/* SEO/GEO baseline: system CJK fonts, 16px body, 1200px shell (detail pages same width) */
:root {
  --seo-font: "PingFang SC", "Microsoft YaHei", "Noto Sans SC", "Segoe UI", system-ui, sans-serif;
  --seo-text: 16px;
  --seo-lh: 1.7;
  --seo-container: 1200px;
  --seo-prose: var(--seo-container, 1200px);
}

:root {
  --primary: #766df4;
  --primary-dark: #5f56e6;
  --success: #16c995;
  --text: #37384e;
  --muted: #737491;
  --heading: #2b2c40;
  --line: #e9e9f2;
  --bg: #ffffff;
  --shadow: 0 0.275rem 1.25rem rgba(11, 15, 25, 0.06), 0 0.25rem 0.5625rem rgba(11, 15, 25, 0.04);
  --shadow-hover: 0 0.6rem 1.8rem rgba(11, 15, 25, 0.12);
  --container: 1140px;
  --header: 76px;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  font-family: "Inter", "PingFang SC", "Microsoft YaHei", "Noto Sans SC", sans-serif;
  color: var(--text);
  background: var(--bg);
  line-height: 1.7;
  font-size: 16px;
}
img { max-width: 100%; height: auto; display: block; }
a { color: var(--primary); text-decoration: none; }
button, a { -webkit-tap-highlight-color: transparent; }
.container { width: auto; margin-left: 200px; margin-right: 200px; }

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 46px;
  padding: 0.65rem 1.6rem;
  border-radius: 0.5rem;
  background: var(--primary);
  color: #fff;
  font-weight: 500;
  font-size: 0.95rem;
  border: 0;
  cursor: pointer;
  transition: background 0.2s ease, transform 0.2s ease, box-shadow 0.2s ease;
  box-shadow: 0 8px 18px rgba(118, 109, 244, 0.25);
}
.btn:hover { background: var(--primary-dark); color: #fff; transform: translateY(-1px); }
.btn-block { width: 100%; }

.text-link {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-weight: 600;
  color: var(--primary);
}
.text-link:hover { color: var(--primary-dark); }
.text-link svg { width: 16px; height: 16px; }

/* Header */
.header {
  position: fixed;
  inset: 0 0 auto 0;
  z-index: 50;
  height: var(--header);
  display: flex;
  align-items: center;
  transition: background 0.25s ease, box-shadow 0.25s ease;
}
.header.on-dark {
  background: #2c2d44 url("../img/cubes-bg.jpg") center / cover no-repeat;
  background-attachment: fixed;
  box-shadow: none;
}
.header.on-light {
  background: #fff;
  box-shadow: none;
}
.header .container {
  display: flex;
  align-items: center;
  flex: 1;
  min-width: 0;
  gap: 28px;
}
.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  flex: 0 0 auto;
  color: #fff;
  font-size: 1.45rem;
  font-weight: 700;
  letter-spacing: 0.06em;
}
.brand-logo {
  width: 39.6px;
  height: 39.6px;
  flex: 0 0 auto;
  display: block;
  filter: drop-shadow(0 4px 8px rgba(61, 109, 255, 0.35));
}
.brand:hover { color: #fff; }
.header.on-light .brand,
.header.on-light .brand:hover { color: #0052d9; }

.nav {
  display: flex;
  align-items: center;
  justify-content: space-evenly;
  flex: 1;
  margin: 0 8px;
}
.nav a {
  color: rgba(255, 255, 255, 0.92);
  font-size: 0.95rem;
  font-weight: 500;
  padding: 8px 4px;
  border-radius: 8px;
  white-space: nowrap;
  text-align: center;
}
.nav a:hover, .nav a.active { color: #fff; }
.header.on-light .nav a { color: #4a4b65; }
.header.on-light .nav a:hover, .header.on-light .nav a.active { color: var(--primary); }
.header-cta { margin-left: auto; }
.menu-btn {
  display: none;
  width: 42px;
  height: 42px;
  border: 0;
  background: transparent;
  padding: 8px;
  cursor: pointer;
}
.menu-btn span {
  display: block;
  height: 2px;
  margin: 6px 0;
  background: #fff;
  border-radius: 2px;
}
.header.on-light .menu-btn span { background: #37384e; }

/* Hero */
.hero {
  position: relative;
  min-height: 570px;
  padding: 148px 0 160px;
  text-align: center;
  color: #fff;
  background: #2c2d44 url("../img/cubes-bg.jpg") center / cover no-repeat;
  background-attachment: fixed;
  overflow: hidden;
}
.hero h2 {
  margin: 0 0 14px;
  font-size: 1.55rem;
  font-weight: 400;
  letter-spacing: 0.01em;
}
.hero h1 {
  margin: 0;
  font-size: 3rem;
  font-weight: 700;
  letter-spacing: 0.02em;
}
.hero-curve {
  position: absolute;
  left: 0;
  right: 0;
  bottom: -1px;
  height: 90px;
  color: #fff;
}
.hero-curve svg { display: block; width: 100%; height: 100%; }

