

.back-top.visible {
  opacity: 1;
  pointer-events: auto;
  transform: translateY(0);
}

:focus-visible {
  outline: 3px solid var(--coral);
  outline-offset: 3px;
}

@media (max-width: 980px) {
  .site-nav {
    position: fixed;
    top: 70px;
    right: 0;
    bottom: 0;
    width: min(340px, 88vw);
    padding: 26px;
    flex-direction: column;
    align-items: stretch;
    background: var(--white);
    box-shadow: -18px 0 40px rgba(22, 36, 41, 0.16);
    transform: translateX(110%);
    transition: transform 180ms ease;
  }

  .site-nav.open {
    transform: translateX(0);
  }

  .site-nav a {
    min-height: 52px;
    border-bottom: 1px solid var(--line);
  }

  .menu-toggle {
    display: grid;
    place-items: center;
  }

  .header-download {
    display: none;
  }

  .hero-copy {
    width: 68%;
  }

  .hero-phone {
    right: 2vw;
    width: 26vw;
  }

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

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

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

  .side-panel {
    position: static;
  }
}

@media (max-width: 720px) {
  :root {
    --page: min(100% - 28px, 1160px);
  }

  .nav-shell {
    min-height: 64px;
  }

  .site-nav {
    top: 64px;
  }

  .brand {
    font-size: 18px;
  }

  .brand img {
    width: 38px;
    height: 38px;
  }

  .hero,
  .hero-inner {
    min-height: 680px;
  }

  .hero::after {
    background: rgba(22, 36, 41, 0.9);
  }

  .hero-inner {
    align-items: flex-start;
  }

  .hero-copy {
    width: 100%;
    padding: 64px 0 300px;
  }

  .hero h1 {
    font-size: 42px;
  }

  .hero-lead {
    font-size: 17px;
  }

  .hero-phone {
    right: 50%;
    bottom: -110px;
    width: 210px;
    transform: translateX(50%) rotate(2deg);
  }

  .fact-strip {
    margin-top: 0;
    grid-template-columns: 1fr 1fr;
  }

  .fact:nth-child(2) {
    border-right: 0;
  }

  .fact:nth-child(-n + 2) {
    border-bottom: 1px solid var(--line);
  }

  .section,
  .section-tight {
    padding: 66px 0;
  }

  .section-heading {
    margin-bottom: 30px;
    align-items: flex-start;
    flex-direction: column;
  }

  .section-heading h2,
  .content-title h1 {
    font-size: 37px;
  }

  .feature-grid,
  .screenshot-track,
  .route-list,
  .deep-links,
  .reviews,
  .feature-detail-grid,
  .footer-grid {
    grid-template-columns: 1fr;
  }

  .screenshot-track {
    gap: 44px;
  }

  .route-list {
    gap: 0;
  }

  .deep-link {
    min-height: 260px;
    padding: 28px;
  }

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

  .guide-grid {
    gap: 40px;
  }

  .step {
    padding-left: 66px;
  }

  .step h2 {
    font-size: 24px;
  }
}

@media (max-width: 380px) {
  .hero h1 {
    font-size: 36px;
  }
}

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    scroll-behavior: auto !important;
    transition: none !important;
  }
}