:root {
  --blue: #0071e3;
  --blue-hover: #0077ed;
  --link: #06c;
  --link-dark: #2997ff;
  --white: #ffffff;
  --bg-alt: #f5f5f7;
  --ink: #1d1d1f;
  --text-secondary: #6e6e73;
  --text-tertiary: #86868b;
  --nav-bg: rgba(22, 22, 23, 0.8);
  --font: -apple-system, BlinkMacSystemFont, "SF Pro Display", "SF Pro Text",
    "PingFang SC", "Helvetica Neue", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
}

* { box-sizing: border-box; margin: 0; padding: 0; }

html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }

body {
  font-family: var(--font);
  color: var(--ink);
  background: var(--white);
  line-height: 1.47;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
}

.wrap { max-width: 1024px; margin: 0 auto; padding: 0 22px; }

a { color: var(--link); text-decoration: none; }
a:hover { text-decoration: underline; }

/* ---------- 导航 ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: var(--nav-bg);
  -webkit-backdrop-filter: saturate(180%) blur(20px);
  backdrop-filter: saturate(180%) blur(20px);
  border-bottom: 1px solid rgba(255, 255, 255, 0.08);
}
.site-header .wrap {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 48px;
}
.brand {
  display: flex;
  align-items: center;
  gap: 9px;
  color: #f5f5f7;
  font-size: 18px;
  font-weight: 600;
  letter-spacing: -0.2px;
}
.brand:hover { text-decoration: none; }
.brand-mark {
  display: grid;
  place-items: center;
  width: 24px;
  height: 24px;
  border-radius: 7px;
  background: linear-gradient(135deg, #0071e3, #2997ff);
  color: #fff;
  font-size: 13px;
  font-weight: 600;
}
.brand small { font-weight: 400; color: #a1a1a6; margin-left: 2px; }
nav { display: flex; gap: 32px; align-items: center; }
nav a {
  color: #f5f5f7;
  font-size: 13px;
  opacity: 0.85;
}
nav a:hover { opacity: 1; text-decoration: none; }
.header-action {
  background: var(--blue);
  color: #fff;
  padding: 6px 16px;
  border-radius: 980px;
  font-size: 13px;
  white-space: nowrap;
}
.header-action:hover { background: var(--blue-hover); text-decoration: none; }

/* ---------- 通用按钮 / 链接 ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
  background: var(--blue);
  color: #fff;
  padding: 13px 26px;
  border-radius: 980px;
  font-size: 16px;
  font-weight: 500;
  cursor: pointer;
  transition: background 0.2s ease;
}
.btn:hover { background: var(--blue-hover); text-decoration: none; }
.btn b { font-weight: 400; }

.link {
  color: var(--link-dark);
  font-size: 16px;
}
.link:hover { text-decoration: underline; }
.link-dark { color: var(--link-dark); }

/* ---------- 区块通用 ---------- */
.section { padding: 96px 0; }
.section-alt { background: var(--bg-alt); }
.section-head { text-align: center; max-width: 720px; margin: 0 auto 60px; }
.eyebrow {
  font-size: 13px;
  font-weight: 600;
  color: var(--text-tertiary);
  letter-spacing: 0.4px;
  margin: 0 0 12px;
}
.section-title {
  font-size: clamp(30px, 4.4vw, 44px);
  font-weight: 600;
  letter-spacing: -0.4px;
  line-height: 1.12;
  margin: 0 0 16px;
}
.section-sub {
  font-size: 17px;
  color: var(--text-secondary);
  line-height: 1.6;
}

/* ---------- Hero ---------- */
.hero {
  background: #000;
  color: #fff;
  text-align: center;
  padding: 96px 22px 104px;
  position: relative;
  overflow: hidden;
}
.hero::before {
  content: "";
  position: absolute;
  inset: 0;
  background:
    radial-gradient(720px 420px at 50% -10%, rgba(0, 113, 227, 0.22), transparent 65%);
  pointer-events: none;
}
.hero .wrap { position: relative; }
.hero .eyebrow { color: #a1a1a6; }
.hero h1 {
  font-size: clamp(42px, 6vw, 72px);
  font-weight: 600;
  letter-spacing: -1px;
  line-height: 1.08;
  margin: 0 auto 22px;
  max-width: 820px;
}
.hero .intro {
  font-size: 18px;
  line-height: 1.6;
  color: #a1a1a6;
  max-width: 620px;
  margin: 0 auto 32px;
}
.hero-actions {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 28px;
  flex-wrap: wrap;
}
.hero-stats {
  display: flex;
  justify-content: center;
  gap: 0;
  margin-top: 72px;
  flex-wrap: wrap;
}
.hero-stats .stat {
  flex: 0 1 200px;
  padding: 0 28px;
  text-align: center;
}
.hero-stats .stat + .stat { border-left: 1px solid rgba(255, 255, 255, 0.16); }
.hero-stats .stat strong {
  display: block;
  font-size: 30px;
  font-weight: 600;
  letter-spacing: -0.4px;
}
.hero-stats .stat span {
  display: block;
  font-size: 13px;
  color: #a1a1a6;
  margin-top: 6px;
}

/* ---------- 核心优势 ---------- */
.feature-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 32px;
}
.feature { text-align: center; padding: 0 8px; }
.feature .icon {
  width: 48px;
  height: 48px;
  margin: 0 auto 18px;
  border-radius: 14px;
  background: linear-gradient(135deg, #0071e3, #2997ff);
  display: grid;
  place-items: center;
  color: #fff;
  font-size: 22px;
}
.feature h3 { font-size: 19px; font-weight: 600; letter-spacing: -0.2px; margin-bottom: 10px; }
.feature p { font-size: 14px; color: var(--text-secondary); line-height: 1.6; }

