:root {
  --blue: #3e6ae1;
  --carbon: #171a20;
  --graphite: #393c41;
  --pewter: #5c5e62;
  --fog: #8e8e8e;
  --white: #ffffff;
  --ash: #f4f4f4;
  --line: #d0d1d2;
  --header-height: 64px;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  padding-bottom: 64px;
  color: var(--graphite);
  background: var(--white);
  font-family: "Microsoft YaHei", "PingFang SC", -apple-system, Arial, sans-serif;
  font-size: 14px;
  line-height: 1.55;
}

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

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

.site-header {
  position: fixed;
  z-index: 20;
  top: 0;
  left: 0;
  right: 0;
  height: var(--header-height);
  display: grid;
  grid-template-columns: 180px 1fr 180px;
  align-items: center;
  padding: 0 32px;
  color: var(--white);
  transition: background-color 0.33s, color 0.33s;
}

.site-header.is-solid {
  color: var(--carbon);
  background: rgba(255, 255, 255, 0.86);
  backdrop-filter: blur(14px);
}

.brand {
  font-weight: 500;
  font-size: 18px;
}

.desktop-nav {
  display: flex;
  justify-content: center;
  gap: 6px;
}

.desktop-nav a,
.nav-link,
.menu-button {
  min-height: 32px;
  padding: 6px 16px;
  border-radius: 4px;
  font-size: 14px;
  font-weight: 500;
  transition: background-color 0.33s, color 0.33s;
}

.desktop-nav a:hover,
.nav-link:hover,
.menu-button:hover {
  background: rgba(255, 255, 255, 0.22);
}

.is-solid .desktop-nav a:hover,
.is-solid .nav-link:hover,
.is-solid .menu-button:hover {
  background: var(--ash);
}

.header-actions {
  display: flex;
  justify-content: flex-end;
  align-items: center;
  gap: 4px;
}

.menu-button {
  display: none;
  border: 0;
  color: inherit;
  background: transparent;
  cursor: pointer;
}

.mobile-nav {
  position: fixed;
  z-index: 19;
  top: var(--header-height);
  left: 0;
  right: 0;
  display: none;
  grid-template-columns: 1fr;
  gap: 0;
  padding: 8px 24px 20px;
  color: var(--carbon);
  background: rgba(255, 255, 255, 0.94);
  backdrop-filter: blur(14px);
}

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

.mobile-nav a {
  padding: 14px 0;
  border-bottom: 1px solid var(--ash);
  font-weight: 500;
}

.section-full {
  min-height: 100vh;
  position: relative;
}

.hero {
  display: flex;
  align-items: flex-start;
  justify-content: center;
  overflow: hidden;
  color: var(--white);
  background: var(--carbon);
}

.hero::after {
  content: "";
  position: absolute;
  inset: 0;
  background: rgba(0, 0, 0, 0.18);
}

.hero-image {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.hero-copy {
  position: relative;
  z-index: 1;
  width: min(760px, calc(100% - 32px));
  margin-top: 124px;
  text-align: center;
}

.eyebrow {
  margin: 0 0 12px;
  color: rgba(255, 255, 255, 0.84);
  font-size: 14px;
  font-weight: 500;
}

.eyebrow.dark {
  color: var(--pewter);
}

h1,
h2,
h3,
p {
  margin-top: 0;
}

h1 {
  margin-bottom: 10px;
  color: inherit;
  font-size: 40px;
  font-weight: 500;
  line-height: 48px;
}

h2 {
  margin-bottom: 24px;
  color: var(--carbon);
  font-size: 40px;
  font-weight: 500;
  line-height: 1.2;
}

h3 {
  color: var(--carbon);
  font-size: 17px;
  font-weight: 500;
  line-height: 1.3;
}

.hero-subtitle {
  max-width: 680px;
  margin: 0 auto 26px;
  color: rgba(255, 255, 255, 0.88);
  font-size: 22px;
  line-height: 1.35;
}

.button-row {
  display: flex;
  justify-content: center;
  gap: 16px;
}

.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 40px;
  width: 200px;
  padding: 4px 16px;
  border: 3px solid transparent;
  border-radius: 4px;
  font-weight: 500;
  transition: border-color 0.33s, background-color 0.33s, color 0.33s;
}

.button.primary {
  color: var(--white);
  background: var(--blue);
}

.button.primary:hover {
  background: #345dc9;
}

.button.secondary {
  color: var(--graphite);
  background: var(--white);
}

.button.secondary-dark {
  color: var(--carbon);
  background: var(--white);
}

.button:focus-visible,
input:focus-visible,
textarea:focus-visible,
summary:focus-visible {
  outline: 2px solid var(--blue);
  outline-offset: 3px;
}

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

.band-ash {
  background: var(--ash);
}

.band-carbon {
  color: var(--white);
  background: var(--carbon);
}

.band-carbon h2,
.band-carbon h3 {
  color: var(--white);
}

.container {
  width: min(1180px, calc(100% - 48px));
  margin: 0 auto;
  padding: 112px 0;
}

