:root {
  color-scheme: light dark;
  --page: #f4f7fb;
  --surface: #ffffff;
  --surface-soft: #eaf0f7;
  --ink: #111b2c;
  --muted: #526176;
  --line: #ced8e5;
  --accent: #145cff;
  --accent-strong: #0845ca;
  --on-accent: #f8fbff;
  --shadow: 0 24px 70px rgba(35, 63, 103, 0.13);
  --radius: 16px;
  --shell: min(1180px, calc(100% - 40px));
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  background: var(--page);
  color: var(--ink);
  font-family: "PingFang SC", "Microsoft YaHei", system-ui, sans-serif;
  line-height: 1.75;
}

a {
  color: inherit;
}

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

.skip-link {
  position: fixed;
  top: 12px;
  left: 12px;
  z-index: 20;
  padding: 10px 14px;
  border-radius: var(--radius);
  background: var(--accent);
  color: var(--on-accent);
  transform: translateY(-160%);
}

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

.site-header {
  position: sticky;
  top: 0;
  z-index: 10;
  border-bottom: 1px solid color-mix(in srgb, var(--line) 82%, transparent);
  background: color-mix(in srgb, var(--page) 90%, transparent);
  backdrop-filter: blur(18px);
}

.nav-shell {
  width: var(--shell);
  min-height: 72px;
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  text-decoration: none;
  white-space: nowrap;
}

.brand img {
  width: 190px;
  height: auto;
}

.brand span {
  padding-left: 12px;
  border-left: 1px solid var(--line);
  color: var(--muted);
  font-size: 12px;
  letter-spacing: 0.08em;
}

.main-nav {
  display: flex;
  align-items: center;
  gap: 24px;
  font-size: 14px;
}

.main-nav a {
  text-decoration: none;
}

.main-nav a:hover,
.main-nav a:focus-visible {
  color: var(--accent);
}

.button {
  display: inline-flex;
  min-height: 44px;
  align-items: center;
  justify-content: center;
  padding: 10px 18px;
  border: 1px solid var(--accent);
  border-radius: var(--radius);
  background: var(--accent);
  color: var(--on-accent);
  font-weight: 700;
  line-height: 1.2;
  text-decoration: none;
  white-space: nowrap;
  transition: transform 180ms ease, background 180ms ease;
}

.button:hover,
.button:focus-visible {
  background: var(--accent-strong);
  transform: translateY(-1px);
}

.button:active {
  transform: translateY(1px);
}

.button-secondary {
  background: transparent;
  color: var(--accent-strong);
}

.button-secondary:hover,
.button-secondary:focus-visible {
  background: var(--surface-soft);
}

.hero,
.content-section,
.final-cta {
  width: var(--shell);
  margin: 0 auto;
}

.hero {
  min-height: calc(100dvh - 72px);
  padding: 72px 0 56px;
  display: grid;
  grid-template-columns: minmax(0, 0.9fr) minmax(420px, 1.1fr);
  align-items: center;
  gap: clamp(40px, 7vw, 92px);
}

.eyebrow {
  margin: 0 0 18px;
  color: var(--accent-strong);
  font-size: 13px;
  font-weight: 800;
  letter-spacing: 0.12em;
}

.hero h1 {
  max-width: 12ch;
  margin: 0;
  font-size: clamp(42px, 5.4vw, 72px);
  line-height: 1.08;
  letter-spacing: -0.05em;
}

.hero-copy > p:not(.eyebrow) {
  max-width: 36em;
  margin: 24px 0 0;
  color: var(--muted);
  font-size: clamp(17px, 1.8vw, 21px);
}

.hero-actions {
  margin-top: 30px;
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

.hero-visual {
  position: relative;
  overflow: hidden;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--surface);
  box-shadow: var(--shadow);
}

.hero-visual img {
  width: 100%;
  aspect-ratio: 3 / 2;
  object-fit: cover;
}

.visual-caption {
  margin: 0;
  padding: 14px 18px;
  border-top: 1px solid var(--line);
  color: var(--muted);
  font-size: 13px;
}

.proof-rail {
  width: 100%;
  border-block: 1px solid var(--line);
  background: var(--surface);
}

.proof-rail-inner {
  width: var(--shell);
  margin: 0 auto;
  display: grid;
  grid-template-columns: repeat(4, 1fr);
}

.proof-item {
  min-height: 126px;
  padding: 26px 24px;
  display: flex;
  flex-direction: column;
  justify-content: center;
  border-right: 1px solid var(--line);
}

.proof-item:first-child {
  border-left: 1px solid var(--line);
}

.proof-item strong {
  font-size: 19px;
}

.proof-item span {
  color: var(--muted);
  font-size: 14px;
}

.content-section {
  padding: 112px 0;
}

.section-heading {
  max-width: 780px;
  margin-bottom: 48px;
}

.section-heading h2 {
  margin: 0;
  font-size: clamp(32px, 4vw, 52px);
  line-height: 1.16;
  letter-spacing: -0.04em;
}

.section-heading p {
  max-width: 62ch;
  margin: 18px 0 0;
  color: var(--muted);
  font-size: 17px;
}

.feature-grid {
  display: grid;
  grid-template-columns: 1.12fr 0.88fr;
  gap: 16px;
}

.feature {
  min-height: 220px;
  padding: clamp(26px, 4vw, 42px);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--surface);
}

.feature:nth-child(3n + 1) {
  grid-row: span 2;
  min-height: 456px;
  background: var(--ink);
  color: var(--page);
}