.showcase {
  position: relative;
  z-index: 2;
  margin-top: -170px;
  padding-bottom: 20px;
}
.browser {
  width: 90%;
  margin: 0 auto;
  background: #2f3148;
  border: 10px solid rgba(255, 255, 255, 0.55);
  border-radius: 16px;
  box-shadow: 0 24px 60px rgba(20, 18, 50, 0.28);
  overflow: hidden;
}
.browser-bar {
  display: flex;
  align-items: center;
  gap: 14px;
  padding: 12px 16px;
  background: #2a2b40;
}
.dots { display: flex; gap: 7px; }
.dots i { width: 11px; height: 11px; border-radius: 50%; display: block; }
.dots .red { background: #f74f78; }
.dots .yellow { background: #ffb15c; }
.dots .green { background: #16c995; }
.browser-url {
  color: rgba(255, 255, 255, 0.72);
  font-size: 0.85rem;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}
.slides { position: relative; background: #111; aspect-ratio: 16 / 10; }
.slides img {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: top;
  opacity: 0;
  transition: opacity 0.45s ease;
}
.slides img.active { opacity: 1; }
.pager { display: flex; justify-content: center; gap: 8px; padding: 18px 0 4px; }
.pager button {
  width: 10px;
  height: 10px;
  border-radius: 50%;
  border: 0;
  padding: 0;
  background: #d5d4e8;
  cursor: pointer;
}
.pager button.active { background: var(--primary); width: 26px; border-radius: 999px; }

/* Sections */
.section, .about, #contact { scroll-margin-top: 88px; }
.section { padding: 78px 0 30px; }
.section-head { text-align: center; margin-bottom: 18px; }
.section-head h2, .about h2, .footer h2 {
  margin: 0 0 10px;
  font-size: 2rem;
  font-weight: 700;
  color: var(--heading);
  letter-spacing: 0.01em;
}
.lead {
  margin: 0 auto;
  max-width: 820px;
  color: var(--muted);
  text-align: center;
}

.service {
  display: grid;
  grid-template-columns: 1.15fr 0.85fr;
  gap: 48px;
  align-items: center;
  padding: 48px 0;
  border-bottom: 1px solid var(--line);
}
.service.reverse { grid-template-columns: 0.85fr 1.15fr; }
.service.reverse .service-copy { order: -1; }
.service img { width: min(100%, 520px); margin: 0 auto; }
.service h3 { margin: 0 0 18px; font-size: 1.35rem; color: var(--heading); }
.service ul { list-style: none; margin: 0; padding: 0; }
.service li {
  display: flex;
  gap: 12px;
  margin-bottom: 12px;
  color: #4a4b65;
}
.check {
  flex: 0 0 22px;
  width: 22px;
  height: 22px;
  margin-top: 3px;
  color: var(--success);
}
.service h4 { margin: 18px 0 6px; font-size: 0.98rem; color: var(--heading); }
.service p { margin: 0 0 14px; color: var(--muted); }

.grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 26px;
  margin: 36px 0 28px;
}
.card {
  background: #fff;
  border-radius: 12px;
  overflow: hidden;
  box-shadow: var(--shadow);
  color: inherit;
  transition: transform 0.25s ease, box-shadow 0.25s ease;
}
a.card:hover { transform: translateY(-6px); box-shadow: var(--shadow-hover); color: inherit; }
.card img { width: 100%; aspect-ratio: 16 / 10; object-fit: cover; }
.card h3 {
  margin: 0;
  padding: 18px 18px 22px;
  text-align: center;
  font-size: 1rem;
  font-weight: 600;
  line-height: 1.65;
  color: var(--heading);
}
#faq .card {
  margin-bottom: 18px;
  padding: 22px 28px 24px;
  text-align: center;
}
#faq .card h3 {
  padding: 0 0 10px;
  font-size: 1.15rem;
}
#faq .card p {
  margin: 0;
  color: var(--muted);
  text-align: center;
}
.center { text-align: center; margin-bottom: 20px; }

.about {
  padding: 70px 0 90px;
}
.about-grid {
  display: grid;
  grid-template-columns: 0.9fr 1.1fr;
  gap: 56px;
  align-items: center;
}
.about img { width: 100%; border-radius: 16px; object-fit: cover; }
.about .eyebrow { margin: 0 0 14px; color: var(--muted); font-size: 1rem; font-weight: 600; }
.about p { color: var(--muted); margin: 0 0 16px; }

.footer {
  position: relative;
  color: #fff;
  background: #2c2d44 url("../img/cubes-bg.jpg") center / cover no-repeat;
  background-attachment: fixed;
  padding: 88px 0 28px;
}
.footer-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 40px;
  align-items: start;
}
.footer h2 { color: #fff; font-size: 1.7rem; }
.footer p { color: rgba(255, 255, 255, 0.9); margin: 0 0 22px; }
.footer a { color: #fff; }
.contact-list {
  list-style: none;
  margin: 0;
  padding: 0;
  font-size: 0.98rem;
  line-height: 1.7;
}
.contact-list li { margin: 0 0 8px; }
.copy {
  margin: 36px 0 0;
  color: rgba(255, 255, 255, 0.55);
  font-size: 0.9rem;
}

