/* 黄石昊宇网络 · 纯静态站点样式
   规则：零 JavaScript、零外链、零框架；仅本地字体栈与本地图片。 */

:root {
  --blue: #185FA5;
  --navy: #042C53;
  --pale: #E6F1FB;
  --ink: #2C2C2A;
  --muted: #5F5E5A;
  --line: #E7ECF2;
  --surface: #F7FAFD;
  --footer-text: #B5D4F4;
  --container: 1160px;
  --font: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
          "Hiragino Sans GB", "Microsoft YaHei", "Noto Sans CJK SC", sans-serif;
}

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

html { scroll-behavior: smooth; }

body {
  margin: 0;
  background: #FFFFFF;
  color: var(--ink);
  font-family: var(--font);
  font-size: 15px;
  font-weight: 400;
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}

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

:focus-visible { outline: 2px solid var(--blue); outline-offset: 3px; }

.container {
  width: 100%;
  max-width: var(--container);
  margin: 0 auto;
  padding: 0 24px;
}

.skip-link {
  position: absolute;
  top: 0;
  left: -9999px;
  z-index: 99;
  padding: 10px 16px;
  background: var(--navy);
  color: #FFFFFF;
  font-size: 13px;
}
.skip-link:focus { top: 12px; left: 12px; }

/* ---------- 顶部导航 ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 20;
  background: rgba(255, 255, 255, 0.96);
  border-bottom: 1px solid var(--line);
  -webkit-backdrop-filter: saturate(180%) blur(8px);
  backdrop-filter: saturate(180%) blur(8px);
}
.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 72px;
}
.brand { display: flex; align-items: center; gap: 11px; }
.brand-name {
  color: var(--navy);
  font-size: 17px;
  font-weight: 500;
  letter-spacing: 1.5px;
}
.nav-links { display: flex; gap: 34px; }
.nav-links a {
  position: relative;
  padding: 6px 0;
  color: var(--muted);
  font-size: 13px;
  letter-spacing: 2px;
  transition: color .2s ease;
}
.nav-links a::after {
  content: "";
  position: absolute;
  right: 0;
  bottom: 0;
  left: 0;
  height: 1px;
  background: var(--blue);
  transform: scaleX(0);
  transform-origin: left;
  transition: transform .2s ease;
}
.nav-links a:hover { color: var(--blue); }
.nav-links a:hover::after { transform: scaleX(1); }

/* ---------- 首屏 ---------- */
.hero {
  position: relative;
  display: flex;
  align-items: center;
  min-height: 560px;
  overflow: hidden;
  background: var(--navy);
}
.hero-media {
  position: absolute;
  inset: 0;
  z-index: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: center;
}
.hero-shade {
  position: absolute;
  inset: 0;
  z-index: 1;
  background: linear-gradient(90deg,
      rgba(4, 44, 83, .95) 0%,
      rgba(4, 44, 83, .87) 30%,
      rgba(4, 44, 83, .56) 62%,
      rgba(4, 44, 83, .20) 100%);
}
.hero-inner { position: relative; z-index: 2; padding: 96px 24px 104px; }
.hero-kicker {
  margin-bottom: 22px;
  color: rgba(255, 255, 255, .74);
  font-size: 13px;
  letter-spacing: 3px;
}
.hero-kicker span { margin: 0 8px; opacity: .5; }
.hero h1 {
  color: #FFFFFF;
  font-size: clamp(34px, 4.2vw, 52px);
  font-weight: 500;
  letter-spacing: 6px;
  line-height: 1.25;
}
.hero-rule {
  width: 32px;
  height: 2px;
  margin: 26px 0;
  background: rgba(255, 255, 255, .68);
}
.hero-lead {
  max-width: 560px;
  color: rgba(255, 255, 255, .84);
  font-size: 15px;
  line-height: 1.9;
}
.hero-actions { display: flex; flex-wrap: wrap; gap: 14px; margin-top: 34px; }
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  height: 44px;
  padding: 0 26px;
  border: 1px solid transparent;
  border-radius: 6px;
  font-size: 14px;
  letter-spacing: 1px;
  transition: transform .2s ease, background-color .2s ease, border-color .2s ease;
}
.btn:hover { transform: translateY(-2px); }
.btn-primary { background: #FFFFFF; color: var(--navy); font-weight: 500; }
.btn-primary:hover { background: var(--pale); }
.btn-ghost { border-color: rgba(255, 255, 255, .55); color: #FFFFFF; }
.btn-ghost:hover { border-color: #FFFFFF; background: rgba(255, 255, 255, .10); }

