/* ===== yun-seo.com 云优AI · 全局样式 ===== */
:root {
  --primary: #4f6ef7;
  --primary-dark: #3a56e0;
  --accent: #00d4ff;
  --bg-dark: #0a0e1f;
  --bg-dark2: #111631;
  --text: #2b2f3a;
  --text-light: #6b7280;
  --white: #fff;
  --radius: 14px;
  --shadow: 0 10px 40px rgba(20, 30, 90, .1);
  --grad: linear-gradient(135deg, #4f6ef7 0%, #00d4ff 100%);
}
* { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; }
body { font-family: "PingFang SC", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif; color: var(--text); line-height: 1.7; background: #f7f9fe; }
a { text-decoration: none; color: inherit; }
img { max-width: 100%; }
.container { max-width: 1200px; margin: 0 auto; padding: 0 20px; }

/* ===== Header ===== */
.header { position: fixed; top: 0; left: 0; right: 0; z-index: 100; background: rgba(10, 14, 31, .85); backdrop-filter: blur(12px); border-bottom: 1px solid rgba(255,255,255,.08); }
.header-inner { display: flex; align-items: center; justify-content: space-between; height: 68px; }
.logo { display: flex; align-items: center; gap: 10px; color: #fff; }
.logo-icon { width: 40px; height: 40px; border-radius: 10px; background: var(--grad); display: flex; align-items: center; justify-content: center; font-size: 18px; }
.logo-text { display: flex; flex-direction: column; line-height: 1.2; }
.logo-cn { font-size: 16px; font-weight: 700; letter-spacing: .5px; }
.logo-en { font-size: 11px; color: rgba(255,255,255,.55); }
@media (max-width: 680px) {
  .logo-cn { font-size: 14px; }
  .logo-en { font-size: 10px; }
}
.nav { display: flex; gap: 6px; }
.nav-link { color: rgba(255,255,255,.75); padding: 8px 14px; border-radius: 8px; font-size: 15px; transition: .2s; }
.nav-link:hover, .nav-link.active { color: #fff; background: rgba(255,255,255,.1); }
.header-contact { color: var(--accent); font-weight: 700; display: flex; align-items: center; gap: 8px; }
.menu-btn { display: none; background: none; border: none; cursor: pointer; flex-direction: column; gap: 5px; padding: 8px; }
.menu-btn span { width: 24px; height: 2px; background: #fff; display: block; }

/* ===== Hero ===== */
.hero { position: relative; padding: 160px 0 110px; background: var(--bg-dark); color: #fff; overflow: hidden; }
.hero::before { content: ""; position: absolute; inset: 0; background:
  radial-gradient(ellipse 60% 50% at 20% 20%, rgba(79,110,247,.35), transparent),
  radial-gradient(ellipse 50% 40% at 85% 70%, rgba(0,212,255,.18), transparent); }
.hero .container { position: relative; }
.hero-badge { display: inline-block; padding: 6px 16px; border: 1px solid rgba(0,212,255,.4); border-radius: 100px; color: var(--accent); font-size: 13px; margin-bottom: 22px; letter-spacing: 2px; }
.hero-title { font-size: 46px; line-height: 1.3; font-weight: 800; margin-bottom: 20px; }
.hero-title .highlight { background: var(--grad); -webkit-background-clip: text; background-clip: text; color: transparent; }
.hero-desc { max-width: 720px; color: rgba(255,255,255,.72); font-size: 17px; margin-bottom: 34px; }
.hero-btns { display: flex; gap: 16px; flex-wrap: wrap; }
.btn { display: inline-flex; align-items: center; gap: 8px; padding: 13px 32px; border-radius: 100px; font-size: 16px; font-weight: 600; transition: .25s; cursor: pointer; border: none; }
.btn-primary { background: var(--grad); color: #fff; box-shadow: 0 8px 24px rgba(79,110,247,.4); }
.btn-primary:hover { transform: translateY(-2px); box-shadow: 0 12px 30px rgba(79,110,247,.55); }
.btn-ghost { border: 1px solid rgba(255,255,255,.3); color: #fff; }
.btn-ghost:hover { background: rgba(255,255,255,.1); }
.hero-stats { display: flex; gap: 56px; margin-top: 56px; flex-wrap: wrap; }
.hero-stat b { font-size: 34px; font-weight: 800; background: var(--grad); -webkit-background-clip: text; background-clip: text; color: transparent; display: block; }
.hero-stat span { color: rgba(255,255,255,.6); font-size: 14px; }

/* ===== Sections ===== */
.section { padding: 90px 0; }
.section-dark { background: var(--bg-dark2); color: #fff; }
.section-head { text-align: center; margin-bottom: 56px; }
.section-tag { color: var(--primary); font-size: 14px; letter-spacing: 3px; font-weight: 600; }
.section-dark .section-tag { color: var(--accent); }
.section-title { font-size: 34px; font-weight: 800; margin: 8px 0 14px; }
.section-desc { color: var(--text-light); max-width: 640px; margin: 0 auto; }
.section-dark .section-desc { color: rgba(255,255,255,.6); }

