:root {
  --seo-ink: #111820;
  --seo-muted: #5f6974;
  --seo-line: #dfe4e8;
  --seo-soft: #f5f7f8;
  --seo-green: #168a67;
  --seo-green-dark: #0d684d;
  --seo-blue: #1671d9;
  --seo-blue-soft: #eef5ff;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  background: #fff;
  color: var(--seo-ink);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
  letter-spacing: 0;
}
a { color: inherit; }
img { display: block; max-width: 100%; }
.seo-shell { min-height: 100vh; }
.seo-inner { width: min(1080px, calc(100% - 40px)); margin: 0 auto; }
.seo-header {
  position: sticky;
  top: 0;
  z-index: 10;
  border-bottom: 1px solid var(--seo-line);
  background: rgba(255,255,255,.96);
  backdrop-filter: blur(12px);
}
.seo-nav {
  min-height: 68px;
  display: flex;
  align-items: center;
  gap: 24px;
}
.seo-brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  margin-right: auto;
  color: var(--seo-ink);
  font-size: 22px;
  font-weight: 850;
  text-decoration: none;
}
.seo-brand img { width: 36px; height: 36px; border-radius: 7px; }
.seo-links { display: flex; align-items: center; gap: 22px; }
.seo-links a { color: #3d4751; font-size: 14px; font-weight: 700; text-decoration: none; }
.seo-links a:hover { color: var(--seo-blue); }
.seo-button {
  min-height: 42px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0 18px;
  border: 1px solid var(--seo-green);
  border-radius: 7px;
  background: var(--seo-green);
  color: #fff;
  font-size: 14px;
  font-weight: 800;
  text-decoration: none;
}
.seo-button:hover { background: var(--seo-green-dark); }
.seo-button.secondary { border-color: var(--seo-line); background: #fff; color: var(--seo-ink); }
.seo-button.secondary:hover { border-color: #bcc6cc; background: var(--seo-soft); }
.seo-hero { padding: 78px 0 48px; overflow: hidden; }
.seo-hero-copy { max-width: 780px; }
.seo-kicker { margin: 0 0 14px; color: var(--seo-green); font-size: 13px; font-weight: 850; }
.seo-hero h1, .seo-article-hero h1 {
  max-width: 900px;
  margin: 0;
  font-size: clamp(38px, 6vw, 66px);
  line-height: 1.08;
  letter-spacing: 0;
}
.seo-hero-copy > p:not(.seo-kicker), .seo-article-hero > p:not(.seo-kicker) {
  max-width: 720px;
  margin: 22px 0 0;
  color: var(--seo-muted);
  font-size: 19px;
  line-height: 1.75;
}
.seo-actions { display: flex; flex-wrap: wrap; gap: 10px; margin-top: 28px; }
.seo-preview {
  position: relative;
  min-height: 0;
  margin-top: 52px;
  overflow: hidden;
  border: 1px solid var(--seo-line);
  border-radius: 8px;
  background: var(--seo-soft);
}
.seo-preview img {
  width: 100%;
  height: auto;
}
.seo-section { padding: 72px 0; border-top: 1px solid var(--seo-line); }
.seo-section.soft { background: var(--seo-soft); }
.seo-section-head { max-width: 700px; margin-bottom: 36px; }
.seo-section h2, .seo-content h2 { margin: 0; font-size: 30px; line-height: 1.25; }
.seo-section-head p, .seo-content > p, .seo-content li {
  color: var(--seo-muted);
  font-size: 16px;
  line-height: 1.8;
}
.seo-feature-grid { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 34px; }
.seo-feature { padding-top: 18px; border-top: 3px solid var(--seo-line); }
.seo-feature:nth-child(1) { border-color: var(--seo-blue); }
.seo-feature:nth-child(2) { border-color: var(--seo-green); }
.seo-feature:nth-child(3) { border-color: #d29b2f; }
.seo-feature h3 { margin: 0 0 10px; font-size: 20px; }
.seo-feature p { margin: 0; color: var(--seo-muted); font-size: 15px; line-height: 1.75; }
.seo-screen-gallery {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 22px;
}
.seo-screen { margin: 0; min-width: 0; }
.seo-screen img {
  width: 100%;
  height: clamp(400px, 46vw, 500px);
  object-fit: cover;
  object-position: top center;
  border: 1px solid var(--seo-line);
  border-radius: 8px;
  background: #fff;
}
.seo-screen figcaption { display: grid; gap: 5px; padding-top: 14px; }
.seo-screen figcaption strong { font-size: 16px; }
.seo-screen figcaption span { color: var(--seo-muted); font-size: 14px; line-height: 1.6; }