/* ---------- 通用区块 ---------- */
.section { padding: 88px 0; }
.section-head { max-width: 720px; margin-bottom: 44px; }
.eyebrow {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 14px;
  color: var(--blue);
  font-size: 12px;
  letter-spacing: 4px;
}
.eyebrow::before { content: ""; width: 24px; height: 1px; background: var(--blue); }
.section-head h2 {
  color: var(--navy);
  font-size: clamp(22px, 2.6vw, 28px);
  font-weight: 500;
  letter-spacing: 2px;
  line-height: 1.5;
}
.section-intro {
  max-width: 640px;
  margin-top: 14px;
  color: var(--muted);
  font-size: 15px;
  line-height: 1.9;
}

/* ---------- 服务领域 ---------- */
.service-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 16px; }
.service-card {
  display: flex;
  flex-direction: column;
  min-height: 252px;
  padding: 30px 32px 32px;
  border: 1px solid rgba(24, 95, 165, .08);
  border-radius: 12px;
  background: var(--surface);
  transition: transform .2s ease, box-shadow .2s ease, border-color .2s ease;
}
.service-card:hover {
  transform: translateY(-4px);
  border-color: rgba(24, 95, 165, .22);
  box-shadow: 0 14px 34px rgba(4, 44, 83, .08);
}
.card-top { display: flex; align-items: flex-start; justify-content: space-between; margin-bottom: 20px; }
.card-index {
  color: #C9DFF3;
  font-size: 40px;
  font-weight: 500;
  letter-spacing: 2px;
  line-height: 1;
}
.card-icon { width: 42px; height: 42px; color: var(--blue); }
.service-card h3 {
  margin-bottom: 8px;
  color: var(--navy);
  font-size: 17px;
  font-weight: 500;
  letter-spacing: 1px;
}
.card-desc { margin-bottom: 20px; color: var(--muted); font-size: 14px; }
.card-points {
  display: flex;
  flex-wrap: wrap;
  gap: 8px 18px;
  margin-top: auto;
  padding-top: 16px;
  border-top: 1px solid var(--line);
}
.card-points li {
  position: relative;
  padding-left: 14px;
  color: var(--ink);
  font-size: 13px;
}
.card-points li::before {
  content: "";
  position: absolute;
  top: 9px;
  left: 0;
  width: 4px;
  height: 4px;
  border-radius: 50%;
  background: var(--blue);
}

/* ---------- 服务流程分隔带 ---------- */
.band { position: relative; padding: 88px 0; overflow: hidden; background: #F8F9FB; }
.band-texture {
  position: absolute;
  inset: 0;
  z-index: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  opacity: .28;
}
.band::after {
  content: "";
  position: absolute;
  inset: 0;
  z-index: 1;
  background: linear-gradient(180deg, rgba(248, 249, 251, .90), rgba(248, 249, 251, .80));
}
.band-inner { position: relative; z-index: 2; }
.steps {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  padding-top: 28px;
  border-top: 1px solid rgba(24, 95, 165, .18);
}
.step { padding-right: 24px; }
.step + .step { padding-left: 24px; border-left: 1px solid var(--line); }
.step-no {
  display: block;
  margin-bottom: 12px;
  color: var(--blue);
  font-size: 13px;
  letter-spacing: 2px;
}
.step h3 { margin-bottom: 8px; color: var(--navy); font-size: 16px; font-weight: 500; }
.step p { color: var(--muted); font-size: 13px; }
.traits { margin-top: 72px; padding-top: 40px; border-top: 1px solid var(--line); }
.trait-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 32px; margin-top: 26px; }
.trait h3 {
  position: relative;
  margin-bottom: 10px;
  padding-left: 14px;
  color: var(--navy);
  font-size: 15px;
  font-weight: 500;
}
.trait h3::before {
  content: "";
  position: absolute;
  top: 8px;
  left: 0;
  width: 3px;
  height: 14px;
  border-radius: 2px;
  background: var(--blue);
}
.trait p { color: var(--muted); font-size: 13px; }