.feature:nth-child(3n + 1) p {
  color: color-mix(in srgb, var(--page) 70%, transparent);
}

.feature h3 {
  margin: 0;
  font-size: clamp(22px, 2.4vw, 32px);
  line-height: 1.28;
}

.feature p {
  max-width: 46ch;
  margin: 14px 0 0;
  color: var(--muted);
}

.media-split {
  display: grid;
  grid-template-columns: 1.08fr 0.92fr;
  align-items: center;
  gap: clamp(40px, 7vw, 88px);
}

.media-split figure {
  margin: 0;
  overflow: hidden;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--surface);
  box-shadow: var(--shadow);
}

.media-split figure img {
  width: 100%;
  aspect-ratio: 3 / 2;
  object-fit: cover;
}

.media-copy h2 {
  margin: 0;
  font-size: clamp(32px, 4vw, 50px);
  line-height: 1.16;
  letter-spacing: -0.04em;
}

.media-copy p {
  margin: 20px 0 0;
  color: var(--muted);
}

.plain-points {
  margin: 28px 0 0;
  padding: 0;
  list-style: none;
}

.plain-points li {
  padding: 15px 0;
  border-bottom: 1px solid var(--line);
}

.plain-points strong {
  display: block;
  margin-bottom: 4px;
}

.process {
  counter-reset: process;
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 0;
}

.process article {
  counter-increment: process;
  min-height: 250px;
  padding: 28px;
  border-top: 2px solid var(--accent);
  border-right: 1px solid var(--line);
}

.process article:last-child {
  border-right: 0;
}

.process article::before {
  content: counter(process, decimal-leading-zero);
  display: block;
  margin-bottom: 36px;
  color: var(--accent-strong);
  font-size: 13px;
  font-weight: 800;
}

.process h3 {
  margin: 0;
  font-size: 21px;
}

.process p {
  margin: 10px 0 0;
  color: var(--muted);
  font-size: 15px;
}

.faq-list {
  max-width: 900px;
}

.faq-list details {
  padding: 24px 0;
  border-bottom: 1px solid var(--line);
}

.faq-list summary {
  cursor: pointer;
  font-size: 19px;
  font-weight: 800;
}

.faq-list p {
  max-width: 68ch;
  margin: 14px 0 0;
  color: var(--muted);
}

.final-cta {
  margin-bottom: 88px;
  padding: clamp(36px, 7vw, 80px);
  display: grid;
  grid-template-columns: 1fr auto;
  align-items: center;
  gap: 32px;
  border-radius: var(--radius);
  background: var(--ink);
  color: var(--page);
}

.final-cta h2 {
  max-width: 16ch;
  margin: 0;
  font-size: clamp(30px, 4vw, 48px);
  line-height: 1.15;
}

.final-cta p {
  max-width: 58ch;
  margin: 14px 0 0;
  color: color-mix(in srgb, var(--page) 70%, transparent);
}

.site-footer {
  border-top: 1px solid var(--line);
  background: var(--surface);
}

.footer-shell {
  width: var(--shell);
  margin: 0 auto;
  padding: 44px 0;
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 32px;
  color: var(--muted);
  font-size: 14px;
}

.footer-links {
  display: flex;
  flex-wrap: wrap;
  gap: 18px;
}

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

@media (prefers-color-scheme: dark) {
  :root {
    --page: #101826;
    --surface: #182335;
    --surface-soft: #202e43;
    --ink: #eef4fd;
    --muted: #b2bfd0;
    --line: #33445c;
    --accent: #6d9dff;
    --accent-strong: #a7c2ff;
    --on-accent: #0b1422;
    --shadow: 0 24px 70px rgba(0, 0, 0, 0.3);
  }

  .feature:nth-child(3n + 1),
  .final-cta {
    background: #09111d;
  }
}

@media (max-width: 900px) {
  .main-nav a:not(.button) {
    display: none;
  }

  .hero,
  .media-split {
    grid-template-columns: 1fr;
  }

  .hero {
    min-height: auto;
    padding-top: 52px;
  }

  .hero-visual {
    order: -1;
  }

  .proof-rail-inner,
  .process {
    grid-template-columns: repeat(2, 1fr);
  }

  .proof-item:nth-child(3) {
    border-left: 1px solid var(--line);
  }

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

  .process article:nth-child(n + 3) {
    border-top-color: var(--line);
  }
}

@media (max-width: 640px) {
  :root {
    --shell: min(100% - 28px, 1180px);
  }

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

  .brand img {
    width: 160px;
  }

  .brand span {
    display: none;
  }

  .main-nav {
    gap: 10px;
  }

  .hero {
    padding: 32px 0 48px;
  }

  .hero h1 {
    font-size: clamp(38px, 12vw, 54px);
  }

  .content-section {
    padding: 78px 0;
  }

  .proof-rail-inner,
  .feature-grid,
  .process,
  .final-cta,
  .footer-shell {
    grid-template-columns: 1fr;
  }

  .proof-item,
  .proof-item:first-child,
  .proof-item:nth-child(3) {
    min-height: auto;
    border-right: 0;
    border-left: 0;
    border-bottom: 1px solid var(--line);
  }

  .feature:nth-child(3n + 1) {
    grid-row: auto;
    min-height: 300px;
  }

  .process article,
  .process article:nth-child(2),
  .process article:nth-child(n + 3) {
    min-height: auto;
    border-top: 1px solid var(--line);
    border-right: 0;
  }

  .final-cta {
    margin-bottom: 48px;
  }

  .footer-shell {
    padding: 34px 0;
  }
}

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

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