:root {
  --brand: #991b2f;
  --brand-dark: #641120;
  --ink: #211d20;
  --muted: #675f63;
  --paper: #ffffff;
  --soft: #f4f1f2;
  --line: #ded8db;
  --accent: #176f68;
  --accent-soft: #e2f1ef;
  --warning: #c68a24;
  --shadow: 0 16px 42px rgba(52, 30, 36, 0.12);
  --container: min(1120px, calc(100% - 40px));
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  color: var(--ink);
  background: var(--paper);
  font-family: -apple-system, BlinkMacSystemFont, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "微软雅黑", Arial, Helvetica, sans-serif;
  line-height: 1.7;
}

body.menu-open {
  overflow: hidden;
}

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

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

button,
input {
  font: inherit;
}

button,
a {
  -webkit-tap-highlight-color: transparent;
}

.skip-link {
  position: fixed;
  top: 8px;
  left: 8px;
  z-index: 100;
  padding: 8px 12px;
  color: #fff;
  background: var(--ink);
  transform: translateY(-150%);
}

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

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

.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  height: 70px;
  border-bottom: 1px solid rgba(153, 27, 47, 0.16);
  background: rgba(255, 255, 255, 0.96);
  backdrop-filter: blur(14px);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 100%;
}

.brand-lockup {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  min-width: 112px;
  font-size: 1.08rem;
  font-weight: 800;
}

.brand-lockup img {
  width: 38px;
  height: 38px;
  border-radius: 7px;
}

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

.site-nav a {
  padding: 8px 13px;
  color: var(--muted);
  font-size: 0.95rem;
  font-weight: 650;
}

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

.site-nav .nav-download {
  margin-left: 8px;
  padding: 8px 18px;
  color: #fff;
  border-radius: 5px;
  background: var(--brand);
}

.site-nav .nav-download:hover,
.site-nav .nav-download:focus-visible {
  color: #fff;
  background: var(--brand-dark);
}

.menu-toggle {
  display: none;
  width: 42px;
  height: 42px;
  border: 1px solid var(--line);
  border-radius: 5px;
  color: var(--ink);
  background: #fff;
  cursor: pointer;
  font-size: 1.45rem;
  line-height: 1;
}

.hero {
  overflow: hidden;
  border-bottom: 1px solid var(--line);
  background:
    linear-gradient(90deg, rgba(153, 27, 47, 0.05) 1px, transparent 1px),
    linear-gradient(rgba(153, 27, 47, 0.05) 1px, transparent 1px),
    #fff;
  background-size: 34px 34px;
}

.hero-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(330px, 0.76fr);
  align-items: center;
  gap: clamp(40px, 7vw, 86px);
  min-height: min(650px, calc(100svh - 118px));
  padding: 44px 0;
}

.eyebrow,
.section-index {
  display: block;
  color: var(--brand);
  font-size: 0.76rem;
  font-weight: 800;
  letter-spacing: 0;
  text-transform: uppercase;
}

.hero h1,
.page-hero h1 {
  max-width: 700px;
  margin: 10px 0 18px;
  font-size: clamp(2.35rem, 5.3vw, 4.8rem);
  line-height: 1.08;
  letter-spacing: 0;
}

.hero-lead {
  max-width: 660px;
  margin: 0;
  color: #4f474b;
  font-size: clamp(1rem, 1.4vw, 1.18rem);
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 28px;
}

.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 48px;
  padding: 10px 22px;
  border: 1px solid transparent;
  border-radius: 5px;
  font-weight: 800;
  cursor: pointer;
  transition: transform 160ms ease, background 160ms ease, border-color 160ms ease;
}

.button:hover {
  transform: translateY(-2px);
}

.button-primary {
  color: #fff;
  background: var(--brand);
  box-shadow: 0 12px 28px rgba(153, 27, 47, 0.24);
}

.button-primary:hover,
.button-primary:focus-visible {
  background: var(--brand-dark);
}

.button-secondary {
  border-color: var(--ink);
  color: var(--ink);
  background: #fff;
}

.hero-points {
  display: flex;
  flex-wrap: wrap;
  gap: 10px 18px;
  padding: 0;
  margin: 26px 0 0;
  color: var(--muted);
  list-style: none;
  font-size: 0.9rem;
}

.hero-points li::before {
  content: "";
  display: inline-block;
  width: 7px;
  height: 7px;
  margin-right: 8px;
  border-radius: 50%;
  background: var(--accent);
  vertical-align: 1px;
}

.hero-media {
  position: relative;
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 510px;
}