/* ---------- 联系我们 ---------- */
.contact { padding: 96px 0; }
.contact-inner {
  display: grid;
  grid-template-columns: 1.15fr .85fr;
  gap: 64px;
  align-items: center;
}
.contact-card {
  padding: 36px;
  border: 1px solid rgba(24, 95, 165, .10);
  border-radius: 12px;
  background: var(--surface);
}
.contact-label { margin-bottom: 16px; color: var(--muted); font-size: 12px; letter-spacing: 3px; }
.contact-mail {
  color: var(--navy);
  font-size: 20px;
  letter-spacing: .5px;
  word-break: break-all;
  -webkit-user-select: all;
  user-select: all;
}
.contact-note {
  margin-top: 18px;
  padding-top: 18px;
  border-top: 1px solid var(--line);
  color: var(--muted);
  font-size: 12px;
}

/* ---------- 页脚 ---------- */
.site-footer { padding: 56px 0 28px; background: var(--navy); color: var(--footer-text); }
.footer-top {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-bottom: 32px;
  border-bottom: 1px solid rgba(255, 255, 255, .12);
}
.footer-brand {
  display: flex;
  align-items: center;
  gap: 10px;
  color: #FFFFFF;
  font-size: 16px;
  letter-spacing: 1.5px;
}
.footer-brand img { filter: brightness(0) invert(1); opacity: .9; }
.footer-links { display: flex; gap: 28px; }
.footer-links a { color: var(--footer-text); font-size: 13px; letter-spacing: 1px; }
.footer-links a:hover { color: #FFFFFF; }
.footer-bottom {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  padding-top: 24px;
  font-size: 12px;
  color: rgba(181, 212, 244, .72);
}
.beian-line a {
  color: rgba(181, 212, 244, .92);
  border-bottom: 1px dotted rgba(181, 212, 244, .45);
}
.beian-line a:hover { color: #FFFFFF; border-bottom-color: #FFFFFF; }
.footer-copy { letter-spacing: 1px; }

/* ---------- 响应式 ---------- */
@media (max-width: 1023px) {
  .section, .band { padding: 72px 0; }
  .service-card { padding: 26px 24px; }
  .steps { grid-template-columns: repeat(2, 1fr); gap: 0; }
  .step { padding: 8px 24px 20px 0; }
  .step:nth-child(3) { padding-left: 0; border-left: none; }
  .step:nth-child(3), .step:nth-child(4) { padding-top: 24px; border-top: 1px solid var(--line); }
  .traits { margin-top: 56px; }
  .trait-grid { gap: 20px; }
  .contact-inner { gap: 40px; }
}

@media (max-width: 767px) {
  .container { padding: 0 20px; }
  .header-inner { height: 62px; }
  .nav-links { display: none; }
  .hero { min-height: auto; }
  .hero-inner { padding: 76px 20px 84px; }
  .hero-media { object-position: 62% center; }
  .hero-shade {
    background: linear-gradient(90deg,
        rgba(4, 44, 83, .96) 0%,
        rgba(4, 44, 83, .86) 58%,
        rgba(4, 44, 83, .62) 100%);
  }
  .hero-kicker { font-size: 11px; letter-spacing: 1.5px; line-height: 1.9; }
  .hero h1 { font-size: 32px; letter-spacing: 3px; }
  .hero-lead { font-size: 14px; }
  .btn { height: 42px; padding: 0 20px; font-size: 13px; }
  .section, .band { padding: 60px 0; }
  .section-head { margin-bottom: 32px; }
  .service-grid { grid-template-columns: 1fr; gap: 14px; }
  .service-card { min-height: auto; padding: 24px 22px; }
  .card-index { font-size: 34px; }
  .steps { grid-template-columns: 1fr; margin-bottom: 48px; }
  .step,
  .step + .step,
  .step:nth-child(3) {
    padding: 20px 0;
    border-left: none;
    border-top: none;
    border-bottom: 1px solid var(--line);
  }
  .step:first-child { padding-top: 0; }
  .step:last-child { border-bottom: none; }
  .traits { margin-top: 48px; padding-top: 28px; }
  .trait-grid { grid-template-columns: 1fr; gap: 22px; }
  .contact-inner { grid-template-columns: 1fr; gap: 28px; }
  .contact-card { padding: 26px 22px; }
  .contact-mail { font-size: 17px; }
  .footer-top { flex-direction: column; align-items: flex-start; gap: 20px; }
  .footer-links { flex-wrap: wrap; gap: 16px 22px; }
  .footer-bottom { flex-direction: column; align-items: flex-start; gap: 10px; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { transition: none !important; }
}