/* =========================================================
   徐州速水云网络有限公司 官网样式
   设计语言：纯白 + 纯蓝，无渐变
   ========================================================= */

:root {
  --blue: #1A56DB;
  --blue-dark: #0F3A9E;
  --blue-soft: #E8F0FE;
  --blue-mid: #3B6FE0;
  --navy: #0A2558;
  --white: #FFFFFF;
  --bg: #FFFFFF;
  --bg-alt: #F4F7FC;
  --text: #1A2B4A;
  --text-muted: #5A6B85;
  --border: #D8E2F0;
  --shadow-sm: 0 2px 8px rgba(10, 37, 88, .06);
  --shadow-md: 0 8px 24px rgba(10, 37, 88, .08);
  --radius: 12px;
  --radius-lg: 16px;
  --container: 1120px;
  --header-h: 72px;
  --ease: cubic-bezier(.22, 1, .36, 1);
  --font-display: "Outfit", "PingFang SC", "Microsoft YaHei", sans-serif;
  --font-body: "PingFang SC", "Microsoft YaHei", "Hiragino Sans GB", "Noto Sans CJK SC", sans-serif;
}

*, *::before, *::after { box-sizing: border-box; }

html { scroll-behavior: smooth; scroll-padding-top: var(--header-h); }

body {
  margin: 0;
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.7;
  color: var(--text);
  background: var(--bg);
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}

a { color: inherit; text-decoration: none; }
img, svg { display: block; max-width: 100%; }
h1, h2, h3, h4, p, ul, ol { margin: 0; }
ul, ol { padding: 0; list-style: none; }

.container { width: min(var(--container), 100% - 40px); margin: 0 auto; }

/* ---------- 按钮 ---------- */
.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 8px;
  padding: 12px 26px; border-radius: 8px; font-weight: 600; font-size: 15px;
  border: 1.5px solid transparent; cursor: pointer; white-space: nowrap;
  transition: transform .25s var(--ease), background .25s, color .25s, border-color .25s, box-shadow .25s;
}
.btn:hover { transform: translateY(-2px); }
.btn--primary {
  color: #fff;
  background: var(--blue);
  box-shadow: 0 4px 14px rgba(26, 86, 219, .28);
}
.btn--primary:hover { background: var(--blue-dark); box-shadow: 0 6px 18px rgba(26, 86, 219, .35); }
.btn--outline {
  color: var(--blue);
  background: transparent;
  border-color: var(--blue);
}
.btn--outline:hover { background: var(--blue); color: #fff; }
.btn--lg { padding: 15px 32px; font-size: 16px; }
.btn--sm { padding: 9px 18px; font-size: 14px; }
.btn--block { width: 100%; }

/* ---------- 导航栏 ---------- */
.header {
  position: fixed; inset: 0 0 auto 0; z-index: 100; height: var(--header-h);
  background: var(--white);
  border-bottom: 1px solid var(--border);
  transition: box-shadow .3s;
}
.header__inner { height: 100%; display: flex; align-items: center; justify-content: space-between; gap: 24px; }
.header.is-scrolled { box-shadow: var(--shadow-sm); }

.logo { display: inline-flex; align-items: center; }
.logo__img { height: 42px; width: auto; display: block; }
.logo__img--light { filter: brightness(0) invert(1); }

.nav { display: flex; align-items: center; gap: 32px; }
.nav__link {
  position: relative; font-size: 15px; font-weight: 500; color: var(--text);
  transition: color .25s;
}
.nav__link::after {
  content: ""; position: absolute; left: 0; bottom: -6px; width: 100%; height: 2px;
  background: var(--blue); transform: scaleX(0); transform-origin: left;
  transition: transform .3s var(--ease);
}
.nav__link:hover::after, .nav__link.is-active::after { transform: scaleX(1); }
.nav__link:hover, .nav__link.is-active { color: var(--blue); }
.nav__cta { margin-left: 4px; }

.menu-toggle {
  display: none; flex-direction: column; justify-content: center; gap: 5px;
  width: 42px; height: 42px; border: 0; background: transparent; cursor: pointer; padding: 8px; border-radius: 8px;
}
.menu-toggle span { display: block; height: 2px; border-radius: 2px; background: var(--navy); transition: transform .3s, opacity .3s; }
.menu-toggle[aria-expanded="true"] span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.menu-toggle[aria-expanded="true"] span:nth-child(2) { opacity: 0; }
.menu-toggle[aria-expanded="true"] span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