.to-top {
  position: fixed;
  right: 22px;
  bottom: 22px;
  width: 46px;
  height: 46px;
  border-radius: 50%;
  border: 0;
  background: #fff;
  color: var(--primary);
  box-shadow: 0 8px 24px rgba(55, 56, 78, 0.16);
  cursor: pointer;
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.2s ease, transform 0.2s ease;
  z-index: 40;
}
.to-top.show { opacity: 1; pointer-events: auto; }
.to-top:hover { transform: translateY(-2px); }

.wechat-rail {
  position: fixed;
  top: 50%;
  right: 16px;
  z-index: 45;
  width: 132px;
  margin: 0;
  padding: 12px 12px 10px;
  transform: translateY(-50%);
  background: #fff;
  border-radius: 14px;
  box-shadow: 0 10px 28px rgba(55, 56, 78, 0.16);
  text-align: center;
}
.wechat-rail p {
  margin: 0 0 8px;
  color: var(--heading);
  font-size: 0.86rem;
  font-weight: 700;
  line-height: 1.3;
}
.wechat-rail img {
  width: 100%;
  height: auto;
  border-radius: 6px;
}
.wechat-rail span {
  display: block;
  margin-top: 6px;
  color: var(--muted);
  font-size: 0.72rem;
  line-height: 1.3;
  word-break: break-all;
}

.drawer {
  display: none;
}

@media (max-width: 980px) {
  .nav, .header-cta { display: none; }
  .menu-btn { display: block; margin-left: auto; }
  .header .container { gap: 12px; }
  .hero { min-height: 0; padding: 120px 0 150px; }
  .hero h1 { font-size: 2.1rem; }
  .hero h2 { font-size: 1.15rem; }
  .showcase { margin-top: -120px; }
  .service, .service.reverse, .about-grid, .footer-grid, .grid {
    grid-template-columns: 1fr;
  }
  .service.reverse .service-copy { order: 0; }
  .section { padding-top: 56px; }
  .drawer {
    display: block;
    position: fixed;
    inset: 0;
    background: rgba(20, 18, 40, 0.45);
    z-index: 60;
    opacity: 0;
    pointer-events: none;
    transition: opacity 0.2s ease;
  }
  .drawer.open { opacity: 1; pointer-events: auto; }
  .drawer-panel {
    width: min(320px, 86vw);
    height: 100%;
    background: #fff;
    padding: 22px 22px 32px;
    transform: translateX(-100%);
    transition: transform 0.25s ease;
  }
  .drawer.open .drawer-panel { transform: none; }
  .drawer-top { display: flex; align-items: center; justify-content: space-between; margin-bottom: 18px; }
  .drawer-top h5 { margin: 0; font-size: 1.05rem; }
  .drawer-top button {
    border: 0;
    background: transparent;
    font-size: 28px;
    line-height: 1;
    cursor: pointer;
    color: #37384e;
  }
  .drawer a {
    display: block;
    padding: 12px 0;
    color: #37384e;
    font-weight: 500;
    border-bottom: 1px solid var(--line);
  }
  .drawer .btn { margin-top: 18px; width: 100%; }
  .wechat-rail {
    width: 108px;
    right: 10px;
    padding: 8px 8px 7px;
  }
}

@media (max-width: 760px) {
  .container { margin-left: 20px; margin-right: 20px; }
}

@media (max-width: 640px) {
  .hero h1 { font-size: 1.7rem; }
  .browser { border-width: 6px; border-radius: 12px; }
  .card h3 { font-size: 0.95rem; }
}

.seo-prose, article.prose, .article { max-width: var(--seo-container, 1200px); width: 100%; margin-inline: auto; }
.legal-bar { background: #2c2d44; color: rgba(255,255,255,.72); text-align: center; padding: 18px 16px; font-size: .9rem; }
.legal-bar a { color: #fff; }
.legal-bar p { margin: 0; }
.blog-list { display: grid; gap: 16px; }
.blog-list article { background: #fff; border: 1px solid var(--line); border-radius: 14px; padding: 18px 20px; box-shadow: var(--shadow); }
.blog-list h2 { margin: 6px 0 8px; font-size: 1.2rem; line-height: 1.4; }
.article-body h1 { font-size: clamp(1.6rem, 2.4vw, 2.1rem); line-height: 1.35; margin: 12px 0; }
.article-body h2 { margin: 1.6rem 0 .4rem; font-size: 1.3rem; line-height: 1.4; color: var(--heading); }
.article-body p, .article-body li { font-size: 16px; line-height: 1.85; }
.article-body ul { padding-left: 1.25rem; }
.article-cover { width: 100%; max-width: 100%; height: auto; border-radius: 12px; margin: 18px 0; }
.crumb, .meta { color: var(--muted); font-size: .92rem; }
@media (max-width: 760px) {
  .article-body h1 { font-size: 1.45rem; }
  .blog-list h2 { font-size: 1.05rem; }
}