.hero-media::before {
  position: absolute;
  width: 82%;
  height: 78%;
  border: 1px solid rgba(23, 111, 104, 0.35);
  background: var(--accent-soft);
  content: "";
  transform: rotate(4deg);
}

.hero-media img {
  position: relative;
  width: min(320px, 84%);
  height: 500px;
  border: 8px solid #191719;
  border-radius: 28px;
  object-fit: cover;
  object-position: top;
  box-shadow: var(--shadow);
}

.snapshot-label {
  position: absolute;
  right: 2%;
  bottom: 9%;
  z-index: 2;
  max-width: 160px;
  padding: 10px 12px;
  border-left: 4px solid var(--brand);
  color: var(--ink);
  background: #fff;
  box-shadow: 0 8px 24px rgba(32, 24, 27, 0.13);
  font-size: 0.8rem;
  font-weight: 750;
  line-height: 1.45;
}

.route-strip {
  color: #fff;
  background: var(--ink);
}

.route-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  min-height: 112px;
}

.route-item {
  display: flex;
  align-items: center;
  gap: 14px;
  padding: 20px 24px;
  border-right: 1px solid rgba(255, 255, 255, 0.15);
}

.route-item:last-child {
  border-right: 0;
}

.route-number {
  color: #78c7c0;
  font-size: 1.45rem;
  font-weight: 900;
}

.route-item strong {
  display: block;
  font-size: 0.95rem;
}

.route-item span:last-child {
  color: rgba(255, 255, 255, 0.68);
  font-size: 0.78rem;
}

.section {
  padding: 88px 0;
}

.section-soft {
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
  background: var(--soft);
}

.section-accent {
  color: #fff;
  background: var(--accent);
}

.section-heading {
  display: grid;
  grid-template-columns: 0.7fr 1.3fr;
  align-items: end;
  gap: 48px;
  margin-bottom: 42px;
}

.section-heading h2,
.guide-section h2,
.faq-shell h2 {
  margin: 8px 0 0;
  font-size: clamp(1.8rem, 3vw, 2.7rem);
  line-height: 1.22;
  letter-spacing: 0;
}

.section-note {
  margin: 0;
  color: var(--muted);
}

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

.feature-item {
  min-height: 220px;
  padding: 30px;
  border-right: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
  background: #fff;
}

.feature-item:nth-child(2),
.feature-item:nth-child(3) {
  background: #faf9f9;
}

.feature-mark {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 42px;
  height: 42px;
  margin-bottom: 24px;
  border: 1px solid var(--brand);
  color: var(--brand);
  font-weight: 900;
}

.feature-item h3 {
  margin: 0 0 8px;
  font-size: 1.17rem;
}

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

.gallery-layout {
  display: grid;
  grid-template-columns: minmax(230px, 0.62fr) minmax(0, 1.38fr);
  gap: 54px;
  align-items: start;
}

.gallery-sticky {
  position: sticky;
  top: 108px;
}

.gallery-sticky h2 {
  margin: 8px 0 18px;
  font-size: clamp(1.8rem, 3vw, 2.7rem);
  line-height: 1.2;
}

.gallery-sticky p {
  color: var(--muted);
}

.gallery-stack {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 18px;
  align-items: start;
}

.screen-figure {
  margin: 0;
}

.screen-figure:nth-child(2) {
  margin-top: 54px;
}

.screen-figure img {
  width: 100%;
  max-width: 400px;
  height: auto;
  border: 6px solid var(--ink);
  border-radius: 18px;
  background: #fff;
  box-shadow: var(--shadow);
}

.screen-figure figcaption {
  padding: 12px 4px 0;
  color: var(--muted);
  font-size: 0.82rem;
}

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

.deep-link {
  display: grid;
  min-height: 260px;
  padding: 32px;
  border: 1px solid var(--line);
  background: #fff;
  transition: border-color 160ms ease, transform 160ms ease;
}

.deep-link:hover {
  border-color: var(--brand);
  transform: translateY(-3px);
}

.deep-link .deep-kicker {
  color: var(--accent);
  font-size: 0.78rem;
  font-weight: 800;
}

.deep-link h3 {
  max-width: 420px;
  margin: 16px 0 10px;
  font-size: 1.55rem;
  line-height: 1.3;
}

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

.deep-link .text-link {
  align-self: end;
  margin-top: 28px;
  color: var(--brand);
  font-weight: 800;
}

.cta-band {
  padding: 64px 0;
  color: #fff;
  background: var(--brand-dark);
}

.cta-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 32px;
}

.cta-band h2 {
  margin: 0 0 8px;
  font-size: clamp(1.65rem, 3vw, 2.5rem);
}

.cta-band p {
  max-width: 680px;
  margin: 0;
  color: rgba(255, 255, 255, 0.76);
}