/* ---------- 首屏 ---------- */
.hero {
  position: relative;
  background: var(--blue);
  color: #fff;
  padding: calc(var(--header-h) + 100px) 0 110px;
  overflow: hidden;
}
.hero::after {
  content: "";
  position: absolute;
  right: -80px;
  top: -80px;
  width: 320px;
  height: 320px;
  border-radius: 50%;
  background: rgba(255, 255, 255, .08);
  pointer-events: none;
  animation: pulseSoft 4s ease-in-out infinite alternate;
}
@keyframes pulseSoft {
  from { transform: scale(1); opacity: .7; }
  to { transform: scale(1.12); opacity: 1; }
}

.hero__inner { position: relative; max-width: 780px; }
.hero__brand {
  font-family: var(--font-display);
  font-size: clamp(28px, 4vw, 42px);
  font-weight: 700;
  letter-spacing: .02em;
  line-height: 1.2;
  margin-bottom: 20px;
  animation: riseIn .8s var(--ease) both;
}
.hero__title {
  font-size: clamp(22px, 2.8vw, 32px);
  font-weight: 600;
  line-height: 1.35;
  letter-spacing: 1px;
  color: rgba(255, 255, 255, .92);
  margin-bottom: 20px;
}
.hero__desc {
  font-size: 17px;
  color: rgba(255, 255, 255, .78);
  max-width: 560px;
  margin-bottom: 36px;
}
.hero__actions { display: flex; flex-wrap: wrap; gap: 14px; }
.hero .btn--primary {
  background: var(--white);
  color: var(--blue);
  box-shadow: none;
}
.hero .btn--primary:hover { background: var(--blue-soft); color: var(--blue-dark); }
.hero .btn--outline {
  color: #fff;
  border-color: rgba(255, 255, 255, .55);
}
.hero .btn--outline:hover { background: #fff; color: var(--blue); border-color: #fff; }

@keyframes riseIn {
  from { opacity: 0; transform: translateY(20px); }
  to { opacity: 1; transform: none; }
}

/* ---------- 数据概览 ---------- */
.stats {
  margin-top: -48px;
  position: relative;
  z-index: 2;
  padding-bottom: 20px;
}
.stats__grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  background: var(--white);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-md);
  padding: 28px 8px;
}
.stat { text-align: center; padding: 10px 16px; border-right: 1px solid var(--border); }
.stat:last-child { border-right: 0; }
.stat__num {
  font-family: var(--font-display);
  font-size: 40px;
  font-weight: 800;
  color: var(--blue);
  line-height: 1;
  letter-spacing: -1px;
}
.stat__unit { font-size: 16px; font-weight: 700; color: var(--blue); margin-left: 3px; }
.stat p { margin-top: 8px; color: var(--text-muted); font-size: 14px; }

/* ---------- 通用区块 ---------- */
.section { padding: 96px 0; }
.section__eyebrow {
  display: inline-block;
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 3px;
  color: var(--blue);
  margin-bottom: 14px;
  padding-left: 28px;
  position: relative;
}
.section__eyebrow::before {
  content: "";
  position: absolute;
  left: 0;
  top: 50%;
  width: 18px;
  height: 2px;
  background: var(--blue);
}
.section__title {
  font-size: clamp(26px, 3.2vw, 38px);
  font-weight: 800;
  line-height: 1.3;
  letter-spacing: 1px;
  color: var(--navy);
}
.section__desc { color: var(--text-muted); font-size: 16px; margin-top: 14px; }
.section__head { text-align: center; max-width: 600px; margin: 0 auto 52px; }
.section__head .section__eyebrow { padding-left: 0; }
.section__head .section__eyebrow::before { display: none; }
.section__head--light .section__title { color: #fff; }
.section__head--light .section__desc { color: rgba(255,255,255,.75); }
.section__head--light .section__eyebrow { color: rgba(255,255,255,.9); }

/* ---------- 关于我们 ---------- */
.about { background: var(--bg-alt); }
.about__inner { max-width: 760px; }
.about__content p { color: var(--text-muted); margin-top: 18px; }
.about__content .section__title { margin-bottom: 6px; }
.check-list { margin: 28px 0 32px; display: grid; gap: 14px; }
.check-list li {
  position: relative;
  padding-left: 36px;
  font-weight: 500;
  color: var(--text);
}
.check-list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 3px;
  width: 22px;
  height: 22px;
  border-radius: 50%;
  background: var(--blue);
}
.check-list li::after {
  content: "";
  position: absolute;
  left: 7px;
  top: 9px;
  width: 8px;
  height: 5px;
  border-left: 2px solid #fff;
  border-bottom: 2px solid #fff;
  transform: rotate(-45deg);
}
.about__meta {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 24px;
  padding-top: 8px;
}
.about__meta-item {
  padding: 16px 22px;
  background: var(--white);
  border: 1px solid var(--border);
  border-left: 3px solid var(--blue);
  border-radius: var(--radius);
}
.about__meta-item strong { display: block; font-size: 17px; color: var(--navy); }
.about__meta-item span { font-size: 13px; color: var(--text-muted); }