.stats-grid {
  width: min(1180px, calc(100% - 48px));
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 16px;
  margin: 0 auto;
  padding: 48px 0;
}

.stats-grid article {
  min-height: 116px;
  display: grid;
  align-content: center;
  justify-items: center;
  background: var(--ash);
  border-radius: 4px;
}

.stats-grid strong {
  color: var(--carbon);
  font-size: 40px;
  font-weight: 500;
  line-height: 1.2;
}

.stats-grid span {
  color: var(--pewter);
  font-weight: 500;
}

.split {
  display: grid;
  grid-template-columns: 0.92fr 1.08fr;
  gap: 64px;
  align-items: start;
}

.copy-stack p {
  margin-bottom: 18px;
  color: var(--graphite);
  font-size: 16px;
}

.inline-cta,
.section-cta {
  display: flex;
  gap: 16px;
  margin-top: 28px;
}

.section-cta {
  justify-content: center;
}

.feature-grid,
.scenario-grid,
.plan-grid,
.delivery-list,
.metric-grid {
  display: grid;
  gap: 16px;
}

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

.feature-grid article,
.scenario-grid article {
  min-height: 220px;
  padding: 28px 24px;
  background: var(--white);
  border-radius: 4px;
}

.feature-grid span {
  display: block;
  margin-bottom: 32px;
  color: var(--fog);
  font-weight: 500;
}

.steps {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 16px;
  padding: 0;
  margin: 0;
  list-style: none;
}

.steps li {
  min-height: 180px;
  padding: 28px 24px;
  color: var(--graphite);
  background: var(--ash);
  border-radius: 4px;
}

.steps strong {
  display: block;
  margin-bottom: 16px;
  color: var(--carbon);
  font-size: 17px;
  font-weight: 500;
}

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

.delivery-list article {
  min-height: 176px;
  padding: 28px 24px;
  background: var(--white);
  border-radius: 4px;
}

.delivery-cta {
  background: var(--carbon) !important;
}

.delivery-cta h3,
.delivery-cta p {
  color: var(--white);
}

.delivery-cta .button {
  width: 100%;
  margin-top: 8px;
}

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

.plan-grid article {
  min-height: 380px;
  display: flex;
  flex-direction: column;
  padding: 32px;
  background: rgba(255, 255, 255, 0.06);
  border-radius: 4px;
}

.plan-grid p,
.plan-grid li {
  color: rgba(255, 255, 255, 0.78);
}

.plan-grid ul {
  flex: 1;
  padding-left: 18px;
  margin: 18px 0 28px;
}

.plan-grid li {
  margin-bottom: 10px;
}

.featured-plan {
  background: rgba(255, 255, 255, 0.1) !important;
}

.metric-grid {
  grid-template-columns: repeat(4, 1fr);
}

.metric-grid article {
  min-height: 220px;
  padding: 28px 24px;
  background: rgba(255, 255, 255, 0.06);
  border-radius: 4px;
}

.metric-grid p {
  color: rgba(255, 255, 255, 0.76);
}

.seo-list {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 10px;
  margin-top: 26px;
}

.seo-list span {
  min-height: 40px;
  display: flex;
  align-items: center;
  padding: 0 14px;
  color: var(--carbon);
  background: var(--ash);
  border-radius: 4px;
}

.keyword-table {
  display: grid;
  gap: 1px;
  margin-top: 28px;
  background: var(--ash);
}

.keyword-table div {
  display: grid;
  grid-template-columns: 160px 1fr;
  gap: 20px;
  padding: 18px 20px;
  background: var(--white);
}

.keyword-table strong {
  color: var(--carbon);
  font-weight: 500;
}

.scenario-grid {
  grid-template-columns: repeat(4, 1fr);
}

.faq-list {
  max-width: 860px;
}

details {
  border-bottom: 1px solid var(--ash);
}

summary {
  cursor: pointer;
  padding: 22px 0;
  color: var(--carbon);
  font-size: 17px;
  font-weight: 500;
}

details p {
  max-width: 760px;
  padding-bottom: 22px;
  color: var(--graphite);
  font-size: 16px;
}

.contact {
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--white);
}

.subpage-hero {
  min-height: 520px;
  display: flex;
  align-items: flex-end;
  position: relative;
  overflow: hidden;
  color: var(--white);
  background: var(--carbon);
}

.subpage-hero::after {
  content: "";
  position: absolute;
  inset: 0;
  background: rgba(0, 0, 0, 0.34);
}

.subpage-hero .hero-image {
  opacity: 0.88;
}

.subpage-copy {
  position: relative;
  z-index: 1;
  width: min(900px, calc(100% - 48px));
  margin: 0 auto;
  padding: 128px 0 80px;
}

.subpage-copy p {
  max-width: 720px;
  color: rgba(255, 255, 255, 0.86);
  font-size: 18px;
}