.cta-band .button-primary {
  color: var(--brand-dark);
  background: #fff;
  box-shadow: none;
  white-space: nowrap;
}

.page-hero {
  padding: 66px 0 54px;
  border-bottom: 1px solid var(--line);
  background: #f8f6f7;
}

.page-hero-grid {
  display: grid;
  grid-template-columns: minmax(0, 1.2fr) minmax(260px, 0.8fr);
  align-items: center;
  gap: 54px;
}

.page-hero .hero-lead {
  max-width: 730px;
}

.page-hero-media {
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 310px;
  border-left: 1px solid var(--line);
}

.page-hero-media img {
  width: min(210px, 76%);
  max-width: 400px;
  height: 300px;
  border: 5px solid var(--ink);
  border-radius: 18px;
  object-fit: cover;
  object-position: top;
  box-shadow: var(--shadow);
}

.guide-section {
  padding: 80px 0;
}

.step-list {
  display: grid;
  gap: 0;
  max-width: 920px;
  margin: 38px auto 0;
  border-top: 1px solid var(--line);
}

.step-row {
  display: grid;
  grid-template-columns: 90px minmax(0, 1fr);
  gap: 28px;
  padding: 30px 0;
  border-bottom: 1px solid var(--line);
}

.step-number {
  color: var(--brand);
  font-size: 2.25rem;
  font-weight: 900;
  line-height: 1;
}

.step-row h3 {
  margin: 0 0 8px;
  font-size: 1.15rem;
}

.step-row p {
  margin: 0;
  color: var(--muted);
}

.safety-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 18px;
  margin-top: 36px;
}

.safety-item {
  padding: 26px;
  border-top: 4px solid var(--accent);
  background: #fff;
}

.safety-item h3 {
  margin: 0 0 10px;
  font-size: 1.05rem;
}

.safety-item p {
  margin: 0;
  color: var(--muted);
}

.walkthrough {
  display: grid;
  grid-template-columns: minmax(260px, 0.72fr) minmax(0, 1.28fr);
  gap: 56px;
  align-items: center;
  margin-top: 40px;
}

.walkthrough-media {
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 550px;
  background: var(--accent-soft);
}

.walkthrough-media img {
  width: min(300px, 82%);
  max-width: 400px;
  height: auto;
  border: 6px solid var(--ink);
  border-radius: 20px;
  box-shadow: var(--shadow);
}

.check-list {
  padding: 0;
  margin: 22px 0 0;
  list-style: none;
}

.check-list li {
  position: relative;
  padding: 13px 0 13px 34px;
  border-bottom: 1px solid var(--line);
}

.check-list li::before {
  position: absolute;
  left: 0;
  top: 17px;
  width: 18px;
  height: 18px;
  border: 2px solid var(--accent);
  content: "";
}

.inline-link {
  color: var(--brand);
  font-weight: 800;
  text-decoration: underline;
  text-underline-offset: 3px;
}

.faq-shell {
  padding: 74px 0 88px;
}

.faq-tools {
  display: flex;
  align-items: center;
  gap: 12px;
  max-width: 760px;
  margin: 30px 0 24px;
}

.faq-search {
  width: 100%;
  height: 50px;
  padding: 0 16px;
  border: 1px solid var(--line);
  border-radius: 4px;
  color: var(--ink);
  background: #fff;
}

.faq-search:focus {
  border-color: var(--brand);
  outline: 3px solid rgba(153, 27, 47, 0.12);
}

.faq-count {
  min-width: 86px;
  color: var(--muted);
  font-size: 0.84rem;
  text-align: right;
}

.faq-list {
  max-width: 900px;
  border-top: 1px solid var(--line);
}

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

.faq-item[hidden] {
  display: none;
}

.faq-question {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 28px;
  align-items: center;
  gap: 20px;
  width: 100%;
  min-height: 76px;
  padding: 17px 4px;
  border: 0;
  color: var(--ink);
  background: transparent;
  cursor: pointer;
  font-weight: 800;
  text-align: left;
}

.faq-question:hover,
.faq-question:focus-visible {
  color: var(--brand);
}

.faq-symbol {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 28px;
  height: 28px;
  border: 1px solid currentColor;
  border-radius: 50%;
  font-size: 1.1rem;
}

.faq-answer {
  max-width: 800px;
  padding: 0 46px 24px 4px;
  color: var(--muted);
}

.faq-answer p {
  margin: 0;
}

.trouble-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 16px;
  margin-top: 34px;
}

.trouble-step {
  min-height: 190px;
  padding: 24px;
  border: 1px solid rgba(255, 255, 255, 0.3);
}