.seo-wide-preview { margin: 0; }
.seo-wide-preview img {
  width: 100%;
  height: auto;
  border: 1px solid var(--seo-line);
  border-radius: 8px;
  background: #fff;
}
.seo-wide-preview figcaption { padding-top: 12px; color: var(--seo-muted); font-size: 13px; }
.seo-steps { display: grid; gap: 0; counter-reset: step; }
.seo-step {
  counter-increment: step;
  display: grid;
  grid-template-columns: 54px minmax(0, 1fr);
  gap: 18px;
  padding: 24px 0;
  border-bottom: 1px solid var(--seo-line);
}
.seo-step::before {
  content: counter(step);
  width: 42px;
  height: 42px;
  display: grid;
  place-items: center;
  border-radius: 50%;
  background: var(--seo-blue-soft);
  color: var(--seo-blue);
  font-weight: 850;
}
.seo-step h3 { margin: 2px 0 6px; font-size: 18px; }
.seo-step p { margin: 0; color: var(--seo-muted); line-height: 1.7; }
.seo-link-list { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); border-top: 1px solid var(--seo-line); }
.seo-link-list a { padding: 20px 0; border-bottom: 1px solid var(--seo-line); color: var(--seo-blue); font-weight: 800; text-decoration: none; }
.seo-link-list a:nth-child(odd) { padding-right: 24px; }
.seo-link-list a:nth-child(even) { padding-left: 24px; border-left: 1px solid var(--seo-line); }
.seo-article-hero { padding: 64px 0 48px; border-bottom: 1px solid var(--seo-line); }
.seo-article-hero h1 { font-size: clamp(34px, 5vw, 54px); }
.seo-content { width: min(780px, calc(100% - 40px)); margin: 0 auto; padding: 56px 0 80px; }
.seo-content h2 { margin-top: 52px; font-size: 26px; }
.seo-content h3 { margin: 30px 0 8px; font-size: 19px; }
.seo-content ul, .seo-content ol { padding-left: 24px; }
.seo-content .seo-actions { margin-top: 32px; }
.seo-note { margin: 28px 0; padding: 18px 20px; border-left: 4px solid var(--seo-green); background: #f0f8f5; color: #25493c; line-height: 1.7; }
.seo-downloads { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 16px; margin-top: 28px; }
.seo-download {
  padding: 24px;
  border: 1px solid var(--seo-line);
  border-radius: 8px;
  background: #fff;
}
.seo-download h2 { margin: 0 0 8px; font-size: 22px; }
.seo-download p { min-height: 54px; color: var(--seo-muted); line-height: 1.7; }
.seo-footer { padding: 36px 0; border-top: 1px solid var(--seo-line); color: var(--seo-muted); font-size: 13px; }
.seo-footer-row { display: flex; align-items: center; justify-content: space-between; gap: 18px; }
.seo-footer-links { display: flex; flex-wrap: wrap; gap: 18px; }
.seo-footer a { color: var(--seo-muted); text-decoration: none; }

@media (max-width: 760px) {
  .seo-inner, .seo-content { width: min(100% - 30px, 1080px); }
  .seo-nav { min-height: 62px; gap: 12px; }
  .seo-links { display: none; }
  .seo-brand { font-size: 20px; }
  .seo-brand img { width: 34px; height: 34px; }
  .seo-nav > .seo-button { min-height: 38px; padding: 0 13px; }
  .seo-hero { padding: 52px 0 34px; }
  .seo-hero h1, .seo-article-hero h1 { font-size: 38px; }
  .seo-hero-copy > p:not(.seo-kicker), .seo-article-hero > p:not(.seo-kicker) { font-size: 17px; }
  .seo-preview { margin-top: 38px; }
  .seo-feature-grid, .seo-downloads { grid-template-columns: 1fr; }
  .seo-screen-gallery {
    grid-template-columns: none;
    grid-auto-flow: column;
    grid-auto-columns: min(78vw, 330px);
    gap: 14px;
    margin-right: -15px;
    padding-right: 15px;
    overflow-x: auto;
    overscroll-behavior-inline: contain;
    scroll-snap-type: inline mandatory;
    scrollbar-width: none;
  }
  .seo-screen-gallery::-webkit-scrollbar { display: none; }
  .seo-screen { scroll-snap-align: start; }
  .seo-section { padding: 52px 0; }
  .seo-link-list { grid-template-columns: 1fr; }
  .seo-link-list a:nth-child(odd), .seo-link-list a:nth-child(even) { padding: 18px 0; border-left: 0; }
  .seo-article-hero { padding: 46px 0 36px; }
  .seo-content { padding-top: 38px; }
  .seo-download p { min-height: 0; }
  .seo-footer-row { align-items: flex-start; flex-direction: column; }
}