/* ===== Cards ===== */
.grid { display: grid; gap: 26px; }
.grid-3 { grid-template-columns: repeat(3, 1fr); }
.grid-4 { grid-template-columns: repeat(4, 1fr); }
.grid-2 { grid-template-columns: repeat(2, 1fr); }
.card { background: #fff; border-radius: var(--radius); padding: 36px 30px; box-shadow: var(--shadow); transition: .3s; border: 1px solid #eef1fb; }
.card:hover { transform: translateY(-6px); box-shadow: 0 18px 50px rgba(20,30,90,.16); }
.card-icon { width: 58px; height: 58px; border-radius: 14px; background: var(--grad); color: #fff; display: flex; align-items: center; justify-content: center; font-size: 24px; margin-bottom: 20px; }
.card h3 { font-size: 20px; margin-bottom: 10px; }
.card p { color: var(--text-light); font-size: 14.5px; }
.card .card-more { display: inline-block; margin-top: 14px; color: var(--primary); font-size: 14px; font-weight: 600; }
.section-dark .card { background: rgba(255,255,255,.05); border-color: rgba(255,255,255,.08); }
.section-dark .card h3 { color: #fff; }
.section-dark .card p { color: rgba(255,255,255,.6); }

/* ===== Steps / process ===== */
.steps { display: grid; grid-template-columns: repeat(6, 1fr); gap: 16px; }
.step { text-align: center; padding: 26px 10px; background: #fff; border-radius: var(--radius); box-shadow: var(--shadow); }
.step b { display: block; font-size: 26px; color: var(--primary); font-weight: 800; margin-bottom: 8px; }
.step span { font-size: 14px; }

/* ===== CTA ===== */
.cta { background: var(--grad); color: #fff; text-align: center; padding: 70px 20px; }
.cta h2 { font-size: 32px; margin-bottom: 14px; }
.cta p { opacity: .9; margin-bottom: 28px; }
.cta .btn { background: #fff; color: var(--primary); }

/* ===== Footer ===== */
.footer { background: var(--bg-dark); color: rgba(255,255,255,.65); padding: 64px 0 0; font-size: 14px; }
.footer-grid { display: grid; grid-template-columns: 1.4fr 1fr 1fr 1.2fr; gap: 40px; padding-bottom: 44px; }
.footer h4 { color: #fff; font-size: 16px; margin-bottom: 18px; }
.footer a { display: block; margin-bottom: 10px; transition: .2s; }
.footer a:hover { color: var(--accent); }
.footer-bottom { border-top: 1px solid rgba(255,255,255,.1); padding: 20px 0; text-align: center; font-size: 13px; color: rgba(255,255,255,.4); }
.footer-bottom a { display: inline; color: inherit; }

/* ===== Page hero (inner pages) ===== */
.page-hero { padding: 140px 0 70px; background: var(--bg-dark); color: #fff; text-align: center; }
.page-hero h1 { font-size: 38px; margin-bottom: 12px; }
.page-hero p { color: rgba(255,255,255,.65); max-width: 700px; margin: 0 auto; }

/* ===== Content article ===== */
.article { background: #fff; border-radius: var(--radius); padding: 48px; box-shadow: var(--shadow); }
.article h2 { font-size: 26px; margin: 32px 0 14px; color: var(--primary-dark); }
.article h2:first-child { margin-top: 0; }
.article p { margin-bottom: 14px; color: #444; }
.article ul { margin: 0 0 14px 22px; color: #444; }
.article li { margin-bottom: 8px; }

/* ===== Contact ===== */
.contact-box { display: grid; grid-template-columns: 1fr 1fr; gap: 30px; }
.contact-item { display: flex; gap: 16px; align-items: flex-start; background: #fff; padding: 28px; border-radius: var(--radius); box-shadow: var(--shadow); }
.contact-item i { font-size: 22px; color: var(--primary); margin-top: 4px; }
.contact-item b { display: block; font-size: 16px; margin-bottom: 4px; }
.contact-item span { color: var(--text-light); font-size: 14px; }

/* ===== Floating contact ===== */
.float-contact { position: fixed; right: 18px; bottom: 90px; z-index: 99; display: flex; flex-direction: column; gap: 10px; }
.float-contact a { width: 52px; height: 52px; border-radius: 50%; background: var(--grad); color: #fff; display: flex; align-items: center; justify-content: center; font-size: 20px; box-shadow: 0 6px 20px rgba(79,110,247,.45); }

/* ===== Responsive ===== */
@media (max-width: 992px) {
  .grid-3, .grid-4 { grid-template-columns: repeat(2, 1fr); }
  .steps { grid-template-columns: repeat(3, 1fr); }
  .footer-grid { grid-template-columns: 1fr 1fr; }
  .hero-title { font-size: 36px; }
}
@media (max-width: 680px) {
  .nav { position: fixed; top: 68px; left: 0; right: 0; background: var(--bg-dark); flex-direction: column; padding: 16px; display: none; }
  .nav.open { display: flex; }
  .menu-btn { display: flex; }
  .header-contact { display: none; }
  .grid-3, .grid-4, .grid-2, .contact-box { grid-template-columns: 1fr; }
  .steps { grid-template-columns: repeat(2, 1fr); }
  .hero { padding: 120px 0 70px; }
  .hero-title { font-size: 28px; }
  .section-title { font-size: 26px; }
  .article { padding: 28px 20px; }
  .footer-grid { grid-template-columns: 1fr; }
}