/* ---------- 业务范围 ---------- */
.services { background: var(--white); }
.services__grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 22px; }
.service-card {
  padding: 32px 28px;
  border-radius: var(--radius-lg);
  background: var(--bg-alt);
  border: 1px solid var(--border);
  transition: transform .3s var(--ease), border-color .3s, box-shadow .3s;
}
.service-card:hover {
  transform: translateY(-6px);
  border-color: var(--blue);
  box-shadow: var(--shadow-md);
}
.service-card__icon {
  width: 52px;
  height: 52px;
  border-radius: 10px;
  display: grid;
  place-items: center;
  margin-bottom: 22px;
  background: var(--blue);
  color: #fff;
}
.service-card__icon svg { width: 26px; height: 26px; }
.service-card h3 { font-size: 19px; color: var(--navy); margin-bottom: 12px; }
.service-card p { color: var(--text-muted); font-size: 15px; }

/* ---------- 核心优势 ---------- */
.advantages {
  background: var(--blue);
  color: #fff;
}
.advantages__grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 20px; }
.adv {
  padding: 32px 26px;
  border-radius: var(--radius-lg);
  background: rgba(255, 255, 255, .1);
  border: 1px solid rgba(255, 255, 255, .18);
  transition: transform .3s var(--ease), background .3s;
}
.adv:hover {
  transform: translateY(-5px);
  background: rgba(255, 255, 255, .16);
}
.adv__num {
  display: block;
  font-family: var(--font-display);
  font-size: 40px;
  font-weight: 800;
  line-height: 1;
  color: rgba(255, 255, 255, .35);
  margin-bottom: 18px;
}
.adv h3 { font-size: 19px; margin-bottom: 12px; }
.adv p { color: rgba(255, 255, 255, .78); font-size: 15px; }

/* ---------- 服务流程 ---------- */
.process { background: var(--bg-alt); }
.steps {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
  position: relative;
  counter-reset: step;
}
.steps::before {
  content: "";
  position: absolute;
  top: 36px;
  left: 12%;
  right: 12%;
  height: 2px;
  background: var(--border);
}
.step { position: relative; text-align: center; padding: 0 10px; counter-increment: step; }
.step__icon {
  position: relative;
  width: 72px;
  height: 72px;
  margin: 0 auto 22px;
  border-radius: 50%;
  display: grid;
  place-items: center;
  background: var(--white);
  border: 2px solid var(--blue);
  color: var(--blue);
  box-shadow: 0 0 0 8px var(--bg-alt);
  transition: transform .3s var(--ease), background .3s, color .3s;
}
.step__icon svg { width: 28px; height: 28px; }
.step__icon::after {
  content: counter(step, decimal-leading-zero);
  position: absolute;
  top: -6px;
  right: -6px;
  width: 26px;
  height: 26px;
  border-radius: 50%;
  background: var(--blue);
  color: #fff;
  font-size: 11px;
  font-weight: 800;
  display: grid;
  place-items: center;
  font-family: var(--font-display);
}
.step:hover .step__icon {
  transform: scale(1.06);
  background: var(--blue);
  color: #fff;
}
.step h3 { font-size: 18px; color: var(--navy); margin-bottom: 10px; }
.step p { font-size: 15px; color: var(--text-muted); }

/* ---------- 联系我们 ---------- */
.contact { background: var(--white); }
.contact__card {
  display: grid;
  grid-template-columns: 1.2fr .8fr;
  gap: 48px;
  background: var(--bg-alt);
  border-radius: var(--radius-lg);
  padding: 52px;
  border: 1px solid var(--border);
}
.contact__list { margin-top: 32px; display: grid; gap: 22px; }
.contact__list li { display: flex; gap: 16px; align-items: flex-start; }
.contact__icon {
  flex: none;
  width: 46px;
  height: 46px;
  border-radius: 10px;
  display: grid;
  place-items: center;
  background: var(--blue);
  color: #fff;
}
.contact__icon svg { width: 20px; height: 20px; }
.contact__list strong { display: block; color: var(--navy); margin-bottom: 4px; }
.contact__list p { color: var(--text-muted); font-size: 15px; }
.contact__list a:hover { color: var(--blue); }
.contact__side { display: flex; flex-direction: column; gap: 16px; justify-content: center; }
.contact__panel {
  padding: 28px 24px;
  background: var(--blue);
  color: #fff;
  border-radius: var(--radius);
  margin-bottom: 8px;
}
.contact__panel-label {
  font-size: 13px;
  letter-spacing: 2px;
  opacity: .75;
  margin-bottom: 10px;
}
.contact__panel strong {
  display: block;
  font-size: 20px;
  margin-bottom: 6px;
}
.contact__panel span { font-size: 14px; opacity: .85; }
.contact__note { text-align: center; font-size: 13px; color: var(--text-muted); }