.trouble-step span {
  color: #9be0d9;
  font-size: 0.8rem;
  font-weight: 850;
}

.trouble-step h3 {
  margin: 14px 0 8px;
  font-size: 1.08rem;
}

.trouble-step p {
  margin: 0;
  color: rgba(255, 255, 255, 0.76);
}

.site-footer {
  padding: 42px 0 28px;
  color: rgba(255, 255, 255, 0.72);
  background: var(--ink);
}

.footer-nav {
  display: flex;
  justify-content: center;
  flex-wrap: wrap;
  gap: 20px;
  margin-bottom: 24px;
}

.footer-nav a:hover,
.footer-nav a:focus-visible {
  color: #fff;
}

.disclaimer,
.copyright {
  max-width: 800px;
  margin: 0 auto;
  text-align: center;
}

.disclaimer {
  font-size: 0.82rem;
}

.copyright {
  margin-top: 10px;
  color: rgba(255, 255, 255, 0.48);
  font-size: 0.76rem;
}

@media (max-width: 860px) {
  :root {
    --container: min(100% - 30px, 700px);
  }

  .site-header {
    backdrop-filter: none;
  }

  .menu-toggle {
    display: inline-flex;
    align-items: center;
    justify-content: center;
  }

  .site-nav {
    position: fixed;
    inset: 70px 0 auto;
    z-index: 60;
    display: none;
    max-height: calc(100svh - 70px);
    padding: 18px 20px 28px;
    overflow-y: auto;
    border-bottom: 1px solid var(--line);
    background: #fff;
    box-shadow: 0 18px 30px rgba(32, 24, 27, 0.14);
  }

  .site-nav.is-open {
    display: grid;
  }

  .site-nav a {
    padding: 12px 8px;
    border-bottom: 1px solid var(--line);
  }

  .site-nav .nav-download {
    margin: 8px 0 0;
    border-bottom: 0;
    text-align: center;
  }

  .hero-grid,
  .page-hero-grid,
  .section-heading,
  .gallery-layout,
  .walkthrough {
    grid-template-columns: 1fr;
  }

  .hero-grid {
    min-height: 0;
    gap: 28px;
    padding: 34px 0 28px;
  }

  .hero-media {
    min-height: 300px;
  }

  .hero-media img {
    width: min(220px, 64%);
    height: 292px;
    border-width: 5px;
    border-radius: 20px;
  }

  .snapshot-label {
    right: 5%;
    bottom: 5%;
  }

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

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

  .route-item:nth-child(-n + 2) {
    border-bottom: 1px solid rgba(255, 255, 255, 0.15);
  }

  .section-heading {
    gap: 18px;
  }

  .gallery-sticky {
    position: static;
  }

  .page-hero-media {
    min-height: 280px;
    border-left: 0;
    border-top: 1px solid var(--line);
  }

  .safety-grid,
  .trouble-grid {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 620px) {
  :root {
    --container: calc(100% - 28px);
  }

  .site-header {
    height: 64px;
  }

  .site-nav {
    inset: 64px 0 auto;
    max-height: calc(100svh - 64px);
  }

  .brand-lockup img {
    width: 34px;
    height: 34px;
  }

  .hero h1,
  .page-hero h1 {
    font-size: 2.42rem;
  }

  .hero-actions {
    display: grid;
  }

  .button {
    width: 100%;
  }

  .hero-media {
    min-height: 276px;
  }

  .hero-media img {
    height: 270px;
  }

  .snapshot-label {
    max-width: 136px;
    font-size: 0.72rem;
  }

  .route-grid,
  .feature-grid,
  .deep-grid,
  .gallery-stack {
    grid-template-columns: 1fr;
  }

  .route-item {
    border-right: 0;
    border-bottom: 1px solid rgba(255, 255, 255, 0.15);
  }

  .route-item:last-child {
    border-bottom: 0;
  }

  .section,
  .guide-section,
  .faq-shell {
    padding: 64px 0;
  }

  .feature-item:nth-child(2),
  .feature-item:nth-child(3) {
    background: #fff;
  }

  .gallery-stack {
    max-width: 330px;
    margin: 0 auto;
  }

  .screen-figure:nth-child(2) {
    margin-top: 0;
  }

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

  .page-hero {
    padding: 44px 0 38px;
  }

  .step-row {
    grid-template-columns: 54px minmax(0, 1fr);
    gap: 14px;
  }

  .step-number {
    font-size: 1.7rem;
  }

  .walkthrough-media {
    min-height: 440px;
  }

  .faq-tools {
    align-items: stretch;
    flex-direction: column;
  }

  .faq-count {
    text-align: left;
  }
}