/* ---------- 服务方案卡片 ---------- */
.plan-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}
.plan {
  background: var(--white);
  border-radius: 18px;
  padding: 36px 30px 32px;
  box-shadow: 0 2px 18px rgba(0, 0, 0, 0.06);
  display: flex;
  flex-direction: column;
}
.plan-no {
  font-size: 12px;
  font-weight: 600;
  color: var(--text-tertiary);
  letter-spacing: 0.4px;
  margin-bottom: 18px;
  display: flex;
  align-items: center;
  gap: 10px;
}
.plan-no .tag {
  background: #e8f2ff;
  color: var(--blue);
  padding: 2px 10px;
  border-radius: 980px;
  font-size: 11px;
  letter-spacing: 0.2px;
}
.plan h3 { font-size: 22px; font-weight: 600; letter-spacing: -0.3px; margin-bottom: 12px; }
.plan > p { font-size: 15px; color: var(--text-secondary); line-height: 1.65; margin-bottom: 22px; }
.plan ul { list-style: none; margin: 0 0 28px; }
.plan li {
  font-size: 14px;
  color: var(--text-secondary);
  padding: 9px 0;
  border-top: 1px solid #f0f0f2;
}
.plan li:last-child { border-bottom: 1px solid #f0f0f2; }
.plan .btn { margin-top: auto; align-self: flex-start; padding: 10px 20px; font-size: 15px; }

/* ---------- 使用步骤 ---------- */
.steps { display: grid; grid-template-columns: repeat(3, 1fr); gap: 32px; }
.step { padding: 8px 4px; }
.step .num {
  font-size: 28px;
  font-weight: 600;
  color: var(--blue);
  letter-spacing: -0.5px;
  margin-bottom: 14px;
}
.step h3 { font-size: 20px; font-weight: 600; letter-spacing: -0.2px; margin-bottom: 10px; }
.step p { font-size: 15px; color: var(--text-secondary); line-height: 1.65; }

/* ---------- 文章 ---------- */
.article-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}
.article-card {
  background: var(--white);
  border-radius: 18px;
  padding: 32px 28px;
  box-shadow: 0 2px 18px rgba(0, 0, 0, 0.06);
  color: var(--ink);
  display: flex;
  flex-direction: column;
}
.article-card:hover { text-decoration: none; transform: translateY(-3px); transition: transform 0.25s ease; }
.article-card .cat {
  font-size: 12px;
  font-weight: 600;
  color: var(--blue);
  margin-bottom: 14px;
}
.article-card h3 { font-size: 19px; font-weight: 600; letter-spacing: -0.2px; line-height: 1.35; margin-bottom: 10px; }
.article-card p { font-size: 14px; color: var(--text-secondary); line-height: 1.6; margin-bottom: 22px; }
.article-card .more { font-size: 13px; color: var(--link); margin-top: auto; }
.article-card .more::after { content: " ›"; }

/* ---------- CTA ---------- */
.cta {
  background: #000;
  color: #fff;
  text-align: center;
  padding: 96px 22px;
}
.cta h2 {
  font-size: clamp(30px, 4.6vw, 46px);
  font-weight: 600;
  letter-spacing: -0.6px;
  line-height: 1.12;
  margin-bottom: 24px;
}
.cta p { font-size: 17px; color: #a1a1a6; margin-bottom: 36px; }

/* ---------- 页脚 ---------- */
.footer {
  background: var(--bg-alt);
  color: var(--text-tertiary);
  padding: 40px 0 48px;
  font-size: 13px;
}
.footer .wrap {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  flex-wrap: wrap;
}
.footer .brand { color: var(--ink); font-size: 16px; }
.footer .foot-links { display: flex; gap: 24px; }
.footer a { color: var(--text-secondary); }
.footer .foot-note { width: 100%; text-align: center; margin-top: 20px; color: var(--text-tertiary); }

/* ---------- 文章详情页 ---------- */
.article-page { max-width: 760px; margin: 0 auto; padding: 80px 22px 120px; }
.article-page h1 {
  font-size: clamp(34px, 5vw, 52px);
  font-weight: 600;
  letter-spacing: -0.6px;
  line-height: 1.18;
  margin: 0 0 20px;
}
.article-page .lead { font-size: 18px; color: var(--text-secondary); line-height: 1.65; margin-bottom: 48px; }
.article-page .body { border-top: 1px solid #e5e5ea; padding-top: 36px; }
.article-page .body h2 { font-size: 22px; font-weight: 600; letter-spacing: -0.2px; margin: 32px 0 12px; }
.article-page .body p { font-size: 16px; color: var(--text-secondary); line-height: 1.8; margin-bottom: 16px; }
.article-page .back {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  color: var(--link);
  margin-bottom: 40px;
  font-size: 15px;
}
.article-page .back::before { content: "‹"; font-size: 18px; }
.article-page .btn { margin-top: 40px; }

/* ---------- 响应式 ---------- */
@media (max-width: 860px) {
  nav { display: none; }
  .feature-grid { grid-template-columns: repeat(2, 1fr); gap: 36px 24px; }
  .plan-grid, .steps, .article-grid { grid-template-columns: 1fr; }
  .hero-stats .stat { flex: 1 1 100%; padding: 18px 0; }
  .hero-stats .stat + .stat { border-left: none; border-top: 1px solid rgba(255, 255, 255, 0.16); }
  .section { padding: 64px 0; }
}