/* ---------- 页脚 ---------- */
.footer { background: var(--navy); color: rgba(255,255,255,.7); }
.footer__grid {
  display: grid;
  grid-template-columns: 1.4fr 1fr 1fr 1.2fr;
  gap: 40px;
  padding: 64px 0 48px;
}
.footer__brand p { margin-top: 18px; font-size: 14px; line-height: 1.8; }
.footer__col h4 { color: #fff; font-size: 16px; margin-bottom: 18px; }
.footer__col a, .footer__col p { display: block; font-size: 14px; margin-bottom: 10px; transition: color .25s; }
.footer__col a:hover { color: #fff; }
.footer__bottom { border-top: 1px solid rgba(255,255,255,.12); padding: 18px 0; font-size: 13px; }
.footer__bottom-inner { display: flex; justify-content: space-between; align-items: center; gap: 12px; flex-wrap: wrap; }
.footer__icp { color: rgba(255,255,255,.7); transition: color .25s; }
.footer__icp:hover { color: #fff; }

/* ---------- 返回顶部 ---------- */
.back-top {
  position: fixed;
  right: 24px;
  bottom: 28px;
  z-index: 90;
  width: 46px;
  height: 46px;
  border-radius: 50%;
  display: grid;
  place-items: center;
  background: var(--blue);
  color: #fff;
  box-shadow: var(--shadow-md);
  opacity: 0;
  visibility: hidden;
  transform: translateY(12px);
  transition: opacity .3s, transform .3s, visibility .3s;
}
.back-top.is-visible { opacity: 1; visibility: visible; transform: translateY(0); }
.back-top:hover { background: var(--blue-dark); }
.back-top svg { width: 22px; height: 22px; }

/* ---------- 滚动进场动效 ---------- */
.reveal {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity .7s var(--ease), transform .7s var(--ease);
}
.reveal.is-in { opacity: 1; transform: none; }
.reveal--delay { transition-delay: .1s; }
.reveal--delay-2 { transition-delay: .2s; }
.reveal--delay-3 { transition-delay: .3s; }

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { animation: none !important; transition: none !important; }
  .reveal { opacity: 1; transform: none; }
}

/* ---------- 响应式 ---------- */
@media (max-width: 1024px) {
  .services__grid { grid-template-columns: repeat(2, 1fr); }
  .advantages__grid { grid-template-columns: repeat(2, 1fr); }
  .steps { grid-template-columns: repeat(2, 1fr); row-gap: 40px; }
  .steps::before { display: none; }
  .contact__card { grid-template-columns: 1fr; padding: 40px; }
  .footer__grid { grid-template-columns: 1fr 1fr; }
}

@media (max-width: 768px) {
  :root { --header-h: 64px; }
  .section { padding: 72px 0; }
  .nav {
    position: fixed;
    top: var(--header-h);
    left: 0;
    right: 0;
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    background: var(--white);
    padding: 12px 20px 20px;
    box-shadow: var(--shadow-md);
    transform: translateY(-12px);
    opacity: 0;
    visibility: hidden;
    transition: transform .3s var(--ease), opacity .3s, visibility .3s;
  }
  .header.menu-open .nav { transform: none; opacity: 1; visibility: visible; }
  .nav__link { color: var(--text) !important; padding: 14px 0; border-bottom: 1px solid var(--border); font-size: 16px; }
  .nav__link::after { display: none; }
  .nav__cta { margin: 16px 0 0; }
  .menu-toggle { display: flex; }
  .logo__img { height: 34px; }

  .hero { padding: calc(var(--header-h) + 64px) 0 88px; }
  .hero__actions { flex-direction: column; align-items: stretch; }
  .hero__actions .btn { width: 100%; }

  .stats { margin-top: -36px; }
  .stats__grid { grid-template-columns: repeat(2, 1fr); row-gap: 16px; padding: 22px 8px; }
  .stat { border-right: 0; }
  .stat:nth-child(odd) { border-right: 1px solid var(--border); }
  .stat__num { font-size: 32px; }

  .services__grid, .advantages__grid, .steps { grid-template-columns: 1fr; }
  .contact__card { padding: 28px 20px; }
  .footer__grid { grid-template-columns: 1fr; gap: 32px; padding: 52px 0 36px; }
  .footer__bottom-inner { justify-content: center; text-align: center; }
}