.article-layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 280px;
  gap: 64px;
}

.article-body {
  display: grid;
  gap: 48px;
}

.article-body section {
  padding-bottom: 48px;
  border-bottom: 1px solid var(--ash);
}

.article-body section:last-child {
  border-bottom: 0;
}

.article-body p,
.article-body li {
  color: var(--graphite);
  font-size: 16px;
}

.article-body ul,
.article-body ol {
  margin: 18px 0 0;
  padding-left: 20px;
}

.article-body li {
  margin-bottom: 10px;
}

.side-nav {
  position: sticky;
  top: 96px;
  align-self: start;
  display: grid;
  gap: 10px;
  padding: 20px;
  background: var(--ash);
  border-radius: 4px;
}

.side-nav strong {
  color: var(--carbon);
  font-weight: 500;
}

.side-nav a {
  color: var(--pewter);
  line-height: 1.5;
}

.side-nav a:hover {
  color: var(--carbon);
}

.related-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 16px;
  margin-top: 24px;
}

.related-grid a {
  min-height: 120px;
  display: grid;
  align-content: center;
  padding: 20px;
  color: var(--carbon);
  background: var(--ash);
  border-radius: 4px;
}

.contact-inner {
  width: min(1120px, calc(100% - 48px));
  text-align: center;
}

.contact-inner p {
  color: var(--graphite);
  font-size: 16px;
}

.contact-grid {
  display: grid;
  grid-template-columns: 1.15fr 0.9fr 1.15fr;
  gap: 16px;
  margin-top: 36px;
  text-align: left;
}

.contact-card {
  display: grid;
  align-content: start;
  gap: 14px;
  min-height: 420px;
  padding: 24px;
  background: var(--ash);
  border-radius: 4px;
}

.contact-card-main {
  background: var(--white);
}

.contact-card img {
  width: 100%;
  max-height: 360px;
  object-fit: contain;
  background: var(--white);
  border-radius: 4px;
}

.contact-label {
  color: var(--pewter);
  font-weight: 500;
}

.contact-card strong {
  color: var(--carbon);
  font-size: 24px;
  font-weight: 500;
  line-height: 1.2;
}

.contact-card p {
  margin: 0;
  color: var(--graphite);
}

.contact-info-card {
  align-content: center;
}

.contact-info-card .button {
  width: 100%;
  margin-top: 8px;
}

.site-footer {
  min-height: 96px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  padding: 0 32px;
  color: var(--pewter);
  background: var(--ash);
}

.site-footer p {
  margin: 0;
}

.consult-bar {
  position: fixed;
  z-index: 21;
  left: 0;
  right: 0;
  bottom: 0;
  min-height: 64px;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 24px;
  padding: 10px 24px;
  color: var(--carbon);
  background: rgba(255, 255, 255, 0.92);
  backdrop-filter: blur(14px);
}

.consult-bar span {
  font-weight: 500;
}

.consult-bar .button {
  min-height: 40px;
  width: 160px;
}

@media (max-width: 980px) {
  .site-header {
    grid-template-columns: 1fr auto;
    padding: 0 20px;
  }

  .desktop-nav,
  .nav-link {
    display: none;
  }

  .menu-button {
    display: inline-flex;
    align-items: center;
  }

  .hero-copy {
    margin-top: 108px;
  }

  h1,
  h2 {
    font-size: 32px;
    line-height: 1.22;
  }

  .hero-subtitle {
    font-size: 18px;
  }

  .split,
  .article-layout,
  .stats-grid,
  .feature-grid,
  .steps,
  .plan-grid,
  .scenario-grid,
  .delivery-list,
  .metric-grid,
  .contact-grid {
    grid-template-columns: 1fr;
  }

  .side-nav {
    position: static;
  }

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

  .container {
    width: min(720px, calc(100% - 32px));
    padding: 80px 0;
  }

  .feature-grid article,
  .steps li,
  .scenario-grid article,
  .delivery-list article,
  .metric-grid article,
  .contact-card {
    min-height: auto;
  }

  .contact {
    min-height: auto;
  }

  .contact-card img {
    max-height: 420px;
  }
}

@media (max-width: 640px) {
  .section-full {
    min-height: 92vh;
  }

  .button-row {
    flex-direction: column;
    align-items: center;
  }

  .inline-cta,
  .section-cta {
    flex-direction: column;
    align-items: center;
  }

  .button {
    width: min(100%, 260px);
  }

  .seo-list {
    grid-template-columns: 1fr;
  }

  .keyword-table div {
    grid-template-columns: 1fr;
    gap: 8px;
  }

  .consult-bar {
    justify-content: space-between;
    gap: 12px;
    padding: 10px 16px;
  }

  .consult-bar span {
    font-size: 13px;
  }

  .consult-bar .button {
    flex: 0 0 116px;
    width: 116px;
  }

  .site-footer {
    flex-direction: column;
    align-items: flex-start;
    justify-content: center;
    padding: 24px;
  }
}